Реферат: Alternative Fuels Essay Research Paper Alternative Fuel
Alternative Fuels Essay, Research Paper
Alternative Fuel Vehicles You Can Buy TodayFrom the earliest days of the automotive industry alternative fuels have always competed with petroleum for powering vehicles. Nicholas Cugnot made the first self-powered road vehicle in 1769 with a steam engine, and the first gasoline automobile didn’t appear until over 100 years later from Karl Benz. Through the late 19th and early 20th century steam and electric power remained strong contenders. The invention of the self-starter for gasoline engines by Cadillac eventually proved the undoing of the early steam cars, which required warming up. Electric cars continued to be produced for a while longer, but the expanding road network gradually made their short range of 8-15 miles between charges too inconvenient for many uses. Today we understand that the wholesale burning of petroleum can’t continue forever. As the new century opens alternative fuel vehicles are becoming more and more common. Major manufacturers such as Ford, Daimler/Chrysler, and Fiat offer dual fuel cars and trucks now. These vehicles allow you to choose between gasoline and compressed natural gas (CNG) for cleaner emissions. Other large manufacturers such as General Motors, Toyota, and Honda are concentrating on electric vehicles. These global automakers are slowly moving from conventional to alternative power as the technology is developed and refined. Current battery technology allows a maximum range of about 125 miles per charge. The leading edge of electric vehicle technology is occupied by much smaller companies. Bombardier, Pivco AS, and S-LEM AG have designed small, lightweight city cars intended for daily use in dense urban environments. Corbin-Pacific and Zebra Motors have chosen to concentrate on performance. Both companies produce creditable sports cars that just happen to be electrically powered. Do you have an idea that you think will work for an alternatively powered vehicle concept? The U.S. Department of Energy invites small businesses (500 employees or less) to submit grant applications on hybrid electric vehicle technology. Applicants may receive up to $75,000 US for a Phase I grant to develop the feasibility of the idea.Hydrogen VehiclesFuel DescriptionHydrogen is the most abundant element in the universe, but is rarely found in its uncombined form on the earth. When combusted (oxidized) it creates only water vapor as a by-product (4H + O2 = 2 H20). When burned in an internal combustion engine, however, combustion also produces small amounts of nitrogen oxides and small amounts of unburned hydrocarbons and carbon monoxide because of engine lubricants. The exhaust is free from carbon dioxide. Hydrogen is normally a gas and can be compressed and stored in cylinders. It can also be kept as a liquid, but the gas only turns liquid at temperatures of minus 423.2 degrees Fahrenheit (below zero)! Today, hydrogen is mostly obtained by cracking hydrocarbon fuels, but it can be produced by electrolysis of water (using electricity to split water into hydrogen and oxygen) and photolysis (chemical decomposition). The main problem with hydrogen is bulk storage required for fuel tanks. For an equivalent energy content of gasoline, liquid hydrogen and the required refrigeration system requires six to eight times more storage space than gasoline and compressed hydrogen gas requires six to ten times more storage space. Another development using hydrogen is as a blend of hydrogen and methane (natural gas) called Hythane. Preliminary information presented in mid- 1994 at the 10th World Hydrogen Energy Conference in Cocoa Beach, Florida, says that a test car’s exhaust using 30 percent hydrogen and 70 percent methane contained 80 percent less nitrogen oxides than U.S. EPA standards for 2003. This blend has much higher content of hydrogen than other Hythane blends, which typically run about five percent. To learn more about hydrogen go to the Hydrogen Fuel Page. Vehicle AvailabilityThere are no vehicles currently available that use hydrogen as a fuel; however, automobile manufacturers have experimented with developing vehicles that use hydrogen. Research vehicles have been produced by Daimler-Benz, BMW and Mazda. The Mercedes-Benz and BMW vehicles use liquid hydrogen. The Mazda vehicle stores its hydrogen as a gas in a metal-hydride lattice of shaved metal. Other vehicles have been built using compressed hydrogen, including