A Study of Catalytic Copyrolysis of Sewage Sludge and Waste Plastics Using Taguchi Method

The catalytic copyrolysis of sewage sludge (SS) and waste polypropylene (PP) was investigated with a hydrogen‐exchanged zeolite catalyst Socony Mobil‐5 (HZSM‐5) catalyst. Both of these feedstocks were waste materials that urgently required more effective treatment. This study used the Taguchi method to identify the optimal operating conditions for different target products based on the main experimental parameters. The results showed that the catalyst loading had the greatest influence on the C 5–19 /C 19+ of the pyrolysis oil. The proportion of higher carbon number compounds (C 13–19 ) was relatively high in the pyrolysis oil, and an increase in the SS content was beneficial for enhancing oil with a lower carbon number range. In addition, the blending ratio had the greatest influence on the maximum oil yield, which was obtained at a blending ratio of 50% PP. The blending ratio had the greatest effect on C 5–19 and C 13–19 , with C 13–19 being the most significantly affected. The exergy efficiencies for the maximum C 5–19 and C 13–19 pyrolysis oils were 28.12% and 39.55%, respectively. The HZSM‐5 catalyst promoted the oil with a higher heating value (HHV) of 43.83 MJ/kg. The GC–MS results revealed that the main components were predominantly long‐chain oxygen‐containing alcohols and cyclic compounds.