Exploiting lignocellulosic feedstocks for lignin and chemicals

摘要

Over the past decade, there has been considerable research on cellulosic biofuels. This involves, breaking down biomass residues be it crop or wood waste into component parts cellulose, hemicellulose and lignin, and breaking down the former two further into C5 and C6 sugars to make them available for the production of fuel ethanol via the conventional fermentation routes. There has been considerable research, by both biotech start-ups and government research establishments to develop process conversion technologies to produce purified lignin, a valuable commodity and platform chemical from which to produce a variety of other useful chemicals and end products (e.g. muconic acid and pyrogallol which currently have a combined market value of US$255.7 billion, carbon fibre composites). This paper provides an overview of current developments in the sector and finds that as yet cost-effective technologies for commercial scale exploitation of lignin into a variety of valuable co-products remain in the distant future. One of the critical stumbling blocks is the high reactivity of separated lignin fractions which are prone to side reactions thwarting their full exploitation.