two vehicles in Arizona operated by the American Hydrogen Association. High production costs and low density have prevented hydrogen’s use as a transportation fuel in all but test programs. It may be 20 to 30 years or more before hydrogen is a viable transportation fuel and then perhaps only in fuel-cell-powered vehicles.What is Ethanol?Ethanol (ethyl alcohol, grain alcohol, ETOH) is a clear, colorless liquid with a characteristic, agreeable odor. In dilute aqueous solution, it has a somewhat sweet flavor, but in more concentrated solutions it has a burning taste. Ethanol, CH3CH2OH, is an alcohol, a group of chemical compounds whose molecules contain a hydroxyl group, -OH, bonded to a carbon atom. Two higher blends of ethanol, E-85 and E-95 are being explored as alternative fuels in demonstration programs. Ethanol is also made into an ether, ethyltertiary-butyl ether (ETBE), that has properties of interest for oxygenated gasoline and reformulated fuels. Chemical Properties: Ethanol is ethane with a hydrogen molecule replaced by a hydroxyl radical. See the fuel properties table (PDF: 116 KB) for more information. How is Ethanol Made?There are basically eight steps in the ethanol production process: 1. Milling: The corn (or barley or wheat) will first pass through hammer mills, which grind it into a fine powder called meal. 2. Liquefaction: The meal will then be mixed with water and alpha-amylase, and will pass through cookers where the starch is liquefied. Heat will be applied at this stage to enable liquefaction. Cookers with a high temperature stage (120-150 degrees Celsius) and a lower Temperature-holding period (95 degrees Celsius) will be used. These high temperatures reduce bacteria levels in the mash. 3. Saccharification: The mash from the cookers will then be cooled and the secondary enzyme (gluco-amylase) will be added to convert the liquefied starch to fermentable sugars (dextrose), a process called saccharification. 4. Fermentation: Yeast will then be added to the mash to ferment the sugars to ethanol and carbon dioxide. Using a continuous process, the fermenting mash will be allowed to flow, or cascade, through several fermenters until the mash is fully fermented and then leaves the final tank. In a batch fermentation process, the mash stays in one fermenter for about 48 hours before the distillation process is started. 5. Distillation: The fermented mash, now called “beer,” will contain about 10% alcohol, as well as all the non-fermentable solids from the corn and the yeast cells. The mash will then be pumped to the continuous flow, multi-column distillation system where the alcohol will be removed from the solids and the water. The alcohol will leave the top of the final column at about 96% strength, and the residue mash, called stillage, will be transferred from the base of the column to the co-product processing area. 6. Dehydration: The alcohol from the top of the column will then pass through a dehydration system where the remaining water will be removed. Most ethanol plants use a molecular sieve to capture the last bit of water in the ethanol. The alcohol product at this stage is called anhydrous (pure, without water) ethanol and is approximately 200 proof. 7. Denaturing: Ethanol that will be used for fuel is then denatured with a small amount (2-5%) of some product, like gasoline, to make it unfit for human consumption. 8. Co-Products: There are two main co-products created in the production of ethanol: carbon dioxide and distillers grain. Carbon dioxide is given off in great quantities during fermentation and many ethanol plants collect that carbon dioxide, clean it of any residual alcohol, compress it and sell it for use to carbonate beverages or in the flash freezing of meat. Distillers grains, wet and dried, are high in protein and other nutrients and are a highly valued livestock feed ingredient. Some ethanol plants also create a “syrup” containing some of the solids that can be a separate production sold in addition to the distiller’s grain, or combined with it. Ethanol production is a no-waste process that adds value to the corn by converting it into more valuable products. Ethanol is also made from a wet-milling process. Many of the larger ethanol producers use this process, which also yields many other products, such as high fructose corn sweetner. Ethanol MarketEthanol will probably be transferred from import terminals or production facilities by barge, rail, or truck to eventually reach retail