Thermal and catalytic degradation of pyrolytic waxy oil in a plug flow reactor

Abstract

Pyrolytic waxy oil as a reactant was obtained from a commercial rotary kiln pyrolysis plant for municipal plastic waste. The characteristics of raw pyrolytic waxy oil are investigated, and in the upgrading of pyrolytic waxy oil, catalytic degradation using a commercial HZSM-5 catalyst is compared with the thermal degradation characteristics. Experiments were carried out in a continuous plug flow reactor at 450 °C for 1 h. The raw pyrolytic waxy oil showed a high boiling point distribution with an approximate range of 300–550 °C. This is a much higher boiling point distribution compared to that of commercial diesel. Upon thermal degradation at 450 °C, the GC peak pattern and carbon number distribution of the product oils show a trend similar to those of raw pyrolytic waxy oil. This indicates that the conversion of pyrolytic waxy oil to light hydrocarbons by the thermal degradation at a high temperature does not occur at a sufficient level. On the other hand, the catalytic degradation using the HZSM-5 catalyst relative to thermal degradation shows a high conversion rate of pyrolytic waxy oil to light hydrocarbons and moreover a high selectivity of light aromatic products in the liquid product. The upgrading of pyrolytic waxy oil is strongly influenced by the HZSM-5 catalyst used in this study.