Report Updated Research Study Gasification, Plasma, Ethanol, and Anaerobic Digestion Waste Processing Technologies Project I.D.: 07R001 Ramsey/Washington County Resource Recovery Project May 2008
Updated Research Study Gasification, Plasma, and Anaerobic Digestion Waste Processing Technologies Distribution No. of Copies Sent To 10 Ms. Katie Shaw Ramsey/Washington County Resource Recovery Project 2785 White Bear Avenue, #350 Maplewood, Minnesota 55109
Updated Research Study Gasification, Plasma Ethanol and Anaerobic Digestion Waste Processing Technologies Project ID: 07R001 Prepared for Ramsey/Washington County Resource Recovery Project 2785 White Bear Avenue, #350 Maplewood, Minnesota 55109 Prepared by Foth Infrastructure & Environment, LLC May 2008 REUSE OF DOCUMENTS This document has been developed for a specific application and not for general use; therefore, it may not be used without the written approval of Foth. Unapproved use is at the sole responsibility of the unauthorized user. Copyright, Foth Infrastructure & Environment, LLC 2008 Eagle Point II 8550 Hudson Blvd. North, Suite 105 Lake Elmo, MN 55042 (651) 288-8550 Fax: (651) 288-8551
Updated Research Study Gasification, Plasma, Ethanol, and Anaerobic Digestion Waste Processing Technologies Contents Page Executive Summary... vii List of Abbreviations, Acronyms, and Symbols... xiii 1 Introduction...1 1.1 Purpose...1 1.2 Scope of Work...1 2 Background Information...2 2.1 Gasification...2 2.1.1 Process...2 2.1.2 Recovered Gas...3 2.1.3 Recovered Liquid...3 2.1.4 Recovered Ash...3 2.2 Plasma...3 2.2.1 Process...3 2.2.2 Recovered Gas...5 2.2.3 Vitrified Residue...5 2.3 Ethanol Production...5 2.3.1 Definition and Overview...5 2.3.2 Process Steps...6 2.3.3 Products, By-Products, and Markets...8 3 Methods...11 4 Technology Update...12 4.1 Gasification...12 4.1.1 Specific Experience...12 4.1.1.1 Alameda Power and Telecom...12 4.1.1.2 Greve in Chianti...13 4.1.1.3 Home Farms Redwood Falls...14 4.1.1.4 Great River Energy...15 4.1.1.5 Shaw Industries...17 4.1.1.6 Ze-Gen...17 4.1.1.7 Collier County, Florida...18 4.1.1.8 Interstate Waste Technologies (IWT)...18 4.1.1.9 City of Los Angeles...21 4.1.1.10 City of New York,...23 4.1.1.11 County of Los Angeles...23 4.1.1.12 Batch Oxidation System (BOS),...25 4.1.1.13 Nippon Steel...27 4.1.1.14 Alstrom/Ebara...27 X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc i
4.1.1.15 Enerkem Technologies...27 4.1.1.16 SVZ...28 4.1.1.17 Emery Energy Company...28 4.1.1.18 SENREQ, LLC,...28 4.1.2 Advantage and Disadvantages...29 4.2 Plasma...29 4.2.1.1 Alter Nrg...30 4.2.1.2 Westinghouse...31 4.2.1.3 Geoplasma...32 4.2.1.4 Plasco Energy (formerly RCL Plasma/Resorption Canada Ltd)...33 4.2.1.5 Hitachi Metals...37 4.2.1.6 Solena Group...38 4.2.1.7 Georgia Tech Research Institute/Geoplasma Honolulu, Hawaii..38 4.2.1.8 Recovered Energy, Inc....39 4.2.1.9 Integrated Environmental Technology...40 4.2.1.10 PEAT...41 4.2.1.11 Phoenix Solutions...41 4.2.1.12 Hawkins Industries...42 4.2.1.13 Pyrogenesis...42 4.2.1.14 Coronal/Laurentian Resource Conservation and Development Authority...42 4.2.1.15 STARTECH...43 4.2.1.16 Green Power Systems, LLC...43 4.2.1.17 Sun Energy Group, LLC...44 4.2.1.18 Cob Creations, LLC...44 4.2.2 Advantage and Disadvantages...44 4.3 Ethanol Production...45 4.3.1 Specific Experience...45 4.3.1.1 Tennessee Valley Authority (TVA)...45 4.3.1.2 Masada-Oxynol...48 4.3.1.2.1 MASADA, Middletown, NY...49 4.3.1.3 Arkenol...50 4.3.1.4 Waste to Energy (WTE)/Genahol Corporation...52 4.3.1.5 Blue Fire Ethanol Fuels, Inc....52 4.3.2 Advantages and Disadvantages...53 4.4 Anaerobic Digestion...54 4.4.1 Specific Experience...54 4.4.1.1 Arrow Ecology...56 4.4.1.2 University of California, Davis...59 4.4.1.3 BRI Energy, LLC...60 4.4.1.4 McElvaney Associates Corporation...60 4.4.1.5 Wright Environmental Management...61 4.4.1.6 Global Renewables Limited (GRL)...61 4.4.2 Advantages and Disadvantages...64 5 Environmental and Regulatory Issues...67 5.1 Environmental Impacts...67 5.1.1 Air Emissions...67 5.1.2 Solid Residuals...68 ii X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
Contents Page 5.1.3 Liquid Residue...69 5.2 Regulatory Issues...69 6 Applicability to Ramsey/Washington Counties...71 Tables Table ES-1 Potential Advantages and Disadvantages of Gasification... viii Table ES-2 Potential Advantages and Disadvantages of Plasma Arc Systems... ix Table ES-3 Potential Advantages and Disadvantages of Waste-to-Ethanol Processes...x Table ES-5 Potential Advantages and Disadvantages of Anaerobic Digestion... xi Table 2-1 Categories of Tars...3 Table 2-2 Theoretical Ethanol Yield from Selected Feedstock A...9 Table 4-1 Operating Gasification Plants 19...12 Table 4-2 Gasification Parameters from City of Los Angeles RFP...22 Table 4-3 City of Los Angeles Development Partners RFP Responses A, B...22 Table 4-4 Technology Suppliers Participating in Phase II...24 Table 4-5 Tipping Fees Estimated by Technology Suppliers...25 Table 4-6 EnerWaste BOS Equipment--US EPA Performance Test...26 Table 4-7 Potential Advantages and Disadvantages of Gasification...29 Table 4-8 RCL Plasma Gasifier Mass Balance...35 Table 4-9 Energy Balance for RCL Plasma Reactor...36 Table 4-10 Potential Electricity Export for the RCL Plasma Process...37 Table 4-11 Material Balance Reported by REI...40 Table 4-12 Synthesis Gas Composition Reported by REI...40 Table 4-13 Potential Advantages and Disadvantages of Plasma Arc Systems...45 Table 4-14 Process Inputs and Outputs for 400 tpd and 2,000 tpd Facilities...46 Table 4-15 TVA s Capital Investment for 2,000 tpd Waste-to-Ethanol Facility...46 Table 4-16 TVA s Projected Operating Costs 2,000 tpd Waste-to-Ethanol Facility...47 Table 4-17 Summary of Assumed and Updated Revenue Credits...48 Table 4-18 Mass Balance for Masada Process (2 Scenarios)...50 Table 4-19 Partial Mass and Energy Balance for the Arkenol Process...51 Table 4-20 Potential Advantages and Disadvantages of Waste-to-Ethanol Processes...53 Table 4-21 Performance Data of AD Plants...55 Table 4-22 Investment Data of AD Plants...56 Table 4-23 Advantages and Disadvantages...65 Figures Figure 2-1 TPS Gasification Process Diagram...2 Figure 2-2 Typical Plasma Arc Process...4 Figure 2-3 Arkenol s Concentrated Acid Hydolysis Process...7 Figure 2-4 TVA s Process...8 Figure 2-5 BRI s Energy Process...8 X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc iii
Figure 2-6 Average U.S. Price for Ethanol and Gasoline 16...10 Figure 4-1 GRE s Gasification Plasma Process...16 Figure 4-2 Thermoselect Process...21 Figure 4-3 Conceptual Cross-section of Westinghouse Plasma Corporation Plasma Direct Melting Reactor...31 Figure 4-4 Geoplasma Process for 1,000 TPD...33 Figure 4-5 Gasification Plant Schematic Hitachi Metals...37 Figure 4-6 GEI/Genahol Hydrolysis and Ethanol Process Schematic...52 Figure 4-7 Arrow Ecology Process Diagram...57 Figure 4-8 UR-3R Process...62 iv X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
Foth Infrastructure & Environment, LLC v Eagle Point II 8550 Hudson Blvd. North, Suite 105 Lake Elmo, MN 55042 (651) 288-8550 Fax: (651) 288-8551
Updated Research Study Gasification, Plasma, Ethanol and Anaerobic Digestion Waste Processing Technologies Executive Summary The Ramsey/Washington County Resource Recovery Project (Project), as part of an updated analysis on alternative waste processing technologies for MSW, desired an updated review and current status of the following technologies: Gasification Plasma Ethanol Production Anaerobic Digestion A brief description of each technology follows, along with its perceived advantages/ disadvantages, regulatory concerns and observations on its applicability to the Project. Gasification Gasification converts waste to gases, liquids, and char. The gasification process allows a small amount of air, steam or oxygen into the conversion process. This addition of oxygen, steam, or air changes the output products from gasification. Output products from gasification are gases, liquids and char. The gases consist of carbon monoxide, hydrogen, nitrogen and carbon dioxide. The liquid portion from the gasification process tends to be in the form of tars. Finally, the char is the ash that is formed since the gasification process does include some air or oxygen which will cause some materials to burn and form ash. Table ES-1 summarizes perceived advantages and disadvantages of gasification. Foth Infrastructure & Environment, LLC vii Eagle Point II 8550 Hudson Blvd. North, Suite 105 Lake Elmo, MN 55042 (651) 288-8550 Fax: (651) 288-8551
Table ES-1 Potential Advantages and Disadvantages of Gasification Advantages Not incineration Efficient energy production through combustion of gases High temperatures can make the process flexible to other waste streams Recycling can be enhanced by up-front separation Disadvantages Requires MSW pre-treatment to remove non-organic waste and homogenize the material Residuals could be hazardous Unproven on a commercial scale for MSW in the United States System is sensitive to non-organic feedstock More expensive than other proven technologies At this time, it is difficult to obtain data from operational gasification processes to determine the applicability to the Project. As potential new facilities are studied (Los Angeles) better information should become available to determine if gasification is viable for the Project s waste stream. Plasma Plasma processes are systems that utilize a plasma arc reactor to convert waste to inert slag and gases. The gases, called syngas can be used as an energy source in a boiler or turbine set up or both. The plasma reactor is an enclosed chamber containing plasma torches. These torches heat the gases in the chamber to 3,000ºC or higher. These high temperatures convert organic materials into gas and inorganic materials into a glassy slag substance. Table ES-2 summarizes the perceived advantages and disadvantages of plasma arc systems. viii X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
Table ES-2 Potential Advantages and Disadvantages of Plasma Arc Systems Advantages Superior thermal destruction Disadvantages High initial investment Limited pollution High power requirements Beneficial use possibilities for gas and ash produced from plasma destruction Potential to expand waste stream to include other non-msw streams High operating costs May require waste pre-shredding to fit into plasma reactor At this time, it is difficult to obtain data on the plasma process. The major plasma facilities are in Japan and limited cost and performance data is available to determine the applicability of plasma arc to the Project. As potential new facilities are studied (St. Lucie County, Florida and Ottawa, Canada) better information should become available to determine if the plasma arc process is viable for the Project s waste stream. Ethanol Production The production of ethanol (grain alcohol) from waste products is known by a variety of process descriptions, including biomass to ethanol and acid hydrolysis. It refers to the process of using thermo-chemical and enzymatic processing of cellulosic biomass to produce nonpetroleum based fuels, fuel cells, and industrial chemicals. In layman s terms, this means turning organic materials, including components of the municipal solid waste stream, into fuel grade ethanol by passing it through a series of refining processes that release, ferment, and distills the available sugars. Production of ethanol through acid hydrolysis is a technology that has been known and used for over 100 years, with its most extensive use occurring during World War II. Low petroleum prices in comparison to high ethanol production costs kept the process from being adopted for commercial use in the late 1940s. However, ethanol production has received increasing attention in the past decade from agricultural generators seeking additional markets for corn and other farm products or byproducts. Similarly, changes in federal and global environmental policies are driving increased interest in the development of non-petroleum based fuel sources. Table ES-3 summarizes potential advantages and disadvantages of ethanol production processes. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc ix
Table ES-3 Potential Advantages and Disadvantages of Waste-to- Ethanol Processes Advantages Minnesota supports and promotes use of ethanol as a fuel additive Disadvantages Limited technical application with MSW Use of bioproducts and bioenergy is encouraged by a Presidential Executive Order May offer opportunities to expand the market uses of MSW. May offer benefits toward sustainable development and resource conservation Lack of history with regulators Capital/operating cost history is limited, unsettled, and likely high Market demand for ethanol could be met by corn plants Markets for other products need to be developed May require separate collection or front-end processing which would raise costs While there appears to be some growing interest in this technology, it simply continues to not be a proven MSW management technology at this time. There is currently very limited technical application to MSW and a lack of history with regulating agencies. Capital and operating cost history is limited and unsettled. To successfully perform using organics from MSW may require source-separated collection of the organics or front-end processing to separate the organic fraction (either of which will increase the system costs). Markets could develop significantly, but at this point, the demand could be met with corn plants. Marketing of the by-products from a waste to ethanol process is untested. With the lack of proven technology and unsettled high costs, this technology should not be considered by the Project at this time. Despite the potential disadvantages, the technology may offer some long-term advantages worth continued observation of its development. If there is waste-to-ethanol plants constructed that handle MSW successfully and prices for petroleumbased fuels continue to increase, the technology could surface as a viable alternative in the future. Anaerobic Digestion Anaerobic Digestion (AD) in the broadest sense is a process to degrade organic material in the absence of oxygen. AD therefore can be used to break down the organic fraction of waste. This includes paper, yard waste, food waste and other organic waste. Microbes that thrive in the x X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
absence of oxygen are active. AD is the end result of this microbial activity occurring among multiple microorganisms. Table ES-5 summarizes the perceived advantages and disadvantages of anaerobic digestion. In general, anaerobic digestion systems are effective only for the highly organic portion of the wastes and have not been used very effectively for MSW in the United States. This lack of development of this technology in the United States makes this technology unattractive as an MSW processing technology. Table ES-5 Potential Advantages and Disadvantages of Anaerobic Digestion Advantages Disadvantages Relatively low capital costs compared to most thermal processes State-of-the art technology in global use including pollution control technology. Uncertainties over the economics and practical applications of AD to treat MSW. AD technology for homogenous waste streams is widely proven in Europe, but there are no full scale plants operating in the U.S. on MSW. Energy recovery potential (methane generation) and possible sale of surplus. Reduces organic wastes from landfill, which reduces the production of landfill gas and leachate. Enclosed system reduces environmental impacts. AD of MSW will need to rely on comprehensive pre-processing of the waste or source separation; plastics for example, can cause operational difficulties. Some systems however are designed to operate with mixed MSW. Odor emissions during material handling. Does not treat the whole MSW stream, only the organic fraction. AD is more capital intensive than composting. Materials handling problems with frontend processing can be costly Contamination of final product often difficult to avoid; marketing problems. Gas handling, storage and cleanup facilities are required, which can be costly. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc xi
Conclusions Of the four technologies examined, each has a proven application with some type of materials, but limited experience with MSW. Each is at a different stage of research and development and may not be applicable to the entire MSW waste stream. The ones with the most future potential appear to be gasification and plasma. Significant feasibility analysis or project development activity is currently being conducted on both of these processes in other locations (e.g., Los Angeles, Florida, Canada, etc.). It is possible that one or both of the technologies may be implemented on MSW in the next 10 years. The Project is advised to continue to regularly examine the technologies for application to MSW every two to four years. The information that may be developed by the project developers will be critical in determining whether these technologies can be depended upon to provide reliable management and disposal of MSW in a cost-effective manner. It is also interesting to note the status and projections noted in European countries in meeting their Landfill Directive. The European Landfill Directive sets demanding targets to reduce the amount of biodegradable MSW landfilled. They face a steady progression of goals over the next several years with a final goal by 2020 to reduce biodegradable MSW landfilled to 35% of that produced in 1995. Frost & Sullivan, the reported world leader in growth consulting and various areas of market research reported in June, 2006 that across Europe, both political and environmental attention is turning toward the waste-to-energy market to address non-recyclable portions of the MSW stream. 1, 2 They report there are over 400 waste-to-energy plants in Europe that process some 50 million tons of MSW per year. To cope with the growing MSW quantities and address the Landfill Directive, they report there will be an increase of waste-to-energy in the next several years with over 100 plants or new lines added by 2012. Their analysis considers the following waste-to-energy plant technologies: Mass burn plants Fluidized bed including circulating, bubbling, and stationary fluidized bed boilers Pyrolysis and gasification plants The majority of existing and projected new plants are mass burn facilities. The Project should also continue to monitor the status of these technologies as they develop in Europe. xii X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
List of Abbreviations, Acronyms, and Symbols AC AD ADC AMBR APS ATR BACT BETF BOD BRI Btu CAD CH 4 COD CO 2 CNG CT DC EPA FOG Foth GRL HCl HHV HRSG H 2 S kw kwh lb LHV MMBtu MRF MSW MW MWh NEPA NESHAPS NOI NPDES NREL O&M PM QA Alternating Current (Electric) Anaerobic Digestion Alternative Daily Cover Anaerobic moving bed reactor Anaerobic Phased Solids Advanced Thermal Recycling Best Available Control Technology Break Even Tip Fee Biochemical Oxygen Demand BRI Energy, LLC British Thermal Unit Computer Aided Drafting Methane Chemical Oxygen Demand Carbon Dioxide Compressed Natural Gas Conversion Technology Direct Current (Electric) United States Environmental Protection Agency Fats, Oil, Grease Foth Infrastructure and Environment, LLC Global Renewables Limited Hydrochloric Acid High Heating Value Heat Recovery Steam Generator Hydrogen Sulfide Kilowatt Kilowatt hour Pound Low Heating Value Million British Thermal Units Material Recovery Facility Municipal Solid Waste Megawatt Megawatt hour National Environmental Quality Act National Emissions Standards for Hazardous Air Pollutants Notice of Intent National Pollutant Discharge Elimination System National Renewable Energy Laboratory Operation and Maintenance Particulate Matter Quality Assurance X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC xiii
QC RDF RFQ RPS scf SCR SNCR TPD or tpd TPY or tpy UASB USDA VOC WCTF Quality Control Refuse Derived Fuel Request for Qualifications Renewable Standards Portfolio Standard Cubic Feet Selective catalytic reduction Selective non-catalytic reduction Tons Per Day Tons Per Year Up-flow Anaerobic Sludge Blanket United States Department of Agriculture Volatile Organic Compound Worst Case Tipping Fee xiv Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
1 Introduction The following report is an update to the September 2004 Foth report titled, Updated Research Study of Alternative Waste Processing Technologies. The following report and analysis researches Municipal Solid Waste (MSW) processes, including gasification, plasma and ethanol process for MSW. 1.1 Purpose The purpose of the report is to provide updated information on the processes of gasification, plasma and ethanol. There is renewed interest in the market to explore these three alternative technologies as they relate to MSW management. This report includes updated information from the 2004 study conducted by Foth. Additionally, select companies were contacted to discuss specific processes. 1.2 Scope of Work The scope of work was defined in the April 27, 2007, proposal. Generally the scope of work includes four tasks: Task 1: Data Gathering Task 2: Report Development Task 3: Report Review Task 4: Final Report Presentation This report encompasses the work in the first two tasks. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 1 February 2008 R-RWCounties Updated Research Study-Final.doc
2 Background Information 2.1 Gasification 2.1.1 Process Gasification converts wastes to gases, liquids and char. The gasification process is a thermal process that utilizes controlled air to support combustion. Gasification using air results in a nitrogen-rich, low Btu fuel gas. If gasification is conducted using pure oxygen, then higher Btu fuel is produced. If the gasification process uses steam to support combustion, the output is a synthetic gas (syngas). The syngas has a composition of hydrogen and carbon dioxide. Gasifiers are usually constructed using fixed bed or fluidized bed reactors. Fixed bed reactors are common since these are easy to design and operate. Fluidized beds offer the best MSW reaction. Fluidized beds have more uniform combustion conditions, which support more efficient reaction of the MSW. Xcel Energy uses fluidized bed technology on French Island for the combustion of RDF. Fluidized beds are further separated into bubbling and circulatory. For large applications, a circulating fluidized bed is typically used. A general process diagram for gasification is provided in Figure 2-1. Figure 2-1 TPS Gasification Process Diagram 2 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
