Chapter 15 - Ionic liquids for bioenergy production

Abstract

The future global economy will be governed by the sustainable production of bioenergy. The abundantly available lignocellulosic biomass is considered as a major and potential feedstock for the generation of biobased energy. However, obtaining bioenergy from lignocellulosic biomass is a very challenging task due to the highly intractable and recalcitrant nature of the lignocellulosic material which makes biomass nonvulnerable and less productive for bioenergy production. Biomass pretreatment could be the clue to improving biomass vulnerability and accessibility for bioenergy production. Among various advanced pretreatment methods and technologies, ionic liquids (ILs) offer efficient pretreatment of lignocellulosic biomass by offering delignification, disrupting the crystallinity of cellulose, and increasing cellulose accessibility. Thus, the use of IL pretreatment of biomass is a perfect solution which makes reluctant biomass materials vulnerable to sugar fermentation and subsequent bioenergy production. Though satisfactory results have been reported with the use of IL in bioenergy production, there remain several major challenges that need special attention and extensive research, which include the IL synthesis price, biodegradability, purity, stability, recyclability, toxicity, costing, scaled-up processing, and the enzymatic and environmental compatibility of ILs. In view of this, this chapter discuss (1) the feedstock for bioenergy production, (2) IL as a potential solvent for bioenergy production, (3) effective IL pretreatment of biomass, (4) significant use of IL for bioethanol, biobutanol, biohydrogen, biomethane, biogas, and biodiesel production, and (5) challenges and opportunities in the utilization of IL for bioenergy production.