Solving two environmental problems simultaneously：Microporous carbon derived from mixed plastic waste for CO2 capture

Abstract

Conversion of plastic waste into porous carbon for CO2 capture is an attractive approach to solve the carbon emission and plastic pollution problems, simultaneously. However, the previous studies are limited to the utilization of single PET plastic. The conversion of mixed plastic waste (MPW), which is of more practical significance, is seldom reported. In this study, mixed plastic waste was converted into porous carbon materials for CO2 capture through cascading autogenic pressure carbonization (APC) and chemical activation. The carbon yield of 56% was achieved through APC of MPW. The activator (KOH) dosage had significant effects on the structure and properties of the prepared porous carbons. Porous carbon prepared with KOH/C ratio of 4 had the largest micropore area and the maximum CO2 adsorption was 2.7 mmol g−1 at 298 K and 1 bar. The experimental data were well fitted to the pesudo first-order kinetic model. The MPW derived porous carbon exhibited not only high CO2 uptake capacity, but also fast adsorption rate, good selectivity of CO2 over N2 and good cyclic stability, which could be regarded as a promising adsorbent for CO2 adsorption.