outlets. While the alcohols are liquids at ambient temperatures and atmospheric pressures, they cannot be moved easily through the existing petroleum product network to end-users. Ethanol is already penetrating the transportation market through gasohol. Although an exact figure is not available, there are many gasohol outlets. However, ethanol used in gasohol is not an alternative fuel as defined by EPAct–It is a replacement fuel. Since E-85 is not being widely used, and E-95 is only undergoing demonstration, few outlets for these alternative fuels are currently available. To learn more about ethanol vehicles and to see which ethanol vehicles are available for sale or lease, go to the AFDC Ethanol Vehicle Page. BenefitsIn general, the benefits to using ethanol are:? Reducing the need for foreign oil? Preventing air pollution by using a low emission vehicle? Using a renewable fuel For more detailed information on ethanol benefits, go to the American Coalition for Ethanol Web Page. FAQsPlease go to the:? Ethanol Information Centre’s FAQs Page? The California Energy Commission’s FAQ page If you have further questions regarding Ethanol, please call the National Alternative Fuels Hotline (800) 423-1DOE. BackgroundThe concept of ethanol as a fuel began as early as the first Model T car designed by Henry Ford. American usage of ethanol-blended gasoline began in the late 1970s. Environmentally, the use of ethanol blends has assisted in reducing carbon monoxide emissions as mandated by the U.S. Clean Air Act of 1990. In addition, as corn prices declined during the 1980s, ethanol production, using corn as a feedstock, came to be seen as a way of expanding the domestic market for grain, helping to stabilize farmers’ incomes.In Canada, air quality issues have taken on a higher profile on the public agenda. For agriculture, the savings in government spending on farm support programs in Canada have not been as evident as in the U.S. Consequently, until recently, fuel ethanol has not received the level of public attention and private investment as it has in the U.S.What is fuel ethanol?Fuel ethanol (or ‘Gasohol’) is a high octane, water-free alcohol produced from the fermentation of sugar or converted starch. It is traditionally used as a blending ingredient at 5% to 10% concentrations (termed E5 or E10, respectively) in gasoline or as a raw material to produce high octane fuel ether additives. Ethanol is made primarily from grains or other renewable agricultural and agroforestry feedstocks.What are the advantages to using ethanol-blended fuels?? Renewable? Cleaner environment? Cleaner burning engines? Lower net carbon dioxide emissions? Less dependence on imported light crude oil? Expanded market opportunity for Canadian farmers? Economic opportunities for rural Canada How does the use of ethanol-blended fuel benefit the environment?Net Reduction in Ground Level Ozone-Forming EmissionsGround-level ozone causes human respiratory problems and damages many plants, but does nothing to increase ozone concentration in the stratosphere that protects the earth from the sun’s ultraviolet radiation.In Canada, where the volatility of ethanol blends must match normal gasoline, the ozone forming potential of ethanol blends is even lower than in the U.S., where ethanol blends are allowed to have increased volatility. The emissions produced by burning ethanol are less reactive with sunlight than those produced by burning gasoline. This results in a lower potential for forming the damaging ozone.The Greenhouse EffectThe ‘Greenhouse Effect’ refers to the Earth’s atmosphere trapping the sun’s radiation. It is a term often used synonymously with ‘Global Warming’, which refers to the increasing average global temperature, arising from an increase in greenhouse gases from industrial activity and population growth. Greenhouse gases contributing to the Greenhouse Effect include carbon dioxide, methane, and nitrous oxide.The term ‘Climate Change’ refers to a wide range of changes in weather patterns that result from global warming. A substantial increase in the Earth’s average temperature could result in a change in agricultural patterns and melting of polar ice caps, raising sea levels and causing flooding of low-lying coastal areas. Use of ethanol fuels has been shown to reduce emissions that contribute to global warming by 35-36%.30% Reduction in Carbon Monoxide (CO) EmissionsCarbon monoxide is a toxic gas that contributes to air pollution. It is of particular