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Global warming is increase in earth's average temperature near the surface and oceans. This started around mid twentieth century and continues to be a challenge globally. Global warming results due to an increase in green house gases concentration as a result of human activities which includes deforestation, fossil fuels use, global dimming from high concentrations of aerosols which block rays of sunlight from reaching earth surface. During the twenty first century, global warming is on the rise as indicated by projections of climate models. Increase in global temperature causes rise in sea levels resulting to precipitation pattern changes and subtropical deserts e expansion. In arctic regions it results to permafrost, sea ice and glacier retreat. Global warming also associated with species extinction, extreme weather changing agricultural yields. It varies with the region and is uncertain. Increase in carbon dioxide in the atmosphere causes oceans to be more acidic. It is associated with health hazards such as skin cancer, respiratory diseases such as asthma and greater damage to the poor (Keppler 2006 p. 13)
Global warming reduction through decreased greenhouse gas and carbon emissions will certainly save money, improve standards of living and reduce pollution. As carbon dioxide is emitted during combustion and fermentation of corn, it is cancelled out during greater crop uptake in the growth process to produce the biomass. Ethanol from corn is therefore a less pollutant as compared to the other fossil fuels. Reducing future climatic changes is called mitigation and one way to accomplish that is through the use of corn ethanol.
In developing countries, ethanol could replace the use of kerosene for cooking and lighting. Ethanol stoves could replace charcoal, wood and kerosene as a source of bio-fuel. This can be locally made in rural areas. The organic origin of ethanol is an advantage. Ethanol burns cleaner than gasoline. Cars which use E85 ethanol in a blend of 85/15 ethanol to gasoline have less toxic emissions. Ethanol has fewer amounts of toxic substances like benzene. Green house and ozone gases from car exhaust is lower in ethanol as compared to gasoline. Corn ethanol is a sustainable and renewable source of energy.
Corn in Relation to Global Warming
Corn is used increasingly to produce heat by use of wood pellets and maize kernels in corn stoves. Maize cobs are source of biomass fuel. Maize is also used as ethanol fuel in feedstock production. Ethanol is added to gasoline so as to reduce pollutants when used in motor vehicles. With increasing fuel prices, ethanol is highly demanded. Corn ethanol has higher density than fuels like methanol thus less volume is required to cover equal distance. Aromatics, hydrocarbons and olefins associated with gasoline combustion are toxic and are eliminated with use of ethanol.
Corn ethanol has higher oxygen percentage than other fossil fuels and its complete combustion means that it has no effect to global warming unlike fuels that are petroleum based. Use of just ten percent ethanol in gas tank decreases emission of greenhouse gas by nineteen percent. Ethanol from corn cause no pollution to ground water as ethanol separates in contact with water. It is environmentally safe as ethanol it is biodegradable. Other fuels pollute ground water (Michael, "Wise Geek")
Corn Ethanol is produced as a biomass from corn by a process of industrial fermentation, chemical reactions and distillation. In Unites States ethanol production is derived from corn and used in gasoline oxygenation resulting to a less pollutant form of fuel.
The corn ethanol results to less greenhouse gas emission and is biodegradable. This ethanol reduces greenhouse gas emission by twenty percent as compared to gasoline. It is more efficient form of renewable energy. Future prospects show that the fuel could result to about eighty two percent reduction of greenhouse gas emission compared to gasoline. Fuels blended with ethanol meet the required standards. Ethanol biodegrades readily causing no harm to environment and is a safe replacement as a high performance fuel additive as compared to others such as MTBE.
Corn ethanol in United States is derived from yellow corn. Other alternatives in the production of bio-fuel are corn Stover which could replace food corn. Cellulosic biomass for ethanol production is a rising trend in bio-fuel production. Food/fuel debaters consider second generation bio-fuels as a solution. (Goettemoeller et al 2007 p.42)
Production of Corn Ethanol
Corn ethanol is produced in two ways. These are wet milling and dry milling. In wet milling, corn grains are added to a solution of water and dilute sulphuric acid for a period of twenty four to forty eight hours so as to separate the corn grain into various components. The slurry mixture is taken to series of grinders so as to separate corn germ. Corn oil is extracted as a by-product. The remaining fiber, starch and gluten are segregated by use of hydroclonic, centrifugal and screen separators. Gluten is extracted, dried and is filtered for corn gluten meals especially used for poultry meals.
Corn starch and water is fermented to ethanol. Corn ethanol production uses water for irrigation and processing. Ethanol processing could either be wet or dry with difference being on the initial treatment of the grain. In wet milling, the grain has to be steeped in water and separated for processing. Eighty percent of corn ethanol production in United States is through dry grid process. This is where the milled grain is slurred using water so as to create a mash where enzymes are added and cooked for hydrolysis of starch to glucose. The sugars are fermented by yeast to produce carbon dioxide and ethanol. Ethanol is then purified through molecular sieve dehydration and distillation to get fuel ethanol.
Dry milling is where the grain is ground into floor called a meal. The meal is slurred with water and enzymes are added for conversion of starch into dextrose. Addition of Ammonia follows so as to control pH as well as a nutrient for yeast. High temperature processing of the mixture is done so as to decrease the level of bacteria. The mixture is cooled in fermenters where it is transferred. Addition of yeast is done which converts sugar to carbon dioxide and ethanol as the final product. The whole process takes about forty to fifty hours and mash is agitated and kept cool so as to facilitate the activity of yeast. Completion of the process is followed by distillation. Ethanol is dehydrated using molecular sieve and denaturant like gasoline is added to make it undrinkable. The product is used as livestock feed and carbon dioxide for carbonating beverages and making dry ice.
With increasing volatility in the oil market, alternative fuel such as corn ethanol is very crucial. Ethyl alcohol blended with gasoline is known as gasohol. In its pure form, ethyl alcohol is an alternative to gasoline. To calculate the amount of corn needed to produce corn ethanol several factors are considered. Corn ethanol yields thirty four percent higher energy than it takes for its production. This involves growth, harvesting, transport and distillation process. Estimating energy input to determine net energy value of corn ethanol, all non renewable energy requirements such as those required in growth and processing ethanol are added up. Improvement in conversion technology has enhanced ethanol production (Hosein et al 2002 p.12)
A positive net energy value of corn ethanol shows that it is highly efficient. When ethanol is produced from domestic corn, united States reduce overreliance on imported fuel. As production of corn increase, energy value of corn is expected to increase. Cellulose ethanol has helped the United States to be 1.5% independent and by twenty seventeen, it is estimated to rise to 3.7%. These figures ignore the foreign input of fossil energy for ethanol production.
Corn Ethanol is a source of bio-fuel that is a less pollutant and cause less emission of greenhouse gases which causes global warming. Countries should consider using this form of alternative fuel so as to preserve the environment and reduce over reliance to fossil fuels which are hazardous to the environment. This not only safeguards people's health but also improves their economic status through use of domestic corn to produce fuel. Corn production should increase so as to attain the required biomass for energy production to run various activities.