An overview on advancements in biobased transesterification methods for biodiesel production: Oil resources, extraction, biocatalysts, and process intensification technologies

Abstract Biodiesel is a non-toxic renewable energy source that is gaining attention globally owing to its direct applicability in preexisting engines without any modification. Various technologies from laboratory scale to industrial scale have been developed, and many plants have been established for biodiesel production using various feedstocks. Using biobased technology in biodiesel production is advantageous as these methods generate less waste and are considered ecofriendly. This article mainly discusses the availability of various oil resources (edible, non-edible, waste cooking oils (WCO)) and the advancements in technology related to oil extraction. Specifically, biobased methods, such as immobilized enzymes (matrix) and heterogeneous catalysts (derived from biomass), reported to catalyze the transesterification reaction for biodiesel production are discussed in detail. Biodiesel production using conventional technologies results in low yield and purity and is time-consuming. Newly introduced process intensification technologies (microreactor, membrane reactor, microwave, reactive distillation, and centrifugal contractor) to overcome these issues are also discussed. The need to develop integrated process technologies for biodiesel production to make the process more economical is emphasized.