Thursday, April 2, 2009

Bioethanol, Alternative Energy

Continuity of fossil fuels (fossil fuel) issue - at least Edua serious threat: (1) economic factors, such as the availability of collateral fossil fuels for several decades, the problems of supply, price, and fluktuasinya (2) pollution resulting from fuel combustion emissions fossil to the environment. Pollution caused by burning fossil fuels have impact directly and indirectly to human health derajad. Pollution can be a direct gas-dangerous gas, such as CO, Nox, and UHC (unburn hydrocarbon), as well as metallic elements such as proportional (Pb). While pollution does not directly form the majority of explosion of the number of CO2 molecules impacting on global warming (Global Warming Potential). Awareness of the threat was serious intensify various research aims to produce the sources of energy (energy resources) or of energy (energy carrier) is more assured Sustainability (sustainable) and more environmentally friendly.
Alcohol for fuel
Use of alcohol as fuel began to be implemented and examined in the USA and Brazil since the occurrence of fossil fuel crisis in the two countries in the 1970s. Brazil recorded as one of the countries that have high seriousness in the implementation of the alcohol fuel for motor vehicles with the use of fuel ethanol at this time reached the national 40ecara (Nature, 1 July 2005). In the USA, relatively cheap fuel, E85, which contains ethanol 85emakin popular in the community (Nature, 1 July 2005).
In addition to ethanol, Methanol was also used as a fuel alcohol in Russia (Wikipedia), while the Environment Ministry of Japan has been in the year 2008 targets gasolin + ethanol mixture 10kan used to replace the entire gasolin in Japan. The same Ministry also ask automobile manufacturers in Japan to create a vehicle that is capable of operating with the fuel mixture to start in 2003 (The Japan Times, 17 December 2002).
The Government of Indonesia, in this case the State Ministry of Research and Technology has been targeting at least one factory making biodiesel and gasohol (a mixture of alcohol and gasolin) in the year 2005-2006. Besides, that also targeted the use of bioenergy will reach 30ari national energy supply in 2025 (Kompas, 26 May 2005).
Ethanol can be used in pure form or as a mixture for gasolin fuel (gasoline) and hydrogen. Ethanol interaction with hydrogen can be used as a source of energy in the fuel cell or combustion in the engine (internal combustion engine) conventional. On this paper, discussed briefly: (1) the impact on the use of ethanol in combustion engines with spark plugs ignition (spark ignition), and (2) the implementation of fuel ethanol in Brazil-the country has serious use of fuel ethanol.
The use of ethanol in combustion engines in
Nowadays, almost all the engine power is used on vehicles using the engine in burning. Gasoline engine (Otto) and diesel are the two types of combustion engines in the most widely used in the world. Diesel engine, which has higher efficiency, grow rapidly in Europe, the USA, while communities that tend to worry in the pollution level of sulfur in diesel and UHC, prefer gasoline engines. Although at this time, the quality of diesel fuel and diesel engines used in Europe is the better of berimplikasi on low sulfur emissions and UHC. Ethanol, which is teoritik have octane number above the maximum standard gas, applied as a suitable substitute in part or in whole on the gasoline engine.
There are a number of internal characteristics, which caused the use of ethanol in the ethanol Otto engine better than gasolin. Ethanol research have the number 108.6 and the motor Octane Octane 89.7 (Yuksel et al, 2004). Numbers (especially research Octane) exceeded the maximum value that may be achieved by gasolin (even after the added aditif on gasolin). As a note, gasoline sold Pertamina has a 88 Octane number research (Website Pertamina) (note: the information is not available for motor Octane Website gasolin in Pertamina, but generally lower motor Octane Octane than research).
Octane number fuel engine on the Otto show terbakarnya ability to avoid the mixture of fuel-air time before the (self-ignition). Terbakarnya mixture of air-fuel engine in Otto akan cause premature phenomenon percussion (knocking), which potentially reduce engine power, can even cause serious damage to the engine components. During this time, percussion phenomenon limiting the use of the compression ratio (the comparison between the volume of the cylinder volume remaining) on the high gasoline engine. The high octane number of ethanol allows the use of a high compression ratio in the Otto engine. The correlation between the efficiency of the compression ratio on the fact that berimplikasi Otto engine based fuel ethanol (in part or in whole) has a higher efficiency compared to gasoline fuel (Yuksel et al, 2004), (Al-Baghdadi, 2003). To the mixture ratio of ethanol: gasoline reaches 60:40 the efficiency up to 10 Yuksel et al, 2004).