2.1.2 Recovered Gas The syngas from gasification consists primarily of carbon monoxide, hydrogen, nitrogen and carbon dioxide. The amount of each gas depends on the amount and quality of air, oxygen or steam used in the gasification process. More air or oxygen brought into the system tends to increase the carbon monoxide and carbon dioxide amounts and can produce acid gases. Increases in steam tend to increase hydrogen quantities. The gas composition is usually dictated by the end user of the gas; however, most commercial products tend to try to balance gas output at 30% to 35% each for carbon monoxide and hydrogen, with the remainder being carbon dioxide and some trace gases. 3,4 2.1.3 Recovered Liquid Liquids from a gasification process tend to be in the form of tars. The amount and composition of tars is dependent on the operating condition of the gasifier. Elliot 5 classified tars into three primary categories. The category of tar that forms during the gasification process depends on the temperature of the process. Table 2-1 provides the categories of tars formed. Table 2-1 Categories of Tars 6 Category Formation Temperature Constituents Primary 400-600 C Mixed Oxygenates, Phenolic Ethers Secondary 600-800 C Alkyl Phenolics, Heterocyclic Ethers Tertiary 800-1000 C Polynucleic Aromatic Hydrocarbons 2.1.4 Recovered Ash With a gasification process and the introduction of oxygen into the process, some materials will burn and ash is formed. The amount of ash and its composition is dependent on feedstock, oxygen availability and temperature of the process. Primarily the ash contains heavy metals remaining from the gasification process. The ash is estimated to be 8% to 15% 7 of the original volume of material. Constituents of concern in the ash would be lead, cadmium and mercury. The ash from gasification would need to be managed in the same manner as the ash from incineration of MSW. 2.2 Plasma 2.2.1 Process 8 Plasma arc is a method of waste management that uses high electrical energy and high temperatures created by an electrical arc. The electric arc forms plasma that is used to break down MSW into elemental gas and slag. The process has been intended to be a net generator of electricity (depending upon input wastes) and to reduce the requirements for redirecting waste to landfill sites. This technology is currently used to process small-scale industrial waste, military, shipboard and medical/biological wastes. There is some limited use of plasma technology for MSW. This is discussed further in Section 4.2. A typical plasma arc process is depicted in Figure 2-2. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 3 February 2008 R-RWCounties Updated Research Study-Final.doc
Figure 2-2 Typical Plasma Arc Process Plasma is a hot ionized gas resulting from an electrical discharge. Plasma technology uses an electrical discharge (some use AC, some DC, and some a combination) to heat gas, typically air, oxygen, nitrogen, hydrogen, or argon, or combinations of these gases, to temperatures above 7,000 F. The heated gas, or plasma, can then be used for welding, cutting, melting, or treating waste materials. There are two types of plasma torches, the transferred torch and the non-transferred torch. The transferred torch creates an electric arc between the tip of the torch and either a metal bath or the conductive lining of the reactor vessel wall. In a non- transferred torch, the arc is produced within the torch itself. Plasma gas is fed into the torch, heated, and then exits through the tip of the torch. There are several approaches to the design of plasma gasification reactors. In one approach, developed by Westinghouse Plasma Corporation (plasma torch manufacturer) and Hitachi Metals (plasma gasification system developer and user), a medium pressure gas (usually air or oxygen) flows through a water-cooled, non-transferred torch, outside of the reactor. The hot plasma gas then flows into the reactor to gasify the MSW and melt the inorganic materials. Another design is an in-situ torch, where the plasma torch is placed inside the reactor. This torch can either be a transferred or non-transferred torch. When using a transferred torch, the electrode extends into the gasification reactor and the arc is generated between the tip of the torch and the molten metal and slag in the reactor bottom or a conducting wall. The low-pressure gas is heated in the external arc. Alternatively, a non-transferred torch can be used for creating plasma gas within the torch, which is injected into the reactor. Several suppliers utilize a completely different approach. In these designs, the reactor is heated by electric induction coils or an electric arc produced by graphite rods, forming a molten metal and slag bath. The MSW enters the reactor, where it is subjected to high temperatures, resulting in partial gasification of the feedstock. From there the syngas exits the reactor. The plasma torch 4 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
is situated either in a secondary reactor or in a recycle line, which goes back to the first reactor, assuring complete gasification of the feedstock. Proponents of the in-situ torch claim its advantages include better heat transfer to MSW and a hotter reactor temperature, resulting in more complete conversion to syngas. The main disadvantage is the potential corrosion of the torch from hot MSW and gases. An external torch is more protected from the corrosive effects, which can prolong the mechanical integrity. A disadvantage of an external torch is the possibility of a somewhat lower reactor temperature, resulting in lower conversion of the MSW. Electrodes in all designs experience some corrosion and must be replaced. Plasma arc gasification typically occurs in a closed, pressurized reactor. The feedstock enters the reactor, where it comes into contact with the hot plasma gas. In some designs, several torches arranged circumferentially in the lower portion of the reactor help to provide a more homogeneous heat flux. When used for gasification, the amount of air or oxygen used in the torch is controlled to promote gasification reactions. 2.2.2 Recovered Gas Gas from plasma based processes typically includes carbon monoxide (CO), hydrogen (H 2 ) and carbon dioxide (CO 2 ). Other gases may also form (SO x, HCL, and HF) but are usually neutralized in a gas scrubber. The gas has a typical heat value of 300 Btu/scf, similar to coal gas. 9 2.2.3 Vitrified Residue The inorganic fraction of the waste stream is converted to a silicate based slag. The slag is formed from the glass, soil, minerals and metals in the MSW. In a plasma pyrolysis process, the lack of oxygen causes metal, halogen and sulfur atoms to bond with the silicate. This atomic bonding makes leaching of the materials difficult. Any waste processing facility generating an ash or slag is required by the United States Environmental Protection Agency (USEPA) to subject the ash to a Toxicity Characteristic Leaching Procedure (TCLP) test. The TCLP test is designed to measure the amount of eight elements that leach from the material being tested. Data from existing facilities, even those processing highly hazardous materials or medical waste, show results that are well below regulatory limits. 2.3 Ethanol Production 2.3.1 Definition and Overview The production of ethanol (grain alcohol) from waste products is known by a variety of process descriptions, including biomass to ethanol and acid hydrolysis. It refers to the process of using thermo-chemical and enzymatic processing of cellulosic biomass to produce nonpetroleum based fuels, fuel cells, and industrial chemicals. 10 This means turning organic materials, including components of the municipal solid waste stream, into fuel grade ethanol by passing it through a series of refining processes to release, ferment, and distills available sugars. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 5 February 2008 R-RWCounties Updated Research Study-Final.doc
Production of ethanol through acid hydrolysis is a technology that has been known and used for over 100 years, with its most extensive use occurring during World War II. Low petroleum prices in comparison to high ethanol production costs kept the process from being adopted for commercial use in the late 1940s. However, ethanol production has received increasing attention in the past 10 to 20 years from agricultural generators seeking additional markets for corn and other farm products or byproducts. Similarly, changes in federal and global environmental policies are driving increased interest in the development of non-petroleum based fuel sources, including ethanol. Corn, it is believed, will continue to be the primary feedstock for ethanol; however, ethanol production from cellulosic materials such as woods, grasses and the organic fraction of MSW is becoming a more viable option. Recent advances in the ethanol production process, enzyme research and the increase in corn prices continue to drive research and application of alternative feedstocks for ethanol production. 11 2.3.2 Process Steps Although specific activities within each process step may vary, a review of several approaches to ethanol production reveals four to five sequential processes that appear common to each: Feedstock preparation: Within this process, the feedstock is received, separated, dried, shredded (usually to a uniform size of 2-4 inches), and otherwise prepared for processing. This usually includes some aspect of a material recovery facility (MRF) to remove nonorganic components and any household hazardous waste (HHW) that may be in the waste stream. Outputs of feedstock preparation are: Feedstock, including cardboard, newsprint, and other organics typically used in production of refuse-derived fuel Non-organic recyclable materials including aluminum, steel, other metals, glass, plastics, styrofoam and bulky waste Non-organic special wastes like batteries, fluorescent lights, tires, leather, etc. Another method of feedstock preparation implemented by BRI Energy, LLC is to first gasify the feedstock (feedstock for BRI is source separated organics) in a two-stage gasifier. The gasifier produces a syngas that is then cooled to 100 F where it is introduced into a fermentation process. 12 Decrystallization: During this process, which is also known as acid hydrolysis, sugars within the organic feedstock are released and captured through the use of heat and/or chemicals. The resulting acids and sugars are separated, with the acids recaptured or mixed with lime to produce gypsum. Fermentation: The sugars released in the previous process are converted to ethanol through the use of either heat or yeasts. The outputs of this process are ethanol and carbon dioxide. With appropriate equipment, the carbon dioxide can be recovered, purified and liquefied, thus producing another marketable product. 6 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Distillation: Ethanol is refined by boiling and re-condensing the vapor. The distilled ethanol is mixed with unleaded gasoline to produce vehicle fuel. Combustion of residue for energy production: This final process, which turns an otherwise unusable residue into a value added byproduct provides the essential step to make waste-to-ethanol a closed loop system. Although the waste-to-ethanol process works without combustion of residue, economic feasibility is enhanced by including it. Although not listed above, a viable waste-to-ethanol process seems likely to also include both a waste collection step, in which targeted organic wastes are collected separately of other components of the municipal solid waste stream, and an intensive marketing effort to ensure that the products produced are distributed. Three figures from ethanol process vendors show their process flows. Figure 2-3 shows a material flow diagram for Arkenol s concentrated acid hydrolysis process. Arkenol has constructed a pilot plant in Orange, California. Figure 2-4 shows a process flow diagram for the TVA s demonstration projects in Muscle Shoals, Alabama. This process was sold to Pencor Masada who plans to relocate the technology to Middletown, New York, in 2007 or 2008. However, the city of Middletown and Pencor Masada are in court due to delays in the start up date of December 2008. 13 Figure 2-5 shows the BRI Energy process. Figure 2-3 Arkenol s Concentrated Acid Hydolysis Process X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 7 February 2008 R-RWCounties Updated Research Study-Final.doc
Figure 2-4 TVA s Process Figure 2-5 BRI s Energy Process 2.3.3 Products, By-Products, and Markets Although researchers of waste-to-ethanol have historically not found uses for the process byproducts and residues, current proponents report it to be a closed system, zero discharge process 14 that produces usable products and by-products: Non-organic recyclables, separated from MSW deliveries Acids, which can be mixed with lime to produce hydrated gypsum 8 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Carbon dioxide, produced during the fermentation process and marketable to industrial gas companies 15 Ethanol, marketed as a fuel additive Part of the residue remaining after hydrolysis, lignin has a reported energy value of 8,500 to 11,000 Btu per dry pound and is said to be usable as a boiler fuel for production of steam or electricity 16 Specialty products (furfural, furans, glycols, etc.) used in industrial chemicals The California Energy Commission s report includes calculations to establish the quantity of ethanol potentially produced from waste feedstocks. Selected theoretical yields from those calculations are shown in Table 2-3. Table 2-2 Theoretical Ethanol Yield from Selected Feedstock A Theoretical Ethanol Yield Feedstock (gallons/bone dry ton) B Packaging papers 133.4 Corn Stover 113.3 MSW (35% fir, 20% almond tree pruning, 20% wheat 109.0 straw, 12.5% office paper, 12.5% newsprint) Coated paper 98.2 Newspaper 96.1 A Evaluation of Biomass-to-Ethanol Fuel Potential in California, California Energy Commission, December 1999, and Ethanol Industry Outlook: 1999 and Beyond, Renewable Fuels Association, February 1999, Table VIA-A-1, Appendix VI-A. B Bone dry ton is the equivalent of 0% moisture content. Ethanol from a waste-to-ethanol facility typically competes with gasoline produced from crude oil or ethanol produced from other feedstock, primarily corn. The primary current market for ethanol is as a fuel additive in gasoline. Ethanol is also considered an appropriate fuel for fuel cell vehicles, which are being tested as replacements for traditional automobiles powered by internal combustion engines. 17 Ethanol can also be further refined for use in the industrial chemical market. Ethanol from all sources supplied about 3.0% of the highway motor vehicle fuel market in the United States in 2005. The Department of Energy expects ethanol consumption to grow to 8% of the total motor gasoline fuel in 2030. Ethanol consumption is expected to grow from 4 billion gallons in 2005 to 14.6 billion gallons by 2030. Ethanol use in 2030 is broken down to 14.4 billion gallons being used for gasoline blending and 0.2 billion gallons used for E85. Domestic ethanol production in 2030 is anticipated to have corn as the primary feedstock (13.6 billion gallons), with cellulosic feedstock and other processes accounting for the remaining ethanol production (1 billion gallons). X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 9 February 2008 R-RWCounties Updated Research Study-Final.doc
Minnesota ethanol production was estimated in 2006 to be 550 million gallons. As of October 2007, Minnesota had 17 operating ethanol plants, with a capacity of 670 million gallons annually and 4 ethanol plants under construction with an additional 400 million gallons of capacity. Minnesota s consumption of ethanol was estimated to be 263 million gallons. 18 Ethanol prices have continued to rise with fuel prices (see Figure 2-6). However, profitability of biofuels and particularly ethanol are heavily influenced by the cost for feedstock. The U.S. ethanol industry relies heavily on corn as the primary feedstock. However, as ethanol production and demand increases, competition for corn supplies among fuel, food and export markets along with the decline in pricing for ethanol co-products will make production of ethanol more expensive. 19 Figure 2-6 Average U.S. Price for Ethanol and Gasoline 16 The increase in the cost of corn-based ethanol may lead to advances in cellulosic ethanol production facilities, which could then meet the growing ethanol needs. It is anticipated the first cellulosic ethanol plants to be developed would be based upon an abundant and inexpensive feedstock like switchgrass, agricultural residues and hybrid poplars. These second generation ethanol plants would open markets for other energy crops beyond corn. However, it is estimated that a cellulosic ethanol plant has capital costs almost five times higher than corn-based ethanol plants. The capital costs required and the risks are a deterrent to cellulosic ethanol production. 10 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
3 Methods Additional research into the three processes of gasification, plasma, and ethanol were conducted. To update the information, sources included the Internet, periodicals, newspapers and interviews. There was considerable duplicative information on several of the process vendors. Sources sited were developed based on the most complete source of information, though the source may have been a compilation of other sources. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 11 February 2008 R-RWCounties Updated Research Study-Final.doc
4 Technology Update 4.1 Gasification Several companies have entered the gasification technology market as gasifier designers, suppliers and marketers. Juniper Research 20 has identified over 80 technology suppliers for gasification. Of the 80+ technology suppliers, Juniper indicates only 9% are at the fully commercial state with gasification technology. The vast majority, about 70%, of the technology suppliers are in the demonstration, pilot, or bench scale phase of the gasification process. The Juniper database identified the plants in Table 4-1 as operating gasification plants. Table 4-1 Operating Gasification Plants 19 4.1.1 Specific Experience 4.1.1.1 Alameda Power and Telecom 21 In May 2004, Alameda Power and Telecom completed a study to investigate pyrolysis, conventional gasification and plasma gasification. The study was based on the issuance and evaluation of a three-phase Request for Qualifications (RFQ) project that obtained information from existing vendors of MSW gasification technology. Alameda Power and Telecom pursued this study to procure additional electrical generating resources. The investigation concluded gasification of MSW to produce electricity is technologically viable. However, MSW gasification is not a mature technology, and therefore some risk mitigation strategies would need to be developed to limit risk. 12 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
A preliminary economic study was also completed as part of the project. The study concluded that the costs for MSW gasification are highly dependent on power purchase revenues, landfill disposal costs and avoided costs of the waste to not be landfilled. From the study and the results of the RFQ, it was concluded, that costs on conventional electrical generation and disposal of MSW in landfills may now be reaching levels at which thermal MSW gasification becomes economic. A key component identified in the economic analysis was control of capital costs for the plant. It was clear from the study that gasification of MSW could not directly compete with natural gas turbines to produce electricity. However, a tipping fee for the MSW may be used to offset capital cost for the plant. Capital costs for a MSW gasification plant were $63 to $91 million ($2002) for a 12 MW to 20 MW plant. Operations and maintenance costs were estimated to be $6 to $9 million ($2002). The plant costs translated to a cost for power of 9.6 to 11.9 cent ($2002) per kwh at a low tip fee (approximately $40/ton) and 3.7 to 5.5 cents per kwh for a high MSW tipping fee (approximately $65/ton). The draft report was accepted by the Public Utilities Board on October 18, 2004. No further action on the report has been conducted. However, the report did recommend that Alameda Power and Telecom: Examine biogasification of MSW (a process of accelerated, anaerobic digestion and gasification) Participation in the development of laws and regulations relating to gasification of MSW Promote third-party development of a gasification project by long-term power purchases from such a project 4.1.1.2 Greve in Chianti 22 The plant at Greve in Chianti has two 15 MW, Termiska Processer AB (TPS) circulating fluidized bed (CFB) gasifiers. Each gasifier has a capacity of 100 tons per day (tpd) of refuse derived fuel (RDF) pellets. Throughput is 2 to 4 tons per hour of RDF pellets. The TPS technology uses a starved air gasification process with a combined bubbling and circulating fluidized bed reactor that operates slightly above atmospheric pressure. Operating temperatures of 700 to 850 C are used. A process diagram is provided in Figure 2-1. RDF pellets are made at a processing plant at Case Passerini, near Florence, Italy. The facility uses standard RDF processes to make the pellets and recycle materials (primarily metals). Recycling rates at the RDF plants are reported to be 25%. The RDF is stored in 80 ton steel silos at the gasification plant. The RDF is fed into the gasifier using a series of screw conveyors, hoppers, and augers. The RDF fuel is delivered to the gasifier plant with the following specifications: Diameter 10-15 mm Length 50-150 mm Bulk density 500-700 kg/m 3 (31-42 lb/ft 3 X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 13 February 2008 R-RWCounties Updated Research Study-Final.doc
Net calorific value (LHV basis) 17.2 MJ/kg (7380 Btu/lb) Volatile matter 71.1% Moisture (typical) 6.5% Fixed carbon 11.4% Sulfur 0.5% Chlorine 0.4-0.6% Total non-combustibles 11% The syngas that is developed as part of the gasification process has a heating value of 202 Btu/scfm. For comparison landfill gas has a heating value of 500 Btu/scfm. Air emissions data from the plant indicates the plant is capable of meeting European Union and USEPA standards. The gasification cycle converts 387 TPD of RDF pellets to produce 25.7 MW of electricity from a gas turbine and another 17 MW from a steam turbine. System power requirements include 7.3 MW to compress and clean the gas before the turbine and 1.7 MW for other equipment needs. The net power output is 33.7 MW which translates to an efficiency of 39%. However, these numbers do not include the energy required to make the RDF pellets and recycle the estimated 25% of the inflow waste. Plant economics are not readily available and are believed to be high since the plant has gone through several renovations and upgrades. Capital costs for a plant consisting of 2 gasification units and a capacity of 1,200 TPD of unpelletized RDF are estimated by the vendor to be about $170 million ($1996). O&M costs were estimated to be $35.6 million and electric sales revenue of $16.3 million. 4.1.1.3 Home Farms Redwood Falls 23 Home Farms Technologies Inc and BlackTree Capital Corp., Cambridge, Ontario are planning to provide the initial funding of the Redwood Falls Energy Supply Agreement, a 20-year contract for Home Farms Technologies USA Inc. to supply thermal energy (steam) to Farmers Union Industries LLC for their rendering and bio-diesel facility at Central Bi-Products near Redwood Falls, Minnesota. The steam will be produced by the gasification of municipal solid waste originating in towns and counties situated in Southwest and South Central Minnesota and from the Twin Cities. The $35 million project involves the installation of Municipal Solid Waste Material Recovery Facilities at Redwood Falls and the Twin Cities and the installation of gasification equipment and boilers at Central Bi-Products near Redwood Falls. The municipal solid waste would be received at the Redwood Falls Waste-to-Energy Power Station by truck and by rail. The power station would be designed to also accept corn stover as feedstock fuel for future energy requirements. The power station was planned to be designed by Utility Engineering of Minneapolis. The gasification process used by Home Farms Technologies was developed by Andy Butler, vice-president of engineering for Home Farms. This process is unique in that it more efficiently burns the municipal solid waste or other biomass and offers a consistent steam output for its customer. No specific information about the process was provided. 14 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
