Ethanol fuel

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Ethanol fuel is ethanol (ethyl alcohol), the same type of alcohol found in alcoholic beverages. It can be used as a fuel, mainly as a biofuel alternative to gasoline, and is widely used in cars in Brazil. Because it is easy to manufacture and process, and can be made from very common crops, such as sugar cane and maize (corn), it is an increasingly common alternative to gasoline in some parts of the world.

Anhydrous ethanol (ethanol with less than 1% water) can be blended with gasoline in varying quantities up to pure ethanol (E100), and most spark-ignited gasoline style engines will operate well with mixtures of 10% ethanol (E10).^[1] Most cars on the road today in the U.S. can run on blends of up to 10% ethanol,^[2] and the use of 10% ethanol gasoline is mandated in some cities where harmful levels of auto emissions are possible.^[3]

Ethanol can be mass-produced by fermentation of sugar or by hydration of ethylene from petroleum and other sources. Current interest in ethanol mainly lies in bio-ethanol, produced from the starch or sugar in a wide variety of crops, but there has been considerable debate about how useful bio-ethanol will be in replacing fossil fuels in vehicles. Concerns relate to the large amount of arable land required for crops,^[4] as well as the energy and pollution balance of the whole cycle of ethanol production.^[5][6] Recent developments with cellulosic ethanol production and commercialization may allay some of these concerns.^[7]

According to the International Energy Agency, cellulosic ethanol could allow ethanol fuels to play a much bigger role in the future than previously thought.^[8] Cellulosic ethanol offers promise as resistant cellulose fibers, a major component in plant cells walls, can be used to generate ethanol. Dedicated energy crops, such as switchgrass, are also promising cellulose sources that can be produced in many regions of the United States.^[9]

Contents 1 Chemistry 2 Sources 2.1 Production process 2.2 Fermentation 2.3 Distillation 2.4 Dehydration 3 Technology 3.1 Ethanol-based engines 3.2 Ethanol fuel mixtures 3.3 Fuel economy 4 Experience by country 4.1 Brazil 4.2 United States 4.3 Europe 4.4 Asia 4.4.1 China 4.4.2 Thailand 4.5 Australia 4.6 Central America and the Caribbean 4.6.1 Costa Rica 4.6.2 El Salvador 4.7 Comparison between Brazil and the U.S. 5 Environment 5.1 Energy balance 5.2 Air pollution 5.3 Manufacture 5.4 Carbon Dioxide 5.5 Change in land use 6 Efficiency of common crops 7 Reduced petroleum imports and costs 8 Recent patents 9 Criticism and controversy 9.1 Fuel system problems 10 Bibliography 11 References 12 See also 13 External links

[edit] Chemistry

During ethanol fermentation, glucose is decomposed into ethanol and carbon dioxide.

C₆H₁₂O₆ → 2C₂H₆O + 2CO₂

During combustion ethanol reacts with oxygen to produce carbon dioxide, water, and heat: (other air pollutants are also produced when ethanol is burned in the atmosphere rather than in pure oxygen)

C₂H₆O + 3O₂ → 2CO₂ + 3H₂O

Together, they add up to:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + heat

Also harmful nitrous oxide gases are produced. Nitrogen dioxide is one of the harmful gases as is a major contributor to the formation of "brown smog".

[edit] Sources

Main article: Energy crop

Ethanol is considered "renewable" because it is primarily the result of conversion of the sun's energy into usable energy. Creation of ethanol starts with photosynthesis causing the feedstocks such as switchgrass, sugar cane, or corn to grow. These feedstocks are processed into ethanol.

About 5% of the ethanol produced in the world in 2003 was actually a petroleum product.^[10] It is made by the catalytic hydration of ethylene with sulfuric acid as the catalyst. It can also be obtained via ethylene or acetylene, from calcium carbide, coal, oil gas, and other sources. Two million tons of petroleum-derived ethanol are produced annually. The principal suppliers are plants in the United States, Europe, and South Africa.^[11] Petroleum derived ethanol (synthetic ethanol) is chemically identical to bio-ethanol and can be differentiated only by radiocarbon dating.^[12]

Bio-ethanol is obtained from the conversion of carbon based feedstock. Agricultural feedstocks are considered renewable because they get energy from the sun using photosynthesis, provided that all minerals required for growth (such as nitrogen and phosphorus) are returned to the land. Ethanol can be produced from a variety of feedstocks such as sugar cane, bagasse, miscanthus, sugar beet, sorghum, grain sorghum, switchgrass, barley, hemp, kenaf, potatoes, sweet potatoes, cassava, sunflower, fruit, molasses, corn, stover, grain, wheat, straw, cotton, other biomass, as well as many types of cellulose waste and harvestings, whichever has the best well-to-wheel assessment.

Current, first generation processes for the production of ethanol from corn use only a small part of the corn plant: the corn kernels are taken from the corn plant and only the starch, which represents about 50% of the dry kernel mass, is transformed into ethanol. Two types of second generation processes are under development. The first type uses enzymes and yeast to convert the plant cellulose into ethanol while the second type uses pyrolysis to convert the whole plant to either a liquid bio-oil or a syngas. Second generation processes can also be used with plants such as grasses, wood or agricultural waste material such as straw.

[edit] Production process

See also: problems associated with corn-derived ethanol

The basic steps for large scale production of ethanol are: microbial (yeast) fermentation of sugars, distillation, dehydration (requirements vary, see Ethanol fuel mixtures, below), and denaturing (optional). Prior to fermentation, some crops require saccharification or hydrolysis of carbohydrates such as cellulose and starch into sugars. Saccharification of cellulose is called cellulolysis (see cellulosic ethanol). Enzymes are used to convert starch into sugar.^[13]

[edit] Fermentation

Main article: Ethanol fermentation

Ethanol is produced by microbial fermentation of the sugar. Microbial fermentation will currently only work directly with sugars. Two major components of plants, starch and cellulose, are both made up of sugars, and can in principle be converted to sugars for fermentation. Currently, only the sugar (e.g. sugar cane) and starch (e.g. corn) portions can be economically converted. However, there is much activity in the area of cellulosic ethanol, where the cellulose part of a plant is broken down to sugars and subsequently converted to ethanol.

