Biodiesel production using Candida rugosa as biocatalytic lipase immobilized on p‐nitrobenzyl cellulose xanthate (NBXCel)

Abstract

This work investigated the best reaction conditions to obtain biodiesel from soybean oil using Candida rugosa lipase (CRL) immobilized on p‐nitrobenzyl cellulose xanthate (NBXCel) support. The alcohols used were methanol and ethanol and the molar ratio used was 1:4 (n/n). The CRL immobilized on NBXCel support showed greater catalytic activity at pH 7.00 and at 45 °C. Thus, 23 experiments were carried out at this pH and at this temperature, varying the reaction time, type of alcohol, and amount of immobilized CRL to achieve a conversion equal to or greater than 96.5% as recommended by EN 14103. The highest conversions of methyl biodiesel were achieved using 4.31%mCRL/mNBXCel and with 3.89%mCRL/mNBXCel. Ethyl biodiesel was achieved at the highest conversion using 5.18% and 4.76%mCRL/mNBXCel. The results were explored with regression analysis to identify the best reaction conditions to obtain a good conversion, and the response surface graphs were plotted to visualize other reaction conditions. We also evaluated the number of reuse cycles of CRL immobilized on NBXCel support, to lower biodiesel production cost, and after 15 cycles of reuse the conversions obtained were above 50%, demonstrating the efficiency of CRL immobilized on the NBXCel support in catalyzing the synthesis of biodiesel. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Ion Exchange Resin and Entrapped Candida rugosa Lipase for Biodiesel Synthesis in the Recirculating Packed-Bed Reactor: A Performance Comparison of Heterogeneous Catalysts

“…Other types of enzymes, such as invertase, are also able to be entrapped using calcium alginate, however, with an optimal reusability of nine cycles [47]. The advancement in immobilization of CRL by Rial et al [48] using p-nitrobenyl cellulose xanthate (NBXCel) was also capable of producing >90% yield using 4.31% (ratio of lipase mass with NBXCel mass). The immobilization can retain >50% conversion even after 15 cycles.…”

“…When the reaction of enzymatic catalysis was terminated after 12 h, low reaction rates were observed and may be caused by inaccessible enzymes due to the gel matrix and low methanol ratio in the substrate. The reaction time for enzymatic biodiesel synthesis is generally conducted for 24 h [23,44,48]. Conversely, resin catalyst can achieve a high yield of biodiesel within 3 h of reaction time [7,8,51].…”