Catalytic Pyrolysis of Municipal Plastic Wastes (MPW) for the Production of Valuable Chemical Products

Abstract

The work was focused on converting plastic mixtures of LDPE (low density polyethylene), PP (polypropylene), and PS (polystyrene) with incorporation of small amounts of organic matter and paper, via catalytic pyrolysis into valuable products. The small incorporation of these materials was due to its low presence in the MPW used in this study. The results were compared with those of thermal pyrolysis. Mixture composition was set to obtain olefins/aromatic ratio of approximately 1 for the success of the next alkylation step. As in thermal pyrolysis, this ratio was difficult to obtain, FCC catalyst was tested. No significant impact in product yields and composition was observed with the incorporation of small amounts of the mentioned materials and with the use of this type of catalysts. The solid seems to contain the incorporated materials in the initial plastic waste mixture. The use of FCC increased the gas and solid content of about 3.7 % and 27.1 %. The liquid-oil decreased 30.8 %. Regarding liquid-oil composition, the use of FCC increased the aromatic compounds. Catalyst increased the quality of the liquid-oils, however it was not observed a significant impact in other products.