[edit] Distillation

For the ethanol to be usable as a fuel, water must be removed. Most of the water is removed by distillation, but the purity is limited to 95-96% due to the formation of a low-boiling water-ethanol azeotrope. The 95.6% m/m (96.5% v/v) ethanol, 4.4% m/m (3.5% v/v) water mixture may be used as a fuel alone, but unlike anhydrous ethanol, is immiscible in gasoline, so the water fraction is typically removed in further treatment in order to burn with in combination with gasoline in gasoline engines.

[edit] Dehydration

Currently, the most widely used purification method is a physical absorption process using a molecular sieve, for example, ZEOCHEM Z3-03 (a special 3A molecular sieve for EtOH dehydration). Another method, azeotropic distillation, is achieved by adding the hydrocarbon benzene which also denatures the ethanol (to render it undrinkable for duty purposes). A third method involves use of calcium oxide as a desiccant.

[edit] Technology

[edit] Ethanol-based engines

Ethanol is most commonly used to power automobiles, though it may be used to power other vehicles, such as farm tractors and airplanes. Ethanol (E100) consumption in an engine is approximately 34% higher than that of gasoline (the energy per volume unit is 34% lower).^[14][15] However, higher compression ratios in an ethanol-only engine allow for increased power output and better fuel economy than would be obtained with the lower compression ratio.^[16][17] In general, ethanol-only engines are tuned to give slightly better power and torque output to gasoline-powered engines. In flexible fuel vehicles, the lower compression ratio requires tunings that give the same output when using either gasoline or hydrated ethanol. For maximum use of ethanol's benefits, a much higher compression ratio should be used,^[18] which would render that engine unsuitable for gasoline use. When ethanol fuel availability allows high-compression ethanol-only vehicles to be practical, the fuel efficiency of such engines should be equal or greater than current gasoline engines. However, since the energy content (by volume) of ethanol fuel is less than gasoline, a larger volume of ethanol fuel (151%) would still be required to produce the same amount of energy.^[19]

A 2004 MIT study,^[20] and an earlier paper published by the Society of Automotive Engineers,^[21] describing tests, identify a method to exploit the characteristics of fuel ethanol that is substantially better than mixing it with gasoline. The method presents the possibility of leveraging the use of alcohol to even achieve definite improvement over the cost-effectiveness of hybrid electric. The improvement consists of using dual-fuel direct-injection of pure alcohol (or the azeotrope or E85) and gasoline, in any ratio up to 100% of either, in a turbocharged, high compression-ratio, small-displacement engine having performance similar to an engine having twice the displacement. Each fuel is carried separately, with a much smaller tank for alcohol. The high-compression (which increases efficiency) engine will run on ordinary gasoline under low-power cruise conditions. Alcohol is directly injected into the cylinders (and the gasoline injection simultaneously reduced) only when necessary to suppress ‘knock’ such as when significantly accelerating. Direct cylinder injection raises the already high octane rating of ethanol up to an effective 130. The calculated over-all reduction of gasoline use and CO2 emission is 30%. The consumer cost payback time shows a 4:1 improvement over turbo-diesel and a 5:1 improvement over hybrid. In addition, the problems of water absorption into pre-mixed gasoline (causing phase separation), supply issues of multiple mix ratios and cold-weather starting are avoided.

Ethanol's higher octane rating allows an increase of an engine's compression ratio for increased thermal efficiency.^[22] In one study, complex engine controls and increased exhaust gas recirculation allowed a compression ratio of 19.5 with fuels ranging from neat ethanol to E50. Thermal efficiency up to approximately that for a diesel was achieved.^[23] This would result in the MPG (miles per gallon) of a dedicated ethanol vehicle to be about the same as one burning gasoline.

Engines using fuel with 30% to 100% ethanol also need a cold-starting system. For E85 fuel at temperatures below 11 °C (52 °F) a cold-starting system is required for reliable starting and to meet EPA emissions standards.^[24] However, the EPA does not require cold start systems on E85 vehicles. No current production E85 vehicles in the USA are equipped with these cold start systems, and they meet EPA emission guidelines.^{[citation needed]}

[edit] Ethanol fuel mixtures

For more details on this topic, see Common ethanol fuel mixtures.

To avoid engine stall due to "slugs" of water in the fuel lines interrupting fuel flow, the fuel must exist as a single phase. The fraction of water that an ethanol-gasoline fuel can contain without phase separation increases with the percentage of ethanol.^[25]. This shows, for example, that E30 can have up to about 2% water. If there is more than about 71% ethanol, the remainder can be any proportion of water or gasoline and phase separation will not occur. However, the fuel mileage declines with increased water content. The increased solubility of water with higher ethanol content permits E30 and hydrated ethanol to be put in the same tank since any combination of them always results in a single phase. Somewhat less water is tolerated at lower temperatures. For E10 it is about 0.5% v/v at 70 F and decreases to about 0.23% v/v at -30 F.^[26]

In many countries cars are mandated to run on mixtures of ethanol. Brazil requires cars be suitable for a 25% ethanol blend, and has required various mixtures between 22% and 25% ethanol, since of July 2007 25% is required. The United States allows up to 10% blends, and some states require this (or a smaller amount) in all gasoline sold. Other countries have adopted their own requirements. Beginning with the model year 1999, an increasing number of vehicles in the world are manufactured with engines which can run on any fuel from 0% ethanol up to 100% ethanol without modification. Many cars and light trucks (a class containing minivans, SUVs and pickup trucks) are designed to be flexible-fuel vehicles (also called dual-fuel vehicles). In older model years, their engine systems contained alcohol sensors in the fuel and/or oxygen sensors in the exhaust that provide input to the engine control computer to adjust the fuel injection to achieve stochiometric (no residual fuel or free oxygen in the exhaust) air-to-fuel ratio for any fuel mix. In newer models, the alcohol sensors have been removed, with the computer using only oxygen and airflow sensor feedback to estimate alcohol content. The engine control computer can also adjust (advance) the ignition timing to achieve a higher output without pre-ignition when it predicts that higher alcohol percentages are present in the fuel being burned. This method is backed up by advanced knock sensors - used in most high performance gasoline engines regardless if they're designed to use ethanol or not - that detect pre-ignition and detonation.

