Alcohol has been used as fuel . The first four aliphatic alcohols (methanol, ethanol, propanol, and butanol) are attractive as fuels because they can be chemically or biologically synthesized, and they have characteristics that allow them to be used in internal combustion engines. The common chemical formula for alcohol fuels is C n H 2n 1 OH .
Most methanol is produced from natural gas, although it can be produced from biomass using very similar chemical processes. Ethanol is generally produced from biological materials through a fermentation process. Biobutanol has an advantage in combustion engines because its energy density is closer to gasoline than simple alcohols (while still maintaining more than 25% higher octane values); However, biobutanol is currently more difficult to produce than ethanol or methanol. When obtained from biological materials and/or biological processes, they are known as bioalcohols (eg "bioethanol"). There is no chemical difference between biologically produced and chemically produced alcohols.
One advantage shared by the four main alcohol fuels is their high octane rating. This tends to increase fuel efficiency and largely offset the lower energy density of vehicle alcohol fuels (compared to gasoline/petrol and diesel fuels), resulting in a comparable "fuel economy" in terms of distance per volume metric, such as kilometers per liter, or miles per gallon.
Video Alcohol fuel
Metanol dan etanol
Methanol and ethanol can both come from fossil fuels, biomass, or perhaps the simplest, of carbon dioxide and water. Ethanol is most often produced by sugar fermentation, and methanol is most often produced from synthesis gas, but there is a more modern way to get this fuel. Enzymes can be used instead of fermentation. Methanol is a simpler molecule, and ethanol can be made from methanol. Methanol can be produced industrially from almost any biomass, including animal waste, or from carbon dioxide and water or steam by first converting biomass into synthesis gas in a gasifier. It can also be produced in laboratories using electrolysis or enzymes.
As a fuel, methanol and ethanol both have advantages and disadvantages over fuels such as gasoline (petrol) and diesel. In a spark-ignition engine, both alcohols can travel at a much higher rate of exhaust gas recirculation and with higher compression ratios. Both alcohols have high octane values, with ethanol at 109 RON (Research Octane Number), 90 MON (Motor Octane Number), (equivalent to 99.5 AKI) and methanol at 109 RON, 89 MON (equivalent to 99 AKI). Note that AKI refers to the 'Anti-Knock Index' which averages the RON and MON (RON MON)/2 ranks, and is used on US gas station pumps. Usually European gasoline is usually 95 RON, 85 MON, equal to 90 AKI. As fuel ignition compression fuels, both alcohols create very small particulates, but their low cetane numbers mean that ignition devices such as glycols must be mixed into the fuel with the surrounding. 5%.
When used in spark-igniting machines alcohol has the potential to reduce NOx, CO, HC and particulates. A test with E85 triggering Chevrolet Luminas shows that NMHC decreased by 20-22%, NOx by 25-32% and CO by 12-24% compared with reformulated gasoline. Benzene toxic emissions and 1.3 butadiene also decreased while increased aldehyde emissions (especially acetaldehyde).
The CO 2 tailpipe emissions also decreased because of the lower carbon-to-hydrogen ratio of these alcohols, and improved engine efficiency.
Methanol and ethanol fuels contain soluble and insoluble contaminants. Halide ions, which are soluble contaminants, such as chloride ions, have a profound effect on the corrosion of alcohol fuels. Halide ions increase corrosion in two ways: they chemically attack passive oxide films on some metals that cause pitting corrosion, and they increase the fuel conductivity. Increased electrical conductivity increases the electrical, galvanic and common corrosion in the fuel system. Soluble contaminants such as aluminum hydroxide, itself a product of corrosion by halide ions, clog up the fuel system over time.
To prevent corrosion, the fuel system must be made of the appropriate material, the power cord must be properly insulated and the fuel level sensor must be of pulse and hold, magneto resistive or other similar non-contact types. In addition, high-quality alcohols should have low concentrations of contaminants and have corresponding corrosion inhibitors added. Scientific evidence suggests that water is a corrosion inhibitor by ethanol.
The experiment was conducted with E50, which is more aggressive & amp; accelerate corrosion effect. It is clear that by increasing the amount of water in an ethanol fuel one can reduce corrosion. At 2% or 20,000 ppm of water in ethanol fuel, corrosion stops. Observations in Japan are in line with the fact that hydro ethanol is known for being less corrosive than anhydrous ethanol. The reaction mechanism is 3 EtOH Al - & gt; Al 3 / 2 H 2 will be the same under the mix medium. When enough water is present in the fuel, aluminum will react better with water to produce Al 2 O 3 , fix the protective aluminum oxide layer. The aluminum alkoxide does not form a dense oxide layer; water is essential to repairing holes in the oxide layer.
