IMPROVING JATROPHA BIODIESEL YIELD THROUGH THE BOX-BEHNKEN PROCESS VARIABLES OPTIMIZATION METHOD

Evolving challenges due to global warming, emissions and depleting natural reserves have prompted the search for alternatives to fossil fuels. Biodiesel is one such promising alternative. However, the significantly low yield from biodiesel feedstock sources has been a deterring factor preventing its large scale production in Nigeria. This research work is therefore aimed at optimizing process variables affecting the yield of biodiesel from jatropha curcas crude. Esterification of the crude was carried out using 1% (w/w) of sulphuric acid as catalyst in order to reduce its free fatty acid content. Upon esterification, three process variables; catalyst concentration, reaction temperature and the reaction time were varied simultaneously at different ratios for 15 run of the BoxBehnken Design while transeterifying the crude maintaining a constant methanol to oil ratio of 6:1. The BoxBehnken method was used to optimize the investigated variables. The result show an optimal yield of 99 % biodiesel for a 60oC reaction temperature, 90 minutes reaction time and 1% (w/w) catalyst concentration. A model equation was also developed that could be used to determine the optimum operating ratios of the process variables for best yields.