Catalytic pyrolysis of polypropylene over Ga loaded HZSM-5

Abstract

The effect of catalyst structure, acidity, and Ga addition of zeolites on the pyrolysis of polypropylene (PP)was investigated by comparing PP cracking efficiency and product distribution properties in this study. Thermogravimetric analysis result indicated that HY(SiO2/Al2O3; 30) is the most effective catalyst loweringPP decomposition temperature, followed by Ga/HZSM-5(30), HZSM-5(30), HZSM-5(80), and HZSM-5(280). Meanwhile, Ga/HZSM-5(30) revealed the lowest apparent activation energy (Ea), 110 kJ/mol, thanHY(30) (159 kJ/mol), and other HZSM-5 catalysts (122 ~ 172 kJ/mol), suggesting its high efficiency loweringEa on PP pyrolysis. Py-GC/MS results also suggested that Ga/HZSM-5 produces the largest amountof aromatic hydrocarbons, followed by HZSM-5(30), HZSM-5(80), HY(30), and HZSM-5(280). The increaseof Ga/HZSM-5(30) amount on PP pyrolysis led the further decrease of Ea value and increase of aromaticsproduction efficiency.