[edit] Fuel economy

In theory, all fuel-driven vehicles have a fuel economy (measured as miles per US gallon, or liters per 100 km) that is directly proportional to the fuel's energy content.^[27]In reality, there are many other variables that come in to play that affect the performance of a particular fuel in a particular engine. Ethanol contains approx. 34% less energy per unit volume than gasoline, and therefore in theory, burning pure ethanol in a vehicle will result in a 34% reduction in miles per US gallon, given the same fuel economy, compared to burning pure gasoline. This assumes that the octane ratings of the fuels, and the thus the engine's ability to extract energy from the fuels, are the same.^[14][15] For E10 (10% ethanol and 90% gasoline), the effect is small (~3%) when compared to conventional gasoline,^[28] and even smaller (1-2%) when compared to oxygenated and reformulated blends.^[29] However, for E85 (85% ethanol), the effect becomes significant. E85 will produce lower mileage than gasoline, and will require more frequent refueling. Actual performance may vary depending on the vehicle. The EPA-rated mileage of current USA flex-fuel vehicles^[30] should be considered when making price comparisons, but it must be noted that E85 is a high performance fuel, with an octane rating of about 104, and should be compared to premium. In one estimate^[31] the US retail price for E85 ethanol is 2.62 US dollar per gallon or 3.71 dollar corrected for energy equivalency compared to a gallon of gasoline priced at 3.03 dollar. Brazilian cane ethanol (100%)is priced at 3.88 dollar against 4.91 dollar for E25 (figures July 2007).

[edit] Experience by country

The top five ethanol producers in 2006 were the United States with 4.855 billion U.S. liquid gallons (bg), Brazil (4.49 bg), China (1.02 bg), India (0.50 bg) and France (0.25 bg).^[32] Brazil and the United States accounted for 70 percent of all ethanol production, with total world production of 13.5 billion US gallons (40 million tonnes). When accounting just for fuel ethanol production in 2007, the U.S. and Brazil are responsible for 88% of the 13.1 billion gallons total world production. Strong incentives, coupled with other industry development initiatives, are giving rise to fledgling ethanol industries in countries such as Thailand, Colombia, and some Central American countries. Nevertheless, ethanol has yet to make a dent in world oil consumption of approximately 4000 million tonnes/yr (84 million barrels/day).^[33]

Total Annual Ethanol Production (All Grades) by Country (2004-2006)[32] Top 15 countries (Millions of U.S. liquid gallons)					Annual Fuel Ethanol Production by Country (2004-2006)[34] Top 15 countries/blocks (Millions of U.S. liquid gallons)
World rank	Country	2006	2005	2004	World rank	Country/Region	2007
1	United States	4,855	4,264	3,535	1	United States	6,498.6
2	Brazil	4,491	4,227	3,989	2	Brazil	5,019.2
3	China	1,017	1,004	964	3	European Union	570.3
4	India	502	449	462	4	China	486.0
5	France	251	240	219	5	Canada	211.3
6	Germany	202	114	71	6	Thailand	79.2
7	Russia	171	198	198	7	Colombia	74.9
8	Canada	153	61	61	8	India	52.8
9	Spain	122	93	79	9	Central America	39.6
10	South Africa	102	103	110	10	Australia	26.4
11	Thailand	93	79	74	11	Turkey	15.8
12	United Kingdom	74	92	106	12	Pakistan	9.2
13	Ukraine	71	65	66	13	Peru	7.9
14	Poland	66	58	53	14	Argentina	5.2
15	Saudi Arabia	52	32	79	15	Paraguay	4.7
	World Total	13,489	12,150	10,770		World Total	13,101.7

[edit] Brazil

Main article: Ethanol fuel in Brazil

Brazil has the largest and most successful bio-fuel programs in the world, involving production of ethanol fuel from sugar cane, and it is considered to have the world's first sustainable biofuels economy.^[35][36][37] In 2006 Brazilian ethanol provided around 20% of the country's road transport sector fuel consumption needs, and more than 40% of fuel consumption for the light vehicle fleet.^{[38][39] [36]} As a result of the increasing use of ethanol, together with the exploitation of domestic deep water oil sources, Brazil, which years ago had to import a large share of the petroleum needed for domestic consumption, in 2006 reached complete self-sufficiency in oil supply.^[40][41][42]

Together, Brazil and the United States lead the industrial world in global ethanol production, accounting together for 70% of the world's production^[43] and nearly 90% of ethanol used for fuel. ^[44] In 2006 Brazil produced 16.3 billion liters (4.3 billion U.S. liquid gallons),^[32] which represents 33.3% of the world's total ethanol production and 42% of the world's ethanol used as fuel.^[44] Sugar cane plantations cover 3.6 million hectares of land for ethanol production, representing just 1% of Brazil's arable land, with a productivity of 7,500 liters of ethanol per hectare, as compared with the U.S. maize ethanol productivity of 3,000 liters per hectare.^[45][35]

Production and use of ethanol has been stimulated through:

• Low-interest loans for the construction of ethanol distilleries
• Guaranteed purchase of ethanol by the state-owned oil company at a reasonable price
• Retail pricing of neat ethanol so it is competitive if not slightly favorable to the gasoline-ethanol blend
• Tax incentives provided during the 1980s to stimulate the purchase of neat ethanol vehicles.^[46]

Guaranteed purchase and price regulation were ended some years ago, with relatively positive results. In addition to these other policies, ethanol producers in the state of São Paulo established a research and technology transfer center that has been effective in improving sugar cane and ethanol yields.^[46]

