ethanol fuel production and use in kenya for sustainable ... - lumes

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Ethanol can be a potential means to phasing out lead because if neat ethanol is used, there iszero lead emissions (Thomas, 2001; WB, 1994).Renewable resource…“Today’s needs should not comprise the ability of future generations to meet their needs”(WCED, 1987). Ethanol is derived from biomass and biomass is a renewable resource ifproper farm management is practised. Ethanol is thus classified as a renewable form of energy.This makes its production and use sustainable in both the long tem and short term because itsuse will meet both the present and the future generations’ ethanol energy and socio-economicneeds. Its renewable nature is also a form of energy security as opposed to energy forms suchas fossil fuels that are threatened by depletion (Figure 3).4.0 DISCUSSIONThis section is divided into two sections; section one, discusses the costs and benefits of usingethanol as opposed to petroleum and section two discusses the potential crops that could beused for ethanol production and the potential size and location of the ethanol plant. It will alsodiscuss the barriers that could hinder the adoption of ethanol in Kenya.SECTION 14.1 ETHANOL END USEIn order to mitigate air pollution that emanates from the combustion of fossil fuels, ethanol ison a global scale increasingly being used as neat ethanol, blended with gasoline and as anoctane booster, as a substitute for imported oil. (Ahmed, 2001) ethanol cuts down air pollutionand improves urban air quality (Figure 5). However, in addition to the good qualities ofethanol there are some negative qualities that are encountered in the production and use ofethanol. This section will discuss the impacts of using ethanol4.1.1 Environmental FactorsNOXThe use of ethanol may actually increase NOx in the atmosphere. This can be deducted fromthe fact that different experiments have come up with different results in the tests that havebeen done to measure NOx emissions from the use of neat ethanol or ethanol blends and fromthe use of pure gasoline. For instance one study reports study, reports a slight lowering ofNOx in ethanol blended fuels while yet another study reports an increase in NOx by 4.8% forthe same; (Niven, 2004). However, Hsieh et al. (2001) concluded that NOx emission is notinfluenced by the presence or absence of ethanol but by how the engine operates. There isthus need for further research to find out if ethanol does cause an increase in NOx or not andif it does, how the NOx emissions can be reduced.AldehydesThere is a general concern that ethanol and ethanol containing fuels produce worrisomeamounts of aldehydes notably acetaldehyde and formaldehyde (Hsieh et al., 2001;Poulopoulos et al., 2001, 2003; Ahmed, 2001; Niven, 2004). When ethanol is burnt is a greatamount of acetaldehyde which is formed when ethanol emissions from car exhaust and from17
evaporative emissions reacts with hydroxide ions is released (Grosjean, 2001). Brazil reliesheavily on ethanol which it uses as an additive to gasoline and is the only country whereethanol is used countrywide as a fuel and thus its urban air is has higher levels ofacetaldehyde emissions (Grosjean, 2001; Niven, 2004). Human exposure at high levels toacetaldehyde is reported to cause respiratory irritation and it is suspected that it could becarcinogenic to humans (Ahmed, 2001). In the environment, a percentage of the acetaldehydeproduced undergoes photochemical reactions to produce peroxyalacetate nitrate (PAN), acompound that in some cases could lead to severe lung lesions and damage the epithelium ofthe upper part of the respiratory tract in humans whereas in plants, it is to some extentmutagenic and a toxin (Ahmed, 2001).In as far as acetaldehyde emissions have negative impacts on both humans and theenvironment, when compared to the health and environmental damage caused by thepollutants emitted during the combustion of fossil fuels aldehyde emissions are by far lessharmful (Hsieh, 2001; Niven, 2004) In addition, (Niven, 2004) argues that high levels ofaldehydes for instance in brazil, are not strictly the result of exhaust pipe emissions but morefrom higher evaporative losses that arises from the lack of control on fuel Reid VapourPressure (RVP). RVP is a standard laboratory method which measures the inherent tendencyto evaporate for instance at 38°C for gasoline (Emission Inventory Guidebook, 1999)..Ground water contaminationApart from the increase of aldehydes into the atmosphere by ethanol, it is of concern that therisk of soil and ground water contamination is higher when gasoline is blended with ethanol(Niven, 2004). This is due to its impact on other compounds and on the constituents ofpetroleum constituents (Niven, 2004). For instance the contact of ethanol with water leads to areaction that causes the corrosion of steel used in underground storage tanks therebyincreasing the risk of leakage to surrounding soils (Niven, 2004). Further leakage to soilscomes from gas stations’ underground fuel feed lines and from the use of certain materialsthat corrode when used to store or handle ethanol; such material includes certain metals suchas aluminium and zinc and to some extent non metallic materials such as natural rubber andpolyvinyl chloride which degrade depending on the percentage of ethanol (Niven, 2004). Oncontact with water ethanol increases the solubility of gasoline components such as benzeneand toluene in water and also makes them non-biodegradable by inhibiting theirbiodegradation thereby increasing contamination of water and soils (Niven, 2004; Ahmed,2001). Nevertheless since it is known that ethanol use could increase the risk of groundwaterand soil contamination, it is possible to put strict measures that control the construction ofstorage tanks and the pipe system (Niven, 2004).Using ethanol could lead to a decline in environmental quality thus reducing its sustainability.However with better control measures and technological improvement it has been noted, theseproblems could be prevented.4.1.2 Economic FactorsCost of EthanolThe major economic disadvantage of ethanol is that it is expensive to produce thereby makingit a more expensive fuel as compared to petroleum fuels making it to depend heavily on18
Page 1 and 2: LUND UNIVERSITYInternational Master
Page 3 and 4: AcknowledgementsI would like to tha
Page 5 and 6: Table of ContentsAbstract .........
Page 7 and 8: List of acronymsACE - Atmosphere Cl
Page 9 and 10: The oil crisis and low sugar prices
Page 11 and 12: patterns that may be used to predic
Page 13 and 14: REINFORCING LOOP (R1)An increase in
Page 15 and 16: World Oil Prices and Inflation Tren
Page 17 and 18: the strengthened greenhouse effect
Page 19 and 20: Available arable land(carrying capa
Page 21 and 22: need for higher agricultural growth
Page 23: atmosphere” leads to a decrease i
Page 27 and 28: particulate emissions from cane fie
Page 29 and 30: the yields on table 1 probably beca
Page 31 and 32: pastoralists and thus do not cultiv
Page 33 and 34: contributes to global warming. Petr
Page 35 and 36: Gariazzo et al. (2005) Monitoring a
Page 37 and 38: Tsai, et al. (2005) A Hematology Su
Page 39 and 40: Fossil fuels1. Does the country imp

ethanol fuel production and use in kenya for sustainable ... - lumes

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