Circular bioeconomy for biodiesel industry: Upgradation of waste glycerol to value-added products

Abstract

The biodiesel industry suffers from unattractive economy due to rather high costs of oil seeds and the processing cost involved. A key by-product of biodiesel synthesis process is glycerol. However, due to high contamination of alcohol, fatty acids, and alkali, this glycerol is not suitable for other usual applications in food and cosmetic industries. Biocatalytic conversion of this waste glycerol to numerous value-added products can be a possible source of additional revenue, and financial viability, and sustainability for the biodiesel industry. This chapter summarizes the current scenario of both biodiesel and glycerol across the world along with highlighting some recent developments in the area of synthesis of value-added products from waste glycerol. It further outlines, the state-of-the-art knowledge on various energy and other value-added chemicals obtained from biodiesel-based crude glycerol through chemical and biochemical routes in order to satisfy the concept of circular bioeconomy by establishing an integrated biorefinery. Further to this, it presents a comprehensive summary of strategies to be considered for boosting up the production yields of various bio-based products from waste glycerol thereby establishing an economical value-added to the biodiesel industry process. © 2022 Elsevier Inc. All rights reserved.