Optimisation of Biodiesel Synthesis from Waste Cooking Oil in the Reactive Distillation Column Using Taguchi Methodology

Abstract

Traditional biodiesel methods have disadvantages of excessive alcohol demand, short catalyst life, high manufacturing cost. Reactive distillation (RD) simplifies operations by combining reaction and separation. In literature, there was a few experimental study on continuous–flow biodiesel in RD column with heterogeneous catalyst. So, it was aimed to develop economical continuous process for producing fatty acid methyl esters from low price waste cooking oil (WCO) in RD column packed with cheaper basic heterogeneous calcium oxide. Taguchi orthogonal arrays were used as experimental design to reduce number of experiments significantly. Conversions and steady state times were obtained in range of (72.99–99.52 )% and (1.67–6.25) hour, respectively. Effects of four parameters were analyzed by statistical analysis of variance (ANOVA) and numerical optimization was performed by programs embedded in Design–Expert 6.0. Optimum conditions at the maximum conversion of 99.48% and steady state time of 1.69 hour were determined as WCO flow rate of 2.90 ml/min, methanol/oil molar ratio of 8.19 and reboiler heat duty of 0.419 kW by numerical optimization. Considering results were quite compatible with literature, it was understood Taguchi, ANOVA and numerical optimization were carried out successfully. Consequently, it was deduced high conversion and economically feasible biodiesel could be probable by using this methodology.