Transesterification of vegetable oils into biodiesel by an immobilized lipase: a review

Abstract

Abstract The goal of biodiesel production is to obtain a clean, biodegradable, and renewable fuel. Industrial-scale processes use homogeneous and heterogeneous chemical catalysts. These are efficient but require the use of very pure reagents and complex product purification steps or processing conditions under high temperature and pressure. Enzymatic catalysis, in contrast, using lipases as biocatalysts, is an alternative that produces a better-quality product under less extreme conditions. Since free lipases are not reusable, it is necessary to immobilize them to stabilize them and allow their reuse over several reaction cycles. This informative review presents various methods of lipase immobilization (physical adsorption, ionic bonding, covalent bonding, entrapment, encapsulation, and cross-linking) as well as their advantages and disadvantages, followed by a comparative study. Articles from 2010 to 2022 were used for bibliometry to show that the topic is still relevant. The immobilization methods are classified into two main groups, physical and chemical, according to the enzyme-support interaction. Among these methods, ionic bonding is recommended, because in addition to this process being easily achievable, lipases immobilized this way are more stable and reusable. In summary, the production of biodiesel from immobilized lipases is in line with sustainable development and respect for the environment.