Ethanol has one molecule in the order OH molekulnya. Inherent in the oxygen molecule in ethanol is helping these burning mixture of air-fuel in the cylinder. Plus the range keterbakaran (flammability) is wide, ie, 4.3 - 19 voldibandingkan with gasoline that has a range keterbakaran 1.4 - 7.6 vol-air combustion mixture of fuel ethanol to be more well-trusted as this causes the relatively low emissions compared to CO-air combustion gasolin, ie, about 4 et al, 2004). Ethanol also has a summer evaporation (heat of vaporization) is high, ie 842 kJ / kg (Al-Baghdadi, 2003). The high heat causes evaporation energy is used to vaporize ethanol is greater than gasolin. About the consequences of this is the peak temperature in the cylinder will be lower in comparison with burning ethanol gasolin.
The low NO emissions, a condition in the atmosphere will form NO2 which is toxic, is relatively low as a result of the peak combustion temperature in ethanol in the cylinder. At the compression ratio of 7, Nox emissions reduction can be reached 33ibandingkan of Nox emissions generated in the combustion gasolin the same compression ratio (Al-Baghdadi, 2003). From the order molekulnya, ethanol has a carbon chain is shorter than gasolin (molecular formula is C2H5OH ethanol, while gasolin has a chain C6-C12 (Wikipedia) with a comparison between the H atom and C is 2:1 (Rostrup-Nielsen, 2005)). Short chains of carbon atoms in the ethanol in the UHC emissions cause burning ethanol are relatively low compared with gasolin, ie, to deviate 130 ppm (Yuksel et al, 2004).
From the above explanation, that the use of ethanol (in whole or in part) at the Otto engine, causing a positive increase in engine efficiency and decrease emissions CO, Nox, and UHC compared with the use gasolin. However, it should be noted that higher aldehyde emissions in the use of ethanol Emeski danger to the environment aldehyde emissions are lower than the various emissions gasolin (et al, 2004). In addition, in principle, the CO2 emissions produced by burning the ethanol will also be used by plants to produce ethanol. So different from fossil fuels, burning ethanol does not create a number of new CO2 to the environment. Especially for cases in Indonesia, where gasoline is sold Pertamina still contain reciprocal (TEL) of 0.3 g / L and 0.2 sulfur wtWebsite Pertamina), the use of ethanol clearly better than gasoline. As known, TEL is one of the substances aditif used to increase the gasoline octane number, and this substance has been banned in many countries in the world because of the nature racunnya. The existence of sulfur is also a concern in the USA and Europe because of the impact of the ditimbulkannya for health.
Akan pure ethanol reacts with the rubber and plastic (Wikipedia). Therefore, pure ethanol can only be used on machines that have been modified. It is recommended to use rubber fluorokarbon as a substitute for rubber components in the conventional Otto engine. In addition, ethanol molecules that are polar will be difficult to mix perfectly with the gasolin relatively non-polar, particularly in the liquid condition. Therefore, modifications need to be done on machines that use a mixture of ethanol-fuel gasolin so that both types of fuel can be evenly mixed in the fuel space. One of the innovations on the problems this is creating additional special carburettor to ethanol (Yuksel et al, 2004). At the time step hisap, steam and ethanol mixed gasolin akan during travel from the carburettor to fuel space Ememberikan level of mixing is better.
Studying the case of fuel ethanol in Brazil
Brazil a program of fuel ethanol in large scale since the occurrence of the oil crisis in the 1970s era (Riberio et al, 1997). Ethanol extracted from sugar cane (sugarcane). The plant is not used in the production of sugar / ethanol, ie, bagasse, are used as fuel for distillation to produce ethanol and electricity Ebaik to meet the needs of electricity and ethanol plant sold to the public. Burning bagasse relatively environmentally friendly fuel than oil and coal. Gynecology only bagasse ash coal 2.5dibandingkan: between 30-50 and bagasse also does not contain sulfur (Wikipedia). By using bagasse, ethanol factory Feed does not require energy from outside, thus he can sell the remaining electricity to the dihasilkannya community. Especially since it occurred in the summer, when the power of water can not meet the maximum demand in the public electricity (Wikipedia).
