Finland-based Exel Composites has completed a four-year project called Next Air Biotreat that explored biotrickling filtration as a way to limit styrene emissions.

One of the most widely-discussed concerns among the composites industry is how to control styrene – a volatile component of polyester resin. In the past, researchers have tried to clean the styrene-contaminated air inside and outside production facilities, but those methods have often been very energy-intensive. To combat this problem, Exel Composites collaborated with the University of Valencia in Spain and Pure Air Solutions from the Netherlands to explore biotrickling filtration.

“Biotrickling filtration is a combination of a biofilter and a bioscrubber. It is a biological system that uses clean and natural processes to remove VOCs [volatile organic compounds],” says Eric Moussiaux, General Manager of Exel Composites’ Belgium unit. “The styrene fumes are absorbed in water and decomposed by bacteria. The pilot unit erected at [our Oudenaarde, Belgium] factory proved to be very efficient. We will certainly do the necessary investments to take this process into use,” he added.

Professor Carmen Gabaldón from the Chemical Engineering Department of the University of Valencia, who led the project, believes the project was a success.

“We are extremely pleased with the results of the project,” Gabaldón said. “In comparison with conventional technologies, biological VOC treatment is economically beneficial, it contributes to a lower ecological footprint and implies a reduction of CO2”, Prof. Gabaldón continues.

The issue has become a particular hot topic in the United States as well, with the California EPA recently adding styrene to its list of substances “known to the state to cause cancer” under its Proposition 65 regulation. While there has not been a significant foray into biofiltration in the United States, the American Composites Manufacturers Association has released guidelines and tools to help manufacturers determine if their products are below Calfornia’s proposed “No Significant Risk Level” of 27 micrograms per day average life time.