Synthesis and optimization of Hydnocarpus wightiana and dairy waste scum as feed stock for biodiesel production by using response surface methodology

Abstract

This study examines that a non-edible dairy waste scum and Hydnocarpus Wightiana oil is claimed to be a highly potential feed stock for biodiesel production. Response Surface Methodology (RSM) in aggregation with Central Composite Design (CCD) is employed to evaluate the best potential combination of catalyst concentration, methanol to oil molar ratio, reaction time and temperature for higher yield of biodiesel content. A statistical model predicted that the highest conversion yield of scum oil methyl ester (SOME) and Hydnocarpus Wightiana oil methyl ester (HWOME) would be 91.636% and 94.091% at the following optimized reaction conditions: Methanol to oil molar ratio of 7.5:1 and 6.526:1, Catalyst Concentration of 0.961 wt% and 0.934 wt%, Reaction Time 49.529 min and 45 min and temperature 63.46 °C and 64.386 °C respectively. Experiments were conducted for SOME and HWOME at the predicted optimum conditions in three independent replicates, an average biodiesel yield of 90.89 ± 5% and 93.68 ± 4% was achieved which was in reasonable agreement with the predicted value. This study shows that the quality of biodiesel production from SOME and HWOME at optimum process conditions satisfies the ASTM D-6751 and EN14214 Standards. The physio-chemical properties of SOME and HWOME were determined and compared with that of diesel.