concern when vehicles are operating at lower temperatures. Oxygenated gasolines, such as ethanol blends, lower the levels of CO emitted, by promoting a more complete combustion of the fuel.6% to 10% Net Reduction in Carbon Dioxide (CO2) Entering the AtmosphereCarbon dioxide is a normal product of burning fuels that contributes to global warming. More CO2 is absorbed by crop growth than is released by manufacturing and using ethanol.”Environmental ChoiceTM”The environmentally beneficial attributes of ethanol-blended gasoline have resulted in its designation as an “Environmental ChoiceTM” product, displaying the “EcoLogoTM” at licensed retail outlets.What are the environmental implications of feedstock production associated with the production of ethanol for fuel?Biological RenewabilityFuel ethanol is produced from biologically renewable sources, such as grain or wood products.Sustainable AgricultureWith the development of sustainable and environmentally sensitive production methods in the agricultural sector, the impact of farming practices is very minimal. The demand for grain to produce fuel ethanol has not resulted in an increased corn or wheat acreage in Canada.What are the by-products/co-products of fuel ethanol production?Flour, Corn Oil, Corn Meal, Corn GritsUsed in producing food for human consumption.FibroteinTMUsed as a high fibre and protein food additive.Corn Gluten Meal and Corn Gluten FeedUsed as high protein animal feed additives.Amino AcidsUsed as animal feed additives.Dry Distiller’s GrainsUsed as high protein and energy animal feed.Carbon DioxideUsed as a refrigerant, in carbonated beverages, to help vegetable crops grow more rapidly in greenhouses, and to flush oil wells.How will fuel ethanol impact Canadian agriculture?Market OpportunitiesFuel ethanol represents an important new market for Canadian grains.Impact on exportsEthanol production will not likely affect Canadian grain exports. If all gasoline sold in Canada contained 10% ethanol made from Canadian grains, 8 million tonnes of grain would be used, compared to current exports of 24 million tonnes, and current production of 50 million tonnes. There will still be a surplus for export.Impact on grain pricesThe prices of grains have historically moved in parallel with oil prices. Distiller’s grains and gluten feed are high-protein feeds that are co-products produced from grains when starch is made into ethanol. Therefore, when the cost of grain is high, a greater portion of the processor’s costs can be recovered through the sale of protein feeds.Co-productsDistiller’s grains, a co-product from ethanol production, will also impact the availability of protein supplements for cattle and other ruminants, thereby decreasing the demand for imported soybean meal. The potential also exists to “partner” fuel ethanol plants with other agricultural operations, such as the combined ethanol plant-cattle feedlot operation in Lanigan, Saskatchewan. Other agricultural partners could include dairy operations, feed mills, grain elevators, greenhouses, mushroom plants, and co-generation plants.Can ethanol be produced from off-grade or damaged corn?Yes. This is a good market for off-grade or damaged corn. As can be expected, the price paid by the ethanol processor for the corn will be affected, as well as the value of the distiller’s grains.What are alternative feedstocks for ethanol production?Currently, corn is the primary feedstock for ethanol production. In some areas of the country, wheat and wood are also used. In the future, other agricultural feedstocks and crop residues such as straw, stover, or corn cobs may be used to produce ethanol.How much ethanol is produced from a bushel of corn or wheat?The industry average is slightly more than 10 litres per bushel in addition to the high protein livestock feeds and carbon dioxide produced.Why is fuel ethanol blended?Brazil is able to operate nearly half of its cars on pure ethanol. Most engines need some modification to run on pure ethanol. A 10% blend requires no engine modification while making a contribution to reducing emissions.How has the government responded to the production and use of ethanol-blended fuels?The Government of Canada has granted an excise tax exemption on the ethanol portion of gasoline, as it is made from a renewable resource. Many Canadian provinces also have provided for road tax exemptions. These tax exemptions allow ethanol-blended fuels to be sold at a competitive price.’FleetWise’ is a federal