EFFECTS OF ZEOLITE ON THE CATALYTIC DEGRADATION OF POLYPROPYLENE

摘要

Effects of zeolite on the catalytic degradation of polypropylene (PP) at atmospheric pressure were studied by a batch operation. The degradation of PP was carried out between temperature 325 °C and 500 °C. HY, silica-alumina, and H-ZSM5 were shown degradation activity. The percentage of PP degradation with active catalysts was more than 97% in comparison with that of 6.96% for thermal degradation at 400 °C. The product proportion included liquid, gaseous, and solid residue for thermal and catalytic degradation were different. The percentage degradation of PP was almost independent of the kinds of PP in thermal degradation. In catalytic degradation, the powder and film of PP samples with HY had higher percentage degradation than pellet PP when the temperature was lower than 375 °C. HY had shown the most active between temperatures 325 °C and 375 °C. Pyrolyzer GC/MS was used to analyze the gaseous product distribution and showed not only the number of gaseous product was reduced but also the products shifted to lower carbon number when PP was degraded over HY and the results were different from the thermal and catalytic degradation of PP with silica-alumina and H-ZSM5.