Position of the fuel ethanol program and products to them in Brazil during the period 2003/2004 (kecual mentioned otherwise) are:
Agricultural area: 45.000 m2 in 2000
Labor: 1 million jobs - (50ertani, 50emrosesan)
Sugarcane: 344 million tons (50-50 for sugar and alcohol)
Sugar: 23 million tons (30ieksport)
Ethanol: 14 million m3 (7.5 anhydrous, 6.5 hydrated; 2.4ieksport)
Bagasse dry: 50 million tons
Electricity generated: 1350 MW (1200 MW is ethanol plant, 150 MW sold to the public) in 2000
Source: Wikipedia
* As a comparison, PLTU Suralaya which is a supplier of electricity 25ebutuhan Java-Bali has a capacity of 3400 MW (Source: Miningindo).
The use of fuel ethanol (pure or mix with gasolin) has calculated the CO2 emissions in Brazil from the year 1995-2010 was 293 tons (hypothetical low) to 461 tons (hypothetical high). This means that the annual CO2 emissions can be reduced in Brazil is about the hypothetical high 12ila (Riberio et al, 1997).
Implementation of fuel ethanol in Brazil does not run forever mulus. Political support and incentives needed for the sustainability of government programs. At the beginning of the implementation program of fuel ethanol, ie, in the 1980s, more than 90obil sold in Brazil is that of a car specific fuel ethanol (Riberio et al, 1997). But not lancarnya ethanol supply in the early 1990s caused car sales to reach the same only less than 1i 1997 (Riberio et al, 1997). In 1997, only half of the whole number of cars in Brazil that uses a special fuel ethanol, while the rest use a mix gasolin + ethanol (up to 22 (Riberio et al, 1997). Meanwhile, at this time, as presented in the beginning, 40asokan energy originating in Brazil of bioethanol (Nature, 1 July 2005).
The influence of the environment
Some American scientists outs bioethanol implementation of the environmental problems appear by bioethanol production chain. Scientists is to highlight the practice of burning their fields in order to make it easier to harvest sugar cane, soil damage due to threats to the biodiversity, the use of large amounts of water to clean the sugarcane, and soil erosion caused by sugar cane cultivation practices (Nature, 1 July 2005). In addition, some people also questioned the ratio between the energy produced to energy required in ethanol production, which only reached 1.1 (Rostrup-Nielsen, 2005).
To minimize the negative impact of ethanol production chain, the government of Brazil has issued rules that prohibit burning cane fields before harvest, and instead used machines pemanen to facilitate and speed up the harvest, (Wikipedia). Assessing the quantitative implementation of ethanol, such as that practiced in Brazil, should also be a factor next to the product of bagasse produces electricity (in a significant amount) and the effect of reducing CO2 emissions correlate positively to the level of public health. In the case of hydrogen fuel, Jacobson et al (2005) estimates that around 3700 - 6400 people per year akan terselamatkan if all vehicles in the USA migrate using hydrogen fuel is raised from wind energy. Therefore, if the factor-factor is calculated succession, appears to be the use of bioethanol will be superior to the gasolin. While the threat to biodiversity may be solved by using some plants as a source of ethanol. Although relatively more difficult in the settings, multicultural practices were expected to decline in the quality of the soil drastically.
Conclusion
Two serious threats that arise due to dependence on fossil fuels, namely: economic factors (the result of limited exploration in the supply, price, and fluktuasinya), and the factors fossil fuel pollution that harm the environment, would not want to force people to consider alternative energy pengadaannya a more assured and friendly towards the environment. Gasohol is an alternative that allows a transition to the implementation of alternative energy to run with mulus.
From the engineering and power generation waste gas emissions, ethanol (in the form of pure or mixture) relative to the superior gasolin. The use of ethanol as fuel in the combustion in the engine will improve engine efficiency, and decrease the level of gas emissions harmful to the environment (relative to gasolin). Side products such as electricity, and the impact of a decrease in CO2 emissions are the two value added which is very positive contribution to the environment.
There are several things you can learn from Brazil in the implementation of the bioethanol fuel, namely: (1) The need to diversify sources of ethanol to avoid the decline in soil quality drastically (2) Implementation of fuel bioethanol better start from mixing gasoline + ethanol, not from the use of bioethanol 100Hal will ensure the transition towards more bioenergy mulus Esembari prepare a more mature era in case the use of bioethanol 100ipandang has arrived (3) Need for close cooperation with the automotive industry to provide a vehicle for the implementation of the optimal fuel gasoline + ethanol (4) Need synergies between institutions and between the central and local governments in the provision of raw materials, processing, and distribution of fuel bioethanol.

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