Researchers in US develop process to make chemical p-xylene from biomass

Researchers from University of Massachusetts Amherst (UMass Amherst) have developed a new chemical process to make p-xylene, an important ingredient of common plastics, from biomass. P-xylene is currently produced from petroleum.

A team of chemical engineering researchers that includes Prof Wei Fan, and doctoral students Hong Je Cho and Vivek Vattipalli from the University of Massachusetts Amherst, has developed a new method, which has a 97 percent yield and uses biomass as the feedstock. 

The key to the new process, which builds on previous work by the research team, is a new zeolite catalyst that directs the liquid chemical reaction to produce p-xylene and discourages the production of other by-products, said Prof Fan. Previous efforts to make p-xylene in this manner have not achieved a yield higher than 75 percent.

The research team synthesised the new zeolite to contain phosphorous which helps create a much more selective chemical reaction that almost exclusively yields p-xylene.

“The phosphorous containing zeolite catalysts exhibit high surface area and well dispersed phosphorous active sites. Different from conventional acid catalysts, the phosphorous containing zeolite catalysts is highly selective for p-xylene production. The selectivity is unique and has not been observed in the past. It can be easily used for many other important catalytic reactions,” explained Prof Fan.

Consumers already know the plastics made from this new process by the triangular recycling label on plastic containers. Xylene chemicals are used to produce a plastic called PET (polyethylene terephthalate), which is currently used in many products including soda bottles, food packaging, synthetic fibres for clothing and even automotive parts. It is estimated that the global market for plastic products using p-xylene will grow by about 5 percent annually.

The ability to create p-xylene from renewable biomass is a major step in creating a commercially attractive process, informed Prof Fan.

The research team is part of the Catalysis Center for Energy Innovation (CCEI) that seeks to find breakthrough technologies for producing biofuels and chemicals from lignocellulosic biomass. The centre is funded by the US Department of Energy as part of the Energy Frontiers Research Center (EFRC) program, which involves more than 20 faculty members with complementary skills to collaborate on solving the world’s most pressing energy challenges.