Alternate Fuels Essay Research Paper Jennifer Allers — страница 3

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proven viable alternative fuels are alcohols, specifically methanol and ethanol both obtainable from petroleum and natural (biomass) sources, many domestic resources, fossil and renewable resources, natural gas, and coal, (Reed, 74). “Replacing gasoline with pure methanol or natural gas as fuels could cut ozone levels by as much as 40%,” (O&GJ, 24). Methanol has certainly proved that it is a desirable fuel whose combustion products are much less harmful to the environment than those of gasoline. Methanol also has many other positive aspects of use both for the environment and for conversion of current vehicles to run with it as fuel. There have been many arguments against methanol; however, technology has rendered many of these arguments null. Methanol first does have the

best potential for widespread use of all of the aforementioned fuels. A methanol powered vehicle is “fundamentally the same as a gasoline powered car,” (Moore, 93). Fuel-flexable vehicles that automatically adjust to operate on alcohol fuels, gasoline, or combinations of both are excellent choices for methanol fuel use. These type of vehicles are excellent since they allow a consumer to still use gasoline if areas of the country are lacking in methanol distribution systems. These type of vehicles have already been tested, as have many of the others mentioned, in California where 1000 are currently in use, (Reed, 74). Ford, Chevrolet, and Volkswagen have been the leaders in fuel-flexable vehicles in the U.S., and Brazil which once fueled its vehicles primarily with ethanol,

(Moore, 93). Methanol also has a 100% octane rating and results in lower overall emissions and higher energy efficiency than gasoline fueled vehicles, (Reed, 74). Finally, in a bold move by General Motors, in 1992, Chevrolet began taking orders for Chevy Luminas running on 85% methanol, 15% gasoline. Methanol has had its drawbacks which petroleum companies have fought to make known, but as aforementioned, many of these drawbacks have found simple solutions with today’s technology. The main problems involve aldehyde emissions, cold starting, low energy density, and corrosiveness. Aldehyde emissions, specifically acetaldehyde, occur with the incomplete combustion of alcohol, which is inevitable in an ICE. In high concentrations, this chemical can cause skin and eye irritations

along with serious lung damage, as stated again by the CEO of Chevron, Mr. Derr. The chemical also has an offensive odor and harms vegetation. In the U.S., its concentrations may not exceed 360 mg/m3. Acetaldehyde though, is dissimilar to gasoline combustion products in that it cannot remain in the atmosphere long, “it quickly combines with other substances and is rendered inert,” (Grammer, 12). Also, a simple catalytic converter can be added to the tail pipe as it already is with gasoline fueled vehicles, eliminating acetaldehyde emissions altogether. This has yet to be done in Brazil. Cold starting is also a drawback to alcohol fuel as alcohol has a higher vaporization temperature than does gasoline, (Grammer, 12), and it has a lower calorific value than does gasoline,

(Mazzone, 59). Two solutions have been implemented to solve this problem. Originally the idea was to heat the fuel before combustion when the temperature drops, circa 1980, (Grammer, 12). Two solutions have grown from this hypothesis. The first solution was implemented in Brazil with pure ethanol vehicles which can run on either pure ethanol or pure methanol. “The system squirts a bit of gasoline into the carburetor to get the engine started. From then on, the alcohol takes over,” (Mazzone, 59). The second recent solution uses “a hydrogen and carbon monoxide gas mixture produced by decomposing liquid methanol using a submerged electric arc,” (Sethuraman, 157). “The device proposed has the ability to produce up to 0.01 m3/Min. (10 l /Min.) of gas with a thermal

efficiency of 18% relative to the theoretical energy requirements for cracking methanol to carbon monoxide and hydrogen,” (Sethuraman, 157). Corrosiveness has been a severe drawback to methanol use, but this too has a solution. In 1981, Volkswagen began coating the fuel tank, pump, and carburetor with a bronze, copper, or cadmium coating. Other engine parts were chromed or aluminized, (Mazzone, 59). In 1993, a parylene coating of seals and gaskets with elastomer-containing components has proven to help prevent their deterioration when exposed to alcohols in the engine, (Pyle, 78). Parylene coatings were tested with a range of aggressive alternative fuels by soaking samples in the fuels for 168 hours at 158?F, (Pyle, 78). Modifications to methanol vehicles or fuel-flexable