Bio-fuels and Biorefining 2013 C Merritt, C&S Companies 1
Objective Discuss the market potential, technical processes and the limitations of making transportation fuels from renewable organic material.
Overview Transportation fuel use in the USA Current role of bio-fuels Policy and challenges Look at the major processes Biochemical route Fermentation corn vs biomass Biodiesel- including the algae story digestion Thermochemical route Direct Combustion Gasification Pyrolysis 3
How much Transportation fuel do we use? 4
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Bio-fuels Bio-fuels are defined as any useful energy source made from a renewable organic feed stock. Bio-refining is associated with renewable fuels Direct combustion of biomass use for fuel Methanol, Ethanol, Butanol production Biodiesel production- including algae Digester gas methane production Syn gas from gasification Bio oils from pyrolysis 6
Ideal bio-fuel characteristics Readily available feed stock Does not compete with food Proven manufacturing technology Low carbon footprint Easy to transport Consistent quality High energy density Cost effective Does not currently exist..but does any fuel meet all these? 7
The Carbon Neutral Pathway 8
Bio-fuels Policy EISA- 2007 Energy Independence and Security Act- intent of moving our nation forward towards greater energy independence. It created RFS Renewable Fuel Standard RFS called for the increase in renewable fuels like ethanol and biodiesel production by 2022. This lead to 10% ethanol in our gasoline. 2013 numbers are 16.55 billions gallons bio-fuels to be blended 1.28 billion biomass based biodiesel 2.75 billion gallons of advanced biofuels 6 million gallons of cellulosic biofuels Puts limit starch based fuels ie corn based ethanol This equates to about 30 days worth of transportation fuels (8% annual fuel usage) 9
USA annual corn based ethanol production 10
Problem. 11
Main focus is the post corn ethanol era 12
Main focus is the post corn ethanol era 13
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What s in biomass Most plant type material ie grasses, trees, corn stalks, etc. have three major components Cellulose- polymer of starches (C6 sugars)- 40-45% Hemicellulose- polymer of pentose (C5 sugars)- (25-35%) Lignin- sulfur containing phenolic polymer that acts like glue for the wood fibers (20-25%) Fermentation of C6 and C5 sugars occur differently. Access to sugars requires harsh pretreatment. 16
Traditional Fermentation Most popular way to make a biofuel today Sugar cane and corn feed stocks compete with food supply Corn to ethanol fuel market is mature Biomass to ethanol/isobutanol is on the verge of commercial viability. Key is genetic engineering yeasts and bacteria How to market the extracted lignin. 17
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(ISO)Butanol as a Bio-fuel Four carbon alcohol that has about the same energy density as gasoline. It also is relatively insoluble in water Can be transported in petroleum pipe lines Made from fermentation of biomass sugars More toxic than ethanol and has a higher boiling point- more difficult to purify. Can be used to make plastics and other chemicals of interest. Can be added to gasoline, diesel fuel or jet fuel Technology is just being commercialized 19
Fuel made from fats Spent cooking oil Animal fats Algae Biodiesel 2013 1.28 billion gal 20
Traditional Biodiesel Production 21
Biodiesel Production Traditional base catalyzed method- needs clean dry oil/ greases and produces a lot of glycerin..marginally valued co-product Supercritical process- catalyst free supercritical methanol at high temperature and pressure- can tolerate water and free fatty acids does not produce as much glycerin. Technology is being commercialized Lipase catalyzed process- uses enzymes as the catalyst. Still in research phase. 22
Algae 23
Algae Algae are very efficient converters of sunlight to lipids Harvest equipment/ extraction technology is underdeveloped Could have synergy with wastewater treatment plants or CO2 from power plant High capital cost of artificial farms and photo bioreactors Navy has done a lot of research in this area 24
Algae can be grown anywhere you have water, light and nutrients 25
Seaweed Macro algae Co-Farming with fish farms along coastal areas Can yield 1kg ethanol/ 3 kg dried seaweed 26
Digestion Anaerobic digestion can take organic matter and use bugs to convert it to methane Used widely in industry to purify water- cobenefits The methane produced needs to be scrubbed to rid itself of H2S Capital investment is high, but the feed stock is generally low cost Hard to compete with low NG prices 27
Bugs need nutrient and fairly tight ph and temperature requirements 28
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Thermochemical Processes Three types Direct combustion- Combust with lots of Oxygen Gasification- Heat up at high temperature in the presence of little Oxygen Pyrolysis- Heat up to high temperatures in the absence of Oxygen 30
Compare direct combustion of wood to natural gas 1 face cord of hardwood (16 x 4 x 8 ) weighs about 1200lbs (@20%moisture) and has about 6000btu/lb available heat. Good wood stove will be about 65% efficient and a good NG furnace will be about 90% efficient. Then each cord of wood will provide the same energy as 1200lbs x 6000btu/lb x.65 = 4.68 million btu or 46.8 therms of NG Taking into account the efficiency of the NG furnace, each cord could displace 46.8/.9 = 52 therms of NG 31
Direct Combustion Biomass boilers are used to make steam Biomass can replace liquid or gaseous fuels that could be used for transportation fuels. Good choice where dry feed stock is available onsite ie lumber mills, furniture manufacturing, etc Hard to regulate.just can t turn off the combustion process easily 32
Gasification Process 33
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Gasification Can gasify a wide variety of feed stacks including biomass, coal, wastes etc. in any condition. Thermo reforming of the syngas to bio-fuels can lead to a variety of different organic species..flexible, but quality issue for transportation fuels Well established in the power generation market Suitable for large scale operations 36
Pyrolysis Heating of biomass at high temperatures in the absence of Oxygen. Charcoal is made this way Can be packaged as a small scale process Real potential for waste material 37
The process of making bio-oils 38
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Why is bio-fuel production still struggling? Logistics- transporting raw material and new fuels is higher cost than well established NG and gasoline pipeline/ terminal system Compressed/ Liquified NG is hot issue Retrofitting service stations is costly Much disagreement on life cycle analysis Texas refiners vs. midwest farmers vs. gas company frackers.. A lot of competing lobbyists Perception is we still have a lot of oil/ NG in the ground.we don t change fast until we have an emergency 41
And then there is CNG/LNG.. 42
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Thinking about bio-fuels is not new 45
When Henry Ford told a New York Times reporter that ethyl alcohol was the fuel of the future in 1925, he was expressing an opinion that was widely shared in the automotive industry. The fuel of the future is going to come from fruit like that sumach out by the road, or from apples, weeds, sawdust almost anything, he said. There is fuel in every bit of vegetable matter that can be fermented. There s enough alcohol in one year s yield of an acre of potatoes to drive the machinery necessary to cultivate the fields for a hundred years. 46
Questions? 47