Membrane Performance on Biodiesel Production and Purification: A Review

Biodiesel is considered as a renewable and cleaner fuel compared to the equivalent fossil fuels. However, the conventional methods of biodiesel production as well as its purification processes present economic and environmental limitations. Membrane based systems can significantly improve biodiesel yield retaining the unrecovered feedstock and recycle it to the reactor for further esterification/transesterification. Moreover, the simultaneous removal of byproducts leads in high purity and quality biodiesel production. The current study presents recent experimental and modeling results based on a PRISMA literature review analysis. Several membrane-based catalytic systems were categorized by their performance and stability on biodiesel production as well as by their biodiesel purification for glycerol removal. Findings indicated that high biodiesel yield can be achieved by using catalytic synthesized membranes of different materials; while their stability presents high rate after several runs in batch mode or continuous running mode. In the purification process, glycerol removal over filtration membrane systems seems to be a viable solution for obtaining high quality biodiesel and avoiding wet washing methods that result in wastewater generation. Membrane technology contributes in biodiesel production and purification processes enhancing cost reduction and environmental protection. Nevertheless, more research is required for further industrialization.