Equilibrium model analysis of waste plastics gasification using CO and steam.

Utilization of carbon dioxide (CO) in thermochemical treatment of waste plastics may significantly help to improve CO recycling, thus simultaneously curtailing dioxins/furans and CO emissions. Although CO is not such an effective gasifying agent as steam, a few investigations have explored the utilization of CO in conjunction with steam to achieve somewhat higher carbon conversion. This work presents a comparative evaluation study of CO and steam gasification of a typical post-consumer waste plastics mixture using an Aspen Plus equilibrium model. The effect of flow rate of gasifying medium (CO and/or steam) and gasification temperature on product gas composition, carbon conversion, and cold gas efficiency has been analyzed. Simulation results demonstrate that CO can serve as a potential gasifying agent for waste plastics gasification. The resulting product gas was rich in CO whereas CO-steam blends yield a wider H/CO ratio, thus extending the applications of the product gas.