The Space Congress® Proceedings 1980 (17th) A New Era In Technology

Apr 1st, 8:00 AM

Alcohol Fuels for Spaceship Earth

Daniel Hunt Program Manager-Alcohol Fuels, TRW Energy Systems Group

Follow this and additional works at: https://commons.erau.edu/space-congress-proceedings

Scholarly Commons Citation Hunt, Daniel, "Alcohol Fuels for Spaceship Earth" (1980). The Space Congress® Proceedings. 3. https://commons.erau.edu/space-congress-proceedings/proceedings-1980-17th/session-6/3

This Event is brought to you for free and open access by the Conferences at Scholarly Commons. It has been accepted for inclusion in The Space Congress® Proceedings by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. ALCOHOL FUELS FOR SPACESHIP EARTH

V. Daniel Hunt, Program Manager-Alcohol Fuels TRW Energy Systems Group McLean, Virginia 22102

ABSTRACT

Foreign crude oil imports currently provide or a combination of both—what we now call raw material for production of half of the "gasohol. 11 Despite an illustrious list of liquid fuels consumed in the United States proponents: Theodore Roosevelt; Dow Chem­ and represents a cash outflow of almost $8 ical chemist, William Jay Hale; Henry Wal­ million per hour. Recent events have dramat­ lace; and Everett Dirkson, Henry Ford lost ically illustrated the substantial vulnera­ his thirty year battle for power alcohol bility of such imports. Ethanol is a liquid to cheap oil. From about 1939 until the late fuel that can substitute domestic renewable 1970's, the only American automobiles resources for imported petroleum products using alcohol fuels were race cars. now and increasingly in the next few years. ALCOHOL FUELS Alcohol fuels and in particular gasohol, a blend of 10% agriculturally derived anhydrous Today, the "race 11 is on to rediscover non- ethanol and 90% unleaded gasoline, will in fossil alcohol fuels as an alternative or the near term be the primary alcohol fuel. extender to decrease our dependence on foreign and rapidly diminishing supplies of This paper describes the market for gasohol petroleum. Currently, the only alcohol produced from fermentation ethanol, the fuel is ethanol or industrial grade grain basic ethanol production process, effective alcohol used either as blending stock with feedstocks, typical plant design and a re- gasoline to produce gasohol or as a comm­ review of the state of the art. ercial motor fuel for a suitable equipped vehicle. However, methanol (derived from INTRODUCTION petroleum or natural gas rather than wood) offers promise as an octane-enhancer and Interestingly enough, it was alcohol fuel component for diesel or other motor fuels, which ushered in the space age 9 following and tertiary butyl alcohol (TBA) is under the propellant research of Dr. Robert H. test as an octane-enhancer. For now, the Goddard. The 20 year old Wernher von Braun introduction of gasohol has paved the way began experimenting with it in 1932 and 10 toward eventual large scale use of alterna­ years later launched the first man-made tive, non-fossil fuel. object to reach space, the alcohol fueled V-2 Rocket. It was a magnificent display 6ASOHQL of power--!0 tons of alcohol and oxygen propel 1 ants converting energy at the rate Gasohol is a mixture of gasoline and ethanol, of half a million horsepower—thrusting at a ratio of nine to one, which can be used the rocket at 3,800 miles per hour. That in unmodified present day automobiles remarkable energy source now offers our without modification, provided a stable, dry greatest hope for renewable supply of fuel is delivered and the user is taught to precious energy to continue to power our maintain a clean, dry fuel system. spaceship Earth. From an environmental standpoint, ethanol As it turns out, we have been tardy in our reduces hydrocarbon and CO emissions but utilization of ethyl alcohol--ethanol--even may increase emission of aldehydes and may though it has long had its ardent proponents. be involved in the evaporative emissions of Henry Ford well knew ethanol's potential and hydrocarbons. Gasohol enhances the octane fought hard, though unsuccessfully, to fuel by 2 or 3 numbers relative to regular un­ the automobile era with power alcohol. He leaded gasoline, thus improving performance saw it as the basis for rural self-suffi­ and reducing or eliminating engine knock. ciency and agricultural prosperity. He even Ethanol does not result in improved fuel built the Model "A" with an adjustable car­ economy and may loosen scale or other buretor to burn either alcohol or gasoline deposits in the fuel systems of older cars so

