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close this bookAlcohol Fuels: Options for Developing Countries (BOSTID, 1983)
View the document(introduction...)
View the documentAcknowledgments
View the documentPreface
View the documentOverview
View the document1 Production and Use
View the document2 Biomass Sources
View the document3 Ethanol Production
View the document4 Methanol Production
View the document5 Social, Economic, and Environmental Implications
View the document6 Conclusions and Recommendations
View the documentAdvisory Committee on Technology Innovation
View the documentBoard on Science and Technology for International Development

Overview

Petroleum-based fuels gained their long-dominant position as energy sources for two reasons: ease of use and low cost. Engines are demonstrably simpler to design and operate with liquid or gaseous fuels than with solid fuels. As the economic attraction of petroleum fuels disappears, their motivity - the power to cause motion - is being sought from other sources.

Although petroleum prices have declined in recent periods of high production and slack demand, their long-term trend is inevitably upward. Moreover, since crude oil production and distribution is subject to disruption by political events, and, since energy consumption in developing countries is increasing at a faster rate than in industrialized countries, alternative indigenous sources of energy such as alcohol fuels are particularly worthy of consideration.

The growth and conversion of various plant species to fuels can represent an alternative to petroleum use in many tropical countries. The production of alcohol fuels from such biomass, however, is only one of many options available to energy planners. Gaseous, solid, and other liquid fuels can be obtained from biomass by both simpler and more complex technologies than those used for alcohol production.

For the various energy-from-biomass alternatives (including alcohols), the supporting technologies range from developmental to proven. In most cases, however, factors beyond the technology will control the choice and approach. Knowledge of current and future energy needs and of actual and potential resources is the only basis for planing a sound biomass energy program.

GLOBAL INTEREST IN ALCOHOL FUELS

A number of countries are pioneering the large-scale use of alcohol fuels. In Brazil, for instance, a country that imported more than 80 percent of its petroleum in 1979, a combination of factors - including the availability of land and labor, a need for liquid fuels, and a strong base in sugarcane production - has coalesced into an ambitious alcohol fuels program. Although Brazil has used alcohol-gasoline blends since the 1930s, this early effort was designed to stabilize sugar and molasses markets. Alcohol-use levels were tied to world sugar prices. Today the goal is energy self-sufficiency, spurred by world oil prices.

All of Brazil's 7 million cars are now running on 17 percent alcohol blends. Further, about 700,000 cars use alcohol alone, and, beginning in 1980, 10 percent of all new cars produced in Brazil were required by law to be powered by straight alcohol. Brazil's success in reducing dependence on foreign oil was recently summarized by Petrobras (the Brazilian National Oil Company) and is shown in Table 1. Brazil hopes to eliminate petroleum imports by the year 2000.

In Costa Rica, a 240,000-liter-per-day distillery to produce alcohol from sugarcane has been installed. The alcohol is expected to replace about 15 percent of Costa Rica's gasoline.

Another sugar-rich country, the Philippines, is installing a large scale alcohol distillery on Luzon and is planning additional distilleries there and in Negros. Until 1978, when oil was discovered on one of their southern islands, the Philippines were totally dependent on imported petroleum.

In Argentina, 90 percent self-sufficient in petroleum, 3,500,000 tons of sugarcane were diverted to alcohol production in 1978. Additional distilleries are being planned and built to produce alcohol for fuel use.

TABLE 1 Brazilian Consumption and External Dependence on Petroleum

Period

Brazilian Production of Internal Consumption barrels per day)

Petroleum, Gas, and Alcohol(barrels per day)

External Imports (barrels per day)

Dependence on Petroleum percent)

July 1979

1,225,000

211,000

1,014,000

82.8

July 1980

1,197,000

253,000

944,000

78.9

July 1981

1,093,000

255,000

838,000

76.7

July 1982

1,064,000

341,000

723,000

68.0

SOURCE: Petrobras.

South Africa, a pioneer in the conversion of coal to liquid fuel, is currently considering a project that would produce 800,000 tons of alcohol per year from biomass.

In Sudan, Kenya, Indonesia, Papua New Guinea, and Thailand, alcohol fuel projects are in progress. Clearly, the production and use of alcohol fuels is growing rapidly throughout the world.

THE TWO FUEL ALCOHOLS

Ethanol and methanol are the two alcohols commonly considered for fuel use. Ethanol (ethyl alcohol, grain alcohol) is produced by yeast fermentation of hexose sugars (such as those derived from cereal grains, sugarcane, or sugar beet) and subsequent separation from the aqueous solution by distillation. Simple distillation processes can yield a product containing up to 95 percent alcohol; additional treatment is required to give completely water-free ethanol.

Methanol can be produced from cellulose products such as wood or crop residues by gasification. At present, almost all commercial methanol is made from natural gas.

