Title Recycling Process for Carbon/Epoxy Composites
Source Composites in Manufacturing
Year 2002
Author(s) Allred, R. E.; Gosau, J. M.; Shoemaker, J. M.
Abstract Adherent Technologies is developing a family of low-temperature, catalytic conversion processes for tertiary recycling of a variety of complex polymer-based waste streams such as scrap electronics, auto shredder residue and aircraft composites [13-18]. Initial results show that all types of plastics, thermosets as well as thermoplastics, can be converted in high yields to valuable hydrocarbon products with these novel catalytic conversion processes. Conversion times are rapid, and the process is closed and, thus, nonpolluting. In addition to hydrocarbon gases and liquids, valuable carbon fibers are recovered from composite materials that can be reused in fabricating new composite parts. The purpose of this study was to determine the operating conditions to support a pilot scale operation of a process using a liquid heat transfer liquid, including reaction rate, activation energy and rate-limiting step, and to verify the carbon fiber product quality. The processing conditions of interest include temperature, time, pressure, catalyst concentration, heat-transfer, liquid-to-feedstock ratio and agitation. Results show that high-purity carbon fibers that have near-virgin properties can be reclaimed from carbon/epoxy composites using this tertiary process. Economic analysis shows that a recycling facility processing scrap carbon/epoxy is an attractive option to landfilling.
Keywords low-temperature catalytic process, tertiary recycling, scrap electronics, carbon fiber composites, thermosets, thermoplastics, carbon/epoxy composites