Evaluation of oil transesterification in a packed‐bed reactor containing lipase immobilized in starch–alginate jet cutting beads

Abstract

AbstractThere has been a growing interest in ecofriendly enzymatic processes. However, enzyme solubility limits the application of many biocatalysts in continuous systems, requiring the development of cost‐effective strategies for enzyme immobilization. Based on this premise, this study investigated the application of lipase immobilized in starch–alginate beads for oil transesterification in a tubular reactor. An economical derivative was produced by immobilizing Eversa Transform 2.0 in 50:50 (w/w) starch–alginate beads using the jet‐cutting technique. The biocatalyst had a particle size of about 500 μm and activity of 138.67 ± 18.53 U g−1. X‐ray photoelectron spectroscopy showed nitrogen content ranging from 6.38% to 7.29%, with uniform distribution of lipase throughout the beads. Nitrogen isotherms were characteristic of mesoporous materials, with an average pore diameter of 48.09 Å and low surface area (0.69 m2 g−1). A face‐centered central composite design was used to study soybean oil transesterification. In the best four runs, the process achieved a mean triglyceride conversion of 45%. High ester productivity levels (2.05 × 10−2% ester g−1 biocatalyst min−1 or 1.5 × 10−4% ester U−1 min−1) were obtained. Biocatalyst reuse led to a twofold increase in ester concentration (14.57% vs 7.7%). These findings confirm the successful development of a low‐cost biocatalyst suitable for use in continuous reactions.