New ways to use biomass

Presently, cellulose is mainly processed by fermentation. For the fermentation process to take effect yeast must be added to the cellulose, this will allow the sugar to be fermented into ethanol as well as carbon dioxide. The next step is the distillation process which is necessary to remove the alcohol from the solids and the water. However, splitting cellulose into its individual sugar components, which can then be fermented, is a slow and cost-intensive process. The direct conversion of cellulose into useful organic compounds is thus an attractive lternative.Researchers in the USA and China have now developed a new catalyst that directly converts cellulose, the most common form of biomass, into ethylene glycol, an important intermediate product for chemical industry. A team led by Tao Zhang at the Dalian Institute of Chemical Physics, China and Jingguang G. Chen at the University of Delaware, Newark, USA has developed a novel process. In this the catalyst is made of tungsten carbide and deposited on a carbon support with small amounts of nickel added to improve the efficiency and selectivity of the catalyst system. A synergetic effect between the nickel and tungsten carbide not only allows 100 % conversion of cellulose, but also increases the proportion of ethylene glycol in the resulting mixture of polyalcohols to an amazing 61 %. Ethylene glycol is an important intermediate in the chemical industry. For example, in the plastics industry it is needed for the production of polyester fibres and resins, and in the automobile industry it is used as antifreeze.