There are no longer light vehicles in Brazil running on pure gasoline. Since 1977 the government made mandatory to blend 20% of ethanol (E20) with gasoline (gasohol), requiring just a minor adjustment on regular gasoline motors. Today the mandatory blend is allowed to vary nationwide between 20% to 25% ethanol (E25) and it is used by all regular gasoline vehicles, plus three million cars running on 100% anhydrous ethanol and five million of dual or flexible-fuel vehicles. The Brazilian car manufacturing industry developed full flexible-fuel vehicles that can run on any proportion of gasoline and ethanol.^[47] Introduced in the market in 2003, these vehicles became a commercial success.^[48] On March 2008, the fleet of "flex" cars and light commercial vehicles had reached 5 million new vehicles sold.^[49] which represents around 10% of Brazil's motor vehicle fleet and 15.6% of all light vehicles.^[50] The ethanol-powered and "flex" vehicles, as they are popularly known, are manufactured to tolerate hydrated ethanol, an azeotrope comprised of 95.6% ethanol and 4.4% water.^[51]

[edit] United States

United States fuel ethanol production and imports (2001-2007)[32] (Millions of U.S. liquid gallons)
Year	Production	Imports	Demand
2001	1,770	n/a	n/a
2002	2,130	46	2,085
2003	2,800	61	2,900
2004	3,400	161	3,530
2005	3,904	135	4,049
2006	4,855	653	5,377
2007	6,485	435	6,847
Note: Demand figures includes stocks change and small exports in 2005

Main article: Ethanol fuel in the United States

The United States produces and consumes more ethanol fuel than any other country in the world. Most cars on the road today in the U.S. can run on blends of up to 10% ethanol, and motor vehicle manufacturers already produce vehicles designed to run on much higher ethanol blends. In 2007 Portland, Oregon, became the first city in the United States to require all gasoline sold within city limits to contain at least 10% ethanol.^[52][53] As of January 2008, three states — Missouri, Minnesota, and Hawaii — require ethanol to be blended with gasoline motor fuel. Many cities are also required to use an ethanol blend due to non-attainment of federal air quality goals.^[54]

Several motor vehicle manufacturers, including Ford, DaimlerChrysler, and GM, sell flexible-fuel vehicles that can use gasoline and ethanol blends ranging from pure gasoline all the way up to 85% ethanol (E85). By mid-2006, there were approximately six million E85-compatible vehicles on U.S. roads.^[55]

In the USA there are currently 1,522 stations distributing ethanol, although most stations are in the corn belt area.^[56][57] One of the debated methods for distribution in the US is using existing oil pipelines,^[58] which raises concerns over corrosion. In any case, some companies proposed building a 1,700-mile pipeline to carry ethanol from the Midwest through Central Pennsylvania to New York. ^[59]

The production of fuel ethanol from corn in the United States is controversial for a few reasons. Production of ethanol from corn is 5 to 6 times less efficient than producing it from sugarcane. Ethanol production from corn is highly dependent upon subsidies and it consumes a food crop to produce fuel.^[31] The subsidies paid to fuel blenders and ethanol refineries have often been cited as the reason for driving up the price of corn, and in farmers planting more corn and the conversion of considerable land to corn (maize) production which generally consumes more fertilizers and pesticides than many other land uses.^[31] This is at odds with the subsidies actually paid directly to farmers that are designed to take corn land out of production and pay farmers to plant grass and idle the land, often in conjunction with soil conservation programs, in an attempt to boost corn prices. Recent developments with cellulosic ethanol production and commercialization may allay some of these concerns.^[60]

[edit] Europe

Production of Bioethanol in the  European Union (GWh)[61]
No	Country	2006	2005
1	Germany	2,554	978
2	Spain	2,382	1,796
3	France	1,482	853
4	Sweden	830	907
5	Italy	759	47
6	Poland	711	379
7	Hungary	201	207
8	Lithuania	107	47
9	Netherlands	89	47
10	Czech Republic	89	0
11	Latvia	71	71
12	Finland	0	77
27	Total	9,274	5,411
100 l bioethanol = 79,62 kg, 1 tonne bioethanol = 0,64 toe

Consumption of Bioethanol in the  European Union (GWh)[61]
No	Country	2006	2005
1	Germany	3,573	1,682
2	Sweden	1,895	1,681
3	France	1,747	871
4	Spain	1,332	1,314
5	Poland	611	329
6	United Kingdom	561	502
7	Netherlands	238	0
8	Hungary	125	28
9	Lithuania	99	10
10	Czech Republic	14	0
11	Finland	9	0
12	Ireland	8	0
13	Italy	0	59
14	Latvia	0	5
27	EU	10,210	6,481
1 toe = 11,63 MWh

The consumption of bioethanol is largest in Europe in Germany, Sweden, France and Spain. Europe produces equivalent to 90% of its consumption (2006). Germany produced ca 70% of its consumption, Spain 60% and Sweden 50% (2006). In Sweden there are 792 E85 filling stations and in France 131 E85 service stations with 550 more under construction.^[56]

On Monday, September 17, 2007 the first ethanol fuel pump was opened in Reykjavik, Iceland. This pump is the only one of its kind in Iceland. The fuel is imported by Brimborg, a Volvo dealer, as a pilot to see how ethanol fueled cars work in Iceland. In a few weeks, the pump will be opened for public use.^{[citation needed]}

In The Netherlands regular petrol with no bio-additives is slowly outphased, since EU-legislation has been passed that requires the fraction of nonmineral origin to become minimum 5,75% of the total fuel consumption volume in 2010. This can be realised by substitutions in diesel or in petrol of any biological source; or fuel sold in the form of pure biofuel. (2007:) There are only a few gas stations where E85 is sold, which is an 85% ethanol, 15% petrol mix.^[62] Directly neighbouring country Germany is reported to have a much better biofuel infrastructure and offers both E85 and E50. Biofuel is taxed equally as regular fuel. However, fuel tanked abroad cannot be taxed and a recent payment receipt will in most cases suffice to prevent fines if customs check tank contents. (Authorities are aware of high taxation on fuels and cross-border fuel refilling is a well-known practice.)

Main article: Ethanol fuel in Sweden

All Swedish gas stations are required by an act of parliament to offer at least one alternative fuel, and every fifth car in Stockholm now drives at least partially on alternative fuels, mostly ethanol.^[63] The number of bioethanol stations in Europe is highest in Sweden, with 792 stations.

