Kinetic study for thermocatalytic degradation of waste mixed cloth over antibiotic residue derived carbon-based solid acids

Abstract

In the present study, the kinetics for waste mixed cloth (WMC) pyrolysis over antibiotic residue derived carbon-based solid acids was investigated for the first time. The kinetic parameters for direct pyrolysis and WMC catalyzed pyrolysis were calculated through isoconvertional method, and different types of mechanism function models were employed to elucidate the catalytic pyrolysis process of WMC. Meanwhile, the most suitable pyrolysis mechanism model was determined by matching the apparent activation energy (Ea). From the kinetical results, the carbon-based solid phosphoric acids significantly reduced the Ea of the main reaction of WMC pyrolysis, which significantly decreased from 366.79 ∼ 434.26 kJ/mol to 141.07 ∼ 184.85 kJ/mol. The matching of mechanistic models confirmed that the catalytic reaction largely depended on both phase boundary control and diffusion control, which corresponded to the interaction of the primary pyrolysis products with the outer surface and inner acidic sites from carbon-based solid acids, respectively. The more acidic sites on the outer surface of the catalyst, the better its catalytic pyrolysis kinetic process matches the phase boundary-control model. This kinetical investigation will provide a promising reference for the rational design of carbon-based solid acids in WMC pyrolysis, with the aim of realizing the high-value utilization of organic solid wastes.