Catalytic Pyrolysis of Biomass and Plastic Mixtures Using HZSM-5 Zeolite

Abstract

The catalytic effect of HZSM-5 zeolite was studied on the thermal decomposition of model waste mixtures of plastics and biomass. The influence of temperature and catalyst ratio as well as the hindering effect of cellulose and lignin on the catalytic decomposition of plastic waste was studied applying low and high heating rate by thermogravimetry/mass spectrometry (TG/MS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), respectively. HZSM-5 catalyst reduced the thermal stability of plastic waste, but the catalytic effect was blocked in the presence of 50% cellulose or 10% lignin. Principal component analysis (PCA) has been applied to reveal correlations between the composition of pyrolysis products, pyrolysis temperature and proportion of the applied catalyst. The hindering effect of biomass can be compensated by applying higher catalyst ratio.