Co-Production of Liquid and Gaseous Fuels from Polyethylene and Polystyrene in a Continuous Sequential Pyrolysis and Catalytic Reforming System

This paper deals with the potential of using sequential pyrolysis and catalytic reforming process in a continuous system for the conversion of polyethylene and polystyrene into liquid and gaseous fuels using the HY-zeolite catalyst for the catalytic reforming of pyrolysis gas generated in a pyrolyzer. The effect of reforming temperature and the weight hourly space velocity on the product yields, liquid and gaseous compositions have been investigated for each feedstock. The experiments were carried out at the pyrolyzer temperature of 450 °C, the reforming temperature of 400, 450, and 500 °C and the weight hourly space velocity of 2, 3, and 4 g-sample g-catalyst-1 h-1. The results show that increasing the reforming temperature and decreasing the weight hourly space velocity have resulted in an increase of gaseous and solid products while the liquid product decreased. The maximum oil production for HDPE (70.0wt%) and PS (88.1wt%) were obtained at the pyrolysis temperature of 450 °C, the reforming temperature of 450 °C and the weight hourly space velocity of 4. The C2, C3 and C4+ gases (>75 mol %) were the main components of the gaseous and liquid products for HDPE. In case of PS, the C2 and C3 gases (>65 mol %) were the main components of the gaseous product. The high quality of gaseous products can be used as a fuel either for driving gas engines or for dual-fuel diesel engines.