Methanol and ethanol are also incompatible with some polymers. Alcohol reacts with a polymer that causes swelling, and over time oxygen breaks the carbon-carbon bond in the polymer causing a decrease in tensile strength. Over the past few decades, most cars are designed to tolerate up to 10% ethanol (E10) without problems. These include fuel system compatibility and lambda fuel delivery compensation with a fuel injection engine featuring a closed loop lambda control. In some ethanol engines can decrease some of the composition of delivery components of plastic or rubber fuels designed for conventional fuels, and also can not lambda properly compensate for fuel.
"FlexFuel" vehicles have improved fuel systems and engine components designed for longevity using E85 or M85, and the ECU can adapt to a fuel mix between gasoline and E85 or M85. General upgrades include modifications to: fuel tanks, fuel tank power cables, fuel pumps, fuel filters, fuel lines, filler tubes, fuel level sensors, fuel injectors, seals, fuel rails, material pressure regulators burn, valve seats and inlet valves. "Total Flex" Cars intended for the Brazilian market can use E100 (100% Ethanol).
One liter of ethanol contains 21.1 MJ, one liter of methanol 15.8 MJ and one liter of gasoline about 32.6 MJ. In other words, for an energy content equal to one liter or one gallon of gasoline, one needs 1.6 liters/gallon of ethanol and 2.1 liters/gallon of methanol. Large amounts of energy per volume produce misleading fuel consumption figures, since alcohol-fueled engines can be substantially more energy efficient. A greater percentage of the energy available in a liter of alcohol fuel can be converted into useful work. This difference in efficiency can partially or totally balance the difference in energy density, depending on the particular machine being compared.
Methanol fuel has been proposed as a future biofuel, often as an alternative to the hydrogen economy. Methanol has a long history as a racing fuel. Early Grand Prix Racing uses mixed mixtures as well as pure methanol. The use of fuel is mainly used in North America after the war. However, methanol for racing purposes is largely based on the methanol produced from syngas derived from natural gas and therefore this methanol will not be considered as biofuel. Methanol is a possibility of biofuels, but when syngas comes from biomass.
In theory, methanol can also be produced from carbon dioxide and hydrogen using nuclear power or renewable energy sources, although this may not be economical on an industrial scale (see methanol economy). Compared with bioethanol, the main advantage of biofuel methanol is the much greater well-to-wheel efficiency. This is particularly relevant in temperate regions where fertilizer is needed to grow sugar or crop flour to make ethanol, while methanol can be produced from lignocellulosic biomass (wood).
Ethanol has been used extensively as a fuel additive, and the use of ethanol fuel alone or as part of a mixture with increased gasoline. Compared to methanol, its main advantage is that it is less corrosive and non-toxic fuel additions, although fuel will produce some toxic exhaust emissions. Since 2007, Indy Race League has been using ethanol as its exclusive fuel, after 40 years of using methanol. Since September 2007 gas stations in NSW, Australia are mandated to supply all their gasoline with 2% ethanol content
Maps Alcohol fuel
Butanol and propanol
Propanol and butanol are much less toxic and less stable than methanol. In particular, butanol has a high flame point 35 ° C, which is useful for fire safety, but it may be difficult to start the engine in cold weather. The concept of a flash point does not directly apply to a machine because compressed air in a cylinder means that the temperature is several hundred degrees Celsius before ignition occurs.
The fermentation process for producing propanol and butanol from cellulose is quite difficult to implement, and the Weizmann organism (Clostridium acetobutylicum) currently used to perform this conversion produces a very unpleasant odor, and this should be considered when designing and locating the fermentation plant.. The organism is also dead when the content of any fermented butanol increases to 7%. For comparison, yeast dies when the ethanol content of the raw material reaches 14%. Specific strains can tolerate greater ethanol concentrations - so-called turbo yeast can last up to 16% ethanol. However, if ordinary Saccharomyces yeast can be modified to increase ethanol endurance, scientists may not yet one day produce strains of Weizmann organisms with butanol resistance higher than the natural limit of 7%. This will be useful because butanol has a higher energy density than ethanol, and since the remaining fiber remaining from the sugar cane plant used to make ethanol can be made into butanol, it increases the alcohol yield of the fuel crop without the need for more plants to become embedded.
Despite these shortcomings, DuPont and BP recently announced that they are jointly to build a small-scale butanol fuel demonstration plant along with their large bioethanol plant jointly developed with Associated British Foods.
The Energy Environment International company developed a method to produce butanol from biomass, which involved the use of two separate micro-organisms sequentially to minimize the production of acetone and ethanol byproducts.
Swiss company Butalco GmbH uses special technology to modify the yeast to produce butanol instead of ethanol. Yeast as a production organism for butanol has a decisive advantage over bacteria.
