Performance and Emissions of a Second Generation Biofuel - DME

Performance and Emissions of a Second Generation Biofuel - DME D. Kittelson 1, W. Watts 1, D. Bennett 1, S. Taff 2, and C. Chan 1 1 Department of Mechanical Engineering, University of Minnesota 2 Department of Applied Economics, University of Minnesota E3 2010 St. Paul RiverCentre St. Paul, Minnesota, November 30, 2010

Performance and Emissions of a Second Generation Biofuel: DME We started working on a three year grant from IREE to investigate the performance and emissions of dimethyl ether, a second generation biofuel in July. The program involves a variety of partners including Chemrec US EPA Pennsylvania State University Johnson-Matthey Volvo Rational Energies General Motors Today I will briefly describe why we are excited about the potential of DME

Outline DME basics Environmental benefits of dimethyl ether Current status Fuel comparison DME production Barriers to DME usage Project purpose and expected outcome Conclusions

DME Basics What is DME? Source: International DME Association DME Properties Physical properties similar to propane DME Uses Cosmetic propellant Propane replacement Diesel fuel High efficiency Soot free combustion Fuel system modifications required Fuel cell fuel Gas turbine fuel

Environmental benefits of dimethyl ether Environmental DME has the highest well-to-wheel energy efficiency and the lowest greenhouse gas emissions (GHG) of any biomass-based fuel. Does not lead to stratospheric ozone depletion Significant reduction in end use emissions Soot free combustion Low NOx emissions Health Virtually non-toxic Not a carcinogen or mutagen Not a groundwater pollution threat Safety Like LPG Heavier than air Visible flame

Current Status Most of the DME worldwide is made from natural gas or coal In the US, DME is used as a nontoxic, non-ozone depleting cosmetic propellant DME is widely used in China as a propane replacement for cooking and heating Current production about 40 million gallons/year Planned production by 2020 about 800 million gallons/year, this corresponds to about, nearly half the current US use Volvo, Nissan, Isuzu and Renault are advocating DME as a second generation Diesel fuel and are testing prototype vehicles but no U.S. companies involved. The first bio DME pilot plant has been built by Chemrec, a Sweden-based development company, at a paper mill in Piteå, Sweden.

From: DME Industry and Association Overview, by Jean-Alain Taupy, IDA Chairman, 4th International DME Conference, Stockholm, September 2010

Fuel comparison - efficiency and greenhouse emissions 40% Fossil Renewables g/kwh 1000 30% 750 20% 500 10% 250 0% Diesel (crude oil) DME (natural gas) MeOH (natural gas) CNG (natural gas) Synthetic diesel (natural gas) DME (wood, black liquor) MeOH (wood, black liquor) Biogas (sewage) DME (wood) RME (rape seed) MeOH (wood) Synthetic diesel (wood) Ethanol (wood) Ethanol (wheat) 0 Energy efficiency, % GHG, g/kwh Source: Volvo Technology Corporation. These estimates include production, transport, and end use GHG emissions. KEY: DME dimethyl ether; MeOH methanol; CNG compressed natural gas; RME rapeseed methyl ester; GHG greenhouse gas.

Heavy duty DME vehicles -from advanced engineering to customer field test, Niklas Gustavsson, Environmental & Public Affairs, AB Volvo

DME Production Unlike current ethanol and biodiesel, DME is produced by thermochemical processes. It can be produced from virtually any carbon containing feedstock, coal, natural gas, biomass, and even CO 2. We are focusing on the biomass path but are also examining production from CO 2 in natural gas. The illustration below shows thermochemical biomass to fuel processes (Source: RENEW, 2008).

Bio DME production Bio DME may be produced from renewable cellulosic biomass such corn stover, prairie grass, and forestry waste. Even municipal solid waste, sewage sludge, and algae are potential feedstocks. One particularly attractive option is to gasify black liquor in a pulp mill, making it into a biorefinery.

