Anhydrous HCl gas-induced alcoholysis of cotton linter fibers

Abstract Alcoholysis has attracted attention because of its potential to isolate platform chemicals and biofuel precursors from cellulosic biomass. We investigated the degradation of native cellulose fibers via alcoholysis using various alcohols (ethanol, 2–propanol, t–butanol, and ethylene glycol) and anhydrous HCl gas as an acid catalyst. We explored the impact of these different systems on the leveling-off degree of polymerization (LODP). Fibers soaked in ethylene glycol and t–butanol reached LODP under the default conditions, i.e., 50 wt.% alcohol content. When subjected to a post-hydrolysis step, the fibers previously alcoholyzed in ethanol and 2–propanol attained the LODP level as well. However, the production of monosaccharides during post–hydrolysis was 20 times higher from the fibers that had been alcoholyzed previously by ethanol than with 2–propanol.