The Potential of Microwave Technology for Glycerol Transformation: A Comprehensive Review

Abstract

Glycerol is a major by-product in biodiesel manufacturing, which accounts for around 10% of the biodiesel volume. A surplus of glycerol has led to the development of technologies for production of value-added products using glycerol as a raw material, following the “waste as a resource” strategy. Various techniques are available to carry out glycerol transformation, viz. carrying out processes under thermal heating, application of ultrasonic or hydrodynamic cavitation, microchannel technologies, etc. Microwave-assisted organic synthesis (MAOS) is a simple and innovative technology, which can be considered as a means of intensifying these processes. This review describes microwave irradiation as a valuable energy-efficient alternative to conventional heating for the production of value-added chemicals from glycerol via dehydration, hydrogenolysis, esterification, transesterification, etherification, and oxidation. In general, innovative and potential catalysts, approaches, and technologies are discussed and critically evaluated in terms of the possibilities and potential for further industrial implementation