The planned facility would require approximately 475 tons of biomass per day and thus the group approached the City of Bloomington to get the additional waste it needed to make the project work. Home Farms explains that the waste haulers will pay reasonable tipping fees for delivery of the municipal solid waste to the material recovery facilities. Following the completion of engineering and permitting, ground breaking was planned in the spring of 2007 and completion of the Waste-to-Energy power station was expected in the spring of 2008. However, in discussions with Julie Rath, 24 Redwood Falls Economic Development coordinator, the Home Farms gasification project is dead. Ms. Rath indicated the group that originally approached Redwood Falls regarding the gasification plant is no longer employed with Home Farms. No future plant is planed for Redwood Falls. 4.1.1.4 Great River Energy 25 Great River Energy (GRE) is headquartered in Elk River, Minnesota and is the second largest electric utility in Minnesota. GREs primary business is to provide wholesale electric service to 28 distribution cooperatives in Minnesota and Wisconsin. GRE has 2,816 megawatts of electrical generation capacity using a mixture of coal, natural gas, oil, wind and RDF as fuel sources. Additionally, GRE has 4,500 miles of transmission lines. The RDF plant, located in Elk River, has a base load capacity of 35 megawatts through burning 1,000 tons per day of RDF delivered to the plant. MSW is converted to RDF two miles east of GRE on MN State Highway 10 and transported to the Elk River Station. MSW source include Anoka County (33%), Hennepin County (53%), Sherburne county (3%), and Tri County (11%). The plant burns an average of 275,000 tons per year of RDF. The RDF has a heating valve of 5,500 Btu per pound at 25% moisture content. Residue consists of ash, about 28%, which is disposed at an ash monofill in Becker, Minnesota. The RDF burner has an availability of 80 85%. There is considerable downtime for maintenance of the boiler due to the corrosive and erosive nature of the RDF. Furthermore, GRE reports RDF is about three times the cost of coal. For greenhouse gas generation, one ton of RDF combusted produces approximately one ton of CO 2 equivalent. In 2006 and 2007 GRE studied an alternative method of processing 250 tons per day of RDF. The process studied was a gasifier followed by a plasma arc process. The process was chosen because the syngas created in the gasifier could be used to produce electricity, hydrogen, ethanol, methanol and gasoline. The plasma process was selected to vitrify the ash from the gasifier and possibly to market the material from the plasma arc process as road aggregate, and thus no need for a landfill. GRE also considered using various feed stocks in an ethanol process. However, their research indicated the enzymes have not been created to effectively convert cellulose to sugars. GRE also had concerns that the RDF, due to its heterogeneity, may poison the ethanol process. Thus, the further study of RDF to ethanol was not pursued by GRE. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 15 February 2008 R-RWCounties Updated Research Study-Final.doc
The gasification plasma process studied by GRE is shown in Figure 4-1. The process requires the RDF to go through size reduction followed by gasification and finally plasma. The process, as studied, has the capacity to produce 775 kw of gross electric power (675 kw, net), and 21,000 cubic feet of hydrogen, and 100 gallons of methanol, and 50 gallons of ethanol and 45 gallons of gasoline per 250 TPD of RDF. Figure 4-1 GRE s Gasification Plasma Process GRE decided to pursue converting the syngas to methanol. Deciding factors included: Available methanol markets. For every 10 gallons of biodiesel, one gallon of methanol is needed. U.S. imports 80% of its methanol needs primarily from South America. Methanol futures indicated a $2.00/gallon price which made the economic favorable. Ethanol industry saturated with corn-based plants. Gasoline industry difficult to enter at such a low production capacity. Catalyst to convert syngas to methanol readily available. Integrated Environmental Technologies has gasifier PEMs system for plasma (10 TPD) Electrical production not cost competitive; estimate $0.25 per kwh needed. Low relative risk when compared to other technologies. The original plant estimate was $40 million in capital costs with 10 full-time employees. The RDF to methanol process requires size deductions to two inch minus so the gasifier can be fed effectively. Additionally, it is anticipated the syngas (75% from gasifier and 25% from plasma) would require significant clean up prior to entering the catalyst for conversion to methanol. The plant is estimated to consume 7 MW of electricity. 16 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
The feasibility and process studies have been completed for the GRE, RDF to methanol plant. During the study of the process, methanol pricing dropped from $2.00 per gallon to $0.70 per gallon. This decrease in price changed the economic feasibility of the proposed plant. At this time GRE is not continuing to pursue RDF to methanol. 4.1.1.5 Shaw Industries 26 Shaw Industries is one of the world s largest carpet producers and is also one of the world s largest producers of carpet waste. A partnership between Siemens Energy and Environmental Solutions and Primenergy Inc. was the solution to Shaw s waste production challenges. Primenergy s gasification equipment can convert 70 to 550 tpd of biomass to steam (or hot air for drying) and up to 12.8 MW of electricity. The gasification process heats the carpet waste to 1,400 º F in a sub-atmospheric chamber. Once the carpet waste ignites it becomes a self-fueling process that produces gas and approximately 5 to 10 percent ash (by volume). Even though the nitrogen and sulfur are trapped in the ash during the gasification process, the gas would still require scrubbing if Shaw wanted to use it to generate electricity, but no special handling is needed to burn it in a waste heat boiler. Primenergy has tested more than 25 different feedstocks, such as rice hulls and straw, sugar cane biogases, tire-derived fuel (TDF), refuse-derived fuel (RDF), paper-plant pulp sludge, and sewage sludge (biosolids) in their gasification equipment. No auxiliary fossil fuel was required to maintain continuous operation of the process for all of the biomass materials tested. A demonstration using carpet as a fuel source was conducted to show that it burns clean enough to meet EPA emission standards. To verify the emissions, a third-party company conducted stack compliance testing in accordance with USEPA test methods and reporting protocol. The project required four silos (one each for feeding carpet fiber, carpet backer, and wood flour and one for ash) and a 10,000 square foot building to house the carpet shredding equipment. The manpower required should consist of a maximum of two people to monitor the boiler and feeding system. The system feeds about 80 to 100 tpd into the Primenergy gasifer and the boiler creates 50,000 lbs of steam per hour. With the total investment estimated at $10 to $15 million and a predicted energy cost reduction of up to $3.5 million per year, the payback could come in less than five years. Additionally, the company plans on selling the ash byproducts as filler for road paving material and other uses. 4.1.1.6 Ze-Gen 27 A demonstration plant capable of accepting up to 10 tpd of construction and demolition (C&D) residual material has been set up by Ze-Gen in New Bedford, Massachusetts. The location is next to an existing transfer station where C&D waste is shredded prior to transfer to landfills. The shredding process yields a mixture of 90% wood, 5% residual metal, and 5% silica. Having the material prepared already allows the feedstock to be more easily tested in the 2,700º F furnace. The feedstock is used in an advanced gasification process that utilizes molten bath technology which produces syngas (primarily carbon monoxide and hydrogen) through a X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 17 February 2008 R-RWCounties Updated Research Study-Final.doc
chemical reduction process and slag that can be used for construction. The high temperature, oxygen-starved environment of the metal bath reduces waste to its elemental components, rapidly and with very low heat loss. Though carbon monoxide and hydrogen gas bubble up from the molten bath; compounds such as NO x, SO x, furans, and dioxins do not form in the gasification process. No ash is formed during this process and the byproducts are metal and inert silica, which can be recycled or used as construction aggregate. Ze-Gen modular systems are specifically designed to process feedstock with high organic content, such as processed C&D waste and scrap tires and can accept 450 and 100 TPD, respectively. The modular design allows facilities to expand based on availability of feedstock and allows for periodic shutdowns for maintenance, modifications, and upgrades without interruption of power generation. The facilities are designed to run 24 hours per day, 7 days per week. The expected syngas production per ton of feedstock could generate 1.654 MW per ton of raw waste. Ze-Gen is a three year old company that is currently working on perfecting the design of the tubes being used to feed the material into the molten bath, which is expected in the next few months. The next step for Ze-Gen will be to go into continuous operation and conduct gas analysis on the syngas produced. Ze-Gen estimates it will be sometime around 2010 or 2011 before they will have a full scale facility accepting waste and producing electricity. 4.1.1.7 Collier County, Florida 28 Collier County, Florida, in developing an integrated waste management program, solicited longterm waste management solutions from private companies. The companies were to be capable of processing a majority of the municipal solid waste in the County (in FY 2002, estimated to be 580,000 tons; by 2010, 730,000 tons). Three proposals were received in April 2002. Proposals were received from Interstate Waste Technologies (IWT), Brightstar Environmental, LLC (Brightstar) and the Slane Company. The Slane Company was initially eliminated since they did not meet the initial technical and financial requirements outlined in the request for proposals. Brightstar and IWT were further evaluated based on their experience, technical approach, business management and cost. The selection committee concluded IWT offered the best experience and technical approach, but the cost for the technology was prohibitive for the County. Brightstar offered lower cost but an experimental process. The committee s final recommendation was to solicit a best and final offer from IWT. In further discussions with the Solid Waste Division staff, IWT could not obtain the financing needed to fulfill the requirement of Collier County. Discussions with Brightstar indicated technology problems have hampered their ability to meet the requirements of Collier County. In late 2003, Collier County canceled its waste project procurement, deciding that it will continue to use landfills to dispose of waste. 4.1.1.8 Interstate Waste Technologies (IWT) Interstate Waste Technologies is marketing a gasification technology called Thermoselect. The technology uses a combination of high temperature and long-residency time to convert organic material to synthesis gas. Information regarding the various plants and processes depicted on their web site is limited. The company does indicate their process produces 100 percent recycling. The company reports an input of 2,000 pounds of waste plus 1,028 pounds of oxygen and 60 pounds of consumables; has an output of 1,790 pounds of synthesis gas, 460 pounds of minerals, 698 pounds of water and 90 pounds of other materials. 18 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
There are currently no IWT plants operating in the United States. However IWT is involved in three on going procurements for facilities in the US including one in New York City (expected to proceed in 2008), one for the County of Los Angeles, and one for the City of Los Angeles (a 1,246 tpd facility). An additional facility in Caguas, Puerto Rico (proposed 450,000 tpy) is in final negotiations and permit applications are expected to be submitted in 2008. The company reports fully operational plants in Chiba, Japan (330 tpd), Mutsu, Japan (140 tpd), Kurashiki, Japan (555 tpd), Nagasaki, Japan (300 tpd), Yorii, Japan (450 tpd), Tokoshima, Japan (120 tpd), and Izumi, Japan (95 tpd). However, details on these plants are not readily available. IWT also has a 110 ton per day demonstration facility constructed in Fondotoce, Italy. 29 A gasification facility in Karlsruhe, Germany (792 tpd) using the Thermoselect process, which IWT was intimately involved with was closed in November 2004. Some of the issues sited with this plant are as follows: Reported losses of $500 million dollars by November 2004 (Start-up Feb. 1999). The Thermoselect Karlsruhe incinerator consumed 17 Mm 3 of natural gas to heat the waste in a single year, while returning no electricity to the grid that year. The Thermoselect Karlsruhe incinerator was only able to process 1/5 of the contracted waste while in operation. Additionally, at the facility in Fondotoce, Italy, Thermoselect s management was convicted of contaminating a lake with cyanide, chlorine, and nitrogen compounds. 30 The steps and principles of the Thermoselect process as described by IWT are as follows 31 and are shown in Figure 4-2. 1. Waste Compaction Unprocessed municipal solid waste has a low density and requires a great deal of space. The Thermoselect process uses standard in-line scrap metal presses to compress the waste and increase its overall density. To accomplish this, presses which have been thoroughly tried and tested in over 30 years of industrial operation are used. The refuse is compacted to about 10 percent of its original volume. The compacting results in highly compressed packets of co-mingled waste where the moisture that is naturally contained in the refuse becomes evenly distributed. The packets are estimated to be 2 inches in diameter. As a result, the residual air content in the compressed refuse packets is reduced to a minimum. 2. Degassing The highly compressed refuse packets are pushed directly to a pressure-resistant channel to form a gas-tight plug. In this channel, the refuse is intensively heated by conduction. The heat (350 C/660 F) vaporizes the volatile portion of the waste, which is primarily water. The hot gas molecules, especially those of water vapor, transfer energy to further heat the waste packets. These hot gases flow through the X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 19 February 2008 R-RWCounties Updated Research Study-Final.doc
heated channel and enter the next stage, the high temperature chamber (HTC). The organic part of the compressed packets is degassed and converted into carbon; the inorganic mineral and metal matter is entrapped in the carbonized material. The hot carbon packets, with the entrapped inorganic components, are continuously moved forward to the next stage by feeding new refuse packets into the degassing channel. The gaseous components: water, carbon monoxide, carbon dioxide, hydrogen, and hydrocarbon gases, are moved continuously from the degassing channel into the high temperature chamber (HTC). 3. High Temperature Gasification The carbon packets break apart as the carbon and inorganic portions enter the high temperature gasification chamber (HTC). Oxygen is introduced, providing a high temperature gasification medium. Oxygen, in the presence of steam, ensures that all chemical reactions occur rapidly. The essential processes are: a. All organic compounds are completely destroyed and are decomposed (cracked) to atomic levels. b. A synthesis gas is formed as carbon, oxygen, hydrocarbon gases, and water combine. Degasification in the absence of air produces a continuous flow of carbon into the high temperature oxygen based gasification process, resulting in a raw synthesis gas volume of about 800 Nm 3 (25,000 cubic feet) per ton of waste input, depending on the heat content of the waste. This process for forming synthesis gas has been utilized for more than 60 years. Significant industry experience assures the integrity and safety of the design and operation of gasifiers at various temperatures and pressures. c. Minerals and metals in the waste are liquefied and refined by oxidation, resulting in the total conversion of all entrapped carbon. The metal/mineral product is recovered in the form of an inert and non-toxic material that meets US Environmental Protection Agency Toxic Characteristics Leaching Procedure test standards. The metallurgy and glass industries have developed methods for converting these materials into useful products. 4. Synthesis Gas Treatment The synthesis gas and other components of the gas steam exit the HTC at a temperature of 1,200 C (2,200 F) and are shock-cooled to below 90 C (194 F) using a water flush. Melted mineral particles and, in some circumstances, traces of carbon that can be carried along with the gas are precipitated in water, separated, and recycled back into the thermal process. The rapid cooling of the hot gas stream in the absence of oxygen prevents a de-novo synthesis (new formation) of dioxin and furan compounds. The multi-stage alkaline wash assures the separation of sulfur compounds. The synthesis gas is separated prior to this second gas washing stage and separately cleaned and cooled to reduce its residual moisture. The purification of the synthesis gas is concluded by passing the gas through an activated coke filter. The use of activated coke filters for the final purification of oxygen-free synthesis gases at temperatures far below 80 C (176 F) is a process and safety advantage. 20 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
5. Water Treatment The aqueous acid washing solutions generated during the gas cleaning process are subjected to conventional chemical material separation processes. Products from the gas cleaning and water recovery process include industrial grade sodium chloride (salt), elemental sulfur, and a separate precipitate containing the heavy metals from the input waste. The precipitate is concentrated to produce a material that is rich enough in zinc and lead to be processed in smelters to recover these two metals. All of the remaining water from this process is recovered and reused within the system. No process water is discharged from the plant. 6. Electricity Generation The clean synthesis gas is transformed directly into electrical energy using generators driven by high efficiency, low speed gas engines. The energy in the engine exhaust gas is used to heat the degassing channel and to provide heat for the evaporation stage of the water treatment process. 4.1.1.9 City of Los Angeles 32 Figure 4-2 Thermoselect Process The City of Los Angeles Board of Public Works, Bureau of Sanitation received proposals from firms across the country and worldwide to bid on building an alternative technology facilities for managing MSW. The Request for Proposals (RFP) called for proposals for both commercial and emerging technology facilities to process post-source separated municipal solid waste, or black bin waste, which is currently disposed of in landfills. The RFP was for (1) a Commercial Facility capable of processing 200 to 1,000 tons of waste per day and for (2) an Emerging Technology Facility capable of processing less than 200 tons of waste per day. Of the technologies presented there were four variations of gasification proposed - Conventional Gasification Fluid Bed, Conventional Gasification Fixed Bed, Gasification/Pyrolysis, and Plasma Arc Gasification - by five suppliers (Ebara, Whitten, IWT, RRA, and Omni). Several X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 21 February 2008 R-RWCounties Updated Research Study-Final.doc
suppliers proposed multiple different equipment sizes (Whitten and IWT), which resulted in comparison of parameters between seven different designs as shown below in Table 4-2. Table 4-2 Gasification Parameters from City of Los Angeles RFP Parameter Range Throughput (tpy) 100,000-400,000 Net Electricity Production (MW) 4-38 Energy Efficiency, Net (kwh/ton) 350-880 Diversion Rate (% of Throughput) 85-100 Worst Case Diversion Rate (% of Throughput) 75-89 Capital Costs ($/TPY) 160-900 Estimated Breakeven Tipping Fee ($) ~19-124 After the initial RFP, the City of Los Angeles released a Request for Proposals seeking Development Partner(s) for Processing Municipal Solid Waste Utilizing Alternative Technology Premised on Resource Recovery for the City of Los Angeles. This RFP was released on February 5, 2007. A subsequent pre-proposal conference was held on March 7, 2007 and was attended by approximately 75 individuals representing companies within the United States and from all over the world, including Spain, Germany, Israel, and Japan. Proposals seeking development partners were submitted on August 22, 2007. Table 4-3 lists the responses received and the technology proposed. It is anticipated that interviews with top-ranking proposers will be scheduled and a development partner for the City selected in 2008. 33 Table 4-3 City of Los Angeles Development Partners RFP Responses A, B Company Zia Metallurigal Processes Interstate Waste Technologies Covanta Energy Corporation Wheelabrator Technologies, Inc. WRSI/DESC Plasco Energy Group Community Recycling Carbon Sequestation, LLC CA Renewable Technologies, LLC (2) Urbasher & Keppel Seghars Rainbow Disposal Proposed Technology TRG Process (gasification) Thermoselect (gasification) Waste to Energy Waste to Energy MUR System (WTE with Flue Gas Cleaning and HCL production) Plasma Gasification Process MRF & AD & BWmap Power & Composting Gasification AD WTG Gasification, AD Gasification A. From City of Los Angeles Press Release dated August 23, 2007. Found at www.lacity.org/sar/solid.resources/strategic_programs/alternative_tech/media B. Clements, Chip. Status of Conversion Technology, California Update. Presented at Southern California Waste Management Forum. November 15, 2007. 22 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
34, 35 4.1.1.10 City of New York Refuse in the City of New York is collected by the New York City Department of Sanitation (DOS) using their fleet of nearly 1,500 trucks. The refuse was disposed of at the Fresh Kills landfill until 1996, when the city started phasing out its use of Fresh Kills in anticipation of the State Legislatures mandated closure of Fresh Kills landfill by January 1, 2002. Currently, the majority of the refuse collected in the city goes to three main locations: (1) refuse from Manhattan is transported to a Waste-to-Energy (WTE) facility in New Jersey, (2) refuse of Brooklyn, Queens and Staten Island is delivered to private waste transfer stations in the City and then transported to landfills in Pennsylvania, Virginia, and Ohio, and (3) some of the refuse from the Bronx is delivered to a private transfer station located in Harlem River Yards where it is loaded into containers and transported by rail to disposal facilities in other states. The New York City Department of Sanitation is currently examining alternatives to transporting the City s refuse and is considering an in-city WTE facility employing gasification as an alternative. Interstate Waste Technologies (IWT) has indicated that they are involved in the procurement process for installation of a WTE facility for the City of New York. No further information as to plant capacity or physical location was found at the time of this update. 36 4.1.1.11 County of Los Angeles 37 In 2004 the County of Los Angeles established the Alternative Technology Advisory Subcommittee to evaluate the development of conversion technologies for MSW and the technologies application to the waste stream in Los Angeles County. The subcommittee was comprised of various elected and appointed officials, consultants and environmental and community leaders. In 2004 the County conducted a study to evaluate the range of conversion technologies and suppliers along with efforts to site an MRF and transfer stations (TS) in Southern California. The Phase 1 report resulted in the identification of a preliminary short list of technology suppliers and MRF/TS sites. The report also provided some long-term strategies for conversion technology development. In Phase II, the County developed a more comprehensive conversion Technology Evaluation Report that required participants to supply detailed information. A total of 32 technology suppliers were initially considered as part of the Phase II study. Ultimately nine suppliers were selected to participate in Phase II. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 23 February 2008 R-RWCounties Updated Research Study-Final.doc
