Catalytic pyrolysis of waste polypropylene: a comparative tudy using zeolite and kaolin catalyst

The present work explores a scientific analysis to utilize polypropylene waste (PPW) through pyrolysis and to convert it into gaseous and liquid fuels, along with carbon-rich solid residue. The study systematically reports the yields of various fractions under different operating conditions. In the pyrolysis process, heavier molecular carbon chains break into shorter carbon chains by applying heat. The thermal stability and degradation pattern of PPW are examined at a heating rate of 5°C/min using the TG apparatus. The degradation events are mainly predominant in the temperature range of 220‐420°C. The possible influence of two low-priced, easily available catalysts, kaolin and zeolite, on the degradation temperature and relative proportions of pyrolytic products has been examined in a batch reactor study. A liquid yield of 73.95% was reported using zeolite at 575°C with a heating rate of 5°C/min (slow heating rate). The FTIR spectra of the pyrolytic oil (PO) reveal that it is a combination of alkanes, alkenes, and aromatic groups. Further examination of pyrolytic oil using GCMS confirmed that the oil contains a considerable amount of aromatics. For gaseous products, the kaolin catalyst was favorable. The 4.36% of hydrogen was produced at 600°C with kaolin. The gas chromatography analysis of gaseous products showed that it mainly comprises hydrogen, propane, and propylene. The GC result indicates that the gas is quite inflammable, indicating its suitability for process heating. The study presents a road map to produce diesel and petrol range fuels from plastic waste, contributing to a green environment.