Stockholm will introduce a fleet of Swedish-made electric hybrid buses in its public transport system on a trial basis in 2008. These buses will use ethanol-powered internal-combustion engines and electric motors. The vehicles’ diesel engines will use ethanol.^[64]

Bioethanol stations  European Union[56]
Country	Stations	No/106 persons
Sweden	792	86.6
Germany	73	0.89
France	36	0.56
United Kingdom	14	0.24
Ireland	13	3.07
Switzerland	6	0.8

[edit] Asia

[edit] China

China is promoting ethanol-based fuel on a pilot basis in five cities in its central and northeastern region, a move designed to create a new market for its surplus grain and reduce consumption of petroleum. The cities include Zhengzhou, Luoyang and Nanyang in central China's Henan province, and Harbin and Zhaodong in Heilongjiang province, northeast China. Under the program, Henan will promote ethanol-based fuel across the province by the end of this year. Officials say the move is of great importance in helping to stabilize grain prices, raise farmers' income and reducing petrol- induced air pollution.^[65]

[edit] Thailand

Thailand already use 10% ethanol (E10) widely on big scale on the local market. Beginning in 2008 Thailand started with the sale of E20 and the in the third quarter of 2008 E85 will come on the mark.

[edit] Australia

Main article: Ethanol fuel in Australia

Legislation in Australia imposes a 10% cap on the concentration of fuel ethanol blends. Blends of 90% unleaded petrol and 10% fuel ethanol are commonly referred to as E10. E10 is available through service stations operating under the BP, Caltex, Shell and United brands as well as those of a number of smaller independents. Not surprisingly, E10 is most widely available closer to the sources of production in Queensland and New South Wales. E10 is most commonly blended with 91 RON "regular unleaded" fuel. There is a requirement that retailers label blends containing fuel ethanol on the dispenser.

[edit] Central America and the Caribbean

United States fuel ethanol imports by country (2002-2007)[32] (Millions of U.S. liquid gallons)
Country	2007*	2006	2005	2004	2003	2002
Brazil	188.8	433.7	31.2	90.3	0	0
Jamaica	75.2	66.8	36.3	36.6	39.3	29.0
El Salvador	73.3	38.5	23.7	5.7	6.9	4.5
Trinidad and Tobago	42.7	24.8	10.0	0	0	0
Costa Rica	39.3	35.9	33.4	25.4	14.7	12.0
*Note: 2007 figures through November only.

All countries in Central America and the Caribbean are located in a tropical zone with suitable climate for growing sugar cane. In fact, most of these countries have a long tradition of growing sugar cane mainly for producing sugar and alcoholic beverages. As a result of the guerilla movements in Central America, in 1983 the United States unilateral and temporarily approved the Caribbean Basin Initiative, allowing most countries in the region to benefit from several tariff and trade benefits. These benefits were made permanent in 1990 and more recently, these benefits were replaced by the Caribbean Basin Trade and Partnership Act, approved in 2000, and the Dominican Republic–Central America Free Trade Agreement that went to effect in 2008. All these agreements have allowed several countries in the region to export ethanol to the U.S free of tariffs.^[47] Until 2004, the countries that benefited the most were Jamaica and Costa Rica, but as the U.S. began demanding more fuel ethanol, the two countries increased their exports and two others began exporting. In 2007, Jamaica, El Salvador, Trinidad & Tobago and Costa Rica exported together to the U.S. a total of 230.5 million gallons of ethanol, representing 54.1% of U.S. fuel ethanol imports. Brasil began exporting ethanol to the U.S. in 2004 and exported 188.8 million gallons representing 44.3% of U.S. ethanol imports in 2007. The remaining imports that year came from Canada and China.^[32]

In March 2007, "ethanol diplomacy" was the focus of President George W. Bush's Latin American tour, in which he and Brazil's president, Luiz Inacio Lula da Silva, were seeking to promote the production and use of sugar cane based ethanol throughout Latin America and the Caribbean. The two countries also agreed to share technology and set international standards for biofuels.^[43] The Brazilian sugar cane technology transfer would allow several Central American, Caribbean and Andean countries to take advantage of their tariff-free trade agreements to increase or become exporters to the United States in the short-term.^[66] Also, in August 2007, Brazil's President toured Mexico and several countries in Central America and the Caribbean to promote Brazilian ethanol technology.^[67] The ethanol alliance between the U.S. and Brazil generated some negative reactions from Venezuela's President Hugo Chavez,^[68] and by then Cuba's President, Fidel Castro, who wrote that "you will see how many people among the hungry masses of our planet will no longer consume corn." "Or even worse," he continued, "by offering financing to poor countries to produce ethanol from corn or any other kind of food, no tree will be left to defend humanity from climate change."'^[69] Daniel Ortega, Nicaragua's President, and one of the preferencial recipients of Brazilian technical aid also voiced critics to the Bush plan, but he vowed support for sugar cane based ethanol during Lula's visit to Nicaragua.^[70][71]

[edit] Costa Rica

Starting in October 2008, all gasoline sold in Costa Rica will be blended with 7.5% ethanol. This follows a two year trial that took place in the provinces of Guanacaste and Puntarenas. The government expects to increase the percent of ethanol mixed with gasoline to 12% in the next 4 to 5 years. The Costa Rican government is pursuing this policy to lower the country's dependency of foreign oil and to reduce the amount of greenhouse gases produced. The plan also calls for an increase in ethanol producing crops and tax breaks for flex-fuel vehicles.^[72]

[edit] El Salvador

As a result of the cooperation agreement between the United States and Brazil, El Salvador was chosen in 2007 to lead a pilot experience to introduce state-of-the-art technology for growing sugar cane for production of ethanol fuel in Central America, as this technical bilateral cooperation is looking for helping Central American countries to reduce their dependence on foreign oil.^[73]

[edit] Comparison between Brazil and the U.S.