Table 4-4 Technology Suppliers Participating in Phase II Technology Supplier Technology Type Proposed Capacity Major Products Arrow Ecology and Engineering (Arrow) Anaerobic Digestion 300 TPD Biogas (Electricity) Digestate (Compost) Recyclables Renewable Diesel Fuel Changing World Thermal Depolymerization 200 TPD Carbon fuel Technologies (CWT) International Environmental Solutions (IES) Interstate Waste Technologies (IWT) NTech Environmental (NTech) Pyrolysis 242.5 TPD (58.9% moisture) 125 TPD (20% moisture) Pyrolysis/High Temperature Gasification Low Temperature Gasification 312 to 935 TPD 1,2,or 3 units Metals Syngas (electricity) Syngas (Electricity) Metals Aggregate 413 TPD Syngas (Electricity) After the nine suppliers were identified, a detailed request for information (RFI) was issued. During the RFI process, four of the nine suppliers chose to withdraw from consideration. The five suppliers that did respond to the RFI included those in Table 4-4. The RFI also identified the candidate MRF/TS sites in Los Angeles, Ventura, Riverside, and Orange County. The Phase II report concluded all technology suppliers in Table 4-4 are ready for application as part of the demonstration project except CWT. CWT has demonstrated their technology on agricultural waste (primary turkey offal) but not MSW. The report did caution that each of the four technologies deemed ready would incorporate one or more new outputs to their technology, such as unique integration of preprocessing equipment and other components. The phase II study also concluded that estimated tipping fees at proposed conversion technology plants would range from $40 to $70 per ton. The exception was the proposed 312 TPD unit by IWT. This unit was considered economically not viable. Estimated cast for the technologies is provided in Table 4-5. The estimated tipping fee for the conversion technology is higher than the current landfill tipping fees that range from $25 to $35/ton. 24 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Table 4-5 Tipping Fees Estimated by Technology Suppliers Design Capacity (tpd) Development, Design and Construction Costs Technology Supplier A Tipping Fee Estimate ($/ton) Arrow (IP) 300 $20,922,000 $1,918,625 $50.00 CWT (GP) 200 $35,000,000 $8,999,684 $46.60 B IES (IP) 242.5 $30,142,000 $2,712,000 $56.00 IWT (GP) 1 Line 2 Line 3 Line 312 623 935 $75,225,00 $126,446,00 $170,425,000 $11,020,687 $16,866,561 $24,591,660 $130.86 $70.58 $59.23 NTech 413 $56,594,060 $6,761,477 $55.00 A IP Means integrated pricing (i.e., use of existing infrastructure) and GP means Greenfield pricing (i.e., a standalone project). B The economic modeling showed that CWTs estimated tipping fee would not be achievable, which is consistent with CWTs determination that the project would incur a substantial annual loss. The subcommittee is currently reviewing a draft request for offers (RFO). The RFO would be sent to the four technology suppliers identified in the Phase II report. The intent of the RFO is to obtain formal site specific offers from the technology suppliers to develop a successful demonstration project. The RFO is anticipated to be distributed in 2008. A demonstration plant start up is anticipated in 2011. 38 39, 40 4.1.1.12 Batch Oxidation System (BOS) The batch process of waste reduction integrates slow gasification and long exposure time at moderate temperature followed by turbulent oxidation of gasses at high temperature. EnerWaste International Corporation (EWI), EnerWaste Europe Ltd. (a subsidiary of EWI and Iceland Environmental Inc.), and Planet Advantage Ltd. are several companies that currently have operating BOS plants. The main concept for the BOS for each manufacturer is similar with some minor differences. Each system can generally accept unsorted/unprocessed waste (the main exception being waste size restrictions). After the waste is loaded into the primary chamber (or two primary chambers in the Planet Advantage Ltd. system) and sealed tight, an auxiliary burner (typically burning natural gas, propane, diesel, or waste oil) is ignited and operates until the interior temperature reaches 200º C (for the EWI system) or 550º C (for the Planet Advantage Ltd system). After the auxiliary burner is shut off the interior temperature is monitored with controls and maintained by allowing sub-stoichiometric amounts of air into the chamber during the gasification process. The combination of relatively low temperatures and only sub-stoichiometric amounts of air in the primary chamber during gasification do not disturb the gasification bed, which is said to minimize particulate emissions, heavy metals, and many noxious gasses. The relatively low temperature environment in the primary chamber does not vaporize most of the inorganic materials such as rock, metals, and glass, which helps reduce emissions and allows for ease of X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 25 February 2008 R-RWCounties Updated Research Study-Final.doc
material recovery from the ash. Depending on the waste type and system layout, the waste reduction process in the primary chamber will take approximately 10 to 15 hours. Vapors produced during the gasification process pass through to the preheated secondary chamber also called an afterburner where most of the remaining noxious emissions are eliminated. As the vapors from the primary chamber enter the preheated secondary chamber, auxiliary burners and excess oxygen create a very turbulent high temperature environment (typically between 850º C and 1200º C). For most applications within the European Union (EU) 850º C is the required minimum temperature, though 1100º C is required for halogenated wastes and in North America, 982º C is usually required. Additionally, residence time in the secondary chamber is important for proper destruction of vapors from the primary chamber. In both the EU and North America a minimum residence time of two seconds is required, though in some isolated cases, codes in North America may allow one second. Emissions: Air emission test results provided by EWI for a BOS combusting 100% biomedical waste with no additional emission controls are presented in Table 4-6. Table 4-6 EnerWaste BOS Equipment--US EPA Performance Test February 1993 Pollutant mg/nm 3 @ 11% O 2 & 0ºC Grains/DSCF @ 7% O2 & 68ºF SO 2 7.7156 0.0044 HCL 14.0284 0.0080 CO 0.1754 0.0001 NO 2 7.7156 0.0044 Particulate/Dust 2.1043 0.0012 Operating Costs: No information as to a specific overall cost per ton was provided by EWI or Planet Advantage Ltd for the operation of a BOS. However, both suppliers claim that the costs of operating and maintaining the BOS are lower than that of conventional incineration facilities of similar size. Additionally, EWI states that the installed cost for a BOS WTE with emission control equipment is under $5,000/kW for a 100 to 200 tpd and 2 to 4 MW system. The estimated fuel consumption for auxiliary firing is about 3 gallons per ton of MSW. The manpower required to operate the system is minimal and EWI states that one person can discharge the ash and reload a 10 ton chamber within half an hour. Additionally, both suppliers claim nearly 100% (between 97 and 100%) utilization of the waste stream between energy recovery and recycling. The ash remaining is about 3 to 8% of the original waste volume (depending on waste composition) and both suppliers claim the ash is virtually inert and can be recycled. The systems are modular and can be increased or decreased in size easily and, depending on supplier, a single afterburner can be used for two (Planet Advantage Ltd.) or four (EWI) primary chambers. 26 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Operating Facilities: EWI states they have over 100 projects installed world wide processing over 1,000,000 tpy. The systems range in size from a portable facility in Donlin Creek, Alaska, capable of 0.5 tpd to a 600 tpd facility in British Columbia. A 100 tpd barge mounted facility was used for cleanup and sludge materials from the Exxon Valdez oil spill, so EWI has had facilities since about 1989. 4.1.1.13 Nippon Steel 41 The Nippon Steel gasification process accepts unsorted MSW that is processed to the proper size. The gasification process is a fixed bed gasifier with enriched oxygen air injection. MSW is mixed with coke at about 5% by weight. The coke reacts with the oxygen and the other gases and provides the energy for full ash melting in the gasifier. Limestone is also added to the waste (about 5% by weight) to act as a buffering agent for the ash melting. Outputs from the process include slag (180 pounds/ton of input material), metals (20 pounds/ton of input) and fly ash (60 pounds/ton of input). Nippon Steel reports about a dozen plants in Japan using this process. The plant capacities range from 110 to 500 tons per day of MSW. Some plants also use other feedstock in addition to MSW including sludges, industrial wastes and incineration residues. 4.1.1.14 Alstrom/Ebara 42 Alstrom Power of France acquired ABB Enertech in 1999 and also the license for Ebara s fluidized bed technology. Ebara built and operated many MSW combustion facilities in Japan and other Asian countries. Ebara also developed the Twin Rec and the EUP gasification systems. Both of the gasification technologies use dual chamber gasifiers. The first gasifier is a fluidized bed reactor. This is then coupled with a secondary chamber where the gas produced from the fluidized bed process is burned with secondary air (Twin Rec) or oxygen (EUP). The EUP process also operates at higher pressures and was designed to gasify higher energy fuels like plastics, tires and auto shredder residues. The company reports there are currently seven Twin Rec gasifiers operating in Japan on MSW feedstock. The smallest plant processes about 34,000 tons per year. The largest plant is reported to process 548,000 tons per year of MSW. The three EUPs processing in Japan (two in Ube City and one on Kawasaki) gasify waste plastics. The largest plant gasifies 107,000 tons of waste plastic into chemicals used in ammonia production. 4.1.1.15 Enerkem Technologies 43 The Enerkem technology is based on a bubbling fluidized bed reactor with a feeding system that is capable of handling fluffy materials, slurries and liquids. The gasification process uses steam and air depending on the syngas needed. The syngas is cleaned and conditioned using a cyclonic inert removal system, a secondary carbon/tar conversion system, heat recovery units, and tar/fines re-injection system. The gasifier operates at temperatures under 1,800 F and below 10 atmospheres. Capacities are stated as being up to 15 tons per hour. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 27 February 2008 R-RWCounties Updated Research Study-Final.doc
Enerkem is working with the City of Edmonton, Alberta to develop an alcohols facility using sorted waste. Household waste is first sorted, recycled and composted. A second sort of the waste removes metals and inert materials. The remaining waste is then gasified using the Enerkem system with the syngas converted to methanol and ethanol. The project is currently in the planning stages. No anticipated start up is available. 4.1.1.16 SVZ 44 One of the oldest and most historic gasifiers is the facility at the Schwarze Pump site in former East Germany. This site is operated by Sekundarrohstoff-Verwertungszentrum (SVZ) which is now part of Global Energy, Inc. The plant has been in existence since 1950 using coal as a feedstock but was converted in 1997 to operate on both solid and liquid waste. The plant is reported to take about 550,000 tons per year of a diverse feedstock including post consumer plastics, sewage sludge, tire derived fuel, wood waste, RDF, oil, paint and refinery residues. The facility has 10 separate gasifiers. The pretreated and processed waste is gasified at high pressures (greater than 25 atmospheres) using oxygen and steam at 1,472 to 2,372 F to complete the gasification process. The facility produces 75 MW of electricity and 300 tons per day of methanol. 4.1.1.17 Emery Energy Company 45 The Emery Energy Company, based out of Salt Lake City Utah has developed a fixed bed gasification process that may work on a range of feedstocks, including MSW as RDF. The process uses a cleaning process before the syngas is used for power generation. The technology is currently in the pre-commercial/pilot stage of development. The company has a 25 ton per day plant in central Utah and a smaller pilot plant in Salt Lake City. 4.1.1.18 SENREQ, LLC 46,4748 SENREQ, LLC is based in Oakbrook, Illinois where a small scale gasification plant (pilot plant) is located. The company was founded in 2001 as an Illinois LLC. The pilot plant was originally founded as part of a project in Morris, Illinois. The pilot system takes a small amount of MSW into a chamber. Gasification takes place in 12 to 24 hours. After gasification is completed, the syngas is burned for thermal energy/recovery and possible power generation. In a response to a request for expression of interest from the Greater Vancouver Sewage and Drainage District, the SENREQ, LLC indicated they have installed nine systems ranging from 3 tons per day to 50 tons per day. The expression of interest requested a 1,400 tpd system to handle the waste from the closing Cache Creek Landfill. Air emissions and other performance information were not provided in detail to make an evaluation of the SENREQ system. The City of Nantucket, through its contract operator, Waste Options, has also expressed interest in the SENREQ system to gasify wood waste. In July 2007, Rhode Island banned wood waste from landfills. This has required the C&D material generated on Nantucket to be trucked, shipped and trucked again to a processing facility in Taunton, Massachusetts. The cost for disposal of C&D material is $130 per ton. A potential gasification plant on the island of Nantucket is currently being explored. 28 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
4.1.2 Advantage and Disadvantages Table 4-7 shows the advantages and disadvantages for an MSW gasification system. Table 4-7 Potential Advantages and Disadvantages of Gasification Advantages Disadvantages Not incineration Requires MSW pre-treatment to remove non-organic waste and Efficient energy production through combustion of gases homogenize the material High temperatures can make the process flexible to other waste streams Recycling can be enhanced by up-front separation Residuals could be hazardous Unproven on a commercial scale for MSW in the United States System is sensitive to non-organic feedstock More expensive than other proven technologies The gasification technology as it applies to MSW in the United States remains unproven. However, there is renewed interest in the technology as landfill tipping fees and fuel costs tend to rise, especially on the West Coast. If a gasification plant to process MSW is to be built, the City and County of Los Angeles are the furthest along in the process. Continued review of the progress towards a full scale plant is recommended. 4.2 Plasma Of the alternative technologies reviewed, plasma technology is by far the most discussed new MSW processing technology. However, plasma technology as it applies to waste has been viable for years. Most of the recent developments have used a plasma process to convert ash and hazardous waste to glassy slag. Of the active projects that use plasma torch methods, throughputs are limited due to reactor size. For example, the largest external torch system has a throughput of 4 tons per hour. The largest internal torch plasma system has a throughput of 10 tons per day. The Westinghouse/Hitachi design, which is commonly cited by plasma torch system developers, has been scaled up to 83 tons per day, per reactor. This plant, located in Utashinai, Japan, treats auto shredder residue and MSW using plasma torch technology. Several plasma technology vendors have entered the market to develop plasma based processes to treat MSW. The following sections detail some of the vendors and the current project status. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 29 February 2008 R-RWCounties Updated Research Study-Final.doc
4.2.1 Specific Experience 4.2.1.1 Alter Nrg 49 Alter Nrg's subsidiary Westinghouse Plasma Corp. (WPC) has developed a Plasma Gasification Reactor (PGR) that is integral for use in the plasma gasification process. The WPC PGR is capable of converting a wide variety of feedstocks including waste, coal and petroleum coke - into synthesis gas (syngas) that can be used to generate power. The PGR accomplishes this by generating temperatures as high as 2,500 C at the reactor's bottom to dramatically increase the kinetic rates of gasification reactions. The high temperatures melt all mineral matter and metals to form an inert slag that is suitable for aggregate use. The PGR is a moving bed gasifier that utilizes an industrially proven plasma torch technology. The design is derived from a cupola or a vertical shaft furnace that is used in the foundry industry, a harsh operating environment for the melting of scrap iron and steel. The WPC technology has an inherent level of flexibility over other gasification processes because it maintains high operating temperatures and slagging conditions throughout wide variations in feedstock composition. This is made possible through the independent energy input via the WPC plasma torch, which transforms electricity into available thermal energy. The WPC PGR virtually eliminates the need for feed preparation, a process step that accounts for a significant portion of the capital and operating cost of other commercial gasification technologies. As well, it has the ability to handle a wide range of feedstocks, including: Feedstocks of variable particle size, containing coarse lumps and fine powders High and low density feedstocks - biomass, paper, plastics and metals unsuitable for recycling High and low energy feedstocks - MSW, coal and petroleum coke Solid and liquid feedstocks - sewage sludge, oil, coal/water slurry, emulsions, run-ofmine coal and parting refuse Hazardous waste Westinghouse Plasma Corporation (WPC) is able to test, modify and/or validate their modeling assumptions using their plasma gasification pilot plant located at the Westinghouse Plasma Centre in Madison County, PA. To date, over 100 pilot tests have been completed on a wide range of feedstocks. On January 14, 2008, Alter Nrg announced it had received an order from Kiplasma Industries and Trade Inc. of Istanbul Turkey for the supply of four (4) Marc 3A plasma torch systems and the engineering design of the Plasma Gasification reactor. The equipment and design will be used to process 144 tons/day of common hazardous waste materials for the production of electricity. WPC is expecting to ship the plasma torch systems for this order in the second 30 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
half of 2008 and the facility is expected to begin commercial operation in the fourth quarter of 2009. The value of the sale was estimated to be $2 million. 4.2.1.2 Westinghouse 50 Westinghouse Plasma (a wholly owned subsidiary of Alter Nrg) manufactures and supplies plasma torches to for industry. The company also has developed a plasma-enhanced gasifier for waste materials (low grade coal, petcoke, MSW, and other industrial wastes). Companies marketing systems that specify the Westinghouse reactor include; Geoplasma LLC, Recovered Energy Inc., and Hitachi Metals. The reactor is an atmospheric air or oxygen-blown gasifier with plasma torches projecting into the lower portion of the vessel. The plasma torches heat the inorganic residue (with air/oxygen injection) and gasify or combust the fixed carbon that has reached the bottom of the reactor. Above the plasma melting zone are two levels of air injection, which allow for partial oxidation of the feed material as in standard gasification (see Figure 4-3). The reactor is fuel-flexible and is based on a blast-furnace design. Westinghouse reports that for 15.4 tph of coal feedstock, the plasma torches require 2.4 MW of power and the reactor will use 64.6 tph or air (air:fuel ratio of 4.2) Figure 4-3 Conceptual Cross-section of Westinghouse Plasma Corporation Plasma Direct Melting Reactor X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 31 February 2008 R-RWCounties Updated Research Study-Final.doc
4.2.1.3 Geoplasma Probably the best know developer of plasma technology is Geoplasma. Geoplasma is an Atlanta, Georgia based plasma technology developer. Geoplasma has also teamed with: Westinghouse Plasma Corporation Plasma equipment/design New Prospect Capital & URS Financing Energy Systems Group Construction, Operation & Maintenance Georgia Tech Research Institute Technical Advisory and Planning. MacTec Engineering and Permitting Edelman Public Relations. Geoplasma, LLC is a subsidiary of Jacoby Development, Inc., a member of the Jacoby Group of Companies. The Jacoby Group of companies focuses primarily on real estate, brownfield and renewable energy projects. Geoplasma entered the MSW processing market using plasma technology by responding to a Request for Qualification (RFQ) 51 by St. Lucie County, Florida The RFQ required the responder to permit, finance, construct, operate and own a plasma gasification facility to process MSW at the St. Lucie County landfill. The RFQ required the plasma process to treat 2,000 tons per day of MSW and 1,000 tons per day of previously baled and landfilled waste from the existing landfill. The $425 million facility is anticipated to require a 100,000 square feet building to house the equipment. Original designs indicated initially 1,000 TPD of MSW would be converted and later 3,000 tons per day of MSW will be converted to synthetic gases and slag. The gases will be used to run turbines to create 120 MW of electricity to be sold on the grid and 80,000 pounds per day of thermal energy that will be sold to the neighboring Tropicana Products plant. The slag from the process will be sold for use as an aggregate for county road projects. 52 Geoplasma s process description is shown in Figure 4-4. Basically, waste is inserted into the plasma cupola (Geoplasma proposes to use 8 plasma area cupolas.) By products include steam and syngas that is converted to electricity to power the plasma process and to sell on the grid. 32 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Figure 4-4 Geoplasma Process for 1,000 TPD Since the award of the initial contract in 2006, Geoplasma has been working on the lease agreement with St. Lucie County. The agreement includes leasing property at the landfill site for the plant and also addresses environmental concerns, primarily air emissions and insurance considerations. Since Geoplasma is required to completely finance and own the plant, St. Lucie County has requested specific issues be addressed in the lease agreement to protect the county. In December 2006, St. Lucie County agreed to issue bonds for the plant s construction. St. Lucie County will bond for $250 million through tax exempt bonds and another $75 million of taxable bonds. The bonds will not be issued until some future date, but Geoplasma can incur expenses that could be reimbursed later with bond proceeds. 53 Recently is has been learned there are also some issues with the power sales agreement that may impact the plant s economic viability. 4.2.1.4 Plasco Energy (formerly RCL Plasma/Resorption Canada Ltd) 54 Plasco Energy Group is a privately held Canadian Company that has operated in Ottawa since 1974. Plasco and its predecessor company, RCL Plasma has operated plasma based processing facilities in Ottawa and Spain for more than a decade. Plasco owns and operates two facilities; a 100 ton per day plant in Ottawa, Canada and a 5 ton per day research facility in Castellagali, Spain. The company indicates that extensive third-party emission testing has been done on the demonstration plant in Ottawa under the auspices of the Ontario ministry of Energy and the Environment. The Plasco system has two primary components; waste conversion/refinement and power generation. During the waste conversion/refinement process, waste is fed into the primary chamber and gasified. The gas from the process is then refined in a secondary plasma chamber. After the gas is refined by the plasma torch, the gas is then further cleaned at the Gas Quality Control Suite (GQCS). At the GQCS, the gases are cooled and cleaned (particulates, metals, and acids). X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 33 February 2008 R-RWCounties Updated Research Study-Final.doc
