Optimization and effect of varying catalyst concentration and trans-esterification temperature on the yield of biodiesel production from palm kernel oil and groundnut oil

Abstract

The negative environmental impact generated by fossil fuel has resulted in the demand to search for alternative routes of renewable sources of energy, such as biodiesel, that have unlimited duration while having little or no hazardous impact. In this study, trans-esterification of palm kernel oil and groundnut oil was carried out using sodium methoxide (CH3 ONa) as a catalyst. The effect of varying Sodium Methoxide (CH3 ONa) catalyst concentrations of (0.25, 0.5, 1.0, 1.5, and 2.0) % w/v at trans-esterification temperatures of (50, 55, and 60)oC on the yield of biodiesel from groundnut oil and palm kernel oil was determined. This was to identify the catalyst concentration and trans-esterification temperature with optimal process yield. The process gave optimum biodiesel yields of 98% and 84% by volume of groundnut oil and palm kernel oil at reaction conditions of 0.5%w/v CH3 ONa as catalyst, trans-esterification temperature of 55oC, 360 rpm mixing rate and a reaction time of 90 minutes. The biodiesel produced was analyzed for fuel properties using the American Society of Testing and Materials (ASTM) standard, and the results obtained were as follows; specific gravity (0.8835, 0.8815 at 15oC), flash point (98, 124)oC, viscosity (5.2, 7.6) mm2S-1at 40oC, pour point (9,-1)oC, iodine value (8.04, 17.11) /100, acid value (0.67, 0.48) mg/ KOH/g, peroxide value (28, 60) mg Kg-1, fire point (108,136)oC for palm kernel oil and groundnut oil respectively.