Assessing the economic viability of pretreatment technologies to make sugars for chemical catalytic upgrading to fuels and chemicals

Abstract

The monomeric/polymeric sugars derived from cellulose and hemicellulose must be nearly pure (>95%) for chemical catalytic upgrading to chemicals and fuels. This work reports the results of a qualitative screening study of biomass pretreatment and fractionation technologies that can meet this purity requirement. Two technologies, combined autohydrolysis and organosolv (AOF) and formic acid pulping (FAP), were found to be suitable for the effective fractionation of lignocellulose to yield cellulose, hemicellulose, and lignin. The estimated costs of making nearly pure (>95%) polysaccharides from a lignocellulosic feedstock were US$0.66 per kg (AOF) and US$0.36 per kg (FAP). The limiting factor for commercialization was the high ratio of liquid-to-dry-solid required for biomass fractionation using both AOF and FAP technologies.