After the gas has been cooled and cleaned at the GQCS, the gases can be used for power generation. Equipment for power generation in the Plasco system is very similar to methane and natural gas power generation equipment. Gases from the Plasco process can be used to run conventional reciprocating engines like the GE Jenbacher. In 2007, the Ottawa plant completed construction and conducted some preliminary test runs. Additionally, more funding was provided to the facility by First Reserve Corporation of Greenwich, Connecticut. First Reserve Corporation purchased C$35 million in common shares of Plasco and has allocated C$115 million for investment in 2008. 55 From June to December 2007, Plasco has been testing the performance of the plant using shredded feedstock and delivering energy to Hydro Ottawa. Converting MSW to energy is the final step in the plant s commissioning, which is expected to be completed in 2008. The Plasco technology can purportedly process a wide variety of waste streams from industrial, hazardous and biomedical waste to MSW. It is conceivable that the complete mixed waste stream could be processed through a plasma arc system, but removal of as much mineral matter (glass/ceramic and metals) as possible is preferred. Post-MRF residue would be an acceptable feedstock for MSW plasma conversion applications (complete removal of glass, metals and inert mineral material before input to the plasma reactor is preferred). Shredding of feedstock will be necessary to provide a homogeneous mix to the feed handling system and a moisture content of 25% is preferred (mixtures that include green and food wastes would be acceptable). The reactor vessel is a refractory lined structure with a means for injecting solid waste material into the reactor with a minimum of included air. Some air is injected at the torch to provide the gas for forming the plasma though inert or burned exhaust gas can be used instead, which will contain little or no oxygen. Injected steam or moisture in the feed can supply reactant for the water-gas shift reaction that is an important steam gasification mechanism. Downstream of the research reactor, the facility incorporated gas conditioning units in order to safely flare the product gas. A commercial facility would make use of the product gas rather than direct flaring. Mass Balance: The mass balance for a plasma facility is fairly straightforward as practically all volatile compounds can be expected to leave the reactor as a gas. The amount of slag material is essentially equivalent to the ash (or miner matter) content that is determined by simple proximate analysis. Plasco reports that a typical MSW would leave about 12% by weight as slag. This would be expected for a feedstock that has had most of the glass and metals removed. The remaining 88% of the feedstock, as well as the mass of input torch gas (either inert gas or air), will exit the reactor as a gas. 34 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Depending on the moisture content of the feedstock, it may be advantageous to add steam to the reactor to ensure all carbon is gasified. The mass balance for the research reactor is displayed in Table 4-8 (RCL patent, Carter, G. W., and Tsangaris, A., 1994). The feedstock is not characterized explicitly in the patent document, but described as refuse or MSW with a moisture content of approximately 35%. The slag and cyclone ash recovered indicate the feed material had an ash content of about 11%, which is consistent with the MSW material used in the survey response. The research reactor used air for the plasma torch gas and allowed a significant amount of air to enter the reactor through the fuel feed mechanism and viewing port. The air in the reactor will reduce the calorific value of the product gas because of oxidation and dilution (nitrogen in the air is unreacted in the product and serves as a dilution). A commercial facility will likely limit unwanted air in the reactor and use an inert gas for forming the plasma in order to improve the product gas quality. Table 4-8 RCL Plasma Gasifier Mass Balance (Average of two lab-scale experiments, source; US patent 5280575) Inputs Outputs Material (lb) MSW (~35% moisture content) 427.1 Air through torch 48.1 Air-feeder and view port 251.6 Total input 726.8 Dry product gas out 608.8 Water vapor in product gas 22.2 Condense Water 47.4 Slag 47.2 Cyclone Ash 1.2 Total Output 726.8 Energy Balance: The flow of energy in the RCL process is listed in Table 4-9. For this energy balance, RCL assumed (or measured) the available energy in the post-sorted MSW to be 10.3 MMBtus per ton. This figure is reasonable (though perhaps a bit low since most inert material has been removed). The energy consumed by the torch (611 Kw, 2.1 MMBtus) is a large amount that must be purchased as electricity or provided by onsite generation. Heat losses in the various unit operations and product streams are listed here as non-recoverable losses though some of the energy could be recovered depending on nearby opportunities for use of heat energy. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 35 February 2008 R-RWCounties Updated Research Study-Final.doc
Table 4-9 Energy Balance for RCL Plasma Reactor (Per ton of MSW and before use of product) Input Outputs Losses Recoverable Energy Component Energy (MMBtus) MSW 10.3 Energy to Torch 2.1 Input total 12.4 Torch loss 0.34 Slag losses 0.084 Vessel losses 0.057 Other losses 1.2 Non Recoverable losses Total 1.7 Gas Sensible Energy 1.2 Producer Gas Chemical 9.5 Energy (based on HHV) Recoverable Total 10.7 Output Total 12.4 The amount of electricity that can be produced from an amount of fuel gas depends on the technology used for the power generation as well as the energy in the gas. Table 4-10 shows potential electricity production for the RCL plasma process using the synthesis gas in one of three electrical generation schemes; 1) fire the gas in a boiler to raise steam for use in a steam turbine (gas to electricity efficiency of 20%), 2) fire the gas in a reciprocating engine-generator set (gas to electricity conversion efficiency of 35%), and 3) fire the gas in a gas turbine combined cycle system after appropriate gas clean-up (gas to electricity conversion efficiency of 45%). With simple gas furnace/boiler and steam turbine technology for electricity production, the plasma process can barely generate enough power to run the torch, leaving no electricity available for export sales. The most efficient electricity production that is feasible in the near term is to fire the fuel gas in a gas turbine combined with steam cycle (GTCC) which has an overall efficiency of perhaps 45% accounting for compression losses and assuming the gas is cleaned to meet the strict requirements of gas turbines. Still, because of the high energy requirements for the plasma torch, the exportable electrical energy from firing the fuel gas in a GTCC amounts to about 700 Kw per ton of feedstock, or an overall electrical energy efficiency of about 24%. This is comparable to the recoverable energy (and net efficiency) of conventional mass combustion units. 36 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Table 4-10 Potential Electricity Export for the RCL Plasma Process 56 (Per ton of feedstock) 4.2.1.5 Hitachi Metals 57 After demonstration of the gasification technology for MSW at the pilot plant in Yoshii, Japan during 1999-2000, the Japanese government certified the technology for construction of a commercial size plant. The system uses the Westinghouse plasma melting reactor. It is an airblown gasifier with plasma heat to assist in complete oxidation of the fixed carbon and slagging of the inorganic residue. The hot synthesis gas is combusted in a burner immediately downstream of the gasifier reactor (see Figure 4-5) The hot combustion product gas can be used in a heat recovery boiler for process steam or to power a steam turbine for power generation. Figure 4-5 Gasification Plant Schematic Hitachi Metals X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 37 February 2008 R-RWCounties Updated Research Study-Final.doc
The following are the Hitachi Metals plasma systems in operation: Yoshii Plant. Plasma of MSW; prototype plant commissioned in 1999; processes 26.4 tons per day; syngas used to provide hot water to adjacent recreational facilities. Mihama-Mikata Plant. Plasma processing of MSW (19 tons per day) and sewage sludge (5.3 tons per day); commissioned in 2002; syngas used to provide hot water supply for plant operations and adjacent recycling center. Utashinai Plant. Plasma processing of MSW and ASR; commissioned in April, 2003; processes 200 tons per day (capacity is 300 tpd if 100% MSW); syngas used to produce electricity with a steam turbine. Gross electricity generated is 7.9MW, with 4.3 MW sold to local power company (46% parasitic load-plasma torches and other facility loads). 4.2.1.6 Solena Group 58 The Solena Group has developed an integrated plasma gasification and combined cycle (IPGCC) plant that process municipal solid waste, industrial, toxic, hospital and other wastes, including tires and plastics. The IPGCC process uses a high temperature plasma torch to dissociate wastes into a synthesis gas, which is used to power a gas turbine and combined cycle steam turbine. No IPGCC systems have been built. The company or current members have been involved in a wide variety of projects and ventures that utilize plasma arc technology. Most of the applications were related to hazardous or low-level nuclear waste volume reduction or in metals production. There have been some test programs on MSW or generic waste disposal, but details were not provided. The company is involved in attempts to locate pilot scale facilities in the Caribbean to help serve the cruise line industry with potential shipboard waste disposal systems. The company is involved in development projects in Spain, France, the UK, the U.S., and Malaysia. The Solena PGV Reactor employs plasma torches to heat the reactor to 7,200 9,000º F at atmospheric pressure. At this operating temperature, the PGV process uses a carbon-based catalyst and oxygen enriched air to cause the hydrocarbon or organic material to undergo partial oxidation creating a gas mixture containing primarily H 2 and CO. CO 2 and N 2 are also present, depending on the amount of air enriched oxygen used. The syngas has a heating value varying from 150 to 300 BTU/scf, which is about 1/6 to 1/3 of that for natural gas. The Solena process requires an air separation plant for oxygen-enriched air for the gasifier. Supplying oxygen to the reaction allows internal heat generation, which reduces required torch power (compared to plasma torch systems heating a pyrolysis reaction) but also reduces the chemical energy content of the produced gas (because it s been partially oxidized). Minimal detail regarding the energy and material balance or feedstock characteristics is available. 4.2.1.7 Georgia Tech Research Institute/Geoplasma Honolulu, Hawaii 59 Georgia Tech Research Institute is part of an eight-member consortium (Geoplasma, LLC) that responded to a City and County of Honolulu RFP for an MSW plasma or gasification conversion system. The proposed facility is a 100,000 TPY (376 TPD) plasma arc waste treatment plant. 38 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
The technology is the Westinghouse Plasma Corporation Plasma Direct Melting Reactor (PDMR) and is essentially the same systems in use by Hitachi Metals in Japan. PDMR technology is claimed to treat all side and liquid organic and inorganic materials. Georgia Tech reports that typical feedstocks entering this kind of facility are 60% MSW, 25 % ASR, and 15% recycling residuals. Preprocessing of the MSW feedstock is not necessary, but is proposed for the Honolulu facility. Additional inputs to the facility include electricity, coke, and limestone (amounts proprietary). The Honolulu facility is estimated to produce 10.6 MW of which 4.1 MW will be consumed by plasma torches and other facility loads (395 parasitic load), and 6.5 MW will be sold to the Hawaiian Electric Company (HECO) under a negotiated power purchase agreement. The net available power amounts to only 415 kwh per input ton, which is less than the existing H-Power combustion facility (540-640 kwh/ton). 60 The syngas (H 2 and CO) could also be used directly as a heating fuel, for H 2 extraction for use with fuel cells, or to produce liquid fuels such as methanol. Georgia Tech also cites the operating plants in Japan and the Hitachi Metals emissions information for reference. 4.2.1.8 Recovered Energy, Inc. 61 Recovered Energy, Inc. (REI) describes the status of their technology as commercial (though they haven t sold any plants for MSW). REI does not hold any patents, but would instead use components and processes for the plant under license from other companies. The company currently does not operate any other units, but cites the three Hitachi plants in Japan for reference (as do several other vendors). REI would use a Westinghouse plasma melting furnace and a gas turbine combined cycle for power generation. The REI process accepts any feedstock that is not radioactive, and technically the plant can process hazardous waste with the same equipment. However, regulatory requirements may not allow the same plant to process hazardous waste. No preprocess shredding is required for anything under 3 ft in diameter. Truck tires would be cut in half, and car tires can go in whole. Feedstock moisture content doesn t matter for technical purposes, but for financial purposes the REI process would like as little water as possible (for example, sewage sludge would be dewatered to 25% moisture). Optimal plant size is 3,000 TPD of MSW. Marketable products from the process are electricity, HCL (up to 20% concentration), sulfur (fertilizer grade), sodium hydrosulfide (whitener for the paper industry), recycled metal, vitrified glass (uses range from road-base and aggregate material to blocks to ceramic type materials), and ethanol. In addition, waste heat can be used to distill water or for desalinization. An MRF is unnecessary, but developers would pursue one if required in order to permit the facility. Material and energy inputs for the system include a small amount of makeup water for cooling (most of the cooling comes from an air-cooled condenser), and natural gas to start up the gas turbine and supplement any turbine capacity not supplied by the syngas. Electricity needs are X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 39 February 2008 R-RWCounties Updated Research Study-Final.doc
supplied internally, although the plant may be configured to sell all the power to the grid and then buy back what is needed internally for operations. All steam requirements are supplied internally. Table 4-11 shows a basic material balance reported by REI. Air comprises the majority of the input mass. The air-to-fuel ratio is 1.4 (mass of air per mass of fuel). Table 4-12 displays expected synthesis gas composition reported by REI. Table 4-11 Material Balance Reported by REI 62 An energy balance was difficult to derive from the given data. REI reports that the net electricity production (from a 3,000 TPD plant) is about 100 MW based on a 29% overall conversion efficiency and a MSW HHV of 4800 Btu/lb (11.2 MJ/kg). Any turbine capacity not fired with syngas will be fired with natural gas. Mass reduction efficiency is reported as 99.9 percent conversion to usable products and the carbon conversion efficiency is reported as >99 percent (small amount of carbon being present in the glass). Table 4-12 Synthesis Gas Composition Reported by REI 63 REI does not have actual reports of gaseous emissions. The company cites statistics of the Hitachi plants in Japan as reported to them by Westinghouse Plasma. REI is in the process of filing for permits on several plants, but cannot divulge the information at this time. 4.2.1.9 Integrated Environmental Technology 64 Integrated Environmental Technology IET was formed in 1995 as a spinoff company from Battelle Pacific Northwest National Laboratory. Integrated Environmental Technologies has developed a steam reforming gasification technology based on plasma technology. The process is called a Plasma Enhanced Melter and utilizes a plasma arc at just below atmospheric pressure to produce a synthesis gas. The PEM system differs from a traditional plasma system in that the 40 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
PEM system has two energy sources. DC power is used for the plasma arc and AC power is used in the joule-heating zone in the process chamber. The DC plasma arc is formed between two carbon electrodes and then extended to the molten glass bath inside the process chamber. This molten glass bath is further heated using electrodes connected to an AC power source. The process chamber has a water jacketed steel vessel lined with refractory. Waste enters the process chamber and falls to the molten glass surface. The waste is exposed to the plasma energy and the molten glass energy simultaneously. Steam is injected into the process to reform organic constituents. Organic constituents are reformed in the absence of oxygen to form syngas. Simultaneously, the inorganic components are melted and incorporated into a vitrified (glassy) product. Syngas is then sent to the process gas scrubber before going to a power conversion unit or for production of other chemicals including hydrogen, carbon monoxide, and methanol. Melted products, including metals are discharged from the process chamber using a side and bottom drain. IET reports operational facilities in Richland, Washington for treating hazardous and radioactive wastes (facility is in cold standby); Honolulu, Hawaii for treating medical waste; Iizuka, Japan for treating plastics and industrial wastes (10 tpd), Okinawa, Japan at Rutgers University as a demonstration project for PCB disposal; Taipei, Taiwan for treating medical waste; Kuala Lumpor, Malaysia as a test facility; and Fort Riley, Kansas as a demonstration facility. All of the facilities are relatively small (~10 tpd) and appear to be based on a batch process system rather than continuous feed. 4.2.1.10 PEAT 65 PEAT (Plasma Energy Applied Technology, Inc.) has developed a plasma process that can be used for the conversion of waste. The plasma pyrolysis process converts the feedstock to a syngas that is subsequently sent through a turbine to produce electricity. The produced gas can also be used to make methane, methanol, and plastics. PEAT has several plants in operation in the U.S. and abroad including a 10 TPD facility operating on hazardous wastes and organic solvents in Taiwan; another 3 TPD facility is also being built there. The smaller unit in Taiwan would be a pilot plant to use for testing with a large range of waste types, but it is intended primarily for vitrifying waste combustion ash. A 6-10 TPD unit has been operating in Virginia since 1999 processing medical waste for the U.S. Army. 4.2.1.11 Phoenix Solutions 66 Phoenix Solutions has developed a technology that converts organic waste to syngas (H 2 and CO) in a furnace using an electric plasma arc. The system produces a pyrolysis gas containing approximately 45% by volume hydrogen gas and 45% by volume carbon monoxide. The process uses steam as the primary medium for carbon gasification. Air is used as the plasma gas medium; however, natural gas can also be used, providing greater flexibility and yield. The plasma arc torches within the furnace have the capability to produce temperatures that range from 7,200-12,400º F (4,000-7,000º C) allowing complete dissociation of the feedstock without the production of tars and partially disassociated hydrocarbons. Inorganic materials in the waste stream is melted into slag and removed from the furnace. The pyrolysis gas is also low in X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 41 February 2008 R-RWCounties Updated Research Study-Final.doc
