Thermo-chemical disposal of plastic waste from end-of-life vehicles (ELVs) using CO_₂

Thesource reduction of plastic waste could be an effective means to attenuatehazardous environmental problems triggered by microplastics. Energy recoveryfrom plastic waste through thermochemical processes is a desirable valorizationroute. To realize the grand challenges, plastic waste derived from end-of-lifevehicles (ELVs) was pyrolyzed. To propose a greener feature, CO_₂ was introduced as a mediator to maximize carbonallocation to the gaseous pyrogenic product (syngas) by CO_₂ reduction to CO and concurrent oxidation of volatilematter (VM) that was evolved from the thermolysis of plastic waste. As such,fundamental and systematic works were conducted to delineate the CO_₂ effects on conversion of VMs. This study experimentallyproved that CO_₂ promotes thermal cracking in line with C–C bondscissions. However, the reaction rate for the conversion of CO_₂ and VM into CO via homogeneous reaction was not fast.Therefore, a Ni-based catalyst was employed to accelerate the reaction rate.However, there was coke deposition on the catalyst surface. To prevent cokeformation, we chose a method to enhance CO_₂ reduction to CO and the oxidation of VM. Thus, threebimetallic catalysts were used for catalytic pyrolysis. Among the threebimetallic catalysts, Rh_₀.₁Ni_₁/SiO_₂ was the most effective. Copyright © 2023 Elsevier Ltd. All rights reserved.