Diesel Engine Emissions and Performance Characteristics under Cape Chestnut Biofuel

Jedidah W.  Maina; Ayub N.  Gitau; James A.  Nyang’aya

doi:10.4236/jpee.2013.16002

Jedidah W. Maina^*, Ayub N. Gitau, James A. Nyang’aya

Abstract: Cape Chestnut oil was processed to biodiesel through transesterification. Cape Chestnut kennels are reported to have oil content of 60% - 63% [1]. Properties of biodiesel were determined and compared with those of diesel and engine tests done at a constant speed of 1500 RPM on the biodiesel blends to evaluate their performance and emissions characteristics. Performance evaluation was in terms of Brake Specific Fuel Consumption (BSFC), Brake Horse Power (BHP) and Brake Thermal Efficiency (ETE). The engine was initially run on diesel to establish the reference characteristics before running on biodiesel blends. The biodiesel was blended with diesel volumetrically to 80% (B80), 50% (B50), 20% (B20) and 5% (B5) the percentage being the volume of biodiesel in the blended fuel. Diesel fuel had the lowest BSFC followed by B5 whose BSFC was 7.3% higher than that of diesel. BTE for B100 was lower than that of diesel by 20.3% while that of B5 was 7.6% lower. Concentration of SO2 in B100 was 92.7% lower than that of diesel fuel while that of B20 was 24.7% lower. NO and NO2 concentrations for B100 were around 15% higher than that of diesel. Particulate matter of less than 10 μm diameter (PM10) for diesel was found to be 72% of the total collected from all the test fuels as compared to that of biodiesel blends at 28%. The study concluded that Cape Chestnut biodiesel blends containing up to 20% biodiesel can be used in an unmodified diesel engine since their performance and emission characteristics were very similar to that of diesel but with reduced toxic gas emissions therefore friendly to the environment.

Keywords: Biodiesel; Transesterification; Performance; Emissions; Brake Specific Fuel Consumption; Brake Horse Power; Engine Thermal Efficiency

Cite this paper: Maina, J. , Gitau, A. and Nyang’aya, J. (2013) Diesel Engine Emissions and Performance Characteristics under Cape Chestnut Biofuel. Journal of Power and Energy Engineering, 1, 9-14. doi: 10.4236/jpee.2013.16002.

References

[1] A. W. Wagutu, S. C. Chhabra, C. L. Thoruwa, T. F. Thoruwa and R. L. A. Mahunnah, “Indigenous Crops as a Source for Production of Biodiesel in Kenya. Bull,” Chemical Society of Ethiopia, Vol. 23, No. 3, 2009, pp. 359-370.

[2] E. Sulle and F. Nelson, “Biofuels Land Access and Rural Livelihoods in Tanzania,” IIED, London, 2009.

[3] A. Monyem and J. H. V. Gerpen, “The Effect of Biodiesel oxidation on Engine Performance and Emissions,” Biomass and Bioenergy, Vol. 20, No. 2001, 1999, pp. 317-325.

[4] A. K. Agarwal, “Bio-Fuels (Alcohols and Biodiesel) Applications as Fuels forInternal Combustion Engines,” Progress in Energy and Combustion Science, Vol. 33, No. 3, 2006, pp. 233-271. http://dx.doi.org/10.1016/j.pecs.2006.08.003

[5] Kenya National Bureau of Statistics, “Leading Economic Indicators,” 2010.

[6] Kenya Bureau of Statistics, “Economic Survey Highlights,” 2012.

[7] D. Mitchel, “Biofuels in Africa: Opportunities, Prospects and Challenges,” The International Bank for Reconstruction and Development, The World Bank, 2011.

[8] Y. Liu, T. Lin, Y. Wang and W. Ho, “Carbonyl Compounds and Toxicity Assessments of Emissions from a Diesel Engine Running on Biodiesels,” Journal of the Air and Waste Management Association, Vol. 59, No. 2, 2009, pp. 163-171. http://dx.doi.org/10.3155/1047-3289.59.2.163

[9] Government of Kenya, Ministry of Energy, “Sessional Paper No. 4 on Energy,” Government Press, 2004.

[10] Government of Kenya, Ministry of Energy, “The Energy Act No. 12 of 2006,” Government of Press, 2006.

[11] D. L. Clements, “Blending Rules for Formulating Biodiesel Fuel,” National Biodiesel Board, 1996.