Ethanol vs Methanol as Gasoline Supplement - Research Paper Example

? Lecturer: Ethanol versus Methanol as a Supplement to Gasoline Gasoline is used as a source of fuel just like nuclear energy, petroleum, coal and electrical energy. Gasoline is a refined product of crude petroleum oil containing hundreds of hydrocarbon ingredients and ethanol is just among the many compounds. The volatility of a hydrocarbon determines the type that is going to be used in the manufacture of gasoline. Crude oil needs distillation and refining to make gasoline because crude petroleum comprises of hydrocarbons more or less volatile than gasoline. Gasoline is made up hydrocarbons molecules hydrogen and oxygen and carbon that can be oxidized to form water and carbon dioxide. The saturated hydrocarbons are the major components of gasoline mainly alkenes like 2-methyl-2-butene, alkanes like isooctane and cycloalkanes. In addition it also contains oxygenators which are pre used hydrocarbons that contain oxygen and are good substitutes for aromatics besides reducing the smog forming properties of exhaust gases. They include ethanol, methanol, methyl tertiary butyl ether and tertiary amyl methyl ether. Gasoline contains octane enhancers, aromatics like benzene, and blending agents to make high quality gasoline by adding preservatives. Methanol is used as safe way of storing energy. It is yielded by recycling carbon dioxide gas from its toxic state to inexhaustible carbon source. It is also environmental friendly due to its reductive conversion from carbon dioxide. It can also be converted to di-methyl ether which possesses a high calorific value and is an excellent diesel and house hold gas substitute. In addition methanol and related oxygenates can be made from carbon dioxide through aqueous electro-catalytic reduction without prior electrolysis of water to yield hydrogen leading to formation of oxygenated fuels through electrolytic conversion of water and carbon dioxide. INTRODUCTION Ethanol fuel usually refers to a gasoline that contains ethyl alcohol. Flex fuel is a gasoline containing 85% ethanol. Ethanol is an alcohol made from carbohydrates and has many uses in the fuel industry. It can be used as an oxygenator, a primary type of gasoline, an octane enhancer and a water absorber making it useful as a gas additive product. When used as a fuel the engine of the motor vehicle must be designed to run on high alcohol levels (Dewick, Green and Miozzo 134). Also fuels containing ethanol release less energy compared to non-alcoholic fuels. Being an excellent solvent it dissolves fuel system parts, rubbers, plastic, fiber glass and to some extent aluminum. In addition the rubber that is used to in the fuel system parts shrink, swell or loose strength when exposed to ethanol reformulated gasoline. Methanol can be used as alternative fuel in small petrol engines having an advantage over gasoline because it is liquid under atmospheric pressure and also its energy density is about half of that of gasoline (Liu and Zhang 56). The distribution of methanol uses the same infrastructure as for distributing gasoline. The vehicles that are to use methanol needed to be installed with direct methanol fuel cells in contrast to hydrogen consuming devices which require liquid fuel to deliver power to run the automobiles. Use of methanol as fuel is eco-friendly hence posing intrinsic advantages to the environment than using gasoline as it enables efficiency of the engine, greater power density and it is cost effective (Liu and Zhang 55). DISCUSSION Ethanol is hygroscopic and an excellent solvent. Ethanol is added at gasoline pumps after the gas has been produced and delivered at the major gas refinery because of the risk of water contamination when traveling through the pipelines. Studies have shown that 10% ethanol gasoline dissolves 50 times more water than the conventional non-alcohol gasoline. Water dissolves in an ethanol blended fuel leading to the occurrence of phase separation (Miller and Spoolman 420-425). Phase separation of gasoline occurs because too much water is absorbed into petroleum based gasoline. An upper ethanol deficient gasoline layer and lower ethanol-rich layers are formed. This compromise with the running of motor vehicle engines because ethanol is completely dissolves in water but only marginally soluble in hydrocarbons. After phase separation the gasoline layer will have a lower octane number as the fuel is less volatile. The various uses of ethanol as a renewable and clean source of energy have led to its increased exploitation (Freudenberger 115). The feed stocks are the raw materials used in the manufacture of ethanol. Fermentation occurs to convert the simple sugars into ethyl alcohol. This further undergoes distillation to produce a high proof fuel grade ethanol. Ethanol has organic emissions that have lower reactivity than gasoline but higher than methanol. It also has lower emissions of toxic gases as it is produced from recyclable domestic sources. Developments are being made for enzyme based production though there is stiff competition at high production levels. (Dreyfus 51) Gasoline contains more compounds as most of the hydrocarbons molecules are alkanes. When gasoline is burned in an engine all the compounds burn to react with oxygen to form carbon monoxide because gasoline contains different several isomers of octane. Complete combustion of gasoline hydrocarbons yields more energy than incomplete combustion in addition to reducing the levels of emission of potentially harmful compounds like carbon monoxide and soot (Hoffman 100). Gasoline on its own composition does not work very efficiently therefore the need for incorporating additives in its mixture. This is because additives improve engine performance, the unwanted engine emissions are also reduced and it also reduces the dependence on imported petroleum products. The first fuel additive was tetraethyl lead as it improved on the compressibility of gasoline though it was very toxic to the environment. This led to being replaced by ethanol. This was because ethanol increased the oxygen content of gasoline making what is referred to as oxygenated fuel (Brown, Brown and Holme 117). Reformulated gasoline is prescribed in areas that have experienced severe pollution. Gasoline