Ethanol, the alcohol consumed in beers, wines, and liquors, is also used as a solvent. Methanol is widely used as a starting material for making other chemicals. It is relatively toxic.

USES OF ALCOHOL FUELS

The best-known fuel use for alcohol is as a substitute for gasoline. Up to 20 percent of ethanol can be used in gasoline without engine modification. For blending, however, the ethanol must be anhydrous; otherwise, a water-containing layer can separate from the mixture, causing erratic engine performance. The 95 percent form of ethanol (the constant-boiling mixture of alcohol and water obtained in simple distillation) can be used directly in modified engines (Figure 1). Methanol can be used at levels up to 15 percent in gasoline and 100 percent in modified gasoline engines.

Alcohol fuels cannot be used as easily in diesel engines because they do not readily combustion the diesel system. The alcohols must either be mixed with relatively expensive substances (such as amyl nitrate) to promote combustion or aspirated into the diesel fuel through a special device in the air intake. No wholly satisfactory means of using alcohol fuels in diesel engines has yet been devised for widespread use. Attention has been focused on vegetable oils as technically simpler substitutes for the diesel fraction of crude oil.

Alcohols can also be used in heating and lighting, in simple wick lamps or heaters, or in pressure stoves and lanterns. They are clean, comparatively safe fuels and have the advantage over petroleum fuels of being miscible with water, which makes accidental fires easier to control.

FIXED AND VARIABLE PRODUCTION COSTS

Certain costs of producing alcohol fuels are inherent in the process and relatively constant: these are likely to be the same for all largescale high-technology plants regardless of whether the plant is operating in a developing or an industrialized country. Under most conditions, economy of scale will mean that alcohol produced in smallerscale plants will be more expensive. This is particularly true for methanol, for which no satisfactory small-scale plant has yet proved economical. Capital investment costs per gallon per year ("annual gallon") are approximately U.S. $1.50 to $2 for ethanol and slightly lower for methanol, roughly $1.20 per annual gallon.

Raw materials comprise between 60 and 70 percent of the total cost of producing ethanol, manufacturing costs approximately 20 percent, and return on investment makes up the remainder. For methanol, the cost of potential raw materials is lower, but plant investment costs are significantly higher and larger volumes of raw materials are required.

The implications are that organization of efficient raw material production and delivery are crucial to a cost-effective production system for either alcohol.

TYPE AND SUPPLY OF RAW MATERIALS

The traditional raw materials for ethanol production are sugarcane (Figure 2), cereal grains (principally maize, barley, and rice), grapes, and some root crops (cassava, sugar beet, and potato). Potentially, any source of hexose sugars can be used. Table 2 indicates a range of average yields per hectare of various raw materials and the corresponding average amounts of ethanol that may be produced by reasonably efficient processes.

Research on raw materials has taken two broad avenues: first, research aimed at increasing the efficiency of producing fermentable hexoses from lignocellulose, the most ubiquitous and cheapest raw material; and second, identifying new plant sources that could be used for their sugar content, such as high-yielding varieties of palm (nipa, caryota), grasses, and fruits. The limitation with plant sources other than sugarcane and sweet sorghum, which supply their own fuel (bagasse) for distillation - is that most of them, including grains, sugar beet, cassava, and fruits, require a separate fuel supply.

Anticipating an economic process for converting lignocellulose directly or indirectly to alcohol in the near future, several developing countries have established pilot-scale fuel-alcohol plants, and planted sources of the biomass that will ultimately be needed as feedstock. This enables the inevitable problems of managing a renewable energy technology infrastructure to be worked out while the technology is being developed, rather than delaying its use once it becomes available. Should the application of the technology be delayed, the trees can be employed for gasification, charcoal production, or other fuel uses.

TABLE 2 Yields of Raw Materials Used in Ethanol Production


Yield

Ethanol

Ethanol

Crop

(ton/ha/yr)

(liters/ton)

(liters/ha/yr)

Sugarcane

50-90

70-90

3,500-8,000

Sweet sorghum

45-80

60-80

1,750-5,300

Sugar beet

15-50

90

1,350-5,500

Fodder beet

100-200

90

4,400-9,350

Wheat

1.5-2.1

340

510-714

Barley

1.2-2.5

250

300-625

Rice

2.5-5.0

430

1,075-2,150

Maize

1.7-5.4

360

600-1,944

Sorghum

1.0-3.7

350

350-1,295

Irish potatoes

10-25

110

1,110-2,750

Cassava

10-65

170

1,700-11,050

Sweet potatoes

8-50

167

1,336-8,350

Grapes

10-25

130

1,300-3,250

Nipa palm



2,300-8,000

Sago palm



1,350

a These figures are derived from many sources and are included only as indications of possible yields, depending on widely varied conditions.
NOTE: About 300 kg of molasses is produced for each ton of sugar. One ton of molasses can be converted to 245 liters of ethanol.