initiative to address the pollution caused by vehicle emissions and its effect on climate change. It involves a gradual phased-in increase in use of alternative fuels, such as ethanol. The Government of Canada has committed to integrating environmental considerations and sound management practices in the operation of its motor vehicles. This includes a phased-in acquisition of alternative fuel vehicles, by the year 2005.Is ethanol production energy efficient?Ethanol contains about 32,000 (high heating value) BTUs per litre. It takes about one fourth of that amount to grow the corn and about one third of that amount to process the corn in a modern ethanol production facility. Some of the processing costs should be allocated to the co-products that are produced with the ethanol. If corn farmers use state-of-the-art, energy efficient and sustainable farming techniques and ethanol plants integrate state-of-the-art production processes, the amount of energy contained in the ethanol and its co-products is more than twice the energy used to grow the corn and convert it into ethanol.How will using ethanol-blended fuels affect my vehicle?What is the effect of using ethanol-blended fuels on the manufacturer’s warranty of my vehicle?When the use of ethanol began in 1979, most automobile manufacturers did not even address alcohol fuels. As soon as each manufacturer tested their vehicles, they approved the use of a 10% ethanol blend. Today, all manufacturers approve the use of 10% ethanol blends, and some even recommend it for environmental reasons.Is it necessary to make changes to my vehicle in order to use ethanol-blended fuels?All cars built since the 1970s are fully compatible with up to 10% ethanol in the mixture.Will ethanol-blended fuels work in fuel-injected engines?Yes. It may be necessary to change the filter more frequently. Ethanol helps to clean out the fuel-injection system, and may aid in the maintenance of a cleaner engine.Since 1985, all ethanol blends and nearly all non-ethanol gasolines have contained detergent additives that are designed to prevent injector deposits. These detergents have been very effective in addressing this issue.Does ethanol in the fuel work as an effective gas line anti-freeze?Gas line anti-freeze contains alcohol-usually methanol, ethanol, or isopropyl, which can be used up to a 0.3% level in a car’s fuel tank. All alcohols have the ability to absorb water, and therefore condensation in the fuel system is absorbed and does not have the opportunity to collect and freeze. If an ethanol blend contains 10% ethanol, it is able to absorb more water than a small bottle of isopropyl, and eliminates the need and expense of adding a gas line anti-freeze.Will ethanol burn valves?Ethanol will not burn engine valves. In fact, ethanol burns cooler than gasoline. Ethanol high-powered racing engines use pure alcohol for that reason.Will using ethanol-blended fuels plug the fuel filters in my vehicle?Ethanol can loosen contaminants and residues that have been deposited by previous gasoline fills. These can collect in the fuel filter. This problem has happened occasionally in older cars, and can easily be corrected by changing fuel filters.Symptoms of a plugged fuel filter will be hesitation, missing, and a loss of power. Once your car’s fuel system is clean, you will notice improved performance.Can I mix fuels?Yes. All gasolines in Canada (including low-level ethanol blends) must meet the specifications of the Canadian General Standards Board (CGSB). They are all interchangeable.What is the effect of using ethanol-blended fuels on fuel economy?Changes in fuel economy are minimal. While a 10% ethanol blend contains about 97% of the energy of ‘pure’ gasoline, this is compensated by the fact that the combustion efficiency of the ethanol-blended fuel is increased. The net result is that most consumers do not detect a difference in their fuel economy, although many people using ethanol-blended fuels have said that their fuel economy has improved.Can ethanol-blended fuels be used in ATV’s, chainsaws or other power or recreational equipment?Yes. An ethanol blend may be used anywhere that unleaded gasoline is used. Farmers, cities, counties, and rural electric co-op fleets, plus snowmobile racers and fishing guides in the U.S. use ethanol blends exclusively with no performance problems. Adjustments may be required for air intake. It is important to consult your owner’s manual.Is it safe to handle fuel ethanol blends?The WHMIS