Optimized Biodiesel Production from Madhuca Longifolia using Two Stage Transesterification Process

Abstract

Optimization biodiesel production from tree borne, non-edible Madhuca longifolia oil was experimentally investigated in the present study. Madhuca longifolia, categorised under second generation of feedstock for biodiesel production, has wide scope in the future. As the Free Fatty Acid (FFA) content of Madhuca longifolia oil was 19% the biodiesel production was carried out by using two stage esterification and transesterification processes. In the first stage acid catalysed esterification was done using H2SO4 and the FFA content of Madhuca longifolia oil was brought down to less than 2%. The second stage of transesterification was carried out using NaOH as base catalyst. During the transesterification, the observation was made on various operating parameters like reaction time, catalyst concentration and methanol to oil molar ratio at three different reaction temperatures 55C, 60C and 65C. The optimised process parameters for the maximum yield of 87.8% of Madhuca longifolia biodiesel were methanol to oil molar ratio of 1:6 % weight of catalyst to oil of 3.00 for a reaction time of 60 minutes at reaction temperature 60C. In order to use the produced Madhuca longifolia biodiesel in the existing engines, the physiochemical properties were measured for its compliance with American Standard for Testing Materials and found to be in accordance with ASTM D6751 standards.