A new study that looked at gasification—one of many technologies that provides an alternative to landfilling non-recycled municipal solid waste (MSW)—found that adding non-recycled plastics to gasification feedstock increased the amount of saleable commodity product produced with minimal increase to energy input. The commodity products include chemicals such as methanol, ethanol, and other useful products. In addition, this process helps keep non-recycled plastics out of landfill while reducing greenhouse gas (GHG) emissions.
The study, “The Effects of Non-recycled Plastic (NRP) on Gasification: A Quantitative Assessment,” also found that including NRP in the feedstock helped significantly reduce the amount of waste byproduct to landfill—by up to 76 percent.
“We are committed to finding solutions for post-use, non-recycled plastics and are pleased to see that gasification is another viable option for creating valuable new products,” said Craig Cookson, senior director of recycling and energy recovery for ACC’s Plastics Division. “The City of Edmonton was a terrific partner for this research and should be commended for developing an integrated materials management system that combines robust recycling with composting and new chemical recycling technology. Edmonton’s facility provides an excellent model of the shift toward a more circular economy.”
The study was conducted by the Earth Engineering Center (EEC) at The City College of New York (CCNY) with the City of Edmonton in Alberta, Canada, at their Edmonton Waste Management Centre, and with Enerkem, a Montreal-based energy company. Edmonton and Enerkem have commercialized a gasification system that processes non-recycled MSW into methanol and ethanol.
EEC conducted four trials of gasification feedstocks with different percentages of plastics: zero percent, eight percent, 15 percent, and 50 percent. The study found that the feedstock with 50 percent NRP yielded the best results. Using a feedstock of 50 percent biomass and 50 percent NRP increased the amount of synthetic gas (syngas) created by 80 percent when compared to a feedstock of 100 percent biomass. The gasification process only required a two percent increase in energy inputs to create the syngas.
This syngas was then converted into methanol. Using the feedstock with 50 percent NRP resulted in up to 42 percent more methanol production, or an additional 4.2 million gallons per year at the Enerkem facility in Edmonton. The increase results in displacement of nearly 21,000 tons of CO2 annually.
“This study demonstrates that because carbon and hydrogen rich plastics have high energy content, there is tremendous potential to use technologies like gasification to convert these materials into fuels, chemicals, and other products,” said Marco J. Castaldi, Ph.D., director of the EEC at CCNY.
“Good scientific analysis and research is continually needed so that policymakers, investors, community leaders and others can make informed decisions about the benefits and trade-offs of newer technologies,” added Demetra A. Tsiamis, associate director of the EEC at CCNY.
The study was released with an accompanying video, “What Will Fuel Your City’s Energy Future?” The video shows how the City of Edmonton and Enerkem collaborated on this project and the benefits of recovering NRP.
The study was a collaborative effort by the North American Plastics Alliance and funded by the American Chemistry Council, with support from Plastics Industry Association, and the Canadian Plastics Industry Association.
For more information, visit www.americanchemistry.com.