6-53 they must be carefully filtered. mash in one of the three cooker fermenters. These operate on a staggered schedule: one In 1979 Americans consumed about 495 million starting; one fermenting; and one pumping gallons of gasohol, displacing about 50 mil­ out. lion gallons of gasoline. Currently, higher producion cost of ethanol over gaso­ Cooking begins by steam injection during line limits use but as petroleum costs rise, slurry-mixing and the liquefying enzyme is the gap should close. Soon a gasohol ratio blended in simultaneously. Sulfuric acid of 25% ethanol and 75% gasoline will be and sodium hydroxide are injected to neutral­ feasible with only slight changes in carbur­ ize the pH value. The temperature is kept etors and manifolds, and present technology at 200 degrees fahrenheit (the optimum enzyme can already produce vehicles which use activity temperature) until most of the starch 100% power alcohol. is converted to dextrin. ETHYL ALCOHOL Dextrin is then saccharified to glucose by means of another enzyme after the mash is Ethanol is ethyl alcohol—C 2 H50H--the time cooled to 135 degrees with circulating water honored result of bioconverting glucose and after the pH is adjusted to between through a process of fermentation with yeast. 3.7 and 4.5 by injecting sulfuric acid It's the same alcohol that powers the martini, or sodium hydroxide. The mash temperature keeps instruments from freezing, fuels is then dropped to 85 degrees by adding laboratory burners, and is the "almost water and continued circulating cooling. universal" solvent used in making medical elixirs, industrial esters, and food extracts. The pH fermentation can begin. Distillers It's ingestive attractiveness is so great that yeast is dispersed from its tank and allowed governments tax it heavily and it must be to ferment for 30 to 36 hours. This results "denatured" (poisoned) before industrial use. in beer with about a 10% volume of ethanol and 90% water. Generally, ethanol is produced from feedstocks of grain, sugar beets or sorghum but it can Step Three be made from virtually any biomass: cheese, whey, agricultural wastes and food processing After a batch is complete, it is pumped to by-products, weeds, and even garbage. This the beer well and the fermenter is hosed results in several valuable by-products: down to remove any residue. A full beer carbon dioxide; yeast; some higher alcohols; well allows the distillation section of the acetic acid; and some fiber and nutrients plant to run continuously. suitable for animal food. Step Four TEN STEPS TO ETHANOL Beer is fed from its well to the beer still Alcohol production from grain is a commercial through a heat exchanger that passes it process without any technical impediment to counter-current to the hot stillage from building a grain fuels industry. It requires the bottom of the still. This heats up 10 relatively simple steps to produce 190 the beer to its boiling temperature of about proof ethanol suitable for fuel and, most 175 degrees fahrenheit and recovers some of importantly, lends itself to relatively the heat from stillage. small scale production, by farmers for example. While production of 200 proof, or Step Five 100% anhydrous or "rectified," ethanol gener­ ally requires a larger scale plant, it can be Beer is pumped to the still for distilla­ accomplished by re-processing the product tion. Steam is injected from a boiler at of the small scale plants. the bottom to provide necessary heat. Vapors move continuously up and flow to Step One the rectifying column for further distil­ lation. Liquids move continuously down to Let's look at a modern small scale plant and the bottom of the beer still. They contain see how it works. Grain is milled so that water and a high-protein by-product called the resulting meal can pass a 20-mesh screen. "stillage," which is pumped to the stillage This assures that the carbohydrate is acces­ tank through the previously identified heat sible and the solids can be removed with a exchanger described in Step 4. finer screen. Meal is stored in a bin. Step Six Step Two In the rectifying section, alcohol vapors Then the meal is mixed with water to make from the rectifying column are cooled by

