Catalytic efficiency of some novel nanostructured heterogeneous solid catalysts in pyrolysis of HDPE

In the present study, the catalytic conversion of high density polyethylene (HDPE) to useful products has been investigated in the presence of BaTiO3 based catalysts in a micro steel reactor at 350 degrees C and 30 min reaction time. The catalysts, including BaTiO3, Pb/BaTiO3, Co/BaTiO3 and Pb-Co/BaTiO3 were prepared in the laboratory by reactive calcination method and characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-rays (EDX), Surface Area Analyzer (SAA) and X-rays Diffractometry (XRD). The product yields (over all yields and yields of liquid, gas and coke/residue) as a function of individual catalyst concentration was studied. The result indicated a promising effect of the catalysts used on conversion to liquid products and their composition in term of carbon range (C-6 - >C-30) & hydrocarbon group types (paraffin's, olefins, naphthenics, and aromatics). Among the catalysts used, Pb-Co/BaTiO3 gave the maximum yield of liquid products (86%) when used in 1 wt % loading. The same catalyst gave the average yield (20-25%) of different range hydrocarbons i.e. C-6-C-12, C-13-C-16, C-7-C-20 and C-20-C-30. Inversely, the un-doped BaTiO3, favored the formation of C-6-C-12 and C-13-C-16 range hydrocarbons, whereas Pb doped BaTiO3 and Co doped BaTiO3 enhanced the yield of C-13-C-16, and C-20-C-30 range hydrocarbons. Regarding the hydrocarbon group types, all catalysts significantly increased the formation of paraffins and reduced olefins and naphthenes. (C) 2013 Elsevier Ltd. All rights reserved.