Pyrolysis of HDPE into fuel like products: Evaluating catalytic performance of plain and metal oxides impregnated waste brick kiln dust

•Catalytic pyrolysis of high density polyethylene (HDPE) is carried out.•The conversion to liquid oil (LO) as a function of catalyst concentration is presented.•ZnO-impregnated WBKD (5%) found to be more active than plain-WBKD.•The liquid oils show conformity with the petro-fuels properties.

The work explores the catalytic activities of plain and metal oxides (Fe2O3, CoO, ZnO, MnO2 and NiO) impregnated waste brick kiln dust (WBKD) for pyrolysis of high density polyethylene (HDPE) in order to get useful liquid oil that can be used as substitute to petro-fuels. The catalysts prepared in the laboratory were characterized by scanning electron microscopy (SEM), energy dispersive x-rays (EDX) analysis, surface area analysis (SAA) and x-ray diffractometry (XRD). The conversion of HDPE into liquid oil (LO) as a function of concentration of catalysts was studied. Based on the yielding results, ZnO- impregnated WBKD (5%) was found to be highly active. The liquid oils obtained in the thermal and ZnO-impregnated WBKD catalyzed runs were analyzed by using fourier transform infra-red spectroscopy (FTIR) and gas chromatographic-mass spectrometry (GC-MS). While comparing the results with the un-catalyzed thermal run, the ZnO-impregnated WBKD altered the liquid oil composition in terms of carbon range and hydrocarbon group type distributions. The fuel properties of the resultant liquid oils showed fuel values resembling to the generic petro-fuels.