Advantages And Disadvantages Of Alternative Fuels Environmental Sciences Essay

Advantages And Disadvantages Of substitute(a) Fuels Environmental Sciences EssayThe worlds push consumption has been increasing progressively since the industrial revolution (SEP, 2009). Global population is continuing to dramatically rise and the increase in economic development, particularly in China and India, over recent decades has contributed to increases in energy consumption (Hillstrom Hillstrom, 2003). Currently, nearly 45 pct of Australias total energy consumption is accounted for by coal, with rock oil providing approximately 35 percent, natural gas supplying around 15 percent and green billet providing just over 5 percent (Hillstrom Hillstrom, 2003). Alternative fuels argon stated to be a potentially viable resource to the purpose of fogy fuels. fogy fuels contribute to almost eighty percent of the total energy used in the world (Evans, 2007 International Energy Agency (IEA) Bioenergy, 2005). Fossil fuels are non-renewable resources that are limited in their sup ply and the burning of fossil fuels on a global scale can produce breeze pollution, such as northward oxides (NOx), release significant amounts of greenhouse gases, such as carbon dioxide (CO2), and contribute to global warming (Evans, 2007 Shahid Jamal, 2008 Hill, et al., 2006 SEP, 2009). Alternative fuels are considered to have a less unfortunate effect on the environment, and are stated to be a solution to the problems created by fossil fuels (SEP, 2009). Alternative fuels, such as ethyl alcohol, methanol, and biodiesel may prospectively provide an selection for global fuel requirements. The main difference betwixt fossil derived fuels and alternative fuels is the oxygen content, with alternative fuels having 10-45 wt% oxygen compared to fossil fuels which contain almost none (Gupta Demirbas, 2010). on that point are however, a number of drawbacks related to to alternative fuels which may inhibit them from completely replacing fossil fuels without technological or geneti c advancements (U.S. Congress, Office of technology Assessment, 1990).OutlineThis paper aims to examine the advantages and blemishs of alternative fuels. The discussion will commence by defining a number of relevant terms. The analysis will accordingly consider ethanol and methanol as alternative fuels, including their payoff. Subsequently, biodiesels and their production will be examined. Following this, the advantages and disadvantages of alternative fuels will be considered. The use and manufacturing of alternative fuels in Australia will then be assessed. Lastly, the main arguments of this account will be summarised.DefinitionsAlternative fuels are a sustainable form of energy, are fuels that have not derived from petroleum and can include alcohols, biofuels, hydrogen, natural gas and propane (Saddleback Educational Publishing, 2009). They are commonly solid, liquid or gas biofuels acquired from biomass, vegetable oil, or generated from agricultural provender crops (Demirba s, 2008 Hill, et al., 2006). A viable alternative fuel must be economical, supply a net energy gain, be beneficial to the environment, and be able to be produced in considerable volumes with limited detrimental impacts (Hill, et al., 2006). The alternative fuels that are presently prevalent throughout the world are ethanol and biodiesel (Vadas, Barnett Undersander, 2008 Groom, Gray Townsend, 2008 Gupta Demirbas, 2010). Ethanol alike referred to as ethyl alcohol, and methanol, methyl alcohol, are colourless liquid alcohols, less dense than wet, with the chemical formulas C2H5OH and CH3OH respectivley (Baird Cann, 2008). Biodiesel is a carbon-neutral fuel that is a mixture of fatty acerbic methyl esters (Baird Cann, 2008 Kemp, 2006).Alcohols Ethanol and MethanolEthanol is one of the most widely utilized liquid biofuels that can be combined with gasoline to create an ethanol blend fuel, or it can be used in pure form (Gupta Demirbas, 2010 Baird Cann, 2008). It may be derived by fermenting carbohydrates obtained from natural sugars, starches or cellulosic biomass in plants including sugar cane, corn or straw (Gupta Demirbas, 2010 Larkin, Ramage Scurlock, 2004). Generally, this process The USA and Brazil are presently the two major producers of bioethanol (Ragauskas, et al., 2006). In the US, corn is the