An overview on the process intensification of microchannel reactors for biodiesel production

Biodiesel produced from esterification or transesterification of oils from renewable energy sources is the only alternate to liquid fuels and can be directly used in currently existent diesel engines. The cost of biodiesel is an important issue and the commercial production of biodiesel should require low energy and minimum downstream steps. The intensification of biodiesel production using microchannel reactors is an exquisite option that improves conversion, lessens the reaction time and enriches product purity. The increased mass transfer rates and high surface to volume ratio are the striking features of this reactor. This review focusses on the feasibility of utilizing microchannel reactors for biodiesel production. The emphasis is given to mixers used, channel configurations, reactor dimensions, flow behaviour and diffusion pathways. The influence of methanol to oil ratio, reaction temperature and catalyst concentration on biodiesel yield is discussed at length. Finally, the problems and the challenges pertaining to these reactors to obtain improved performance are elaborated.