6-54 water circulated through a condenser. A The main difference portion between existing beverage of the condensed ethanol is pumped to ethanol production and that for fuel use, is the top of the rectifying column where it the desirability of making a 200 proof or helps in the distillation process. The rest water free product. The extra equipment re­ of the condensed ethanol flows to the molec­ quired to upgrade industrial production (up ular sieves column for the anhydration pro­ to 190 proof) and beverage production (up cess. to 160 proof) to anhydrous ethanol is a major cost factor in the conversion of Step Eight existing facilities. Still age from the beer still is stored in a tank which provides surge capacity when a However, the relative simplicity of the truck is unavailable to haul the stillage ethanol process lends it to small scale to a feeder operation. production for as little as 10 gallons per hour. If we are to produce enough power Step Nine alcohol to make a significant difference in dependence on oil as quickly as the The final 4% to 6% of water remaining with federal program has suggested, we must the ethanol is removed by means of two molec­ achieve a widespread use of large and small ular sieve columns where the alcohol liquids ethanol plants by individual farms, farm from the condenser are passed through the cooperatives, and agri-businesses throughout sieves. When one column reaches saturation, America. the flow is switched to the second. To regen­ erate the first column, carbon dioxide from the Because of the time lag involved in building fermentation phase passes through an exchanger and operating large facilities, small scale which is heated by steam from the boiler and operations must be constructed as rapidly then rises through the first column to evapo­ as possible. Basic information has already rate water in this regeneration process. been provided in "Fuel from Farms--A Guide to Small Scale Ethanol Production," a manual Step Ten prepared by SERI and sponsored and dis­ tributed by DOE. It presents the current The resulting 200 proof alcohol from the mo­ status of on-farm fermentation ethanol lecular sieves columns is put in the ethanol production, as well as an overview of some storage tank. This tank provides storage key technical and economic factors. during the times a tank truck is unavailable to transport the alcohol to markets. Significantly, a small scale ethanol plant lends itself well.to automation and is not STATE OF THE ART labor intensive during operation. Modern control devices, electronic warning units, Although commercial production of beverage and automatic relays add reliability and ethanol from grain feedstocks is as old as efficiency. recorded history, only recently has the process been well understood. The modern sciences Studies to date indicate the positive but of biochemistry, genetics, chemistry, and limited economic viability of operating a process engineering have all converged to small scale ethanol plant. Ways to further create a truly effective ethanol brewing and enhance their operation are not being distilling system. considered. For example, heat—therefore energy investment—is required in both the Existing commercial processes produce ethanol cooking of the mash and distillation of from renewable resources based on yeast ethanol, just as it is for making gasoline fermentation of six carbon-atom sugars and mining coal. So intensive efforts are (hexoses such as glucose). Processes which underway to conserve energy in small scale convert crops with sugar content, such as plants and by expanded use of alternative sugar cane, take essentially two steps-- fuels. By-products can be developed for the sugar content is fermented to a mixture cattle feed or industrial uses. of water and up to 15 percent ethanol--and the latter is separated from the water by NET ENERGY BALANCE distillation. For crops containing starch, such as corn, one extra step is required—the Rapid growth in alcohol production capacity starch is-converted by enzymes into sugar will contribute to achieving our energy prior to. .fermentation. Fibrous-cellulosic goals. Alcohol plants require energy to material, such as corn stover or wheat straw, cook the mash and distil! the alcohol* When can theoretically be treated with chemicals this energy comes from coal, wood, agricul­ or enzymes to produce fermentable sugars tural residues, waste heat, geothermal energy, and methods are now under development. or solar energy, the nation benefits in