containing 10% ethanol can be used in any automobiles but an 85% mixture is for specially designed engines. At these high levels the ethanol is used as an alternative fuel rather than a gasoline additive. Another additive is methyl tert-butyl ether (Brown, Brown and Holme 118). Gasoline has been widely used as a source of fuel in many countries to propel motor vehicles. Chrysler on merging with Daimler Benz advocated the use of methanol as an alternative fuel in the automotive industry. In 1999 the functional aspects of the industry made the Daimler-Benz company left the oil industry to develop methanol infrastructure to conform to the environmental image (Dewick, Green and Miozzo 144). The use of methanol as source of fuel has resulted in limited environmental pollution because it produced from recycled products alleviating the menace of global warming due to high level emissions of the carbon dioxide (Sack 116). Methanol can be used for household use and combustion of engines as it is also suitable fuel for fuel cells. The production of methanol offers a convenient way of storing energy and recycling carbon dioxide gas which is harmful to the environment. Using selective absorption and other separation technologies carbon dioxide is harnessed to produce products that have inexhaustible renewable carbon source (Goeppert, Olah and Prakash 8). Methanol is produced from fossil fuels, from methane without producing syn-gas and from biomass including the cellulosic sources. As discussed earlier methanol is a convenient energy storage material and an excellent method of fuel transportation and being a liquid with a boiling point of 64.6oC it is easily transported. Methanol can easily be converted into dimethyl ether which has a high calorific value compared to gasoline and is an excellent diesel fuel and household gas substitute (Goeppert, Olah and Prakash 55). When using methanol the vehicle development must be advanced, the organic emissions from methanol combustion have lower reactivity than gasoline. Also it has abundant natural gas feedstock and less flammable than gasoline. The disadvantages of methanol over gasoline are that its more toxic than gasoline, it costs more than gasoline especially during the transition period as its more expensive when manufactured from coal. It has also low vapor pressure making it unsuitable in the cold weather (Dreyfus 50-51). RESULTS AND CONCLUSION Ethanol has an energy content of about two thirds that of gasoline and an octane level of 101.5 and a less vapor pressure in comparison to gasoline. Because of the high octane levels ethanol powered automobiles outperforms an equivalent of a gasoline powered vehicle in addition to energy efficiency. Due to ethanol’s affinity for water, phase separation and water contamination occurs faster reducing engine capacity of machines. Also ethanol requires an excellent fuel system management besides ethanol being safer for the environment. It is also a cleaner burning fuel (Dreyfus 51). It also helps to reduce our dependence on foreign oil imports. Methanol is not a source of energy but a convenient way to store, transport and use any form of energy. The need hydrogen for conversion of carbon dioxide into methanol can be produced from water using any renewable or atomic energy source. The fuel preferences of methanol and gasoline in the automotive industry are determined by a combination of institutional differences, technological characteristics and firm specific interests (Hoffman 112). The use of methanol has led to elimination of green house gases because of chemical recycling of carbon dioxide to methanol offers a new feasible long term solution to render coal use cleaner. The chemical recycling of natural and industrial carbon dioxide sources into methanol and its derived products is widely implemented making use of the natural carbon neutral and regenerative mitigating the grave environmental problem linked to global warming. The process also provides economic value for the carbon recycled for fuels and synthetic hydrocarbon products. Methanol and ethanol can be used as the supplements for gasoline but they experience barriers like the high costs of these fuels in addition to the highly developed technology and massive infrastructure that exists to produce, distribute and use gasoline as the primary fleet fuel. This leads to the slow take over of using the alternative sources as they all depend on public acceptance. Both ethanol and methanol have organic emissions that have a lower reactivity than gasoline making them better suplements of gasoline gas(Dorf 67). Though methanol and ethanol are limited in their supply addition of small quantities of ethanol to gasoline is aimed at reducing the carbon monoxide emission levels. The using 100% ethanol is seen as way of reducing the concentration of ozone in the urban areas. By supplementing gasoline the fuel infrastructure needs to be overhauled to suit the properties of ethanol and methanol which is very expensive to the economy. WORKS CITED Brown, Larry, Lawrence Stephen Brown and Tom Holme. Chemistry for Engineering Students. Texas: Cengage Leraning, 2010. Dewick, Paul, Kenneth Green and Marcela Miozzo. Technology, Knowledge And The Firm: Implications for Strategy and Industrial Change. New York: Edward Elgar Publishing, 2005. Dorf, Richard C. Technology, Humansand Society: Toward a Sustainable World. Carlifornia: Academic Press, 2001. Dreyfus, Daniel. Energy Technology Choices: Shaping our Future. Washington DC: Diane Publishing, 1991. Freudenberger, Richard. Alcohol Fuel: A Guide to Making and Using Ethanol as a Renewable Fuel. Gabriola Island: New Society Publishers, 2009. Goeppert, Alain, George Olah and Surya G.K Prakash. Beyond Oil and Gas:The Methanol Economy. Weinheim: John Wiley and Sons Publishers, 2011. Hoffman, J A. From Heresy to Dogma: An Institutional History of Corporate Environmentalism. Boston MA: Stanford Buisness Books, 2000. Liu, Hansan and Jiujin Zhang. Electrocatalysis of Direct Methanol Fuel Cells:From Fundamentals to Applications. Hong Kong: John Wiley and Sons Publishers, 2009. Miller, Tyler and Scott Spoolman. Living in the Environment. Belmont: Cengage Learning, 2011. Sack, Phillip. Geothermal Market:A renewable Energy for the Future. London: Grin Verlag, 2006. Read More