The burning of butanol is: C 4 H 9 OH 6O 2 -> 4CO 2 5H 2 O heat
Combustion of propanol is: 2C 3 H 7 OH 9O 2 -> 6 CO 2 8 H 2 O heat
The 3-carbon alcohol, propanol (C 3 H 7 OH), is not often used as a direct fuel source for gasoline engines (unlike ethanol, methanol and butanol), with mostly directed to be used as solvent. However, it is used as a source of hydrogen in some types of fuel cells; it can produce a higher voltage than methanol, which is the fuel of choice for most of the alcohol-based fuel cells. However, since propanol is more difficult to produce than methanol (biologically OR from oil), fuel cells using methanol are preferred over propanol using propanol.
By country
Brazil
Brazil is by far the largest producer of alcohol fuels in the world, usually fermenting ethanol from sugar cane.
The country generates a total of 18 billion liters (4.8 billion gallons) each year, of which 3.5 billion liters is exported, 2 billion of them to the US. Alcoholic cars debuted in the Brazilian market in 1979 and became very popular because of the huge subsidies, but in the 1980s prices rose and gasoline regained the leading market share.
However, starting in 2003, alcohol quickly increased its market share once again due to new technologies involving flexible fuel engines, called "Flex" or "Total Flex" by all major car manufacturers (Volkswagen, General Motors, Fiat, etc.). The "Flex" engine works with gasoline, alcohol or a mixture of both fuels. As of May 2009, more than 88% of new vehicles sold in Brazil are flexible fuels.
Due to Brazil's leading production and technology, many countries became very interested in importing alcohol fuels and adopting the concept of "Flex" vehicles. On March 7, 2007, US President George W. Bush visited the city of SÃÆ' Â £ o Paulo to sign an agreement with Brazilian President Luiz InÃÆ'¡cio Lula da Silva about importing alcohol and his technology as an alternative fuel.
China
In early 1935, China had built an alcohol-fueled car. China has reported with the use of 70% methanol for conventional gasoline and independent of crude oil.
The National Coordinating Committee for Planning and Action for Clean Cars has listed key technologies related to alcohol/ether fuel and the acceleration of industrialization on its main agenda. Alcohol fuel has become part of five major alternative fuels: Two of them are alcohol; methanol and ethanol
United States
- See E85 in the United States
The United States at the end of 2007 produced 26.9 billion liters (7 billion gallons) per year. E10 or Gasohol is generally marketed in Delaware and E85 is found in many states, particularly in the Midwest where corn ethanol is produced locally.
Many states and cities mandated that all petrol fuels be mixed with 10 percent alcohol (usually ethanol) for some or all year. This is to reduce pollution and allow this area to comply with federal pollution limits. Because alcohol is partially oxygenated, it produces less pollution, including ozone. In some areas (especially California) regulations may also require other formulations or add chemicals that reduce pollution, but add to the complexity of fuel distribution and increase fuel costs.
European Union
Japanese
The first alcohol fuel in Japan started with GAIAX in 1999. GAIAX was developed in South Korea, and imported by Japan. The main ingredient is methanol.
Since GAIAX is not gasoline, it is Japan's tax-free natural gas tax object. However, as a result, the use of GAIAX is considered an act of smuggling in Japan by the government and the petroleum industry. GAIAX Retailing is conducted to avoid tax embezzlement criticism by independently paying diesel fuel taxes in legal system regulations.
Unintentional vehicle fires where GAIAX was refueling began to report around 2000 when the tax evasion discussion was almost over. The automobile industry in Japan criticized GAIAX, saying that "fires occur because of the high concentrations of alcohol have damaged the fuel pipes". GAIAX is named "high-density alcohol fuel," and campaigns are implemented to exclude it from long-term markets. Finally, the Ministry of Economy, Trade and Industry also joined this campaign.
The method of gasoline quality was revised under the guise of security issues in 2003. It prohibited the manufacture and sale of "high-density alcoholic fuels", and added a substantial ban on GAIAX sales. By revising the law, fuel producers are prohibited from adding 3% or more of alcohol to gasoline. The revision of this law is the reason for not being able to sell alcohol fuels bigger than E3 in Japan.
The petroleum industry in Japan is now beginning with the research and development of genuine alcohol fuels different from GAIAX. However, commercial manufacture and sale of new fuels may be prohibited by existing laws that currently exclude GAIAX from the market. In addition, the strong aversion of Japanese consumers to high-density alcoholic fuels of any kind can prevent the commercial success of any new fuel.
See also
References
External links
- The World Bank, Biofuels: Promises and Risks. World Development Report 2008: Agriculture for Development
- Biobutanol by EERE.
- http://www.greencarcongress.com/biobutanol/index.html
- https://web.archive.org/web/20080528051420/http://www.ethanol.org/pdf/contentmgmt/2007_Ethanol_Fact_Book.pdf
Source of the article : Wikipedia
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