Pyrolysis and catalytic reforming of disposable plastic waste for syngas production with adjustable H2/CO ratio

Abstract

The gasification technology has shown great potential to upcycle plastic waste for clean and high-value fuel. Gasification of disposable plastic masks was investigated in a two-stage pyrolysis-catalytic reforming system, aiming at producing the syngas with flexible H2 to CO ratio which can be tuned for various downstream applications without further purification and adjustment. To maximize the syngas yield and minimize the carbon deposition, different gasifying agents in the staged catalytic process was explored. The results showed that CO2 significantly promoted syngas production mainly by increasing CO yield. However, H2-rich syngas was obtained via using steam as the gasifying agent. Competitive and synergistic relationships between CO2 and H2O agent at co-feeding process were further revealed. CO2 facilitated the reforming of H2O at low dose of steam while exhibiting a main competition with adequate steam except for synergy at 5 mL/min CO2 flow rate. An optimum H2-rich syngas yield of 135.59 mmol/gplastic with H2/CO ratio of 2 was obtained at co-feeding reactants. Therefore, the co-feeding of H2O and CO2 could show positive effect for both coke removal and syngas quality regulation. Results found in this work increased the overall operational flexibility and economy of pyrolysis and catalytic reforming of plastic waste.