Intensified synthesis of medium chain triglycerides using novel approaches based on ultrasonic and microwave irradiations

Abstract

Glycerides of C8–C10 fatty acids, commonly known as medium chain triglycerides (MCTs), have wide applications in neutraceutical, food and pharmaceutical industries. In the present study, intensification of synthesis of MCTs has been investigated based on the use of ultrasound and microwave irradiations. Effect of different operating parameters such as molar ratio, reaction temperature and catalyst loading on the conversion has been investigated. It was observed that the conversion increases as the molar ratio of lauric acid to glycerol increases till an optimum value beyond which only marginal changes are observed. Similar trends have also been observed for the effect of temperature and catalyst loading. The sequential approach of microwave followed by ultrasound gave the best results with maximum conversion as 99.7% in 20min whereas sequential approach of ultrasound followed by microwave resulted in slightly lower conversion of 99.1% but in 40min of reaction time. In the case of individual approaches, maximum conversion as 97.8% was obtained in only 20min using microwave irradiation while using ultrasonic irradiation, the obtained conversion was 97.3% in 120min. The extent of conversion obtained using the conventional approach was only around 40% in 180min as the reaction time. Overall it has been conclusively established that the use of microwave and ultrasonic irradiations result in significant process intensification benefits with the sequential approach of microwave followed by ultrasound being the best approach.