nitrogen and carbon dioxide. The cost of the gas is estimated to be $3.63/MM BTU if the tipping fee is $37/ton. The technology can also be coupled with a combined cycle gas turbine to provide electricity. The Phoenix system purportedly is capable of higher operating temperatures without the formation of tars, and there is no requirement for combustion air in the processing vessel. Other downstream subsystems are smaller and less expensive than traditional gasification systems. Vapor conditioning as gas cleanup is also simplified due to the absence of tars, nitrogen, and carbon dioxide in the pyrolysis gas. The Phoenix system has been operated on hazardous waste, medical waste, and PCBs. However, it has not been operated on municipal solid waste. A conceptual design has been developed to accept MSW without preprocessing. Thirty-three commercial waste destruction systems are currently operating in the field. 4.2.1.12 Hawkins Industries 67 Hawkins Industries has a plasma pyrolysis process that has been developed for them by PEAT. Hawkins Industries is planning to implement the technology at a site in Indianapolis. The unit will be co-located on the site of a materials recovery facility. The unit will be designed primarily for processing of higher-priced feedstocks such as medical waste. The company has also proposed to put a facility in a Kaiser medical facility in San Diego, California. 4.2.1.13 Pyrogenesis 68 Pyrogenesis, Inc. designs, develops, manufacturers, and supplies plasma-based waste to energy systems for marine and land-based applications. Pyrogensis provides commercial solutions for the processing of waste into energy and other useful by-products. The company builds plasmabased waste treatment systems, plasma torch systems, metal dross recovery systems, and custom high temperature equipment. Its plasma resource recovery system is used for treating clinical, hazardous, industrial, and municipal solid waste (MSW). The company was founded in 1991 and is headquartered in Montreal, Canada. Pyrogenesis has two distinct plasma waste treatment systems; the Plasma Resource Recovery System (PRRS) and the Plasma Arc Waste Destruction System (PAWDS). Both systems use plasma arc technology to convert waste into energy and non-hazardous by-products. The PRRS is designed to treat various wastes in land applications. The PAWDS is compact and designed to treat ship board wastes. PAWDS is being used on Carnival Cruise Line ships for waste destruction at sea 69. The U.S. Navy has also expressed interest in the PAWDS for large naval vessels. The estimated capital costs for the PRRS is $985 thousand (U.S.) to $29 million (U.S.) depending on the size of the system. The PAWDS cost range is from $1.5 million (U.S.) to $4.0 million (U.S.) depending on the capacity of the system and energy recovery options. 4.2.1.14 Coronal/Laurentian Resource Conservation and Development Authority 70 Coronal, LLC is a plasma gasification consulting and development company. The company contains two principals; John D. Howard and Stephen W. Korstad. Howard serves as the Chief Technical Officer and Korstad is the Chief Financial Officer. Coronal does not have any active plasma facilities for reference. Rather, Coronal appears to be a marketer of the technology. 42 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Coronal and the Laurentian Resource Conservation and Development Authority teamed with the Koochiching Economic Development Authority to obtain a $400,000 grant from the State of Minnesota in the 2007 legislative session to complete a plasma gasification facility in International Falls, Minnesota. As of March 2008, the contract to complete the feasibility study has not been executed with the selected contractor. In discussions with John Howard, he indicated the feasibility report should be completed by April 2008. Mr. Howard also indicated that Coronol has had over 24 inquiries for plasma based waste facilities. 4.2.1.15 STARTECH 71 STARTECH Environmental Corporation (Startech) is an environmental technology company primarily focused on the production and sale of their processing and plasma system called Plasma Converter System (PCS). Startech does not call the PCS a disposal system rather; it is essentially a manufacturing system that also produces commodity products from processes feedstocks that were previously regarded as waste. Startech has licensed the Hydrogen-Selective Ceramic Membrane, developed by Media and Process Technology that converts a portion of the syngas from the plasma process to hydrogen. This is called the StarCell system. For the fiscal year ending October 31, 2006 Startech reported revenues of $948,794. The revenues were attributed to three projects: Distributorship agreements in Australia, New Zealand, Puerto Rico and Spain ($250,000) Initiation of engineering specifications for a 10 tpd industrial waste plant in China ($100,000) Sale of parts to Mihama in Japan ($583,794) Installation of the industrial waste system in Hiemji, Japan was completed in January 2006. PCB disposal testing was completed in October 2006. Ideally, Mihama can use the Hiemji facility to demonstrate a working plasma facility. In 2007, Startech announced a planned facility in the City of David, Panama. This follows another planned 200 tpd facility in Center of Las Tablas, Panama. Startech reports a commissioning date for the sale of three PCS units to convert waste to methanol in Puerto Rico. Most of the plants are reported to be operational in 2008. 4.2.1.16 Green Power Systems, LLC 72 Green Power Systems is a Jacksonville, Florida based company that is attempting to develop electrical generating facilities using plasma arc technology to convert organic matter to syngas to be used in a turbine or similar unit and converted to electricity. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 43 February 2008 R-RWCounties Updated Research Study-Final.doc
The company reports the following affiliates working with Green Power Systems to develop a plasma gasification system: The Harris Group WW Guy Mechanical Contractors Westinghouse Plasma Corporation Thus, Green Power Systems is another marketer of the Westinghouse system. In 2007, Green Power Systems obtained agreements to acquire waste form the City of Tallahassee. The proposed facility, in Leon County, is anticipated to be a 200,000 square foot building on a 24-acre site. The plant is being designed for 1000 tons per day. Expected electrical output from the plant is 40 MW. The City of Tallahassee agreed to purchase 35 MW from the plant at $58.90 per MWh 73. The Leon County plant is scheduled for completion in October 2010. Funding for the project is coming from a Brazilian investment group, Controlsud International for an estimated cost of $182 million. Controlsud International Group s principal business lines include industrial electronics, food, forestry, miscellaneous services and banks. 4.2.1.17 Sun Energy Group, LLC 74 Sun Energy Group, LLC is a renewable energy company formed by D`Juan Hernendez, a former executive of NRG Energy, Inc and Jordan Oxley a former Investment banker. Sun Energy Group is proposing a plasma gasification plant in New Orleans. The proposed plant is designed for 2,500 tons per day of MSW and a power capacity of 138 MW. It is indicated that a Westinghouse plasma system will be the plasma system for the plant. However, Sun Energy Group is listing the technical advisors as the Georgia Technical Research Institute and LSU Center for Energy Studies. Costs for the plant are estimated to be $441 million. The plant is scheduled to be commissioned in 2008. 4.2.1.18 Cob Creations, LLC 75 Cob Creations, LLC markets a Management Waste System (MWS) plant that converts MSW into extrusions or pellets. Cob Creations began their business in the recycled plastic lumber market and appear to be expanding to include waste destruction. Cob Creation has teamed with Los Alamos National Laboratories to utilize plasma technology to process organic waste in the process. Details of the process are dependent on the waste streams. However, the system appears to be based on a MRF concept to remove as much waste for reuse or conversion to pellets or plastic lumber as possible and if need be an add on plasma system for residuals destruction. Cob Creations has no active plants or any firm commitments for their technology. 4.2.2 Advantage and Disadvantages The potential advantages and disadvantages of a plasma arc process are provided in Table 4-13. 44 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Table 4-13 Potential Advantages and Disadvantages of Plasma Arc Systems Advantages Superior thermal destruction Disadvantages High initial investment Limited pollution High power requirements Beneficial use possibilities for gas and ash produced from plasma destruction Potential to expand waste stream to include other non-msw streams High operating costs May require waste pre-shredding to fit into plasma reactor At this time, it is difficult to obtain data on the plasma process. The major plasma facilities are in Japan and limited cost and performance data is available to determine the applicability of plasma arc to the Project. As potential new facilities are studied (St. Lucie County, Florida and Ottawa, Canada) better information should become available to determine if the plasma arc process is viable for the Project s waste stream. 4.3 Ethanol Production 4.3.1 Specific Experience 4.3.1.1 Tennessee Valley Authority (TVA) 76 For several years in the late 1980s and early 1990s, the Biotechnical Research Department of the Tennessee Valley Authority (TVA) conducted a pilot project on converting MSW and waste cellulose to ethanol. In 1990, researchers recommended that the TVA conduct a research and development project to provide data for designing a commercial MSW conversion facility. The study was completed for two facilities: one a demonstration facility with 400 tons per day (tpd) capacity and the other, a commercial facility with a 2,000 tpd capacity. 77 The study concluded that waste-to-ethanol processing is technically and economically feasible for facilities processing over 500 tpd of MSW. 78 Table 4-14 shows projected mass balances for the two facilities (400 tpd and 2,000 tpd). 79 Table 4-15 summarizes projected capital costs, which were reported in the study as mid-1992 and estimates an equivalent year 2003 value of $263 million for the 2,000 tpd facility 80. The capital cost averages $131,594 per daily design throughput ton. Table 4-16 summarizes projected operating costs and also estimates equivalent year 2007 values. 81 The projected $36 million operating cost equates to a gross facility cost of approximately $50 per ton, with an additional $36.50 per ton required to cover annual capital costs (debt service and depreciation). X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 45 February 2008 R-RWCounties Updated Research Study-Final.doc
Table 4-14 Process Inputs and Outputs for 400 tpd and 2,000 tpd Facilities (Based on 24 hours per day operation and 96% plant availability) Demonstration Plant (tpd) Commercial Plant (tpd) Input MSW 400 2,000 Outputs Recyclables 96 477 Ethanol (@ 25 gallons/dry ton of RDF) 15 72 Carbon dioxide 14 71 Cellulosic Residue (@ 50% moisture) 224 1,122 Gypsum (@ 50% moisture) 40 201 Furfural 8 40 Total outputs A 397 1,983 A Differences between the input and output totals were attributed to moisture loss and incomplete capture (92.6 percent) of furfural. Table 4-15 TVA s Capital Investment for 2,000 tpd Waste-to-Ethanol Facility Cost Breakdown Total Cost (1992$) Estimated Cost (2007$) A Direct costs MSW classification component $42,866,400 $62,442,598 Hydrolysis component $25,410,728 $36,998,019 Purification/neutralization component $8,687,254 $12,648,641 Fermentation/distillation component $34,495,266 $50,225,107 Product handling component $602,601 $877,387 Direct investment $112,062,249 $163,191,752 Indirect costs Engineering and supervision $8,964,980 $13,053,010 Construction and contractor fees $16,809,337 $24,474,394 Contingency $11,206,225 $16,316,263 Indirect costs $36,980,542 $53,843,667 Other Allowance for startup $11,923,423 $17,360,504 Interest during construction $14,904,279 $21,700,630 Land $2,679,760 $3,901,730 Working capital $22,356,419 $32,550,946 Other costs $51,863,881 $75,513,810 Total all costs $200,906,672 $292,549,229 A Based on the CPI for all urban consumers from 1992 through 2007at http://data.bls.gov 46 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Table 4-16 TVA s Projected Operating Costs 2,000 tpd Waste-to-Ethanol Facility Cost Breakdown Total Cost (1992$) Estimated Cost (2007$) A Direct costs Raw Materials (supplies) $5,361,351 $7,806,127 Operating labor and supervision $207,300 $301,829 Utilities $2,103,346 $3,062,472 Waste disposal $3,569,621 $5,197,368 Waste treatment $343,876 $500,683 Maintenance $5,961,712 $8,680,253 Analysis $316,095 $460,234 Supplies $894,257 $1,302,038 Direct operating $20,657,558 $27,311,004 Indirect costs Plant overhead $1,053,650 $1,534,114 Administration overhead $421,460 $613,646 Marketing overhead $2,094,425 $3,049,483 Taxes and insurance $3,569,535 $5,197,243 Indirect operating $7,139,070 $10,394,486 Total annual operating $27,796,628 $36,413,585 Annual capital (debt & depreciation) $19,420,978 $25,441,481 Total annual costs $47,217,606 $61,855,066 A Based on the CPI for all urban consumers from 1992 through 2003. http://data.bls.gov/ Table 4-16 reports assumed revenue credits in both 1992 dollars and estimated 2007 dollars. 82 Note that the estimated 2007 dollars are escalated from TVA assumptions, rather than reported based on current market conditions. The final column in Table 4-17 pulls market data from a variety of sources including the May 10, 2003, Waste News Commodity Pricing Report. If the current market values were used in place of the TVA s assumptions, the economic feasibility of a waste-to-ethanol plant decreases from that projected by the TVA researchers. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 47 February 2008 R-RWCounties Updated Research Study-Final.doc
Table 4-17 Summary of Assumed and Updated Revenue Credits Revenue Item $/Unit (1992$) A Escalated $/Unit (2007) B Typical Value from 2007 C MSW tipping fees $45/ton $65.52/ton $28 to $85/ton Ethanol $1.50/gallon $2.18/gallon $2.25/gallon D Carbon dioxide $10/ton $14.56/ton -- Furfural $620/ton $902.72/ton $1,000/ton E Cellulosic residue $0.95/mmBtu $1.38/mmBtu -- Aluminum $900/ton $1,310.00/ton $760/ton Glass $10/ton $14.56/ton $4.50/ton HDPE $140/ton $203.84/ton $380/ton PET $140/ton $203.84/ton $400/ton Ferrous metals $50/ton $72.80/ton $90 to $150/ton Non-ferrous metals $20/ton $29.12/ton -- A Table 19. Summary of Revenue Credits. TVA: Volume VI: Technical and Economic Evaluation. B Based on the CPI for all Midwest urban consumers from 1992 through 2007. C http://grn.com/ D Price is taken from http://www.dtnethanolcenter.com/ E Price is taken from http://old.dalinyebo.co.za/dyt/furfuralmarket.htm 4.3.1.2 Masada-Oxynol 83 The Masada OxyNol process converts biomass components of MSW into ethanol and other byproducts. These by-products include carbon dioxide, lignin, gypsum, fly ash and all recyclable materials (glass, plastic, ferrous and non-ferrous metals). Key components or steps in the process include: MRF Feedstock preparation (shredding and drying) Acid hydrolysis unit Fermentation and distillation units The MSW delivered to the facility is sorted manually and mechanically; all recyclable materials are recovered and inert materials removed. The remaining fraction of the waste stream is shredded and dried. Wastewater biosolids can also be processed in a separate, parallel process train. Concentrated sulfuric acid is used to hydrolyze the feedstock. The lignin and other solid residues can be used as a renewable boiler fuel to help meet internal steam demands which include the stem hear used in drying the feedstock(natural gas is used to produce steam as well). The sulfuric acid is recovered and recycled. The sugar stream is then treated with lime to remove heavy metals and undergoes a concentration step and ph adjustment prior to fermentation and distillation into alcohol. The metals precipitate out of the solution as a crystalline synthetic gypsum. Fermentation of the sugar stream is accomplished using commonly available yeast and yields recoverable carbon dioxide in addition to ethanol. The technology is currently pre-commercial, with construction of the first commercial facility anticipated to start in 2008 at Middletown, New York. The facility has been permitted for 230,000 TPY of MSW and 71,000 TPY of bone dry biosolids. Based on the Middletown waste volume and characteristics, Masada estimates this facility s ethanol production will be 8.5 48 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
million galls per year (37 gallons EtOH per ton or presort MSW). Ten percent of the materials (by weight) coming into the process is inert and/or non-recyclable and will need to be landfilled. 4.3.1.2.1 MASADA, Middletown, NY The MASADA Resource Group of Birmingham, Alabama, is working to open the Orange County Recycling and Ethanol Production Facility on 22 acres adjacent to the Middletown, NY, wastewater treatment facility. Construction on the proposed waste-to-ethanol facility is to begin in late 2008, with waste acceptance beginning in 2009 at full scale operation. 84 The Middletown facility has been issued all necessary environmental permits including a Part 360 Solid Waste Management Facility permit from the New York State Department of Environmental Conservation, which administers a Federal title V Air Permit from the U.S. EPA. The facility is being financed through a combination of private equity and local revenue bonds. The typical facility will import electricity since the primary product is ethanol (though some or all of the required heat and electricity can be produced from the lignin fraction). The process heat requirements (e.g., drying, distillation, etc.) may be a better use for the lignin. Some water will be required for the Masada process. The scenario being analyzed for the life cycle analysis study (RTI/NREL) assumes the process converts 34 TPH of sorted MSW producing 940 gallons per hour of ethanol. In the RTI scenario, the lignin fraction is used to supply all internal heat and power needs with a 4.5 MWe surplus for export. If, as in Middletown, New York, a facility is located near a wastewater treatment facility, it can utilize raw or partially treated waste water for some of its process water requirements. See Table 4-18 for material balances for two feedstock scenarios (one using sorted MSW and WWT biosolids and the other using a sorted MSW feed stream). Table 4-18 shows the amounts of product and input streams per ton of sorted MSW. Notable is the large amount of water required for the process (The reason for the large difference is required water between the two scenarios is unclear. One would expect the biosolids/msw scenario to require less water because of water brought in with the biosolids). Masada indicates that the majority revenue stream for a typical OxyNol facility comes from waste not products produced from waste. Reliance on stable tipping fees for economic viability of this type of facility seems characteristic. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 49 February 2008 R-RWCounties Updated Research Study-Final.doc
Table 4-18 Mass Balance for Masada Process (2 Scenarios) MSW + WWT Biosolids a MSW Only Inputs (Tons) (% of total) (Tons) (% of total) MSW 1.00 19.9 1 44.0 Biosolids 1.94 38.6 Water 2.04 40.5 1.20 52.6 Sulfuric Acid 0.039 0.8 0.06 2.6 Lime/wwt chems 0.02 0.7 Nutrients 0.006 0.1 0.0009 0.04 Ammonia 0.008 0.2 0.0006 0.03 Totals 5.04 100 2.27 100 Outputs Lignin/ash (dry) 0.52 10.3 0.11 4.7 Stillage 1.39 27.6 Treated Water 0.68 13.5 0.61 27.1 Boiler and cooling water blowdown 2.04 40.4 1.21 53.3 and lignin moisture Ethanol 0.13 2.6 0.09 4.0 CO2 0.14 2.7 0.08 3.6 Gypsum - - 0.02 1.0 Recyclables 0.14 2.8 0.14 6.2 Totals 5.04 100 2.27 100 Ethanol production (gallons per ton 14 28 of wet Feedstock) c (gallons per ton wet feedstock) 326 139 a Data provided by Masada b Data provided by RTI/NREL. Note that one scenario uses large amount (2:1 by mass compared to MSW) of high moisture biosolids (87% moisture). 4.3.1.3 Arkenol 85 Arkenol develops cellulosic ethanol production facilities that use concentrated acid hydrolysis. The company has operated various pilot scale facilities that use concentrated acid hydrolysis. The company has operated various pilot scale facilities and has designed and built a facility in Japan that is currently operating using urban wood as feedstock. Ethanol production is currently viewed as the primary product from cellulose hydrolysis and fermentation. For MSW, the preferred feedstock is the cellulosic and other biomass components of MSW. Arkenol assumes that those materials within the feedstock stream that have market value as recycled material are first removed from the stream. 50 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Feedstock, preparation requires shredding the material to ¾ minus using standard industry equipment (for example, tub grinder) and drying to about 10% total moisture using low value heat energy that is recovered and recycled from the process. While the 10% moisture is preferred, moisture can range up to 30% for short periods of time without causing upset. The concentrated acid hydrolysis route to the production of fermentable sugars is remarkably tolerant of changes in feedstock composition. This is an advantage because it increases the range of acceptable feedstocks. Opportunistic or co-feedstocks can be therefore utilized. Simple (and partial) mass and energy inputs for what Arkenol reported for a typical ethanol from cellulosic feedstock using concentrated acid hydrolysis is displayed in Table 4-19. The mass balance does not close completely, and no conversion of the lignin residue for energy was indicated. The masses are based on feedstock dry weight, so the ethanol production quantities cannot be directly compared to Masada s process. Adjustment to comparable feedstock moisture basis would be needed before directly comparing ethanol production. Table 4-19 Partial Mass and Energy Balance for the Arkenol Process Inputs Lb/hr (tons) Cellulose Feedstock (Dry) 32480 1 Water 1767 0.05 Conc. Acid 1028 0.03 Lime 507 0.02 Nutrients 209 0.0006 Totals 35991 1.11 Natural Gas Used (MMBTU/hr) Electricity Used 8257 (MWh) 1.36 Outputs Lb/hr (Tons) Lignin Cake 18387 0.57 Gypsum Cake 2475 0.08 Sewer - Landfill - Protein Crème 443.5294 0.01 Fuel Ethanol 7085 0.22 CO2 2104 0.06 Totals 30495 1 % Unaccounted 9.9 Gallons Ethanol per day Ton of feed 67 X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 51 February 2008 R-RWCounties Updated Research Study-Final.doc
4.3.1.4 Waste to Energy (WTE)/Genahol Corporation WTE is working with Genahol Corp. to install a commercial validation plant for ethanol production in Santa Maria, California. The project would use post-mrf biomass material for ethanol production and then pyrolyze the residual lignin and plastics for process electricity. Genahol is developing a hydrothermal and mild acid hydrolysis, followed by fermentation-toethanol process (the Brelsford Engineering, Inc. Process; see Figure 4-6. The project reportedly will also use a pyrolysis with catalyst procedure to convert plastic from the MRF to a liquid fuel to provide power for the ethanol production facility. UNCI Engineering and Merrick and Company, Aurora, Colorado, will probably develop the pyrolyzer. Figure 4-6 GEI/Genahol Hydrolysis and Ethanol Process Schematic 4.3.1.5 Blue Fire Ethanol Fuels, Inc. 86 Blue Fire Ethanol Fuels, Inc. filed for permits with Los Angeles County for California s first cellulose to ethanol production facility. The location for this facility is near Lancaster, California in northern Los Angeles County. The proposed plant will use the Arkenol process to produce ethanol. 52 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
The production facility will be located adjacent to the Lancaster landfill. The facility will use green & wood waste streams as its feedstock and will produce approximately 3.1 million gallons of cellulosic ethanol per year as well as serve as a future demonstration facility for BlueFire s Bio-Butanol production process. To reduce the environmental footprint to an absolute minimum, the facility will use recycled water and will meet roughly 70% of its total energy needs by utilizing the energy stored in lignin, a process co-product. This plant will be the platform from which system modules will be factory constructed for rapid deployment of all other planned facilities. Through this facility, BlueFire will provide the California fuel market with its first homegrown fuels from existing cellulosic resources. Thanks to progressive federal legislation, fuel blenders can blend cellulosic ethanol at a 2.5 to 1 credit over traditional ethanol to meet their renewable fuel compliance requirements thereby providing even more incentive for the industry to lead the way in reform. BlueFire estimates that of the 1 billion tons of recoverable waste in the US, over 70 billion gallons of fuel grade ethanol can be produced. For Southern California, the potential exists to covert there waste streams into several hundred million gallons of ethanol fuel per year. It is anticipated that construction will occur in 2007/2008 with operations planned to commence end of 2008. 87 4.3.2 Advantages and Disadvantages The potential advantages and disadvantages of a waste to ethanol systems are provided in Table 4-20. Table 4-20 Potential Advantages and Disadvantages of Waste-to-Ethanol Processes Advantages Foth supports and promotes use of ethanol as a fuel additive Use of bioproducts and bioenergy is encouraged by a Presidential Executive Order May offer opportunities to expand the market uses of MSW. May offer benefits toward sustainable development and resource conservation Disadvantages Limited technical application with MSW Lack of history with regulators Capital/operating cost history is limited, unsettled, and likely high Market demand for ethanol could be met by corn plants Markets for other products need to be developed May require separate collection or front-end processing raising costs While there appears to be some growing interest in this technology, it simply continues to not be a proven MSW management technology at this time. There is currently very limited technical X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 53 February 2008 R-RWCounties Updated Research Study-Final.doc
