Experimental investigation of waste polyolefin composition on thermal conversion into petroleum-derived products.

• XRD, CPMAS, NMR, FTIR,TGA Characterization of different waste PE and PP. • Pyrolytic conversion of waste plastics and degradation pathway. • Composition and performance analysis of pyrolytic liquid from waste plastics. • Correlation between composition of plastics and pyrolysis liquid. • Recommendation for optimal use of different types of plastics for management. Thermal pyrolysis of polyolefins has been proposed as one of the possible ways to obtain petroleum-derived products (fuels and chemicals) from waste plastics however, there is a lack of deep understanding of the correlation between the structure and composition of polyolefin feedstock with pyrolysis oil. Pyrolysis oil has been obtained from polyethylene (PE) and polypropylene (PP) in a tubular reactor at 500 °C. TGA-DTG, 13C CP-MAS NMR, FTIR, and XRD were used to analyze the polyolefin (PE and PP) feedstock, while pyrolysis oil was characterized by GC–MS, FTIR, and 1H NMR techniques. The pyrolysis oil from virgin and waste PP yielded branched alphaolefins and cycloparaffins, while virgin and waste PE produce linear alpha olefins and linear paraffins. Mixed waste plastic (MWP) produces major amount of linear paraffins and linear alpha olefins, indicating the overall trend of branching in polyolefins (PE and PP) from feedstock to product oil is retained after pyrolysis. The alpha olefins can be used as chemical intermediates, while 2,4 dimethyl 1-heptene from PP can be used as a fine chemical precursor better feedstock for gasoline. Segregation of waste plastics is challenging task in real life but source segregation and selective collection of waste plastics from various sources can produce useful products like high octane gasoline range hydrocarbons and high-value chemicals. [ABSTRACT FROM AUTHOR]