Material Safety Data Sheet (MSDS) reveals that the properties of ethanol blends are substantially the same as conventional gasoline blends. Occupational health and safety risks presented by the use of ethanol gasoline do not appear to be any different than those posed by conventional gasoline blends.Do ethanol blends need special handling or storage?Only in special circumstances. The gasoline marketer should pump any accumulated water from the storage tank, and add a final filter to the dispensing hose. It is wise also to check seasonally used small engines such as chainsaws and outboard motors (which are more susceptible to water contamination) for the presence of water, and drain the tank if necessary.What are the alternatives to ethanol as an oxygenate? How do they compare?MethanolMethanol is a derivative of natural gas. It is less expensive to produce than ethanol but is highly corrosive, more volatile than ethanol, and more damaging to plastic and rubber fuel system components (elastomers). It also requires a co-solvent (usually ethanol). Ethanol provides better water tolerance than methanol.MTBEMTBE (Methyl Tertiary Butyl Ether) is a high octane, low volatility, oxygenated fuel component made by combining methanol and isobutylene from oil refineries. It is not as sensitive to water as the alcohols, and does not increase the volatility of most gasolines. It is known to have a very distinct odor. It is non-corrosive and relatively low-priced. It is currently the most widely used oxygenate, but is derived from a non-renewable resource.ETBEETBE (Ethyl Tertiary Butyl Ether) has properties similar to MTBE, but is produced by combining ethanol (derived from a renewable resource) and isobutylene.TAME and TAEETAME (Tertiary Amyl Methyl Ether) and TAEE (Tertiary Amyl Ethyl Ether) are complex methyl and ethyl ethers, respectively. They are relatively new and have similar characteristics to MTBE and ETBE.How much fuel ethanol is being produced?Canada’s current annual ethanol production, for all markets (1998) is approximately 234 million litres a year. With additional proposed development of ethanol production plants, Canadian potential production in the next few years is at 664 million litres per year.How much fuel ethanol is being used?It is difficult to ascertain current levels of fuel ethanol use in Canada. In the U.S., it now represents about 9% of total gasoline sales, or the equivalent of the total Canadian gasoline consumption. Over two trillion kilometres have been traveled using fuel ethanol blends.Who produces alcohol?? Mohawk Oil Canada Ltd., Minnedosa, Manitoba (Capacity = 10 million litres);? Pound-Maker Agventures, Ltd., Lanigan, Saskatchewan (Capacity = 12 million litres);? Commercial Alcohols Inc., Tiverton, Ontario (Capacity = 23 million litres);? Commercial Alcohols Inc., Chatham, Ontario (Capacity = 150 million litres);? Agri-Partners International, Inc. (API), Alberta (Capacity = 22 million litres);? Tembec, Temiscaming, Quebec (Capacity = 17 million litres). Additional proposed development of ethanol production plants includes those by? Seaway Grain Processors, Inc., Cornwall, Ontario (Capacity = 66 million litres);? Commercial Alcohols, Inc., Varennes, Quebec (Capacity = 150 million litres);? Commercial Alcohols Inc.’s Chatham plant plans to expand by another 150 million litres;? Metalore Resources Inc. is continuing development on a wheat-based ethanol production facility. Who sells ethanol-blended fuels? Where can I purchase them?Across Canada, there are approximately 950 retailers of ethanol-blended fuels (July, 1998), excluding those who are not listed with the Canadian Renewable Fuels Association.Mohawk Oil is presently selling ethanol blends at over 290 stations in British Columbia, Alberta, Saskatchewan, Manitoba, the Yukon and Northern Ontario. Across southern Ontario, UPI Inc. retails ethanol blends at over 60 UPI Inc., FS and Co-op gasbars and cardlocks. They are available in all grades of gasoline and for on-farm delivery. On January 1, 1998, Sunoco Inc. launched ethanol-enhanced fuels at all its 275 retail outlets in Ontario. In eastern Ontario and western Quebec, MacEwen Petroleum Inc. is retailing ethanol blends at over 60 locations. Fuel ethanol retailing has expanded into Quebec with over 100 Sonic stations and other independent retail outlets. Other companies that have joined in the retailing of ethanol-blended fuels include Mr. Gas, Pioneer Petroleum, Frances Fuels, Stinson Petroleum and Sunys.