Brazil's sugar cane-based industry is far more efficient than the U.S. corn-based industry. Brazilian distillers are able to produce ethanol for 22 cents per liter, compared with the 30 cents per liter for corn-based ethanol.^[74] Sugarcane cultivation requires a tropical or subtropical climate, with a minimum of 600 mm (24 in) of annual rainfall. Sugarcane is one of the most efficient photosynthesizers in the plant kingdom, able to convert up to 2% of incident solar energy into biomass. Ethanol is produced by yeast fermentation of the sugar extracted from sugar cane.

Sugarcane production in the United States occurs in Florida, Louisiana, Hawaii, and Texas. In prime growing regions, such as Hawaii, sugarcane can produce 20 kg for each square meter exposed to the sun. The first three plants to produce sugar cane-based ethanol are expected to go online in Louisiana by mid 2009. Sugar mill plants in Lacassine, St. James and Bunkie were converted to sugar cane-based ethanol production using Colombian technology in order to make possible a profitable ethanol production. These three plants will produce 100 million gallons of ethanol within five years.^[75]

U.S. corn-derived ethanol costs 30% more because the corn starch must first be converted to sugar before being distilled into alcohol. Unfortunately, despite this cost differential in production, in contrast to Japan and Sweden, the U.S. does not import much of Brazilian ethanol because of U.S. trade barriers corresponding to a tariff of 54-cent per gallon – a levy designed to offset the 51-cent per gallon blender's federal tax credit that is applied to ethanol no matter its country of origin.^[76] One advantage U.S. corn-derived ethanol offers is the ability to return 1/3 of the feedstock back into the market as a replacement for the corn used in the form of Distillers Dried Grain.^[51]

Comparison of key characteristics between the ethanol industries in the United States and Brazil
Characteristic	Brazil	U.S.	Units/comments
Feedstock	Sugar cane	Maize	Main cash crop for ethanol production, the US has less than 2% from other crops.
Total ethanol production (2007) [32]	5,019.2	6,498.6	Million U.S. liquid gallons
Total arable land [45]	355	270(1)	Million hectares.
Total area used for ethanol crop [45][51]	3.6 (1%)	10 (3.7%)	Million hectares (% total arable)
Productivity per hectare [45][35][51]	7,500	4,000	Liters of ethanol per hectare. Brazil is 727 to 870 gal/acre (2006), US is 424 gal/acre (2006)
Energy balance (input energy productivity) [37][51][77]	8.3 to 10.2 times	1.3 to 1.6 times	Ratio of the energy obtained from ethanol to the energy expended in its production
Estimated greenhouse gas emission reduction [44][51][78]	86-90%(2)	10-30%(2)	% GHGs avoided by using ethanol instead of gasoline, using existing crop land.
Ethanol fueling stations in the counrty[35][36]	33,000 (100%)	873 (0,5%)	As % of total fueling gas stations in the country. U.S. has 170,000 (see Inslee, op cit pp. 161)
Fuel ethanol used by the road transport sector [39][38]	20%(3)	3.6%	As % of the sector's total on a volumetric basis for 2006.
Cost of production (USD/gallon) [35]	0.83	1.14	2006/2007 for Brazil (22¢/liter), 2004 for U.S. (35¢/liter)
Government subsidy (in USD) [45][36]	0	0.51/gallon	U.S. as of 2008-04-30. Brazilian ethanol production is no longer subsidized.
Import tariffs (in USD) [37][35]	0	0.54/gallon	As of April 2008, Brazil does not import ethanol, the U.S. does
Notes: (1) Only contiguous U.S., excludes Alaska. (2) Assuming no land use change. [78] (3) Excluding diesel-powered vehicles, ethanol consumption in the road sector is more than 40% [35][36]

[edit] Environment

[edit] Energy balance

Main article: Ethanol fuel energy balance

All biomass goes through at least some of these steps: it needs to be grown, collected, dried, fermented, and burned. All of these steps require resources and an infrastructure. The total amount of energy input into the process compared to the energy released by burning the resulting ethanol fuel is known as the energy balance. Figures compiled in a 2007 by National Geographic Magazine^[31] point to modest results for corn ethanol produced in the US: one unit of fossil-fuel energy is required to create 1.3 energy units from the resulting ethanol. The energy balance for sugarcane ethanol produced in Brazil is more favorable, 1:8. Energy balance estimates are not easily produced, thus numerous such reports have been generated that are contradictory. For instance, a separate survey reports that production of ethanol from sugarcane, which requires a tropical climate to grow productively, returns from 8 to 9 units of energy for each unit expended, as compared to corn which only returns about 1.34 units of fuel energy for each unit of energy expended.^[79]

Carbon dioxide, a greenhouse gas, is emitted during fermentation and combustion. However, this is canceled out by the greater uptake of carbon dioxide by the plants as they grow to produce the biomass.^[80] When compared to gasoline, depending on the production method, ethanol releases less greenhouse gases.^[81][82]

[edit] Air pollution

Compared with conventional unleaded gasoline, ethanol is a particulate-free burning fuel source that combusts cleanly with oxygen to form carbon dioxide and water. Gasoline produces 2.44 CO2 equivalent kg/l and ethanol 1.94 (this is -21% CO2). The Clean Air Act requires the addition of oxygenates to reduce carbon monoxide emissions in the United States. The additive MTBE is currently being phased out due to ground water contamination, hence ethanol becomes an attractive alternative additive. Current production methods includes air pollution from the manufacturer of macronutrient fertilizers such as ammonia.

A study by atmospheric scientists at Stanford University found that E85 fuel would increase the risk of air pollution deaths relative to gasoline.^[83] Ozone levels are significantly increased, thereby increasing photochemical smog and aggravating medical problems such as asthma.^[84][85]

[edit] Manufacture

In 2002, monitoring of ethanol plants revealed that they released VOCs (volatile organic compounds) at a higher rate than had previously been disclosed.^[86] The Environmental Protection Agency (EPA) subsequently reached settlement with Archer Daniels Midland and Cargill, two of the largest producers of ethanol, to reduce emission of these VOCs. VOCs are produced when fermented corn mash is dried for sale as a supplement for livestock feed. Devices known as thermal oxidizers or catalytic oxidizers can be attached to the plants to burn off the hazardous gases.

