Improved biodiesel production through the chaotic motion of magnetic whole-cell biocatalysts in an electrical-induced magnetic microchannel reactor.

This study focuses on the application of magnetic whole cells biocatalysts (MWCBs) ofCandida catenulataas the intracellular lipase source for methanolysis of soybean oil in a microchannel reactor under a direct current-induced magnetic field (DC-IMF) and an alternating current-induced magnetic field (AC-IMF). The results showed the active mixing of MWCBs under both IMF systems improved the performance of the microreactor to achieve higher fatty acid methyl ester yield (YEFME) and transesterification rate (R)however, the DC-IMF was more efficient than the AC-IMF. Different magnetic field intensities and their applied direction, geometrical characters of the microchannel (length and diameter), and operational factors including feed flow rate and MWCB loading were evaluated on the transesterification performance and the washout of MWCBs in the systems. The highest YEFME = 45.68 % and R = 5.61 × 105 µmol gBiocatalyst-1min-1 were obtained without any biocatalyst washout under a DC-IMF with intensity of 32 mT for the microreactor operated at a diameter of800 nm, length of 60 cm,feed flow rate of 0.23 mL min-1,and the MWCB loading of 0.2 %wv-1. This microreactor was checked for continuous production under these optimal conditions and the results showed the sustainability which kept 87 % of the original YEFME. A cascade consisting of three microchannels gained a high FAME yield up to 94 % under the DC-IMF system.