6-55 particular. encouraging ethanol production through: grants to build facilities in economically Questions have arisen over whether a net depressed areas; plans for a Synthetic Fuels energy gain results from the production Corporation; the Agricultural, Forestry and of alcohol fuels. Numerous studies have Rural Energy Act of 1979 which aims at making examined this issue and most conclude that rural America energy self-sufficient and the net balance is small but positive. Esti­ biomass energy oriented; and the Gasohol mates differ, depending on the feedstock and Motor Fuels Act of 1979. process employed. However, all studies con­ clude that power alcohol production if fueled The U.S. Department of Energy has established with a domestic nonpetroleum energy source the Office of Alcohol Fuels as a major DOE could significantly reduce the nation's depen­ entity under its Assistant Secretary for. Con­ dence on imported oil. Improvement in tech­ servation and Solar Energy. The Office was nology efficiency and use of feedstock by­ formed to encourage the development and utili­ products will improve the net energy balance. zation of alcohol fuels and is responsible A plant using food processing residue for feed­ for providing research, engineering, testing, stock and coal for fuel may achieve a net evaluation, and demonstration skills needed reduction in imports approaching its total to develop programs to support the objectives production. Also, the use of coal in the of the President's Alcohol Fuels Program. alcohol production process improves the oil The Office provides financial incentives, savings attainable through increased use marketing analysis, technical support, educa­ of gasohol . tional programs and procurement guidance for projects involving alcohol fuels. It serves The use of coal or non-fossil fuels for al­ as a point of contact on alcohol fuels for cohol production is highly preferable to use DOE, acts as liaison among federal, regional, of oil or natural gas. Ethanol conversion state, and local agencies, and with consumers. facilities can readily be designed to use Its four Office divisions are: Financial other fuels. Small-scale on-farm plants can Incentives Programs; Technology Development utilize corn stover as a boiler fuel, and and Utilization; Information, Liaison, and larger plants can rely on coal to produce Public Response; and Program Control and process steam. The ethanol production process Evaluation. Its alcohol fuels strategies are can then be viewed as a means of converting designed to implement the President's Program. less versatile energy forms, such as coal, dis­ tressed crops or solar energy, into premium Recognizing the obstacles has led the transportation fuel. Ethanol production using government to adopt a program encouraging low grade fuels can be compared to electric domestic production of ethanol. power generation, in which 9,000 to 10,500 Btu's of coal are converted into 3,413 Btu's PRESIDENT'S ALCOHOL FUELS PROGRAM equivalent of electricity. On January 11, 1980, the White House announced FEDERAL PROGRAMS an expanded Alcohol Fuels Program to acceler­ ate production. The immediate goal is to Without incentives, in 1980 production of quadruple current capacity by the end of 1980 ethanol is not economically attractive when and the President's target is to produce 500 compared to gasoline, although rising world million gallons of ethanol during 1981. If oil prices continue to improve alcohol's this amount were all blended to make gasohol, position. Net production costs for ethanol, it would account for 10 percent of our anti­ after credits for sale of the by-products, cipated demand for unleaded gasoline in 1981. are approximately $1.30 per gallon compared to wholesale unleaded gasoline prices of The program includes a variety of incentives, $.85 to $.95 per gallon. from tax credits to loan guarantees, which focus on two main objectives: to permit Subsidies already available, combined with gasohol to compete economically with unleaded the proposed new federal subsidies, are gasoline at the pump; and to stimulate new rapidly changing the prospects for ethanol investment in ethanol production facilities. production. Indeed, primarily as a result of the 4<£ per gallon federal excise tax exemp­ Key elements of the President's Program in­ tion signed into law in November of 1978, clude: permanent exemption for gasohol from our capacity to produce ethanol increased the federal gasoline excise tax; a 40<£ per from almost zero to about 80 million gallons gallon production tax credit; a $3 billion by the end of 1979. Federal credit program; proposal for an En­ ergy Security Corporation to financially as­ The Farm Act of 1977 began the effort to pro­ sist construction of ethanol plants; a re­ vide loan guarantees for building pilot plants. vision of the oil entitlements program to Now federal and state legislators are

