Anju Chadha

Biodiesel was prepared from the non-edible oil of Pongamia pinnata by transesterification of the crude oil with methanol in the presence of KOH as catalyst. A maximum conversion of 92% (oil to ester) was achieved using a 1:10 molar ratio of oil to methanol at 60°C. Tetrahydrofuran (THF), when used as a co-solvent increased the conversion to 95%. Solid acid catalysts viz. Hβ-Zeolite, Montmorillonite K-10 and ZnO were also used for this transesterification. Important fuel properties of methyl esters of Pongamia oil (Biodiesel) compare well (Viscosity = 4.8 Cst @ 40°C and Flash point = 150°C) with ASTM and German biodiesel standards. © 2005 Elsevier Ltd. All rights reserved.

Polyols undergo rapid selective transesterification with β-ketoesters upon microwave irradiation in solvent-free and catalyst-free conditions to form monoesters. Copyright © Taylor & Francis, Inc.

The kinetics of the transesterification of vegetable oil is known to follow a three-step reaction mechanism. The third step involves the transesterification of MG. In this study, the transesterification of MG obtained from crude Pongamia oil was achieved with methanol in the presence of KOH as the catalyst. A MG/methanol ratio of 1:10 was used at different temperatures (30, 45, 55, and 60°C). 1H NMR was used to monitor the progress of transesterification. The study revealed that the kinetics of this reaction followed a reversible second-order model, with a good fit obtained for all temperatures except 30°C. This result is explained as arising out of the importance of transport effects at low temperatures. The forward rate constant increased with an increase in temperature, whereas the reverse rate constant showed a decreasing trend, suggesting that the proposed reverse reaction was not an elementary step.