Thermochemical Conversion of Cellulose and Hemicellulose

Abstract

Thermochemical conversion process is an important and potential route to transform biomass feedstocks into powers, fuels, and a variety of chemical platforms. The chapter describes general characteristics of thermochemical processes of biomass including combustion, pyrolysis, liquefaction, and gasification, with the focus on the thermal decomposition of individual biomass components such as cellulose and hemicellulose. Thermochemical processes occur at a wide range of temperatures and pressures with or without catalysts, in which cellulose and hemicellulose undergo serial primary and secondary reactions to form a variety of product types and yields. Primary reactions of cellulose and hemicellulose are associated with the dehydration and depolymerization process to smaller fragments, monosaccharides units, and volatiles which further decompose to low molecular weight compounds at severe conditions of temperature, times, pressures, and catalysts. Thermochemical decomposition of cellulose and hemicellulose typically produces various fuel sources including bio-char, bio-oil, bio-crude, and syngas, along with diverse substances such as anhydrosugars (levoglucosan, mannosan, galactosan), furans (furfural, 5-hydroxymethylfurfural), organic acids (acetic acid, formic acid, levulinic acid), ketones, and aldehydes. Cellulose and hemicellulose are the most abundant constituents in lignocellulosic biomass. Understanding the mechanism of thermochemical conversion of cellulose and hemicellulose leads to the choice of suitable biomass feedstocks and the transformation process for targeted production.

The research content is presented in chapter 6 of the book "Biomass Utilization: Conversion Strategies". Read more: https://link.springer.com/chapter/10.1007/978-3-031-05835-6_6