| dc.description.abstract | Due to the fluctuation in oil prices and global warming there is a global move to adopt renewable energies (RE) and energy efficient (EE) technologies in-order to reverse green house gas emission and mitigate climate change. Finland for example has a total share of 25% renewable energy technologies, 18% nuclear power, 5% peat and only 5% 'imported electricity and 47% fossil fuel (Eerola, 2009). Whereas, Kenya is a net importer of fossil fuel - mainly from Murban(72.4 percent) and Arabian medium crude oil (27.6 percent) as at 2007 (KNBS, 2007),which accounts for 90 percent of the total commercial energy consumed in the country.
Ethanol is an agricultural product that can be used as renewable energy in the form of blended mixture of ethanol and gasoline, or in pure form as ethanol fuel. Blended ethanol - gasoline fuel are referred to as EX - E referring to ethanol and X referring to the percentage blend. Bio-ethanol in Kenya can be dated back to the year 1982 after the energy crisis caused by the 1973 oil embargo followed by the 1980 - 1981 IranIraq war. Kenya Agro-Chemical Company was set to produce absolute ethanol to supplement conventional petrol during the 1982 world oil crisis, ana the main feed stock was molasses.
The objectives of the study were to produce ethanol from high cyanide cassava species, to carry out physiochemical characterization of the ethanol - unleaded gasoline blend, and carry out performance analysis of three fuel blend (E10, E15, E20) against unleaded gasoline and to establish the exhaust emissions characteristics. The project was segmented in three phases, cassava harvesting, ethanol production and yield estimation; ethanol - unleaded gasoline blending and physiochemical characterization and finally engine performance test and exhaust gas analysis. A 1300 cc Toyota engine was coupled to an eddy current - Heenan dynamometer for engine performance test and a Testo 350 - XL flue gas analyzer was used in exhaust gas emission analysis.
Cyanide level analysis showed complete dissociation of the poisonous hydrogen cyanide in the cassava tuber from 2.441% w/w to insignificant amounts in fermented mash and distilled ethanol. Ethanol from high cyanide cassava estimated yield was 12% w/w which gives an approximate yield of 1.15 tonnes of ethanol per hectare of land. The engine test illustrated that the rate of fuel consumption increased with percentage
ethanol in the fuel blend however the BSFC fall by 2.7%,5.4% and 5.3% for E10, E15 and E20 respectively compared to unleaded gasoline. The emission data showed reduction of CO and rise in CO2 composition in the exhaust gas emissions with increased ethanol - unleaded gasoline fuel blend.
From the tests E20 was found to be the best performing fuel blend under the study circumstances. | en_US |