Quantity of DME produced from pulp mill The first step to get DME production started in Minnesota could be adding a small black liquor gasifier to an existing mill to produce about 7 million gallons of DME per year. This amount is sufficient to fuel 700 buses or about 2/3 of the current Metro Transit fleet. Alternatively enough methanol could be produced to replace all fossil based methanol used for biodiesel production Replacement of 4 to 6% of the state s diesel fuel requirements or 14 to 20% of the propane requirements could be done using only the black liquor from existing Minnesota pulp mills. MN could produce about 1.2 times our current Diesel fuel needs or nearly 5 times our propane needs based on DOE estimates of existing biomass resources in MN.

Barriers to DME usage Lack of public awareness No active lobbying groups No preferred tax status Capital costs associated with gasification plant Chicken and egg problem - no end use, no production no production, no end use As a propane replacement Performance of typical U.S. appliances not well defined Uncertainty about suitable DME/propane blend ratios As a Diesel fuel replacement DME cannot be blended with petroleum-based fuel Engine and fuel system modifications are also required. It is not a drop-in replacement fuel.

Project purpose and expected outcome Conduct a business/economic/environmental analysis to determine the viability of bio DME as a transportation fuel in areas with substantial biomass resources like Minnesota. Examine performance and emissions of DME in a Diesel engine First generation engine based on EPA 4.7 L Navistar engine Second generation engine based on GM 2.0 L engine with proprietary U of M fuel injection system Raise awareness of DME in Minnesota through presentations, publications, and networking Use the results of the work as the basis for applying for further funding from DOE, DOT, and industry

Conclusions This project is the first step to demonstrate how DME will be used as a second generation renewable biofuel in MN. This project is a platform to demonstrate our research capabilities so that we may seek research partners and funding from other organizations such as Department of Energy s National Renewable Energy Laboratory. Engine companies Metro Transit Forestry industry? Other? If you are interested in further details contact me at kitte001@umn.edu. I can provide links to current bio DME partners, Chemrec, Haldor Topsoe, and Total.

From: DME Industry and Association Overview, by Jean-Alain Taupy, IDA Chairman, 4th International DME Conference, Stockholm, September 2010

From: Dr. Kyriakos MANIATIS Principal Administrator Energy Technologies & Research Coordination DG ENER, European Commission

From: BioDME Project status update, Per Salomonsson, Volvo Powertrain, 4th International DME Conference, Stockholm, September 2010

Basics for a small black liquor gasification to motor fuel plant An typical pulp mill produces 1000-1200 dry pulp per day and processes 1800-2100 tons of black liquor solids per day (ton ds/d). There are some 60+ such mills in Europe and some 150 of them in N America. A small BLGMF plant at 400 t ds/d (~60 MW t ) thus corresponds to an additional capacity of approximately 15% to such a mill. Biomass WOOD FOR PULPING O 2 The Original Pulp (&Paper) Mill Black Liquor Green Liquor Plant O 2 Gasification Gas Cleaning + Synthesis BLGAMF PLANT CO 2 Methanol/ DME Sulphur Expanded Mill incl. BLGMF PULP/ PAPER 9/26/2005 1 CHEMREC Courtesy Ingvar Landalv, Chemrec

Heavy duty DME vehicles -from advanced engineering to customer field test, Niklas Gustavsson, Environmental & Public Affairs, AB Volvo

Engineering issues associated with DME as a diesel fuel substitute Install a laboratory DME fuel distribution system. Install DME fuel injectors in the diesel engine. Determine the best operating regimes for DME in the diesel engine. Measure gaseous and particulate matter emissions from the diesel engine using DME as the fuel and compare them to the same engine fueled with diesel fuel. Very low soot emissions expected but nanoparticles may be an issue Control of unregulated emissions with catalytic converter

Raise awareness of DME within MN Post findings on the Center for Diesel Research web site http://www.me.umn.edu/centers/cdr/. Share results with colleagues at the University Center for Transportation Studies and the Institute on the Environment by making conference presentations. Publish findings in scientific journals. Work to establish communications between Minnesota pulp mill operators and makers of DME gasifiers.