[edit] Carbon Dioxide

The calculation of exactly how much Carbon Dioxide is produced in the manufacture of bioethanol is a complex and inexact process, and is highly dependent on the method by which the ethanol is produced and the assumptions made in the calculation. A calculation should include:

• The cost of growing the feedstock
• The cost of transporting the feedstock to the factory
• The cost of processing the feedstock into bioethanol

Such a calculation may or may not consider the following effects:

• The cost of the change in land use of the area where the fuel feedstock is grown.
• The cost of transportation of the bioethanol from the factory to its point of use
• The efficiency of the bioethnol compared with standard gasoline
• The amount of Carbon Dioxide produced at the tail pipe.
• The benefits due to the production of useful bi-products, such as cattle feed or electricity.

The graph on the right shows figures calculated by the UK government for the purposes of the Renewable transport fuel obligation.^[87]

The January 2006 Science article from UC Berkeley's ERG, estimated reduction from corn ethanol in GHG to be 13% after reviewing a large number of studies. However, in a correction to that article released shortly after publication, they reduce the estimated value to 7.4%. A National Geographic Magazine overview article (2007)^[31] puts the figures at 22% less CO₂ emissions in production and use for corn ethanol compared to gasoline and a 56% reduction for cane ethanol. Carmaker Ford reports a 70% reduction in CO₂ emissions with bioethanol compared to petrol for one of their flexible-fuel vehicles.^[88]

An additional complication is that production requires tilling new soil^[89] which produces a one-off release of GHG that it can take decades or centuries of production reductions in GHG emissions to equalize.^[90] As an example, converting grass lands to corn production for ethanol takes about a century of annual savings to make up for the GHG released from the initial tilling.^[91]

[edit] Change in land use

Large-scale farming is necessary to produce agricultural alcohol and this requires substantial amounts of cultivated land. University of Minnesota researchers report that if all corn grown in the U.S. were used to make ethanol it would displace 12% of current U.S. gasoline consumption.^[92] There are claims that land for ethanol production is acquired through deforestation, while others have observed that areas currently supporting forests are usually not suitable for growing crops.^[93][94] In any case, farming may involve a decline in soil fertility due to reduction of organic matter,^[95] a decrease in water availability and quality, an increase in the use of pesticides and fertilizers, and potential dislocation of local communities.^[96] However, new technology enables farmers and processors to increasingly produce the same output using less inputs.^[92]

There is a concern that as demand for ethanol fuel increases, food crops are replaced by fuel crops, driving food supply down and food prices up. Growing demand for ethanol in the United States has been discussed as a factor in the increased corn prices in Mexico.^[97] Average barley prices in the United States rose 17% from January to June 2007 to the highest in 11 years. However, some commentators suggest that recent food price increases mainly reflect high oil prices in recent years, not specific pressures associated with ethanol production.^[98]

Cellulosic ethanol production is a new approach which may alleviate land use and related concerns. Cellulosic ethanol can be produced from any plant material, potentially doubling yields, in an effort to minimize conflict between food needs versus fuel needs. Instead of utilizing only the starch by-products from grinding wheat and other crops, cellulosic ethanol production maximizes the use of all plant materials, including gluten. This approach would have a smaller carbon footprint because the amount of energy-intensive fertilisers and fungicides remain the same for higher output of usable material. The technology for producing cellulosic ethanol is currently in the commercialization stage.^[99][100]

Many analysts suggest that, whichever ethanol fuel production strategy is used, fuel conservation efforts are also needed to make a large impact on reducing petroleum fuel use.^[101]

[edit] Efficiency of common crops

As ethanol yields improve or different feedstocks are introduced, ethanol production may become more economically feasible in the US. Currently, research on improving ethanol yields from each unit of corn is underway using biotechnology. Also, as long as oil prices remain high, the economical use of other feedstocks, such as cellulose, become viable. By-products such as straw or wood chips can be converted to ethanol. Fast growing species like switchgrass can be grown on land not suitable for other cash crops and yield high levels of ethanol per unit area.^[31]

Crop	Annual yield (Liters/hectare)	Annual yield (US gal/acre)	Greenhouse-gas savings (% vs. petrol)	Comments
Miscanthus	7300	780	37–73	Low-input perennial grass. Ethanol production depends on development of cellulosic technology.
Switchgrass	3100–7600	330–810	37–73	Low-input perennial grass. Ethanol production depends on development of cellulosic technology. Breeding efforts underway to increase yields. Higher biomass production possible with mixed species of perennial grasses.
Poplar	3700–6000	400–640	51–100	Fast-growing tree. Ethanol production depends on development of cellulosic technology. Completion of genomic sequencing project will aid breeding efforts to increase yields.
Sugar cane	5300–6500	570–700	87–96	Long-season annual grass. Used as feedstock for most bioethanol produced in Brazil. Newer processing plants burn residues not used for ethanol to generate electricity. Only grows in tropical and subtropical climates.
Sweet sorghum	2500–7000	270–750	No data	Low-input annual grass. Ethanol production possible using existing technology. Grows in tropical and temperate climates, but highest ethanol yield estimates assume multiple crops per year (only possible in tropical climates). Does not store well.[102][103][104][105]
Corn	3100–3900	330–420	10–20	High-input annual grass. Used as feedstock for most bioethanol produced in USA. Only kernels can be processed using available technology; development of commercial cellulosic technology would allow stover to be used and increase ethanol yield by 1,100 - 2,000 litres/ha.
Source (except sorghum): Nature 444 (December 7, 2006): 670-654.

[edit] Reduced petroleum imports and costs

One rationale given for extensive ethanol production in the U.S. is its benefit to energy security, by shifting the need for some foreign-produced oil to domestically-produced energy sources.^[106] Production of ethanol requires significant energy, but current U.S. production derives most of that energy from coal, natural gas and other sources, rather than oil.^[107] Because 66% of oil consumed in the U.S. is imported, compared to a net surplus of coal and just 16% of natural gas (2006 figures),^[108] the displacement of oil-based fuels to ethanol produces a net shift from foreign to domestic U.S. energy sources.

