Two-stage thermocatalytic conversion of waste XLPE to diesel-like fuel Scientific paper

Abstract

Cross-linked polyethylenes (XLPE) are not preferred in industrial pyrolysis applications and mechanical recovery methods due to great thermo­chemical resistance to heat and deformation. The studies on pyrolysis of XLPE up to 600 °C on obtaining fuel have generally yielded high levels of wax and have not been of interest to the energy sector. In this study, two-stage pyrolysis of XLPE was carried out catalytically and also without catalyst (thermal, T-pyr) under 500 °C with heating rates of 5 and 10 °C min^-1. In the pyrolysis experiments, three different catalytic studies were performed by adding MCM-41 + HZSM-5 catalyst mixture to the polymer phase only (PPC-pyr), by filling Cu(I)-MAS + HZSM-5 catalyst mixture to the gas outlet column only (GPC-Pyr) and adding catalyst mixtures in both polymer phase and gas phase (MPC-pyr). The highest diesel-like fuel (91.40 wt. %) was obtained in multiphase catalytic pyrolysis experiments at 460 °C with a heating rate of 5 °C min^-1. The calorific value, kinematic viscosity, density, flash point and cetane number of the fuel were found as 45.97 MJ kg^-1, 2.72 cSt, 832.5 kg m-3, 57 and 59 °C, respectively. The results of the two-stage catalytic cracking and the heating rate profile will be a guide for industrial pyrolysis applications. The simple feasibil­ity for industrial applications showed that it would be a very profitable inves­tment.