Microwave Assisted Gasification for Recycling Polymer Matrix Composites
DOE Phase I SBIR Contract DE-FG02-07ER84878
Polymer matrix composites have better strength/weight ratios, improved durability and corrosion resistance than metal and can be used to replace metal in automobiles. However, they are often considered unrecyclable and novel methods must be developed to recover the inorganic reinforcements and convert the polymer matrix to value-added products, instead of another waste in landfills.
In this project, two strategies are being utilized to efficiently convert the organic matrix of polymer composites to usable chemicals or fuels without degradation in strength or size reduction of the inorganic reinforcement, allowing the reinforcements to be directly recycled into new composite structures. The first strategy entails utilizing microwaves to enhance catalytic activity and increase the efficiency and reaction rate of the gasification of existing polymer matrix composites. The second strategy entails designing new glass fiber or particle reinforcements that act as internal, dielectric heaters to initiate heating of the composite during the gasification process, resulting in cheaper and faster composite recycling.
Composites are employed on aircraft, shipboard structures, automobiles and public transportation vehicles. The primary benefits of composites over traditional structural materials are a higher strength-to-weight ratio and increased corrosion resistance. These two property advantages lead to reduced weight, increased fuel efficiency and payload capacity, and decreased lifetime cost of ownership.
Besides enabling recycling of fuel efficient, lightweight automotive vehicles, the technology derived from this research will sustain and expand the automotive recycling industry. Eleven million vehicles are recycled each year at over 7,000 recycling companies, by more than 45,000 employees. Metal shredder revenues are shrinking, since they depend on recycling the metallic portions of vehicles and metal automobile parts are being replaced with plastic and composite parts. And while the energy-related costs for microwave heating are comparable to conventional heating methods, this technology reduces overall costs through faster, more efficient gasification. Plus, the elimination of separation, purification, or flotation processes further reduces costs.