Abstract:
Rice bran is a by-product of the rice milling process and contains 10–25% oil depending on
rice variety, milling procedure, and other agro-climatic factors. To supplement the dwindling fossil fuel
reservoirs and reduce environmental pollution, there is need to investigate rice bran oil for use as a bio-diesel.
Rice bran was sourced from small scale rice millers in Mwea, Kirinyaga County, chemically processed to
biodiesel which was used then used in a diesel engine to determine its performance. The engine performance
was studied using a single cylinder four stroke engine and EA10 Dynamometer using diesel as a control and
biodiesel blends of 5:95, 10:90, 15:95,20:80, 25:75, and 30:70 biodiesel to diesel respectively. It was observed
that the engine speed decreased with increase in load for all the fuels. Brake power increased with increase in
the percentage of biodiesel in the blend. The average brake power for B5 was 2.636KW while that of B30 was
2.682KW. The average BSFC increased by 47% when using biodiesel B100. However this reduced to 13.2%
when using a blended ratio of 5:95. Thermal efficiency was the same for biodiesel, diesel and blends meaning
the engine was converting the chemical energy to mechanical energy with the same efficiency for all the fuel
types. This study revealed that bio-diesel from rice processing gave similar characteristics as diesel and that it
is readily available and can thus be used as a fossil fuel subsidy. It will go a long way in poverty reduction in
line with the millennium development goals.