6-56 include ethanol production; and a 10% etha- patterns nol investment tax of crop rotation. As commercial credit above the existing processes become available for small scale general 10% credit applied to alcohol pro­ conversion duction facilities. of nongrain forage crops, which Also, the Program calls require less fertilizer,and chemicals, the for use of gasohol in federal vehicles; opportunity U.S. Department of exists to achieve the equiva­ Agriculture support in lent value to current crops with decreased raising feedstocks; and USDA/DOE research demands on soil and and development programs to improve produc­ energy resources. tion methods. With the President's Program The impact of vastly increased ethanol pro­ in place, an equivalent federal subsidy of duction almost 50<£ on the American economy is obvious. per gallon of alcohol will be Reducing our dependence on foreign available to producers, thus improving the oil economic prospects through gasohol/ethanol consumption is for ethanol production. one of our most promising near-term domes­ tic production methods to balance our Other administrative government actions and foreign deficits. policies are helping The technology is extant make ethanol production and we already have the agricultural capa­ attractive. The Environmental Protection city needed Agency has approved to produce this proven synthetic gasohol and made plant fuel. Moreover, national benefits derived environmental approval easier to obtain. from The U.S. Department construction of ethanol facilities as of Treasury's Bureau well as those to farmers and plant of Alcohol, Tobacco and Firearms has stream­ operators lined will occur when and where the economy needs the permit process and adopted bond­ a boost. Economic improvement ing methods more appropriate to fuel-alcohol money will production. stay in rural America—in the form of capital investment, jobs, and land values. These IMPACTS OF ETHANOL in turn will strengthen the whole economy PRODUCTION (weakened by soaring energy prices). Conversion of crops with significant human SUMMARY food value to fuel is, of course, undesir­ able. Fortunately, production of fermenta­ How good is alcohol fuel? Based tion ethanol does not make this an "either- on gaso­ or" consideration. hol 's first year, it's made a great begin­ Much of the cereal grain ning and there is no insurmountable pro­ (including most of the corn) currently pro­ blem with duced in the its expanded use. "Try it, United States is used as animal you'll like it, too," say most consumers. feed which must contain protein and carbo­ Its characteristics hydrates. While are a little different fermentation of cereal from gasoline but there are several poten­ grains to produce ethanol uses most of the carbohydrate, tial advantages. Considering the alterna­ almost all of the protein is tives, its an ideal solution to our present recovered in the stillage coproduct. This energy problems. high protein source can be fed directly to animals and carbohydrate requirements can Think of it this way. All of us are on be met by using high energy forage which kind of a "Star has no value as Trek" journey and we've human food. This procedure, just learned that our spaceship Earth is along with the use of spoiled perishable rapidly exhausting crops, distressed its supplies of internal and marginal crops, pro­ energy. The situation is critical and vides a feedstock base for ethanol produc­ we must utilize tion that doesn't some form of renewable energy displace human food crops source immediately or our civilization will and enhances the agricultural economy. die. The ability of American agriculture to pro­ Someone suggests solar energy but we don't duce a surplus is well known but the impact yet have the of ethanol production technology to use it directly. on it as a whole must Then we hit on the idea of "indirect" solar be considered. The production of more etha­ energy, using nol than is obtainable living plant's ability to from surplus and dis­ convert sunlight into carbohydrates and that tressed crops will require cultivation of of another kind land that is currently of plant, yeast, to turn them fallow and will shift into a marvelous potent fuel called alcohol. emphasis to specialized high-yield crops. Just like in a This switch may allow space adventure we can have a decrease in use of a happy ending. We must get busy using our fertilizers, pesticides, and herbicides, technology and production and intelligence to produce transportation of which re­ Alcohol Fuels to Power Spaceship Earth. quire petroleum fuels and natural gas. This diversification, according to agri­ cultural experts, may benefit farmers by modifying cultural practices and create new

6-57 89-9