major master(a) base for ethanol production while in Brazil, sugar cane is dominant (Brown, 2003). Groom, Gray and Townsend (2008) showed that current fuel yield for corn ethanol was surrounded by 1135 1900 L/hectare and that the necessary area of land to meet even 50% of US transport fuel needs was over 157% of US cropland.MethanolBiodieselBiodiesel is obtained from the oil in a variety of seed plants, a large majority world developed from soybean (Larkin, Ramage Scurlock, 2004 Demirbas, 2008). Biodiesel is currently manufactured around the world in countries such as the USA, Germany and Malaysia (Larkin, Ramage Scurlock, 2004 Groom, Gray Towns end, 2008). Globally, approximately 1.5 million tonnes of biodiesel per year is produced (Larkin, Ramage Scurlock, 2004). In Table 4, it can be seen that current fuel yield for soybean biodiesel was between 225-350 L/hectare and that the necessary area of land to meet even 50% of US transport fuel needs was over 180% of US cropland.Advantages and Disadvantages of Alternative FuelsAlternative fuels such as methanol, ethanol and biodiesel have numerous advantages and disadvantages regarding environmental and societal impacts. The backup of fossil fuels with alternative fuels could result in a cliff of CO2 emissions, decrease air pollution and reduce acid rain (Evans, 2007). Additional benefits include sustainability, fuel security, regional development and a decrease in rural poverty (Gupta Demirbas, 2010). The land area required to generate sufficient alternative fuel to meet demands however, may compete directly with agriculture requirements, water use, may cause pollution from the use of herbicides and pesticides, and could result in the destruction of natural habitats and a decrease in biodiversity (Evans, 2007 Giampietro Ulgiati, 2005). In developing countries, the expansion of the alternative fuel industry could increase deforestation, decreasing the removal of CO2 from the atmosphere through photosynthesis (Groom, Gray Townsend, 2008).Methanol and EthanolAdvantagesThere are several advantages concerning the use of methanol and ethanol as alternative fuels. Carbon dioxide in the atmosphere is removed by the crop used for ethanol generation, resulting in the process being carbon neutral (Larkin, Ramage Scurlock, 2004). Using ethanol over fossil derived fuels can result in a reduction of CO2 up to 75 percent (Howard Olszack, 2004). Higher densities of ethanol fuel and air can be combusted in an engine compared to petroleum due to ethanols constricted boiling point range and high latent heat of vaporization (Brown, 2003 Demirbas, 2008). Additionally, higher(prenominal) energy density can be achieved in the engine due to a commence stoichiometric air to fuel ratio (Brown, 2003 Demirbas, 2008).This may produce enhanced engine efficiency and elevated power outputs in ethanol fuelled vehicles when contrasted to petroleum fuelled vehicles. The use of ethanol as an alternative fuel can result in lower pollution emissions compared to fossil fuels, particularly regarding particulates, alkenes, aromatics and carbon monoxide (Baird Cann, 2008).Table 2 Alternative fuel properties compared to fossil derived fuels(Adapted from Borman Ragland, 1998, pp. 37).DisadvantagesThere are numerous economic drawbacks to the use of ethanol as a substitute for petroleum-based fuels. Ethanol is still far from being economically agonistic when compared to fuels derived from fossil fuels (Larkin, Ramage Scurlock, 2004 Howard Olszack, 2004). Expensive direct costs required for the production of ethanol can include fertilisers, pesticides, irrigation, fuels and electricity as well as machine or equipment maintenance (Vadas, Barnett Undersander, 2008). Fixed costs tend to include land charges, wages for labourers, insurance and depreciation of assets such as equipment and buildings (Vadas, Barnett Undersander, 2008). The economics of ethanol production are very uncertain its viability depends on the price of crude oil and the world prices of the raw material, for example, sugar (Larkin, Ramage Scurlock, 2004). The production and use of ethanol is not economically militant at present, suggesting that it is not a viable alternative.There are disadvantages linked to the use of methanol and ethanol as alternative fuels. Ethanol has a lower amount of energy generated per litre combusted