Environment friendly butyl ester biodiesel production from mahua oil: optimization and characterization

Abstract

An attempt was made to optimize the key parameters of acid catalyst esterification and base catalyst transesterification processes for higher biodiesel yield from mahua oil with butanol using traditional optimization procedure. In esterification stage quantity of acid catalyst and molar ratio of butanol to mahua oil were considered for optimization of lowest value of free fatty acid (FFA). In transesterification stage molar ratio of butanol to mahua oil, quantity of alkaline catalyst, process temperature, process time and stirring speed were considered for maximum yield of mahua oil butyl ester. From the results, 6:1 molar ratio of butanol to mahua oil, 2% (w/w) concentrated sulphuric acid (H2SO4) were identified as optimized values with 1.1% FFA value which was reduced from 19.8%. In the second stage results, 6:1 molar ratio of butanol to oil, 1.5% (w/w) potassium hydroxide (KOH), 80 °C process temperature, 90 min process time and 500 rpm stirring speed were recorded as optimized values with 94.8% yield of mahua oil butyl ester. The butyl ester produced with optimum values of transesterification process parameters has been characterized and ensured the satisfaction of EN14214 biodiesel standards requirements.