Thermal and catalytic degradation of pyrolytic oil from pyrolysis of municipal plastic wastes

Thermal and catalytic degradation of pyrolytic oil obtained from the commercial rotary kiln pyrolysis plant for municipal plastic waste was studied by using fluid catalytic cracking (FCC) catalyst in a bench scale reactor. The characteristics of raw pyrolytic oil and also thermal and catalytic degradation of pyrolytic oil using FCC catalyst (fresh and spent FCC catalyst) under rising temperature programming was examined. The experiments were conducted by temperature programming with 10 °C/min of heating rate up to 420 °C and then holding time of 5 h. During this programming, the sampling of product oil was conducted at a different degradation temperature and also different holding time. The raw pyrolytic oil showed a wide retention time distribution in GC analysis, from 5 of carbon number to about 25, and also different product characteristics with a comparison of those of commercial oils (gasoline, kerosene and diesel). In thermal degradation, the characteristics of product oils obtained were influenced by reaction temperature under temperature programming and holding time in the reactor at 420 °C. The addition of FCC catalyst in degradation process showed the improvement of liquid and gas yield, and also high fraction of heavy hydrocarbons in oil product due to more cracking of residue. Moreover, the characteristic of oil product in catalytic degradation using both spent and fresh FCC catalysts were similar, but a relatively good effect of spent FCC catalyst was observed.