Affordable catalyst converts cellulose to ethylene glycol

By Erin Voegele
Researchers in the United States and China are working to develop a new catalyst that converts cellulose directly into ethylene glycol. The research team is led by Tao Zhang at the Dalian Institute of Chemical Physics in China and Jingguang Chen at the University of Delaware in Newark.

The technology that the team is developing uses heat, pressure, and a catalyst made of tungsten carbide and nickel deposited on a carbon support to produce a mixture of polyalcohols from cellulosic biomass. The small amount of nickel in the catalyst improves the efficiency and selectivity of the catalyst system. According to Chen, the catalyst, which likely works through hydrolysis and hydrogenation reactions, converts 100 percent of the cellulose in biomass materials.

Ethylene glycol accounts for approximately 61 percent of the polyalcohols created by the process. The chemical compound is an important intermediate in the chemical industry. It's used as an antifreeze or coolant, and is needed to produce polyester fibers and resins in the plastics industry. The remaining 39 percent of the polyalcohols are primarily C6 sugars, which can be further processed into hydrogen and chemicals.

One benefit of the catalyst that Chen's team is developing is that it's affordable. To date, similar research has generally centered on precious-metal catalysts that would be too expensive to use in large-scale applications. In addition, the ability to convert cellulose directly into organic compounds is potentially faster and cheaper than splitting cellulose into individual sugar components, which can then be fermented.

The research team is performing additional studies to better understand how the catalyst works. Chen said the next steps include improving the conditions of temperature and pressure, as well as identifying other promising catalysts. Several patents have been filed for the technology.