Razia Khan

Catalytic Performance of Metal Impregnated Carbon (Darco) in Conversion of Polypropylene and High-Density Polyethylene into Useful Products

Catalytic pyrolysis is considered as the promising route for getting valuable chemicals from plastics. Pyrolysis reactions of polypropylene (PP) and high-density polyethylene (HDPE) were carried out in a fixed bed reactor in the presence of carbon-based catalysts under optimized conditions. The catalysts used were original (Darco (20-40 mesh) and transition metal salts impregnated activated carbons (AC, Fe/AC, Ni/AC, Zn/AC, Mn/AC, and Co/AC). The performance of each catalyst and its concentration in terms of overall yields of pyrolysates and yields of liquid, gas, and coke/solid residue was evaluated by comparing the results with the non catalyzed run. The results indicated that the catalysts used greatly affected the liquid yields in case of PP, however in case of HDPE, the yields were comparable with the thermal run. The catalysts used also altered the hydrocarbon group type distributions in the liquid pyrolysates. In case of PP, the Fe/AC catalyzed run caused the yield of olefins to increase by 16% while in case of HDPE, the Zn/AC catalyzed run, caused the yield of paraffins to increase from 59% to 64% as compared to thermal run.