Determination and Evaluation of Fuel Properties of Groundnut (Arachis hypogaea, L.) Biofuel Blended with Diesel
Vegetable oils have attracted attention as potential renewable resources for the production of alternatives for petroleum based diesel fuel. This study focused on the evaluation of fuel properties of groundnut oil and its ethyl ester blended with diesel to establish their suitability for use in compression ignition engines. Twenty biodiesel blends (10, 20, 30, 40, 50, 60, 70, 80, 90 and 100%) of groundnut oil and its ethyl ester by volume with Automotive Gas Oil (AGO) were used. The fuel properties of the biodiesel blends such as specific gravity, viscosity, cloud and pour point, flash point, heating value, sulphur content and carbon content were determined according to ASTM standards. Data were analyzed using ANOVA and correlations between fuel properties and blending ratios of groundnut biofuel with AGO were developed. Pure AGO was used as a basis for comparison. Results showed that viscosity of 10 - 30% groundnut ester-AGO blends (5.5 – 5.8 mm2/s) fell within the limit specified by ASTM standards. The heating values of groundnut biodiesel blends decreased from 38.4 – 30.07MJ/l. Groundnut ethyl-ester had higher cloud point of 7oC compared to -12oC obtained for AGO. The flash points, cloud and pour points of groundnut oil and its ethyl-ester AGO blends were higher than for reference AGO. The specific gravity obtained for all groundnut ester-diesel blends ranged from 0.8 – 0.9 and it fell within limit specified by international standards. All the biodiesel blends had sulphur contents ranging from 9.16 – 13.2% and lower than that of reference AGO. Predictive fuel properties’ models gave R2 of 0.55-0.98. Biodiesel blends with 10 and 20 percent groundnut ethyl ester content were found to have acceptable fuel properties for use as supplementary fuel in compression ignition engines.