application to MSW and a lack of history with regulating agencies. Capital and operating cost history is limited and unsettled. To successfully perform using organics from MSW may require source-separated collection of the organics or front-end processing to separate the organic fraction (either of which will increase the system costs). Markets could develop significantly, but at this point, the demand could be met with corn plants. Marketing of the by-products from a waste to ethanol process is untested. With the lack of proven technology and unsettled high costs, this technology should not be considered by the Project at this time. Despite the potential disadvantages, the technology may offer some long-term advantages worth continued observation of its development. If there is waste-to-ethanol plants constructed that handle MSW successfully and prices for petroleumbased fuels continue to increase, the technology could surface as a viable alternative in the future. 4.4 Anaerobic Digestion 4.4.1 Specific Experience Each plant in Europe uses one of the basic processes described in Section 2.5. The major AD suppliers have potential processes to generate the biogas and compost from the organic waste. Centralized source separation is also a critical component to the process. Performance of the plants varies by process and feedstock. To provide a general overview of plant performance, Table 4-21 shows general performance for some European plants. 54 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Table 4-21 Performance Data of AD Plants Ft 3 Ft3 gas/ft 3 Waste Waste Biogas/ Digester Location Type* Tons/Yr Ft 3 Digester Ft 3 Gas Production Ton /Day Aarburg Yard 12,128 52,973 28,605,150 2,359 1.48 1.25 Baar Yard 4,410 16,951 13,419,700 3,043 2.17 1.43 Bachenbhlach Yard & 9,482 18,364 30,017,750 3,166 4.48 2.83 Food Baden-Baden Food & 7,166 211,890 51,206,750 7,146 0.66 0.19 Kitchen lbs./day/ Ft 3 Digester Braunschweig Kitchen 17,640 59,329 60,035,500 3,403 2.77 1.63 Buchen MSW 110,250 141,260 141,260,000 1,281 2.74 4.28 Geneva Yard 13,230 35,315 42,378,000 3,203 3.29 2.05 Grindsted** Biosolids & Food 38,036 98,882 22,954,750 603 0.64 2.11 Holsworthy** Manure 160,965 282,520 137,728,500 856 1.34 3.12 & Food Karlsruhe Yard & 8,820 47,675 30,935,940 3,507 1.78 1.01 Kitchen Lemgo Yard & 37,485 90,053 134,197,000 3,580 4.08 2.28 Kitchen Mhnchen Yard & 27,563 84,050 52,972,500 1,922 1.73 1.80 Kitchen Niederuzwil Yard 11,025 31,784 30,724,050 2,787 2.65 1.90 Otelfingen Yard 13,781 29,665 38,846,500 2,819 3.59 2.55 Rhmlang Yard & 7,718 16,245 28,252,000 3,661 4.76 2.60 Food Samstagern Yard & 8,489 18,364 28,958,300 3,411 4.32 2.53 Food Average 30,512 77,207 54,530,774 2,922 2.65 2.10 *When there is more than one type of waste, the higher percentage feedstock is provided first. **While not a part of the survey, sufficient information was gathered to make consistent comparisons. As Table 4-21 indicates, large variability in production of biogas can be expected depending on the quality and quantity of the feedstock. Cost data for the plants is provided in Table 4-22. The table indicates large variation in the installed cost per ton. This variation can be attributed to the type of waste to be processed. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 55 February 2008 R-RWCounties Updated Research Study-Final.doc
Table 4-22 Investment Data of AD Plants Waste Installed Cost Provider Tons/Year $ Installed Cost $/Ton Type Remarks Baar Dry BRV 4,410 14,000,000 3,175 w/8,800 tons/yr composting Baden-Baden Wet BTA 7,166 3,470,000 484 Cogen added Braunschweig Dry Kompogas 17,640 10,200,000 578 w/postcomposting Buchen Wet ISKA 110,250 15,500,000 141 Earlier work cost Geneva Dry Valorga 13,230 5,100,000 385 Grindsted Wet Kruger 38,036 8,860,000 233 Holsworthy Wet Farmatic 160,965 8,000,000 50 Lemgo Dry BRV 37,485 15,600,000 416 w/building Mhnchen 2- Stage BTA 27,563 10,500,000 381 w/pretreatment & planning Niederuzwil Dry Kompogas 11,025 4,100,000 372 w/o air treatment Otelfingen Dry Kompogas 13,781 5,350,000 388 Average(weighted) 40,141 9,152,727 228* 4.4.1.1 Arrow Ecology 88 The ArrowBio process is an anaerobic digestion conversion process designed to accept the full unsorted MSW stream. Inherent in the process is a fully integrated water-vat sorting and cleaning facility, which yields sorted recyclables much like a typical MRF (the exception being that all biomass components, including paper and cardboard, are eventually carried into the low solids biochemical treatment system). If paper recovery is desired, paper must be separated upstream of the water-vat stage. The sorting process also separates most of the non-recyclable inert material from the biodegradable matter. The biochemical processing concept employed is unique to MSW anaerobic digestion systems in that it utilizes up-flow anaerobic sludge blanket (UASB) technology commonly used by wastewater treatment plants. The company has experience with designing and building wastewater treatment facilities. The process outputs are sorted into the following categories: ferrous and non-ferrous metals, glass and other mineral matter, plastics, biogas, non-digestible residue, and low-strength (low chemical oxygen demand [COD] or biochemical oxygen demand [BOD]) wastewater. The biogas can be burned in gas engines on-site for heat and power or upgraded to pipeline quality gas, or processed to a liquid natural gas-like compound for use as transportation fuel. The emissions from the biogas utilization, therefore, depend on the end use of the gas, but would be similar to those from existing biogas and natural gas applications. The low-grade wastewater can be used for irrigation (as is done at the facility in Israel for the on-site landscaping), or it can be treated in the local municipal wastewater treatment plant. Arrow Ecology built and operates a 70,000 TPY commercial scale facility using the ArrowBio process. The facility is collocated with the Tel Aviv transfer station which currently handles approximately 1 million TPY for transport to a distant landfill. Arrow Ecology indicates that a 56 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
220 TPD facility (60,000 70,000 TPY depending on number of operating days) requires approximately 3 acres. Currently the operating plant in Israel receives $24.50 per ton of material processed, and a new landfill tax will bring this tipping fee to $33.30 per ton. The facility was financed with company funds and a bank loan. Estimated capital costs are estimated to be(for a U.S. installation) $12 million for a 220 TPD plant. The required break-even tipping fee is approximately $50 per ton. Reported product types and value for the Tel Aviv facility are listed below: Electricity $50/MWh ($.05/kWh). Plastic $72/ton. Metal $63.5/ton. Glass Given away. Organic soil amendment Given away. Liquid water Used internally as makeup process water, with the excess used Figure 4-7 Arrow Ecology Process Diagram Process Description Pre-Treatment and Preparation of the Waste: The waste is delivered by trucks into the preparation building. This building is equipped with exhaust fans and Bio-Filters, which assure that no odors escape into the environment. The waste is emptied directly into a reception chute and passed through a bag opening unit and a wet shredder. Water, essential for the shredding process, is re-circulated within the plant and no X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 57 February 2008 R-RWCounties Updated Research Study-Final.doc
additional water needs to be added. From there the waste is transferred directly into the dissolving tank. Water is added and by imposing high shearing forces, the organic material is disintegrated down to fiber size, forming thin slurry so that it is separated from any inert material. Heavy components like broken glass, batteries, stones, metal parts etc. sink to the bottom and are separated from the slurry via a special discharge chamber. 1st Stage Acidogenic Fermentation: The organic slurry is pumped into the first Bio-Reactor or fermentation tank for facultative anaerobic digestion of the organic phase. Naturally occurring microorganisms start the fermentation process and transform the complex organic material into simpler compounds such as organic and fatty acids. Maintaining correct ph and organic material concentration in the reactor, together with proper liquor circulation and hydraulic retention time controls the process. This stage is a continuous process where fresh slurry is fed into the 1st reactor and fermented liquid is drawn off simultaneously and transferred to the 2nd stage. 2nd Stage Anaerobic Methanogenic Fermentation: The liquids leaving the 1st stage reactor are rich in organic material in the form of various organic acids. These liquids are being heated to ~40 C and pumped into the second Bio-Reactor for anaerobic degradation of the organic materials and the generation of biogas. Here too, naturally occurring microorganisms perform the degradation process and transform the organic material into biogas (~ 70% CH 4 : 30% CO 2 ) and biomass. This process is controlled by maintaining correct ph and organic material concentration in the reactor, together with proper solids concentration in the liquor and correct circulation and hydraulic retention time. This stage is also a continuous process where liquids from the 1st reactor are fed to the 2nd reactor and effluents are removed from the 2nd reactor. These effluents are being recycled within the system in order to maintain proper solids levels in the 1st reactor and for the initial stages of shredding of the incoming waste and the separation of inert material. Basically, no fresh water is added to the system. The biogas, which is formed in the 2nd reactor, is being collected at the upper part of the reactor by means of a specially designed built-in compartment. This gas is re-circulated by a compressor and re-injected into the 2nd reactor close to its bottom, thus assuring a permanent agitation without mechanical devices. During routine operation, the biogas is also routed out of the system directly to energy generating units as steam boilers or electrical generators. The biogas can also be stored in simple inflating buffer tanks. Treatment of final Products: The biological sludge formed in the 1st and 2nd reactors is drawn off at pre-set periods, dictated by the process control. This sludge contains many plant nutrients as ammonia and phosphorus in a readily available form to the plants. This fraction, called ArrowBio compost, can be dewatered rather simply and sold as a high value soil conditioning agent. Further processing such as pelletization of this product will increase the market potential and value of the ArrowBio compost. The long solid retention time in the 1st and 2nd reactors ensures a fully stabilized product which does not deplete the soil of nutrients due to intrinsic microbial activity and also is free of all pathogenic germs, bacteria, weed seeds, etc. The biogas generated in the 2nd stage reactor is transported into a gas storage tank via filters which remove excess humidity and trace pollutants such as naturally formed H 2 S. The biogas is then used as a fuel for water heating, 58 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
steam generation or electricity generation. The liquid from the dewatering process of the ArrowBio compost is partly reused for shredding and dissolving the incoming waste. Excess water is stored in a separate tank and is being discharged directly into the public sewage system or into a simple biological treatment plant. 4.4.1.2 University of California, Davis 89 This system was developed and patented by Professor Ruihong Zhang and Dr. Zhiqin Zhang from UC Davis (Zhiqin Zhang is currently at the California Energy Commission). The system is licensed to Onsite Power Systems for commercialization. Laboratory and pilot scale reactors are located at UC Davis. A facility is proposed for a site on the California State University at Channel Islands campus. The facility would process 250 TPD of green waste diverted from Ventura County landfills and presumably some waste from the campus. It should produce sufficient biogas for generating 2 MWe of power. A byproduct would be 25-50 TPD of fertilizer. The capital cost of the project is reported to be $12 million ($6,000/kW installed). Revenues from the project include the price of the energy displaced by the facility, fertilizer sales, and tipping fees from waste hauled in from off campus. The facility would operate at the thermophilic temperature (135º F) and have a solids retention time of 12 days. The anaerobic phased-solids (APS) digester decouples solid-state hydrolysis and acetogenic fermentation from the methane producing fermentation, allowing for separate optimization of the two processes. The two reactors are connected through a closed liquid recirculation loop that transfers the soluble material released in the hydrolysis reactor to the biogas producer (methanogenesis). The biogas reactor can be designed for relatively short liquid retention time by using suspended growth, attached growth, anaerobic moving bed reactor (AMBR), or upflow anaerobic sludge blanket (UASB) reactor types. The hydrolysis reactor can accept high solids feedstock that, depending on its characteristics, may need some kind of pretreatment such as shredding to increase hydrolysis rate. The hydrolysis reactor operates in batch mode. Because of this batch operation, the concentration of the soluble compounds in the liquid being transported to the biogas reactor will vary from zero immediately after enclosing a fresh batch of feed in the hydrolysis vessel to a maximum when the rate of hydrolysis is highest. The soluble compound concentration will then taper off as the remaining soluble biomass declines. Correspondingly, the biogas production rate will vary from low to high to low again because it depends on the strength and rate of the inflow liquid arriving from the hydrolysis stage. By using several batch-loaded hydrolysis reactors, the loading of each being timed (or phased) one after another, the strength of solubilized biomass flowing from all hydrolysis reactors has an overall average that is more stable. This relatively stable average strength liquid allows for suitable size and design of the single biogas reactor in order to optimize the methanogenic portion of the process. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 59 February 2008 R-RWCounties Updated Research Study-Final.doc
4.4.1.3 BRI Energy, LLC 90 BRI is marketing technology based on Dr. James I. Gaddy s research in bioengineering. More than 15 years ago, he isolated bacteria that can be used uniquely for digestion processes. These bacteria metabolize synthesis gas and emit ethanol as a product. The BRI technology is a hybrid thermo chemical and biochemical conversion system. A gasifier is used to create a synthesis gas that is injected into the bioreactor where ethanol is produced. BRI claims that 75 80 gallons of ethanol and 160 kwh per dry ton of biomass can be produced. (With used tires as fuel, this is doubled to 150 gallons per dry ton). BRI claims that the process takes less than seven minutes from feeding into the gasifier to the production of ethanol. By contrast, standard methods for sugar fermentation require 36 48 hrs. This process consumes 90 to 95% of the carbon-based feedstock, leaving a residue of non-hazardous ash. BRI reports that the bacteria used have a health hazard rating of Level 1, the lowest possible rating for any microorganism. BRI claims to create no environmental or health hazards, no ground or water contamination, and emissions that are easily controllable. There is one pilot facility in Fayetteville, Arkansas. Currently, this plant is processing salt water immersed wood from Alaska. BRI reports that several demonstration projects are being negotiated. 4.4.1.4 McElvaney Associates Corporation 91 McElvaney has developed and patented (U.S. Patent no. 6,254,775) an AD system that can be characterized a single-stage low solids fixed (immobilized) film anaerobic digester called the Bioconverter. Recent announcements indicate the company has negotiated a 20-year agreement to provide the Los Angeles Department of Water and Power with electricity from the bioconversion of green wastes for the amount of $16 million per year ($48/MWh). The facility will begin operation in 2008 and consume 3,000 TPD of Los Angeles green wastes and generate 40 MW of electricity. Other costs to the city for the project are unknown (presumably, a tipping fee will also be paid to McElvaney for disposal of the feedstock). Approximately 1,000 TPD of digester residue will be created, which potentially can be used in compost operations or as soil additives. If no market exists for the material, it will likely be disposed in landfills. Another announced project is with the City of Lancaster, California. A $16 million facility is proposed to convert 200 TPD of local green wastes and produce 5,000 gallons per day of compressed natural gas (CNG) that can be used as a transportation fuel. Press releases claim that digester residue will be used in poultry feeding operations. The project will pursue alternative fuel and air pollution reduction-related grants through the local air pollution control district, but otherwise the facility is expected to be funded privately. The feed material is primarily green wastes and source-separated food wastes. The process can also accept waste paper (magazines and junk mail, mixed residential, etc.), FOG (fats, oils, and grease), and high strength wastewaters. Feed and liquid are added to obtain a slurry with TS of ~10%. Gas and liquid are recirculated in the digester to promote mixing. 60 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
The single stage digester relies on a fixed support matrix of polyethylene for growing and immobilizing the methanogenic microorganisms. Reactor liquids and biogas are recirculated through the medium to maintain solids suspension. The system is probably operated in the mesophilic temperature range (95º F) because solids retention time is approximately 30 days. Products are typical for AD systems and include methane and solid soil amendments/fertilizers and liquid soil amendments/fertilizers. Bioconverter systems have been installed in the Caribbean 92 and Hawaii. In Hawaii, a 2 TPD system operated on food and green wastes for four years with some sale of liquid fertilizer. The company cooperated with the UNISYN system in Waimanalo, Hawaii, which used feedstock including manure from 2,000 cows, 250,000 poultry layers (egg laying hens) and waste from a USDA fruit fly rearing facility. The system was co-located with the animal operations as well as a greenhouse. Residue from the digesters was used as protein supplement in the poultry operation and aquaculture. The facility also transitioned to processing food and grease wastes but was closed in 1999. 4.4.1.5 Wright Environmental Management 93 Wright Environmental Management supplies in-vessel composting systems. These are managed and accelerated aerobic conversion processes. The material is loaded into a tunnel like enclosure and moves slowly in plug flow fashion. Any leachate is recirculated, and air is actively pumped through the material throughout the length of the enclosure. In situ mixing and moisture management results in a 10 14 day retention time for material. Excess air and gaseous products can be fed through a biofilter for odor control before release to the environment. The system is modular, and capacities can be scaled from 600 lbs per day to 30 TPD through one enclosure tube. MSW can be processed after appropriate separation of non-compostable materials. The company lists several reference plants, including: Aberdeenshire, Scotland: 32,000 TPY MSW. Isle of Wright, U.K.: 22,000 TPY mixed food/green waste. Dept. of Corrections, Powhatan, Virginia: 730 TPY food waste. Dept. of Corrections, Ogendburg, NY: 730 TPY food waste. Allegheny College, Pennsylvania: 365 TPY food waste. Albany, NY: 18,250 TPY organic fraction MSW. 4.4.1.6 Global Renewables Limited (GRL) 94 Global Renewables is a wholly owned subsidiary of GRD Limited that has developed and marketed AD systems, pimarily in Australia. Their system, called the UR-3R process is discussed below. The Eastern Creek UR-3R Facility is a public private partnership with WSN Environmental Solutions (formerly Waste Service NSW, Australia). The Facility was built and is owned and operated by Global Renewables under long-term contract to WSN Environmental Solutions. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 61 February 2008 R-RWCounties Updated Research Study-Final.doc
Figure 4-8 UR-3R Process The UR-3R Facility receives and processes municipal solid waste (MSW), which includes collected household, commercial and green waste and is able to deliver a truly sustainable waste management solution. The UR-3R Facility integrates unit process technologies in: Waste stream separation ISKA Percolation SCT Composting and refining Energy recovery. Each unit process is proven and currently in commercial operation around the world. The Eastern Creek UR-3R Facility in Sydney is the first to fully integrate these leading technologies to provide a total solution for waste management. Waste Steam Separation: The first stage of the UR-3R Process uses the ResourceSort technology (patent pending) for materials sorting and separation. This involves the waste deposited in the receiving area being loaded into a bag opener, and then separated component of the waste stream, (i.e. size, shape, magnetism, density, emissivity, colour, rigidity, etc.) The products recovered during the ResourceSort separation process include typical recyclables such as cardboard, mixed paper, mixed plastic, plastic containers (mainly PET and HDPE), glass containers, ferrous metals and non ferrous metals. 62 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
