Researchers find new use for biomass
A China–US team has developed a new catalyst to directly convert cellulose, the most common form of biomass, into a useful chemical.
The chemical, ethylene glycol, is widely used in products from polyester fibres to antifreeze for cars.
Once industrialised, the improved catalyst will lower the cost of ethylene glycol production. Additionally, as the raw material is not a food crop, it will not compromise food security, say the researchers.
Currently ethylene glycol is mainly produced from crude oil — whose reserve is rapidly reducing — and cellulose, commonly found in crop straws and wood waste, is considered a better alternative.
But converting cellulose into ethylene glycol is a slow process involving several expensive agents, including platinum-group metals.
The new catalyst, comprising the chemical compound tungsten carbide and nickel, will greatly simplify the process and allow 100 per cent conversion of cellulose, says Jingguang Chen at the US-based University of Delaware, a co-leader of the research team.
Chen adds that this combination increases the proportion of ethylene glycol to 61 per cent from 27 per cent using tungsten carbide alone.
Zhang Tao, head of the Dalian Institute of Chemical Physics in China and another co-leader, says the new catalyst could potentially lower the cost of ethylene glycol production by 50 times compared with platinum-group metals.
But two key problems remain before commercialisation is possible, the researchers say.
Firstly, the catalyst needs high temperatures and pressures to work. "It will be costly for such a high-pressure industrial process," says Chen.
The other issue concerns the purification of final products. "We still require further work on the separation of all the alcohol by-products," Zhang says.
Wang Zhongying, a senior official with the Energy Research Institute of the National Development and Reform Commission, says that although it is too early to draw conclusions on the prospect of this catalyst, such research is "strategically significant" for any country in the face of fuel shortage and increasing food demand.
The research was published online in Angewandte Chemie International Edition last month (September) and is scheduled to appear in the print version in November.
Angewandte Chemie International Edition 10.1002/anie.200803233 (2008)