According to a 2008 analysis by Iowa State University, the growth in US ethanol production has caused retail gasoline prices to be US $0.29 to US $0.40 per gallon lower than would otherwise have been the case.^[109]

[edit] Recent patents

In 2006-2-23, Veridium Corporation announced the technology to convert exhaust carbon dioxide from the fermentation stage of ethanol production facilities back into new ethanol and biodiesel. The bioreactor process is based on a new strain of iron-loving blue-green algae discovered thriving in a hot stream at Yellowstone National Park.^[110]

In 2006-11-14, US Patent Office approved Patent 7135308, a process for the production of ethanol by harvesting starch-accumulating filament-forming or colony-forming algae to form a biomass, initiating cellular decay of the biomass in a dark and anaerobic environment, fermenting the biomass in the presence of a yeast, and the isolating the ethanol produced.^[111]

[edit] Criticism and controversy

Main article: Food vs fuel

In 2007, biofuels consumed one third of America's corn (maize) harvest. Filling up one large vehicle fuel tank one time with 100% ethanol uses enough corn to feed one person for a year. Thirty million tons of U.S. corn going to ethanol in 2007 greatly reduces the world's overall supply of grain.^[112] However, 31% of the corn put into the process comes out as distiller's grain, or DDGS, which is very high in protein, and is used to feed livestock.^[113]

Jean Ziegler, the United Nations Special Rapporteur on the Right to Food, called for a five-year moratorium on biofuel production to halt the increasing catastrophe for the poor. He proclaimed that the rising practice of converting food crops into biofuel is "A Crime Against Humanity," saying it is creating food shortages and price jumps that cause millions of poor people to go hungry.^[114]

The European Organisation for Economic Co-operation and Development warns that “the current push to expand the use of biofuels is creating unsustainable tensions that will disrupt markets without generating significant environmental benefits.”^[115]

When all 200 American ethanol subsidies are considered, they cost about $7 billion USD per year (equal to roughly $1.90 USD total for each a gallon of ethanol).^[116] When the price of one agricultural commodity increases, farmers are motivated to quickly shift finite land and water resources to it, away from traditional food crops.^[117]

The 2007-12-19 U.S. Energy Independence and Security Act of 2007 requires American “fuel producers to use at least 36 billion gallons of biofuel in 2022. This is nearly a fivefold increase over current levels.”^[118]

When cellulosic ethanol is produced from feedstock like switchgrass and sawgrass, the nutrients required to grow the cellulose are removed and cannot decay and replenish the soil. The soil is of poorer quality, and unsustainable soil erosion occurs.

Ethanol production consumes large quantities of unsustainable petroleum and natural gas. Even with the most-optimistic energy return on investment claims, in order to use 100% solar energy to grow corn and produce ethanol (fueling farm-and-transportation machinery with ethanol, distilling with heat from burning crop residues, using NO fossil fuels), the consumption of ethanol to replace current U.S. petroleum use alone would require about 75% of all cultivated land on the face of the Earth, with no ethanol for other countries, or sufficient food for humans and animals.^[119]

[edit] Fuel system problems

Several of the outstanding ethanol fuel issues are linked specifically to fuel systems. Fuels with more than 10% ethanol are not compatible with non E85-ready fuel system components and may cause corrosion of ferrous components.^[120][121] Ethanol fuel can negatively affect electric fuel pumps by increasing internal wear,^[121] cause undesirable spark generation,^[122] and is not compatible with capacitance fuel level gauging indicators and may cause erroneous fuel quantity indications in vehicles that employ that system.^[123] It is also not always compatible with marine craft, especially those that use fiberglass fuel tanks.^[124][125]

Using 100% ethanol fuel decreases fuel-economy by 15-30% over using 100% gasoline; this can be avoided using certain modifications that would, however, render the engine inoperable on regular petrol without the addition of an adjustable ECU.^[126] Tough materials are needed to accommodate a higher compression ratio to make an ethanol engine as efficient as it would be on petrol; these would be similar to those used in diesel engines which typically run at a CR of 20:1,^[127] versus about 8-12:1 for petrol engines.^[128]

In April 2008 the German environmental minister cancelled a proposed 10% ethanol fuel scheme citing technical problems: too many older cars in Germany are unequipped to handle this fuel. Ethanol levels in fuel will remain at 5%.^[129]

[edit] Bibliography

• Goettemoeller, Jeffrey; Adrian Goettemoeller (2007), Sustainable Ethanol: Biofuels, Biorefineries, Cellulosic Biomass, Flex-Fuel Vehicles, and Sustainable Farming for Energy Independence, Praire Oak Publishing, Maryville, Missouri, ISBN 978-0-9786293-0-4 . Brief and comprehensive account of the history, evolution and future of ethanol. 

• The Worldwatch Institute (2007), Biofuels for Transport: Global Potential and Implications for Energy and Agriculture, Earthscan Publications Ltd., London, U.K., ISBN 978-1-84407-422-8 . Global view, includes country study cases of Brazil, China, India and Tanzania. 

[edit] References

[edit] See also

Alcohol fuel Aventine Renewable Energy Biobutanol, a gasoline replacement. Bioconversion of biomass to mixed alcohol fuels Biodiesel Biofuel Biomass Cellulosic ethanol Corn Ethanol Comparison of automobile fuel technologies DMF (potential ethanol competitor biofuel)

Energy crop Energy development Ethanol fuel in Australia Ethanol fuel in Brazil Ethanol fuel in Sweden Ethanol fuel in the Philippines Ethanol fuel in the United States Flex Fuel Food vs fuel Hydrogen fuel Leavening Liquid fuels List of energy topics

MTBE (now banned). Oil crisis P-series fuels Sugarcane Timeline of alcohol fuel Vegetable oil economy

[edit] External links

• World Bank, Biofuels: The Promise and the Risks. World Development Report 2008: Agriculture for Development
• Biofuels: Ethanol at the Open Directory Project

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