Waste Gasification as a Means of Reducing PFAS Accumulation and Generating Renewable Power for Sustainable Liquid Fuel Production
Environmental accumulation of toxic per- and poly-fluorinated alkane substances (PFAS) as near ubiquitous “forever chemicals” is emerging as a significant human health issue. PFAS are present in a wide variety of products including fire resistant fabrics and water repellant clothing and packaging materials. Shown in Figure 1 are structures for two PFAS of concern.
Due to the strong chemical bonds formed when fluorene replaces hydrogen in hydrocarbon side chains, PFAS are highly stable. They are not metabolized or excreted and so accumulate in the environment and in plant and animal food chains. Certain PFAS are cytotoxic, genotoxic, or exhibit other adverse health effects.
Figure 1. Two PFAS structures: Perfluoro sulfonic acid (Top), Perfluoro carboxylic acid (Bottom)
While early sources of PFAS were mainly industrial sites where they were made or used, the accumulation of these compounds in landfills from which they can migrate to surface water, ground water, soil and air have made landfills source of environmental concern.
The thermal processes shown in Figure 2 exceed the USEPA criteria for temperatures and residence times required to dissociate PFAS. Reducing the accumulation of PFAS in the environment is one of many benefits from thermal conversion of municipal solid waste to electrical energy.
Figure 2. High level process flow diagram for gasification of MSW to destroy PFAS and generate power for production of sustainable liquid fuels and commodities from biomass.
As depicted in Figure 2, air fed rotary kiln gasification of municipal solid waste can produce process steam and renewable electrical power. EPR has multiple options for using a portion of the power generated to convert feedstocks such as wood biomass to liquid fuels and activated carbon. Further technical information can be provided under NDA.