Integrated microsystems for lipase-catalyzed biodiesel production and glycerol removal by extraction or ultrafiltration

Competition among renewable energy sources in today's market is growing rapidly. Renewables have grown to the point where they are taking significant material market share from coal, gas, and uranium. Recently, biodiesel production has been intensified by lipase-catalyzed transesterification performed in microsystems. Another challenge in biodiesel production is the purification of the biodiesel. Common purification methods are usually more energy and time consuming than the biodiesel production itself. In this work, an integrated biodiesel production process composed of lipase-catalyzed trans-esterification of sunflower oil and product purification was performed in microreactor and micro-separator units connected in series. Glycerol, the by-product of the transesterification process, was removed from the reaction mixture by two different separation methods, deep eutectic solvent extrac-tion and membrane separation. Different integrated setups were developed and evaluated in terms of FAME yield and purity. The most promising integrated process was found to be the one combining 2-inlets feeding strategy for biodiesel production in a microreactor with a microseparator connected in series, in which a choline chloride-glycerol deep eutectic solvent was used. In this integrated system, a FAME yield of 94% and a glycerol content below 0.02% (w/w) were achieved for the residence time of 20 min. (c) 2021 Elsevier Ltd. All rights reserved.