than gasoline (Baird Cann, 2008). The use of pure ethanol and methanol is limited in colder climates by their low vapour pressures (Baird Cann, 2008). A disadvantage in using methanol is that it is more toxic than gasoline (U.S. Congress, Office of Technology Assessment, 1990). Erosion, northward leaching and denitrification are also other significant problems related to corn produced alcohols (Vadas, Barnett Undersander, 2008). Environmental degradation is an issue related to ethanol production from crops, which leads to the concern of whether biofuel generation is indeed sustainable for certain crops (Vadas, Barnett Undersander, 2008). Ethanol yield from non-homogeneous crops can vary significantly, and are usually inefficient (Larkin, Ramage Scurlock, 2004 Ragauskas, et al., 2006). The production and use of ethanol does not always provide a sufficient net energy gain and there are adverse environmental effects, indicating that it is not a viable alternative.BiodieselAdvantagesThere are a number of positive factors when considering biodiesel over petroleum-based diesel. Biodiesel production is deemed renewable (Shahid Jamal, 2008). The fuel itself is generally non toxic and biodegradable (Demirbas, 2008 Shahid Jamal, 2008). The fuel properties of biodiesel are similar to petroleum-based diesel, revealed in Table 2, allowing it to be used in unmodified confirming injection diesel engines with only minor drawbacks (Brown, 2003 Shahid Jamal, 2008). Biodiesel has a higher flash point, also seen in Table 2, meaning that it is safer to transport and store than diesel (Brown, 2003 Demirbas, 2008).The consume emissions from the fuel contain considerably less nitrogen and sulphur oxides (Shahid Jamal, 2008). These factors support the idea that biodiesel is an alternative form of fuel however this does not make it a viable alternative to petroleum-based diesel.DisadvantagesThere are many limitations related to the use of biodiesel as a substitute for petroleum-based fuels. Biodiesel can achieve an energy ratio as low as three to one (Larkin, Ramage Scurlock, 2004). The production of biodiesel from crops, such as soybean, can result in adverse environmental effects. These can include nitrogen and phos phorus leaching that can lead to the loss of biodiversity and the release of nitrous oxide, a greenhouse gas (Hill, et al., 2006). In some countries, such as Indonesia, Malaysia and Thailand, capacious expanses of forests are being cleared to produce oil-palm plantations for biodiesel (Groom, Gray Townsend, 2008). Biodiesel, compared to fossil fuel derived diesel, tends to produce lower power and torque as well as higher fuel consumption (Demirbas, 2008). Biodiesels are not cost competitive when compared to petroleum-based fuels (Hill, et al., 2006). The cost of biofuel tends to vary on a number of factors including the price of crude petroleum, the variability in the crop and the cost of the feedstock used (Demirbas, 2008). The production and use of biodiesel is associated with some adverse environmental effects and it is not economically competitive at present, indicating that it is not a viable alternative.Alternatives Fuels Use and Manufacturing in Australia-sugar cane (ethan ol)ConclusionAlternative fuels such as methanol, ethanol and biodiesel have both advantages and disadvantages regarding impacts on the environment and society. At present, commercialised biofuel production is a controversial issue that is still relatively new. It is conceivable that biofuels will become a selective alternative to fossil fuels as a source for transportation fuels but not a complete substitute. As oil prices become increasingly more expensive, biofuels do become more economically viable. Biofuels are effective on a small scale basis, but not on a large scale. There are numerous problems currently associated with the manufacturing of biofuels such as the vast amount of land, labour and water required. The development of better second and third generation biofuels would be more effective as they potentially use less land and have a greater chance of being a viable alternative for fossil fuels. Great improvements in current technology, genetic advancements for biomass c rops and reduced environmental and societal effects could see biofuels become a selective substitute but not a replacement for global energy demands.