Advantages and Disadvantages of Ethanol as Fuel

Advantages and Disadvantages of Ethanol as Fuel The top five producers and users of ethanol in 2005 were Brazil producing 4.35 billion gallons per year, The United States producing 4.3 billions gallons per year, China producing 530 million gallons per year, The European Union producing 250 millions gallons per year and India producing 80 million gallons per year. Brazil and The United States account for about 90 per cent of all ethanol production, although in the last few year the United States production of ethanol has grown to about 4.6 billion gallons per year and are now widely consider the worlds largest producer of ethanol. The advantages of ethanol use are: The fuel can utilise existing distribution outlets. Other fuel sources such as hydrogen would require the creation of distribution networks and technology with accompanying establishment costs It is a renewable resource and so would reduce the use of non-renewable materials. It could reduce green house gas emissions if solar energy was used to distil it from aqueous solutions. It reduces dependence on imported oil and the influence of the oil cartels that currently control oil production and price. This reduced dependence on imported oil also protects consumers from the economic variations that are caused by the political and social events in oil producing countries While it is very unlikely that ethanol will ever replace the worlds main energy source, it will reduce the total amount of oil the country would need to import. Disadvantages: There are claims that the production and distribution of ethanol as an alternative motor vehicle fuel source will in fact increase greenhouse gas emissions over those generated by conventional fuels. Large areas of agricultural land would need to be used to grow suitable crops, leading to soil erosion, deforestation fertiliser run off and salinity. There is just not enough land to produce the crops needed for ethanol to become a major alternative fuel, with crops at the moment only sustaining about 1 per cent of the worlds transport fuel. There is also a worry that the land needed for ethanol production will compete with food production. The disposal of the large amounts of smelly waste fermentation liquors after removal of ethanol would present major environmental problems. There is a cost involved in making ethanol is nearly twice as much as the cost of making gasoline. There is also a cost involved in modifying vehicles to use ethanol or methanol. Ethanol also has smaller energy density than gasoline, taking about 1.5 times more ethanol than gasoline to travel the same distance. However with new technologies the advancements in ethanol engines are improving every year. Although ethanol does reduce the toxicity of the car exhaust, it can also be corrosive. Ethanol can absorb water and dirt easily and if those contaminants are not filtered out successfully that can damage the inside of the engine block. The politics that surround the increased use of ethanol in Australia are uncertain. The major political parties have a clear policy position on this initiative at either State or Federal level. There is even debate within the minor political groups that usually defend the environment as to the long term benefits and consequences of increased ethanol consumption. With conflicting claims and a lack of clear evidence, a cautious approach has been adopted by politicians. At State Government level, it is the NSW Government that has principally supported the introduction of ethanol. It has been suggested that the NSW Labor governments position has been influence by donations from major ethanol producers and even the Rudd Federal Labor government is critical of a number of aspect of NSW expansion of ethanol production. Against this background, the NSW Government has consistently refer to the greenhouse benefits of ethanol as one of the reasons for its decision to require that 10% of all fuel sold is to be ethanol (E10) by 2011. There are claims that the long term uses of ethanol are as equally damaging to the environment as conventional fuels. For consumers acceptance of this alternative fuel source is as much about the price at which it will be delivered at the petrol pump, as it is about the environmental motivations. Fermentation and distillation have been used to produce ethanol for centuries, making it one of the earliest organic compounds to be obtained in nearly pure form. Fermentation is a process in which glucose is broken down to ethanol and carbon dioxide by the action of enzymes present in yeast. These enzymes act as biological catalysts, which first convert the starch or sucrose in the mixture into glucose and or fructose. Finally enzymes will convert the glucose and or fructose into ethanol and carbon dioxide. Yeast can produce ethanol contents up to 15 per cent. If the alcohol concentrations were above this level the yeast would be killed and further fermentation would be stopped. To further produce higher alcohol content, up to 95 per cent fractional distillation or even to 100 per cent more elaborate distillation procedures of the liquid are then needed. Plant materials suitable for fermentation must have a high concentration of simple sugars (sucrose, glucose and fructose). Starchy grains like corn, tubers like potatoes and fruits like grapes with high simple sugar contents are most commonly used. Cellulose and starch are biopolymers which are formed by condensation polymerisation of glucose monomers. Cellulosic ethanol is produced from woods, grasses and non-edible parts of the plants. There are two ways of producing ethanol from cellulose; gasification or cellulolysis processes. Gasification transforms raw lignocelluloses materials which are composed of cellulose, hemi cellulose or lignin into gaseous carbon monoxide and hydrogen. These gases can then be converted into ethanol by fermentation and distillation. Cellulolysis processes use hydrolysis, which is where enzymes are used to break up the complex cellulose structures of lignocelluloses materials into simple sugars which then followed by fermentation and distillation can be changed into ethanol. Bibliography: http://www.o2.org/ideas/cases/biopolymers.html http://www.wisegeek.com/what-are-the-advantages-and-disadvantages-of-ethanol-fuel.htm http://www.pictonhigh.net/moodle/course/view.php?id=29 http://science.jrank.org/pages/2576/Ethanol-Disadvantages-ethanol-an-alternative-fuel.html http://www.ethanolproducer.com/article.jsp?article_id=2222 http://www.abc.net.au/catalyst/stories/s1763365.htm http://www.abc.net.au/catalyst/stories/s1763365.htm http://www.smh.com.au/execute_search.html?text=ethanolss=smh.com.au http://www.chemlink.com.au/ethanol.htm http://www.crikey.com.au/2009/01/20/ethanol-not-really-all-that-green/