Chemical recycling of polyolefins: a closed-loop cycle of waste to olefins

The unsuitable disposal of plastic wastes has caused serious environmental pollution, and finding a green manner to address this problem has aroused wide concern. Plastic wastes, especially polyolefin wastes, are rich in carbon and hydrogen, and chemical recycling shows distinct advantages in their conversion into olefins and realizes a closed-loop cycling of plastic wastes. Plastic wastes should be labeled before disposal. The necessity for, and methods of, pretreatment are introduced in this paper and the whole recycling process of polyolefin wastes is also summarized. As the core technology pyrolysis, including thermal, catalytic and solvolysis processes, is introduced in detail due to its potential for future development. We also briefly describe the feasible strategies of pyrolytic oil refining and life cycle assessment of the chemical recycling process. In addition, suggestions and perspectives concerning the industrial improvement of polyolefin chemical recycling are proposed. This paper gives an overview of the whole chemical recycling process of polyolefin wastes, including the pretreatment of feedstocks, chemical recovery, product refining to olefins, and LCA analysis of chemical recycling.

Automated summary

The inappropriate disposal of plastic wastes has led to significant environmental pollution, and there is a growing concern about finding a sustainable solution. Chemical recycling offers distinct advantages in converting plastic wastes, especially polyolefins, into olefins, thus achieving a closed-loop recycling. This paper provides an overview of the entire process of polyolefin chemical recycling, including feedstock pretreatment, chemical recovery, olefin refining, and life cycle analysis.