Feasibility Assessment for Production of Sorbents Based on Secondary Carbon Fibers

Аннотация

A preliminary feasibility assessment for recycling composites reinforced with carbon fibers and cloths was performed. The recommended pyrolysis temperature ranges for extracting secondary carbon fiber from the samples were determined using synchronous thermal analysis as 450-500°C for disperse-reinforced composite EPAN-2B and 500-550°C for composite UTZF-2UMN. The sorption properties of the secondary carbon fibers after activation in CO₂ were 222.4 m²/g specific sorption area by BET with 80 and 20% micro- and mesopores, respectively. The limiting adsorption volume for UTZF-2UMN composite fiber was 0.1169 cm³/g with a sorption capacity for benzene vapor of 0.134 cm³/g. The sorbents had high characteristic adsorption energies (by the Dubinin—Radushkevich method) that averaged 14.6 kJ/mol, which was only 30% less than primary fiber sorbents. The sample of UTZF-2UMN consisting of carbon cloth and phenol-formaldehyde resin had higher sorption properties with BET specific sorption areas for sorbents made of it that were three times higher than fibers made of EPAN-2B epoxide carbon-fiber plastic. The specific capacity for benzene vapor was 2.2 times higher, which was explained by the EPAN-2B fibers being highly contaminated by mineral impurities.