The Effect of Temperature on Catalytic Pyrolysis of HDPE Over Ni/Ce/Al2O3

Abstract

The main objective of the current work is to investigate the influence of reaction temperature on catalytic pyrolysis of High-Density Polyurethane (HDPE) over Ni/Ce/Al2O3 into enriched hydrocarbons of pyrolytic oil and gas The experiments were performed at four different pyrolysis reaction temperatures (500, 600, 700, and 800 °C) via in-situ fixed bed reactor. The Al2O3 (75 wt.%) was used as a support, while nickel (20 wt.%) and cerium (5 wt.%) were impregnated as promoters via incipient wetness impregnation method. The catalyst to plastic mass ratio was kept constant at 1:1 for all investigated samples. The results revealed that the Ni/Ce/Al2O3 catalyst has synergistic effects on the catalytic pyrolysis of HDPE into a high yield of hydrocarbon compounds (C5 – C20) in pyrolytic oil and hydrogen gas composition in pyrolytic gas. The highest yield of pyrolytic oil was achieved at 700 °C (53.23 %), while the highest yield of pyrolytic gas was achieved at 800 °C (67.85 %). The small molecular hydrocarbons in pyrolytic oil (C5 - C9) decreases with increasing temperature from 500 to 800 °C. The highest hydrogen gas yield of 77.59 %. was achieved at 700 °C. Thus, this research has economic feasibility in producing alternative valuable energy from the plastic waste stream.