Catalysis Today, Vol.234, 13-23, 2014
Some important catalytic challenges in the bioethanol integrated biorefinery
The concept of integrated biorefinery is presented and discussed. Integrated biorefineries demand the use of innovation, or rather, new chemical routes must be introduced in order to add value to intermediates and residues. The concept of integrated biorefinery is then applied to an ethanol producing facility and a flow sheet of the main catalytic routes to promote modifications of residues is proposed. CO2 and bagasse are considered the most promising residues to undergo catalytic transformations. Hydrogenation of CO2 to produce syngas/methanol is an interesting alternative to add value to this molecule. Nickel supported on a mixed oxide NiCeZr is presented as an excellent catalyst to produce syngas out of CO2. Furthermore, the potential use of two main components of bagasse, lignin and hemicellulose, is discussed, lignin being deployed as a feedstock to produce activated carbons and acidic sulfonated carbons, Acid sulfonated carbons are shown to be excellent catalysts for hydrolysis/dehydration of biomass derivatives such as polysaccharides and polyols. Moreover, activated carbons may also play an important role as outstanding supports for metal-supported catalysts, which may be used in the hydrogenation of sugars. (C) 2014 Elsevier all. All rights reserved.
Keywords:Ethanol;Biorefinery;Hydrogenation;Carbon dioxide;Lignin;Active carbon;Hemicellulose;Xylitol;Anhydroxylitol