Box-Behnken response surface methodology was employed to optimize the process variables in alkaline-catalysed transesterification of oils from seeds of Lophira lanceolata into biodiesel following initial acid-catalysed esterification. The model equation obtained from regression analysis adequately express the relationship between the biodiesel yield and the process variables with R2 of 96.05%.The optimization result suggested the best combination of the process variables for optimum biodiesel yield of 85.0%, are: reaction temperature (500C); reaction time (120min); amount of methanol (6 cm3/g oil) and catalyst concentration (0.30 mol/dm-3). Validation yield of 83% compares favorably with the predicted value, showing that the model is reliable in describing the transesterification process. Results of GC-MS analysis of the biodiesel revealed it mainly consists of methyl esters of octadecenoic acid (69.5%), palmitic acid (9.4%) and hexacosanoic acid (5.6%). The biodiesel was very fluid with most of it fuel properties in conformity with ASTM standards making it suitable as fuel for diesel engines.
Key words: Optimization, Lophira lanceolata, transesterification, Biodiesel, Behnken design
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