Catalytic Co-pyrolysis of Biomass and Different Plastics (Polyethylene, Polypropylene, and Polystyrene) To Improve Hydrocarbon Yield in a Fluidized-Bed Reactor

Biomass catalytic fast pyrolysis can produce aromatics and olefins, which are used as petrochemicals. However, the yields of aromatics and olefins are still very low. In this work, catalytic co-pyrolysis of pine sawdust and plastics (polyethylene, polypropylene, and polystyrene) was conducted in a fluidized-bed reactor to improve the yields of aromatics and olefins. The effects of different temperatures, polyethylene/pine sawdust ratios, different catalysts, and plastics on the product distributions were studied. The results show there are some positive synergistic effects between the two feedstocks. The maximum carbon yield of petrochemicals (71%) was obtained at 600 degrees C with a spent fluidized catalytic cracking (FCC) catalyst and polyethylene/pine sawdust ratio of 4:1. LOSA-1 presents better catalytic performances than Al2O3 and spent FCC catalysts. The petrochemical carbon yield with LOSA-1 is almost 2 times that without catalyst. Catalytic co-pyrolysis of polystyrene and pine sawdust produced the highest and lowest yields of aromatics (47%) and olefins (11.4%), respectively.