Chapter 13 - Conversion of cellulosic biomass to furanics

Abstract

Transformation of naturally abundant and sustainable biomass to biobased chemicals has recently received much attention and is appealing. Among various value-added chemicals, furanic compounds represent one of the most important classes of intermediates that can be derived from cellulose and hemicellulose part of biomass and further valorized to a wide variety of products. In line with this the chapter covers the recent development in the production of furanics, such as 5-hydroxymethylfurfural (HMF) and furfural (FUR), from different sources of biomass. This chapter discusses the influence of ionic liquids (ILs) with and without metal salt on the production of HMF and FUR from various biomass resources. Imidazolium-based ILs are profoundly studied as they can enhance the solubility of lignin and other polysaccharides via hydrogen bonding; however, due to high viscosity of ILs, cosolvents like dimethylacetamide–LiCl or methyl isobutyl ketone–H2O are also employed. Apart from the use of ILs, this chapter also focuses on the effect of mono and biphasic solvent systems in the presence of different homogeneous (e.g., CrCl3) and heterogeneous (e.g., zeolites) catalysts on the yield of HMF and FUR. Biphasic or binary solvent systems (e.g., 2-methyl tetrahydrofuran–water and tetrahydrofuran–water) are usually preferred due to simultaneous production and extraction of formed furanics from the aqueous phase. Further, this chapter also delineates the industrial approach for HMF and FUR productions to a small extent.