Tailoring Olefin Contents Formation during Waste Plastic Pyrolysis

As reported herein, we investigated the effect of feedstock composition, reactor type, and catalyst on the olefinic composition of oil recovered through plastic pyrolysis. We investigated an open reactor versus an autoclave closed reactor using polypropylene, linear low-density polyethylene, high-density polyethylene (HDPE), and low-density polyethylene, including both virgin and waste mixed plastics as feedstocks. The obtained oils were analyzed for comparison to their olefin contents. Additionally, the effects of H2 gas absorbers such as activated carbon and magnesium powder and an oxidant such as manganese stearate were evaluated regarding their impact on the olefin content of oils derived from both virgin and recycled HDPE. Our findings suggest that the formation of olefins (R–CH = CHR, where R is H or an alkyl group) during pyrolysis can be tailored through the selection of the reactor, feedstock, and catalysts, potentially enhancing the production of olefinic monomers from polyolefin waste plastics.