ISKA Percolation: The organic rich stream from separation and sorting is fed into the ISKA Percolation process. The Percolator uses wash water from the digester and operates in a semi-continuous fashion, loading fresh material and discharging washed and percolated solid residue during the operating schedule of the sorting facility. The wash water is sprayed over the organic material in the Percolator. As the solution percolates through the stirred bulk waste, the volatile organic component of the MSW, colloidal material and sands are discharged to the sand washer. After passing through the sand washing and sludge removal circuits, the percolate solution is processed through the anaerobic digestion circuit. This produces biogas and excess water, which is then used in the composting operation. SCT Composting and refining: After being washed and cleaned in the ISKA Percolation process, the solid organic material is directed to the compost bay within the SCT composting building. Intensive composting occurs inside the fully enclosed composting building, in a negatively aerated bay. Aeration rates and moisture content are controlled to maintain aerobic conditions and high decomposition rates. The material is maintained in the thermophilic temperature range of 45ºC to 75ºC. A patented auger bridge crane (named BioMax-G) runs above the composting bay. It consists of a portal bridge crane that travels on rails fixed on the ground outside of the bay containment walls for the full length of the composting bay. An auger carrying trolley runs transversely on the bridge crane. The auger carrying trolley is fitted with two inclined counter rotating augers with their tips turned towards the bay loading side. The combined rotation action of the augers, the tripper trolley and the auger bridge crane translation, turns the composting material and transports it from the loading to the unloading side of the composting bay. The product from the intensive composting stage must then pass through a maturation phase. The maturation phase begins in the thermophilic range, where all of the remaining simple sugars are broken down. After approximately two weeks the temperature of the pile reduces to the mesophilic range. This allows the actinomycetes and fungi to flourish and decay the lignin, hemicellulose and cellulose materials as well as allowing phytotoxins to be metabolised. After maturation, the product is passed through the secondary refining process to remove any remaining glass, stones, plastic or foil. This stage removes an oversize fraction that can be used as composted garden mulch. The screened undersize is then processed to produce a clean product, a light fraction residual and a screened heavy undersize residual. The light fraction then passes through a polishing stage to capture any organic matter, with the oversize fraction being added to the residuals. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 63 February 2008 R-RWCounties Updated Research Study-Final.doc
Energy recovery: The anaerobic digester produces biogas during anaerobic conversion of the volatile solids in the percolate solutions. The biogas will typically contain 60 per cent to 70 per cent methane and 20 per cent to 30 per cent CO 2 and a range of trace contaminant gasses, particularly H 2 S. The occurrence of H 2 S will depend on the precise nature of the MSW processed. The biogas produced is cleaned to remove the H 2 S prior to being used for electricity generation in a purpose-designed power station, and for process heat generation in gas fired water heaters. 4.4.2 Advantages and Disadvantages Advantages and disadvantages of AD systems are presented in Table 4-23. In general, AD systems are effective for processing the organic portion of MSW but ineffective at non-organic waste. Thus, expensive pre- and post-processing activities are usually required to eliminate contamination. 64 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
Table 4-23 Advantages and Disadvantages Advantages Disadvantages Relatively low capital costs compared to most thermal process Uncertainties over the economics and practical applications of AD to treat MSW. AD technology for various homogenous waste streams is widely proven in Europe, but there are no full scale plants in operation in the UK on municipal derived wastes. There are however proposals to develop facilities at the State-of-the-art technology in global use including pollution control technology Energy recovery potential (methane generation) and possible sale of surplus Contributes to national recycling/recovery objectives Reduces organic wastes from landfill which reduces the production of landfill gas and leachates; a key aim of the landfill Directive Totally enclosed system, reduces environmental impacts. Complies with Animal By-Product legislation Eligible for Renewables Obligation Certificates on electricity generated Reduces the mass of organic waste input present. AD of MSW will need to rely on comprehensive pre-processing of the waste or source separation; plastics for example, can cause operational difficulties. Some systems however are designed to operate with mixed municipal-type wastes. Odor emissions during material handling Does not treat the whole MSW stream, onyx the organic fraction, however may be used on residual municipal waste stream with contaminants rejected as part of the process. AD is more capital intensive than composting. Materials handling problems with front end processing can be costly. Contamination of final product often difficult to avoid; marketing problems Gas handling, storage and clean up facilities are required, which can be costly Digestate produced, if landfilled may still cont as BMW and be subject to active Landfill Tax X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 65 February 2008 R-RWCounties Updated Research Study-Final.doc
Generally, AD processes are not applicable to the MSW stream in the United States without extensive pre-processing of the waste to remove inorganics. Attempts have been made to conduct in vessel AD process for MSW; however the output product tends to be of marginal value and is typically used as low grade alternative daily cover at landfills or possibly land applied depending on the quality. 66 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
5 Environmental and Regulatory Issues 5.1 Environmental Impacts There are a number of environmental factors to take into consideration when assessing the impacts that conversion technologies may have. These impacts include: Air emissions, particularly dioxin, furans, heavy metals, and greenhouse gas emissions. Management of ash, char, and other solid residues. Management of any liquid residues. While a number of studies have characterized emissions from individual waste conversion processes, there is a lack of consistent comprehensive data for use in comparative analyses to make broad conclusions within and among technology classes. This is due to the wide variety of process configurations; feedstock processed; and control strategies that are uniquely applied to individual facilities and to the general immaturity of conversion technologies as applied to MSW. 5.1.1 Air Emissions Emissions from alternative technologies in this study may include such things as NOx, SOx, hydrocarbons, carbon monoxide, particulate matter (PM), heavy metals, greenhouse gas emissions such as CO 2, and dioxins/furans. However, the conversion process may utilize end of stack devises (such as baghouses, scrubbers and electrostatic precipitators) to control air emissions. Of the four processes studied as part of this report, it is apparent that gasification and plasma technologies have the potential to be met with resistance from the environmental community and the public. Some of this resistance has stemmed from the perception that plasma arc and gasification processes are variations of incineration. Some have stated that federal law includes gasification and plasma arc as part of the definition of incineration. Title 40, Part 60, Standards of Performance for New Stationary Sources, Subpart E Standards of Performance for Incinerators defines Incinerator as any furnace used in the process of burning solid waste for the purpose of reducing the volume of the waste by removing combustible matter. The federal definition does not include the term gasification or plasma arc. According to the University of California researchers 95, thermochemical conversion technologies (like gasification and plasma arc) differ dramatically from incineration in several key respects: The volume of output gases from a gasifier or plasma arc is much smaller per ton of feedstock processed than an equivalent incineration process. While these output gases may be eventually combusted, the alternative process provides an intermediate step where gas cleanup can occur. Mass burn incineration is limited by application of air pollution control equipment to the fully combusted exhaust only. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 67 February 2008 R-RWCounties Updated Research Study-Final.doc
Output gases from plasma arc reactors or gasifiers are typically in a reducing environment, and can be treated with different technologies compared with a fully combusted (oxidative) exhaust. Reactant media can also be hydrogen or steam. Gasification and plasma arc produce intermediate synthesis gases composed of lower molecular weight species such as natural gas, which are cleaner to combust than raw MSW. Plasma arc and gasification processes use very little air/oxygen or none at all. Dioxins and furans are of particular concern in terms of potential environmental consequences. These compounds are formed under high temperatures when chlorine and complex mixtures containing carbon are present, and can be found in the gas and liquid phases. Dioxins and furans are typically formed downstream of the combustion process as the flue gases cool in a temperature range of 400-1290 o F, with a maximum formation rate at approximately 600 F. Combustion conditions that enhance the downstream formation of dioxins and furans include poor gas-phase mixing during combustion, low combustion temperatures, incomplete combustion of carbon species, and high PM loading. The same air pollution control technologies used in large MSW incinerators that resulted in the dramatic emissions reductions could also be used on other conversion facilities and could result in much lower emissions if proper feedstock preparation is utilized. Common exhaust gas cleanup technologies include spray dryers, fabric filters, carbon injection, selective non-catalytic reduction, electrostatic precipitation, and duct sorbent injection. 5.1.2 Solid Residuals Essentially all conversion technologies will produce a solid residue because all components of the solid waste stream contain inorganic material, or ash. The amount of ash varies with the material and how it is handled before it becomes a feedstock. Depending on markets and hazardous content of solid residue it may find commercial use or may need to be disposed in non-hazardous or hazardous waste landfills. All organic matter including biomass and waste contains trace quantities of heavy metals. Whether the feedstock is landfilled, composted, gasified, or incinerated, the heavy metal quantity remains identical; the only difference is that thermal decomposition processes retain most of the heavy metals in their residue/ash in a concentrated form. More volatile heavy metals, such as mercury, will enter the gas phase in thermal conversion and must be managed or captured before exhausted to the atmosphere. Conversion technologies do not generate heavy metals in ash but do concentrate heavy metals already present in the feedstock that would otherwise be landfilled. With proper management, the concentrated heavy metals can be treated and disposed of in a controlled manner that poses no greater environmental threat than landfilling. In some cases, metals may even be reclaimed from the solid residue. Leachability testing is done by using the Toxicity Characteristic Leaching Procedure (TCLP). 68 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
In many processes (like plasma arc), the ash is vitrified by heating above the melting point or fusion temperature of the ash. This slag is a hard glassy substance that has little if any leachability. The bottom ash and slag may also be used in different construction and other applications. A small amount of residue is generated by baghouse filters and scrubber solids, which must be periodically cleaned. 5.1.3 Liquid Residue As with the solids residue, the amount of liquid residue is dependent on the specific conversion process and feedstock. There are well-defined mechanisms already in place for dealing with these waste streams. Generally, these waste streams are subjected to conventional chemical treatment processes. Products from the gas cleaning and water recovery processes include industrial-grade salts and a separate precipitate containing the heavy metals from the feedstock stream. In some cases, this precipitate may be rich enough in zinc and lead to warrant recovery in a smelter operation. These types of liquids are common to plasma arc and gasification processes. For ethanol processes, an acid hydrolysis and liquid digestate are formed and must be managed. In some instances, the water from the ethanol process could be land applied depending on the constituents in the water. 5.2 Regulatory Issues The Minnesota waste management hierarchy is stated in Minnesota Statute 115A.02b as; "The waste management goal of the state is to foster an integrated waste management system in a manner appropriate to the characteristics of the waste stream and thereby protect the state's land, air, water, and other natural resources and the public health. The following waste management practices are in order of preference: (1) waste reduction and reuse; (2) waste recycling; (3) composting of yard waste and food waste; (4) resource recovery through mixed municipal solid waste composting or incineration; (5) land disposal which produces no measurable methane gas or which involves the retrieval of methane gas as a fuel for the production of energy to be used on-site or for sale; and (6) land disposal which produces measurable methane and which does not involve the retrieval of methane gas as a fuel for the production of energy to be used on-site or for sale." As stated previously, the alternative technologies of gasification and plasma arc processes are similar to incineration and would be treated by the MPCA as such. However, it is likely the MPCA would require significant start up testing and monitoring to verify the technology s performance to established standards for air quality and water quality. Residue from the operation would also be subject to TCLP testing to determine the leachability of components and disposal requirements for the residue. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 69 February 2008 R-RWCounties Updated Research Study-Final.doc
The MPCA has established its position that waste-to-energy is an important part of satisfying the waste management hierarchy The MPCA's current Strategic Plan calls for the combined proportion of municipal solid waste that is captured for WTE and for source-separated composting to rise from about 20% in 2005, to 35% by 2011. This is an ambitious goal. 96 The MPCA's latest Solid Waste Policy Report, released in February 2006, reiterates this WTE-source separated composting goal as something the state, local governments, and waste industry should work toward. The Policy Report also went to the next level of detail, in suggesting specifically that source-separated composting rise from 0.5% of MSW to 5%, and that the share of mixed waste going to WTE should rise from 20% to 30% of MSW. Together this would bring the combined WTE-composting share to 35%. 97 It is apparent from the reports issued by the MPCA, that they support further development of technologies so further their goal of 35% of waste to be composted or incinerated. However, development of an alternative technology such that it could obtain a permit to operate in Minnesota could be a challenge. The current permitting structure including the Environmental Assessment Worksheet, Environmental Impact Statement and the permitting at the local and state levels make the process of advancing an alternative technology risky and lengthy. 70 Foth Infrastructure & Environment, LLC X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc R-RWCounties Updated Research Study-Final.doc February 2008
6 Applicability to Ramsey/Washington Counties The four alternative technologies examined in this report include gasification, plasma arc, ethanol and anaerobic digestion. None of the three technologies studied are ready for full scale development in the United States. Several other public agencies are currently conducting feasibility studies on the technologies. Ramsey/Washington counties should continue to watch the developments from other agencies and implementation of technologies to MSW. If the technologies are feasible, it is likely a full scale plant would be constructed and operated in the United States within the next decade. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc Foth Infrastructure & Environment, LLC 71 February 2008 R-RWCounties Updated Research Study-Final.doc
References 1 http://www.frost.com/prod/servlet/company-info.pag Viewed on 4/7/08. 2 http://frost.com/prod/serlet/report-brochure.pag?id+b738-01-00-00-00. Viewed on 4/7/08. 3 Klein, Alexander. Gasification as an Alternative Process for Energy Recovery and Disposal of Municipal Solid Waste. Masters Thesis. Columbia University. May 2002. 4 www.interstatewastetechnologies.com. 5 Elliott, D.C. Relation of Reaction Time and Temperature to Chemical Composition of Pyrolysis Oils, ACS Symposium Series 376, Pyrolysis Oils from Biomass. 6 Evans, R.J., Milne, T.A. Chemistry of Tar Formation and Maturation in the Thermochemical Conversion of Biomass, Developments in Thermochemical Biomass Conversion, Vol. 2, 1999. 7 Waste Gasification Impacts on the Environment and Public Health, A Blue Ridge Environmental Defense League Report, April 1, 2002. 8 Evaluation of Alternative Solid Waste Processing Technologies. City of Los Angeles and URS Corporation. September 2005. 9 Processing of Waste Materials, http//maven.gtri.gatech.edu/geoplasma/processing.htm 10 Martin, Kay. Conversion Technologies: The New Frontier. Senior Manager Symposium, SWANA, Amelia Island, Florida, Jan. 15, 2000. 11 Kalogu, Youssouf; Shirva Habibi, Heather L. MacLean, and Satish V. Joshi; Environmental Implications of Municipal Solid Waste-Derived Ethanol ; Environmental Science Technology, ASAP Article 10.1021/es0611176 SOU13-936X(06)01117-5. 12 BRI Energy Inc., Press Release, November 21, 2005. 13 Pencor-Masada Oxynol, No Work Yet on Middletown Trash-to-Ethanol Plant. Times Herald-Record, October 9, 2007. http://www.recordonline.com. 14 Martin, pg. 2. 15 Tennessee Valley Authority, Municipal Solid Waste and Waste Cellulosics Conversion to Fuels and Chemicals, Volume V: Product Markets, March 1993. 16 TVA, Volume V: Product Markets, pg. 10. 17 DOE, EIA, Annual Energy Outlook 2007, February 2007. 18 Minnesota Department of Agriculture, Minnesota Ethanol Production Consumption, and Economic Impact. http://www.mda.state.mn.us/renewable/ethanol/productionimpact.htm. 19 Biofuels in the U.S. Transportation Sector, DOE Annual Energy Outlook 2007, February 2007. 20 Presentation at Gasification Technology 2002, San Francisco, CA, October 28, 2002. 21 Investigation Into Municipal Solid Waste Gasification for Power Generation, Advanced Energy Strategies, Inc., May 27, 2004. 22 Granatstein, D.L., Case Study on Waste-Fuelled Gasification Project, Greve in Chianti, Italy, IEA Bioenergy Task 3b Report, June 2003. 23 http://www.homefarmstech.com/news/ 24 Insert footnote for Julie Rath 25 Hanson, Wayne C. Elk River Renewable Fuels Facility presentation May 2007. 26 Evaluation of Conversion Technology Processes and Products. University of California. 2004 27 Ecoworld. October 23, 2007. Ze-Gen Waste to Energy and Waste to Energy Article. Advanced Gasification Converts Waste to Synthetic Natural Gas. 28 (http://stocks.us.reuters.com/stocks/fulldescription.asp?symbol=iglpa.pk&wtmodloc=l2leftnav-8.5- FullDescription) (Viewed 12/20/2007) 29 (http://www.iwtonline.com/index.html. (viewed 12/20/2007). 30 http://www.greenaction.org/incinerators/documents/factsheet_thermoselectrealitycheck.pdf (viewed 12/20/2007) 31 Ibid. X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc
32 http://www.lacity.org/san/alternative-technologies-final-city-report.pdf (viewed 12/21/2007) 33 http://www.mswmanagement.com/mw_news_090407_lax.html (viewed 12/21/2007) 34 http://www.seas.columbia.edu/earth/wtert/sofos/deangelo_thesis_final.pdf (viewed 12/24/2007) 35 http://home.nyc.gov/html/dsny/downloads/pdf/guides/cwms/ccwms/ccwms01.pdf (viewed 12/24/2007) 36 http://www.iwtonline.com/facilities/proposed-facilities.html (viewed 12/24/2007) 37 http://www.enerwaste.com/ (viewed 12/26/2007) 38 Los Angeles County Conversion Technology Evaluation Report; Phase II Assessment. Executive Summary. ARI. October 2007. 39 http://www.enerwaste.com/ (viewed 12/26/07) 40 http://www.planetgroup.co.uk/bos%20narrative.pdf (viewed 12/26/2007) 41 Evaluation of Conversion Technology Processes and Products. University of California. 2004 42 Ibid. 43 Ibid. 44 Ibid 45 Ibid. 46 SENREQ, LLC Web Site; www.senreq.com 47 SENREQ, LLC response to Expression of Interest, Cache Creek Landfill Alternatives. July 4, 2006. www.gvrd.bc.ca. 48 I&M Online. Landfill Operator Considering Gasification to Reduce Waste Stream. Jason Gruziadei. January 7, 2008. 49 http://www.alternrg.ca/ 50 Evaluation of Conversion Technology Processes and Products. University of California. 2004 51 Request for Qualifications to Permit, Finance, Construct, Operate and Own a Plasma Arc Gasification Facility to Process Municipal Solid Waste for St. Lucie County. April 30, 2006. 52 Florida County Planning to Vaporize Landfill Trash; $425 million Facility Expected to Generate Electricity. Public Works Online. www.pwmag.com 53 Florida County Approves Bonds for Plasma Arc Gasification Plant. The Bond Buyer. December 1. 2006. 54 Evaluation of Conversion Technology Processes and Products. University of California. 2004 55 First Reserve Leads Plasco Energy Equity Funding. Plasco Energy News Release. December 3, 2007. 56 Ibid. 57 Ibid. 58 Ibid. 59 Ibid. 60 Ibid. 61 Ibid. 62 Ibid. 63 Ibid. 64 Ibid. 65 Ibid. 66 Ibid. 67 Ibid. 68 PyroGenesis to Float on AIM. Biofuel Review. July 25, 2006. www.biofuelreview.com. 69 Innovative Plasma Waste Treatment on Carnival Cruise Ship. Naval Architect. May 2006. p. 62. 70 www.coronal.us 71 Startech Environmental: More Hot Air Than Profit. February 15, 2007. http://seekingalpha.com. 72 http://www.greenpwersystems.com 73 Changing Economics Improve Plasma Technology s Outlook. December 5, 2007. ENR.com 74 Company Proposes to Build Plasma Plant in New Orleans. Waste Business Journal. October 14, 2007. http://www.wastebusinessjournal.com. 75 Phone interview. Marilyn Elliot. January 10, 2007. 76 Tennessee Valley Authority Biotechnical Research Department, Municipal Solid Waste and Waste Cellulosics Conversion to Fuels and Chemicals, April 1990 to September 1992 Final Report. March 1993. 77 Ibid.
78 TVA, Volume 1: Summary Report, pg. 14. 79 TVA, Volume 1: Summary Report, pg. 13. 80 TVA, Volume VI: Technical and Economic Evaluation, pg. 29. 81 TVA, Volume VI: Technical and Economic Evaluation, pg. 31. 82 TVA, Volume VI: Technical and Economic Evaluation, pg. 28. 83 Evaluation of Conversion Technology Processes and Products. University of California. 2004. 84 Masada webpage http://mesadaonline.com 85 Evaluation of Conversion Technology Processes and Products. University of California. 2004 86 http://www.mswmanagement.com/mw_news_080307_iblue.html 87 Ibid. 88 http://www.arrowecology.com/mainpage/index2.htm 89 Evaluation of Conversion Technology Processes and Products. University of California. 2004. 90 Ibid. 91 Ibid. 92 http://www.dwacaribbean.com/articles.html 93 Evaluation of Conversion Technology Processes and Products. University of California. 2004. 94 http://www.globalrenewables.com.au/ 95 Evaluation of Conversion Technology Processes and Products. University of California. 2004 96 http://www.pca.state.mn.us/publications/reports/strategicplan-2006.pdf 97 http://www.pca.state.mn.us/publications/reports/lrw-sw-1sy06.pdf X:\MS\IE\2007\07r001\10000 reports\r-rwcounties Updated Research Study-Final.doc