Latest trends and challenges in feedstock recycling of polyolefinic plastics

Recent focus on ocean plastics pollution, and the decision to ban waste plastic import by China have significantly impacted several industrial sectors around the world. Yet, the global waste plastic generation is steadily growing, which has driven substantial and rapid growth in worlds’ plastics recycling capacity to meet the needs for sustainable plastics use. In Japan, the Resource Circulation Strategy for Plastics was formulated in May 2019. One of the highlights of this Strategy was the milestones established: 25 % reduction of single-use plastics by 2030, 60 % reuse/recycling of plastic containers and packaging by 2030, complete waste plastic utilization through reuse and recycling by 2035, and introduction of 〜 2 Mt of bio-based plastics by 2030. Thus, immediate and substantial promotion of research and development of technologies for plastic waste recycling and creation of social and legislative frameworks for accelerating plastic recycling are in high demand. To enable substantial enhancement in the world’s recycling capacity, we believe that feedstock recycling via pyrolysis technologies is of considerable importance. Thus, this review firstly summarizes global trends in waste plastics recycling and examines the trends and challenges regarding pyrolysis technologies, such as reactor design and effective catalytic pyrolysis, toward chemical feedstock recovery from polyolefinic plastics. The authors’ current project on feedstock recycling, i.e., development of pyrolysis technologies using existing petroleum refinery processes, is introduced, and the potential sources of waste polyolefinic plastics, based on material flow analysis, are discussed.