Fuel production by thermal and catalytic co-pyrolysis of polyethylene terephthalate and polyethylene using waste iron as catalyst

Abstract

Waste low-density polyethylene (LDPE), high-density polyethylene (HDPE) and polyethylene terephthalate (PET) were co-pyrolyzed thermally and catalytically using waste iron dust (Fe) as a catalyst in a close-packed steel batch reactor. Various reaction conditions like temperature, reaction time, mixing ratio, catalyst proportion and initial mass of the reactants were optimized for effective conversion of the waste plastics. Outcomes of the thermal and catalytic reactions were compared to evaluate the catalytic activity of waste Fe in terms of oil yield and total percent conversion. The product oils were fractionated in gasoline, kerosene and diesel ranges. The physicochemical properties of the samples fractions were found to be in close resemblance with the physicochemical properties of the standard fuels. The FTIR analysis indicates aromatic, saturated and unsaturated hydrocarbons in all the samples and alcoholic OH in the Fe-catalyzed reaction product. The GC–MS analyses confirmed the saturated, unsaturated and aromatic hydrocarbons in various fractions ranging from lighter to heavier hydrocarbons in accordance with their boiling point distribution. The catalytic oils were found to contain relatively lighter hydrocarbons as compared to the non-catalytic oils. Calorific values of the catalytic oil and fractionated samples were found to be higher than the corresponding standard fuels.