Alkali catalyzed transesterification of cottonseed oil by microwave irradiation

In this work microwave assisted transesterification of cottonseed oil was carried out in the presence of methanol and potassium hydroxide (KOH). Parametric studies were done to investigate the optimum conditions (catalyst amount, reaction time and temperature). To compare the heating systems conventional heating was also employed in transesterification. As a result, 7 min reaction time, 333 K temperature and 1.5% catalyst–oil ratio were obtained as optimum reaction parameters for microwave heating. Similar results were found out for conventional heating but 30 min of reaction time. Mono, di and triglyceride contents of cottonseed methyl esters (biodiesel) were determined by gas chromatography analysis. Biodiesel yield and purity were in the range of 89.5–92.7% and 78.9–99.8%, respectively. The results show that microwave heating has effectively reduced the reaction time.