BIOMASS PLANTING AND AGRICULTURAL PRODUCTION

A widely feared social consequence of large-scale alcohol fuel production is the diversion of food crops, or the land on which they are grown, for alcohol production, with the wealthy sector satisfying its thirst for liquid fuels at the expense of food staples for the poor. A corollary of this argument is that expanding acreage to produce crops for alcohol will lead to accelerated soil erosion and depletion, or that widespread monocultural crop production will make large areas vulnerable to devastation by diseases or pests.

Proponents of alcohol fuels argue that these need not be inevitable consequences, and that, in fact, alcohol fuel production from agricultural products can help agriculture. They point out that agricultural productivity per hectare is woefully low in many developing countries because of the lack of price incentives and the shortage or high cost of fuel to mechanize production and move crops to market. Linking food and fuel production could, if properly managed, provide impetus to productivity without necessarily bringing additional acreage into production. With the markets, price incentives, and tight management required by this kind of agroindustry, much higher levels of productivity could supply both food and fuel biomass needs and could revitalize rural areas. The increased crop productivity could then be used to sustain future population growth, with fuels increasingly produced from nonfood sources such as fuelwood plantations on soils unsuitable for staple crops, or multipurpose trees grown in agroforestry systems.

For sugar-producing countries affected by erratic world market prices, fuel alcohol production can provide an outlet for excess sugar production as it has done in the past. It can offer a breathing space for planning agricultural alternatives at the same time that it is providing greater self-sufficiency in energy; establishing alternative applications for existing crops (such as fuel alcohol production from sugarcane) is usually easier than switching to new crops.

The key to overall economic improvement through alcohol production is the availability of capital and management, both of which are in desperately short supply in most developing countries. However, when petroleum prices rise again, there will be increasing attention to the feasibility of local production, and the possibility of using fuel production to benefit agriculture should not be overlooked.

ALCOHOL FUEL PRODUCTION DRAWBACKS

There are limitations that must be faced before ethanol can be considered as a potential large-scale fuel source for every gallon of ethanol produced, there are 10-15 gallons of stillage residue to be disposed of; large amounts of cooling water are required, both for the fermentation and for the distillation; ethanol is traditionally handled as a potable substance, with production regulations and standards that reflect this use rather than its use as fuel.
Methanol has a slightly different set of limitations. Its manufacture from biomass is not as readily understood as that for ethanol, and the capital equipment is more complex and expensive. Methanol is poisonous and more corrosive to handle and use than ethanol and requires replacement of some of the construction materials in existing engines and storage facilities.
Nevertheless, the technologies are available, and ethanol and methanol are inherently no more - and in some ways less - difficult fuels to handle than their petroleum-based counterparts.

SELECTED READINGS

Alcohol Production - General

Abelson, P.H.1982. Fuels from biomass (Interciencia Symposium). Interciencia 7(4): 225- 228.

Barnard, G.W. 1981. Liquid Fuel Production from Biomass in the Developing Countries. Master's Thesis. Imperial College of Science and Technology, University of London, London, England.
Bungay, H.R. 1983. Commercializing biomass conversion. Environmental Science and Technology 17(1):24A-31A.

Bungay, H.R. 1982. Biomass refining. Science 218:643-646.

Coombs, J. 1980. Ethanol-the process and the technology for production of liquid transport fuel. In: Energy from Biomass. International Conference at the Brighton Centre, November 4-7, 1980, Brighton, England.

Del Rosario, EJ. 1981. Alcohol Fermentation Technology. Paper prepared for a Short Course on Solar Power Technology-Philippine Scenario. Center for Nonconventional Energy Development, Diliman, Quezon City, Philippines.

Faber, M.D. 1981. Production of ethanol from renewable resources: an assessment. Development in Industrial Microbiology 22:11 1-119.

GDC, Inc. 1981. Alternative Fuels for Use in Internal Combustion Engines. World Bank Energy Department Paper No. 4. Washington, D.C., USA.

Huff, G.F. 1981. Ethanol from biomass. In: Alternative Sources of Energy, edited by J.T.Manassah. Academic Press, New York, New York, USA.

Solar Energy Information Data Bank. 1981. Ethanol Fuels: Use, Production, and Economics.
Solar Energy Research Institute, Golden, Colorado, USA.

Trevelyan, W.E. 1975. Renewable fuels: ethanol produced by fermentation. Tropical Science 17(1): 1 -13.

Wickson, EJ. 1981. Monohydnc Akohols: Manufacture, Applications, and Chemistry. ACS Symposium Series, Vol. 159. American Chemical Society, Washington, D.C., USA.

World Bank. 1980. Alcohol Production from Biomas in the Developing Countries. World Bank, Washington, D.C., USA.

Country Reports

Anonymous. 1981. Indonesia follows a plant policy for fuel. New Scientist February 5:341.

