Biocatalysis as a green route for recycling the recalcitrant plastic polyethylene terephthalate.

Ren Wei,Wolfgang Zimmermann

doi:10.1111/1751-7915.12714

Abstract

Biocatalysis can enable a closed-loop recycling of post-consumer PET waste.

Highlights

The global production of fossil-based plastics has grown more than 20-fold since 1964 to 322 million tons in 2015, and a slowdown of this rate is not expected (Ellen MacArthur Foundation and World Economic Forum, 2014; PlasticsEurope, 2016)
Only 14% of plastic packaging materials used worldwide is currently collected for recycling while another 14% is incinerated for energy recovery (Ellen MacArthur Foundation and World Economic Forum, 2014)
Enzymatic degradation of Polyethylene terephthalate (PET) in composite materials such as PET-polyethylene blends, metallized PET-based packaging films or in textiles containing PET could open up further opportunities to recover value from plastic waste using a biocatalytic approach (Gallagher, 2003)

Summary

Introduction

The global production of fossil-based plastics has grown more than 20-fold since 1964 to 322 million tons in 2015, and a slowdown of this rate is not expected (Ellen MacArthur Foundation and World Economic Forum, 2014; PlasticsEurope, 2016). Only 14% of plastic packaging materials used worldwide is currently collected for recycling while another 14% is incinerated for energy recovery (Ellen MacArthur Foundation and World Economic Forum, 2014). The remaining 72% of plastic packaging is not recovered with 40% land filled and 32% estimated to completely escape the collection system. In 2015, the global production of PET resins was 27.8 million tons which was dominantly used for the manufacture of packaging materials and beverage bottles (Plastic Insight, 2016). Almost half of the postconsumer PET bottles worldwide are collected for mechanical recycling to produce polyester fibres (Ellen MacArthur Foundation and World Economic Forum, 2014). Fossil feedstocks can be saved by the commercialization of bio-PET bottles, the challenges for their recycling remain as their recalcitrant properties are the same as those of petroleum-derived PET bottles (Chen et al, 2016)

Microbial polyester hydrolases can degrade PET

Not reported

Key challenges for biocatalytic PET recycling

Findings

Concluding remarks