Ethanol plants

Because most fuel ethanol manufactured ia the United States is made from com, price plays a cmcial role ia determining the competitive position of ethanol ia an open market. With com priced at about 2.50/bu, the embedded feedstock cost of product ethanol is about 0.14—0.23/L ( 0.52—0.87 gal), depending on over-all yield and by-products ignored (125). Euel ethanol plants may have contingency plans to close if com prices rise to a certain level, eg, 3.50/bu or above (126). 

Capacity Limitations and Biofuels Markets. Large biofuels markets exist (130—133), eg, production of fermentation ethanol for use as a gasoline extender (see Alcohol fuels). Even with existing (1987) and planned additions to ethanol plant capacities, less than 10% of gasoline sales could be satisfied with ethanol—gasoline blends of 10 vol % ethanol the maximum volumetric displacement of gasoline possible is about 1%. The same condition apphes to methanol and alcohol derivatives, ie, methyl-/-butyl ether [1634-04-4] and ethyl-/-butyl ether. 

Dehydration The growing use of isopropanol as a clean-rinse fluid in microelectronics produces significant quantities of an 8.5-90 percent isopropanol waste. Removing the water and trace contan ii-nants is required before the alcohol can be reused. Pervaporation produces a 99.99 percent alcohol product in one step. It is subsequently polished to remove metals and organics. In Europe, dehydration or ethanol is the largest pei vaporation application. For the very large ethanol plants typical of the United States, pei vaporation is not competitive with thermally integrated distillation. 

Corn-to-ethanol plants have been the most rapidly growing source of feed gas for C02 recovery. 

By 2006, the U.S. had 77 ethanol plants producing more than 3 billion gallons of ethanol per year. Canada produced an additional 60 million gallons. Corn was the feedstock in 62 of the 77 U.S. plants. Other feedstocks included seed corn, corn and barley, corn and beverage waste, brewery waste, cheese whey, corn and milo, corn and wheat starch, potato waste and various sugars. The U.S. had 11 additional plants under construction and 55 proposed. West Central Soy processes soybeans to a food grade oil. Alcohol and a catalyst are then used to produce biodiesel fuel and glycerin. 

BP has investments in an ethanol plant with DuPont and Associated British Foods. It is also investing in cellulosic ethanol research and developing jatropha as a biodiesel feedstock. BP and DuPont are planning a biobutanol demonstration plant and BP would like to eventually convert their ethanol plant to biobutanol production. BP has a 400 million investment with Associated British Foods and DuPont to build a bioethanol plant in the U.K. that may be converted to biobutanol. It has spent 500 million over 10 years at the Energy Biosciences Institute in California to research future biofuels and 9.4 million over 10 years to fund the Energy and Resources Institute (TERI) in India to study the production of biodiesel from Jatropha curcas. It also has a 160 million joint venture with D1 Oils to develop the planting of Jatropha curcas. 

In 2007 Verenium began work on a demonstration-scale cellulosic ethanol plant in Jennings, LA. The plant is expected to have an output of 1.4 million gallons a year, using sugar cane bagasse and a special breed of energy cane as feedstocks. 

In most of today s ethanol plants for the conversion of wheat, rye and corn, the required thermal energy is provided by natural gas, heavy fuel oil or coal. The protein-rich by-products of ethanol plants are referred to as dried distillers grains with solubles , abbreviated as DDGS, and are mostly used for animal fodder. Alternatively, they can be converted to biogas for heat and electricity production. The resulting residue can then be used as fertiliser (see Table 7.16). 

We learned to formulate com ethanol way back— it s nothing more than moonshine. What makes the E3 Biofuels facihty so novel isn t its spectacular equipment but the way the equipment is fueled. The most important structures here happen also to be the least beautiful a pair of four-story milhon-gallon fuel tanks, each filled to the brim with cow manure. Historically, ethanol plants were fired by coal or natural gas. But methane, produced from manure, powers this operation. Not only do no fossil fuels go into the plant, very fitde pollution comes out. It s a nearly closed energy loop (some corn has to be bought from other farms). (Khosla)... 

Consider the emergence of bioethanol as an instructive example. The federal excise exemption for ethanol plus Clean Air Act regulations has created a 2.5 billion gal/yr ethanol industry. Evidence from Minnesota and Missouri indicates that this has increased the price that farmers are getting for their corn from local ethanol plants by 5-10(2/bushel.7... 

However, if farmers own the ethanol plant, they receive the additional price that results from increased markets plus they receive a part of the profit generated at the manufacturing level. Information on returns on ethanol investments is closely guarded and the returns vary dramatically from year to year and from plant to plant. Nevertheless, it is not unusual for the dividend in an average year to be 25-50(2 /bushel. One unreleased study of the farmer-owned Minnesota Com Processors ethanol plant found that farmer-investors earned about 18% annually over the 20-yr life of the plant as a cooperative. 

Thus, the 20t incentive made up for the difference between small and large biorefineries. The result was that rather than one or two 100 million gal/yr plants, by 2002 Minnesota was home to 15 ethanol plants, the average capacity of which was 15 million gal/yr. The scale of the plants also encouraged farmer ownership. In 2002,12 of the 15 plants were owned by more than 9000 grain farmers. These plants provided almost 10% of the transportation fuel sold in the state. 

Personal communication from several ethanol plant managers in Minnesota. Also see Van Dyne, D. L., Employment and Economic Benefits of Ethanol Production in Missouri. Department of Agricultural Economics, University of Missouri-Columbia, February 2002. 

Whey is a coproduct of cheese manufacturing. In 2000, California produced an estimated 1.5 billion lb of cheese, yielding 747,000 t of dried whey. It is costly to dispose whey in municipal water systems. Hence, an alternative use for whey would enhance the economics of cheese production. Currently, whey protein is used as a food additive, a protein supplement, and an animal feed. In addition, there are a few ethanol plants in California and the Midwest that use whey as a feedstock. The current California whey production would yield approx 4.7 million gal of ethanol. 

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