Anonymous. 1981. Islands looking to new fuel sources (Fiji and Papua New Guinea). Pacific Islands Monthly July:57-59.

Anonymous. 1982. Alcohol power for Kenya. New African 178:51.

Anonymous. 1982. Sweden charts out 3-year $19-million biomass fuel development program. Synfuels January 15:6.

Bejraputra, K. 1979. Prospects of developing power alcohol industry in Thailand. In: Workshop on Fermentation Alcohol for Use as Fuel and Chemical Feedstock in Developing Countries, March 26-30, 1979. Vienna, Austria.

Belardo, A. 1980. Alcohol research and development outlook for Puerto Rico. In: Symposium on Fuels and Feedstoch from Tropical Biomas, November 24-25, 1980. Caribe Hilton Hotel, San Juan, Puerto Rico.

Blocksidge, T. 1980. Sugar in Petrol. The Sunday Mail, March 30. Salisbury, Rhodesia.

Dutkiewicz, R.K. 1980. Scenarios for alcohol fuels (South Africa). In: IV International Symposium on Alcohol Fuels Technology. Guaraja, Sao Paulo, Brazil.

Elias, A.R. 1980. Sudan experience in using alcohol as automotive fuel. In: IV International Symposium on Alcohol Fuels Technology. Guaruja, Sao Paulo, Brazil.

Fonseca, E. 1980. Alcohol fuels in Portugal. In: IV International Symposium on Alcohol Fuels Technology. Guaruja, Sao Paulo, Brazil.

Guelder, O.L. 1980. Technical and economical aspects of ethanol as an automotive fuel for Turkey. In: IV International Symposium on Alcohol Fuels Technology. Guaruja, Sao Paulo, Brazil.

Gupta, R.K., and Ahluwalia, J.S. 1980. Utilization of ethanol in Indian cars, scooters, motorcycles and tractors. In: IV International Symposium on Alcohol Fuels Technology. Guaruja, Sao Paulo, Brazil.

Holligan, PJ. 1980. Biomass Fuel Production in the United States, Brazil and South Africa: A Report on a Stud, Tour. Department of Agriculture, New South Vales, Australia.

Institute of Energy Economics. 1981. Some considerations on alcohol fuels in the Republic of Indonesia. Pp. 177-279 in: The Alcohol Fuels from Energy Farming, edited by H. Shozawa and Y. Hara. Institute of Energy Economics, Tokyo, Japan.

Karan, R. 1979. Cane molasses fermentation alcohol industry in Fiji. In: Workshop on Fermentation Alcohol for Use as Fuel and Chemical Feedstoch in Developing Countries, March 26-30, 1979. Vienna, Austria.

Lloyd, A. 1981. France turns to alcohol for fuel. New Scientist January 22:197.

Morgan, C. 1981. Developing a power alcohol industry: how the Philippines plans to do it.Agribusiness Worldwide 2(4):16-24.

National Research Council, Board on Science and Technology for International Development. 1981. Workshop on Ethanol an Alternative Source of Fuels. National Academy Press, Washington, D.C., USA.

New Zealand Energy Research and Development Committee. 1980. The Potential I of If energy Farming for Transport Fuels in New Zealand. New Zealand Energy Research and Development Committee, University of Auckland, Auckland, New Zealand.

Petterson, E. 1980. Introduction of Alternative Motor Fuels: Report from Swedish Commission of Oil Substitution. Stockholm, Sweden.

Sangster, I. 1979. The potential of sugar cane derived alcohol as a fuel in Jamaica. In: Workshop on Fermentation Alcohol for Use as Fuel and Chemical Feedstock in Developing Countries, March 26-30, 1979. Vienna, Austria.

Stewart, G.A., Gartside, G., Gifford, R.M., Nix, H.A., Rawlins, W.H.M., and Siemon, J.R. 1979. Liquid fuel production from agriculture and forestry in Australia: resume of a survey of the national potential. Search 10(11):382-387.

Titchener, A.L., and Walker, B.V. 1980. Alcohol fuels in New Zealand's energy future. In: IV International Symposium on Alcohol Fuels Technology. Guaruja, Sao Paulo, Brazil.

Vergara, W., and Pimentel, D. 1979. Fuels from biomass: comparative study of the potential in five countries: the United States, Brazil, India, Sudan, and Sweden. In: Advances in Energy Systems and Technology, Vol. 1, edited by P.L. Auer. Academic Press, New York, New York, USA.

Vicharangsan, T. 1980. Thailand's experience with hydrated ethyl alcohol—gasoline blended motor fuel. In: IV International Symposium on Alcohol Fuels Technology. Guaruja, Sao Paulo, Brazil.

Wonder, B., and Simpson, D. 1982. Economics of large-scale and on-farm production of fuel from crops in Australia. Energy in Agriculture 1:155-170.