Fuel Production from Waste Plastics Over Copper/Zeolites

The paper reports the production of liquid fuels from waste plastics’ thermal and catalytic pyrolysis, including polypropylene (PP), high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polystyrene (PS). For this purpose, three different types of zeolites (4A, ZSM-5, and 13X) and Cu/4A, Cu/ZSM-5, and Cu/13X were used in catalytic pyrolysis. The acidity and textural properties of the catalysts are the main parameters in the decomposition of polymers. The order of acidity of the catalysts was as follows: Cu/13X Cu/4A Cu/ZSM-5. The main product of thermal pyrolysis was liquid, mostly linear heavy hydrocarbons, whereas catalytic pyrolysis by copper/zeolite catalysts produced liquid products containing more branched hydrocarbons at lower temperatures. The liquid products carried out analysis through the use of FTIR and GC/MS techniques. The results indicated the presence of paraffin, olefins, and aromatic hydrocarbons in the liquid products. It was also found that light liquid hydrocarbons and gaseous products were produced over Cu/13X (higher acidity, large pore size, and high surface area). For Cu/4A, Cu/13X, and Cu/ZSM-5 catalysts, the main liquid products of catalytic pyrolysis were in the range of diesel, gasoline, and kerosene, respectively.