DISTRIBUTION OF CATALYTIC PYROLYSIS PRODUCTS OF POLYOLEFIN PLASTICS

Abstract

Abstract: To enhance the utilization rate and added value of waste plastics, the effects of catalyst type, protective gas atmosphere, reaction temperature, and pressure on the product yield and the composition of gas and liquid products of cracking reaction of polypropylene (PP) and mixed plastics (PP-HDPE-PS) were investigated using a high-pressure autoclave reactor. The results showed that both PP and PP-HDPE-PS achieved oil and gas yields exceeding 94% by mass, with liquid products predominantly composed of gasoline fractions. Water vapor atmosphere was conducive to the generation of liquid products of PP and mixed plastics cracking, and the catalyst was conducive to the generation of gas products. The yield of PP cracking liquid products increased first and then decreased with the increase of temperature, and decreased with the increase of reaction pressure. Under the combined action of water vapor and S-type FCC catalyst, the content of aromatics in PP liquid product was multiplied, and the generation of olefin was inhibited. For the cracking reaction of mixed plastics, the coke formation could be inhibited by steam atmosphere, and the total yield of benzene, toluene, ethylbenzene and xylene (BTEX) could exceed 29%.

Key words: waste plastics, deep catalytic cracking, gasoline fraction, aromatic hydrocarbons

References

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