Pyrolysis-Catalytic-Dry Reforming of Waste Plastics and Mixed Waste Plastics for Syngas Production

Abstract

The CO2 dry reforming of various types of waste plastics (LDPE, HDPE, PS, PET, and PP) and a simulated mixture of the different waste plastics was investigated over a Ni–Co–Al catalyst using a two-stage reactor. The first stage pyrolyzed the plastics, and the second stage involved catalytic-dry reforming of the product pyrolysis gases with CO2. The introduction of CO2 without a catalyst markedly increased the dry reforming reaction and significantly improved the production of H2/CO synthesis gas (syngas). The introduction of the Ni–Co–Al catalyst further significantly improved the production of syngas. LDPE produced the highest yield of syngas at 154.7 mmolsyngas g–1plastic from the pyrolysis-catalytic-dry reforming process. The order of syngas production for the different plastics was LDPE < HDPE < PP < PS < PET. The syngas yield from the processing of the simulated waste plastic mixture was 148.6 7 mmolsyngas g–1plastic which reflected the high content of the linear polyalkene plastics (LDPE, HDPE, PP) in the simulated waste plastic mixture.