Chemical Recycling of Plastic Waste via Production of Ethylene from Gasification Syngas

We investigated the plastic waste to ethylene (PtE) process through steam-oxygen gasification, methanation, and oxidative coupling of methane. Gasification was modeled using a stochastic reactor model, while the downstream process was modeled using Aspen Plus. The carbon efficiency of the process ranges from 13 to 23%, depending on feedstock used. We investigated a base case scenario with CO2 venting and a case with CO2 compression and transport. While 5.7 kgCO2eq/kg ethylene can be avoided in the former one, the latter one leads to an avoidance of 18.4 kgCO2eq/kg ethylene. The costs of CO2 avoided are 666 €/tCO2eq and 230 €/tCO2eq, respectively.