Biobased plastic: A plausible solution toward carbon neutrality in plastic industry?

• Published in: Journal of hazardous materials 2022-08, Vol.435, p.129037-129037, Article 129037
• Main Authors: Sun, Xiangfei, Xie, Mengyi, Mai, Lei, Zeng, Eddy Y.
• Format: Article
• Language: English
• Subjects: Biobased plastic; Carbon neutrality; Clastic carbon reservoir; Greenhouse gas emission; Plastic recycling
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.129037

Biobased plastic exhibits unique benefits for achieving carbon neutrality, a key step toward reducing atmospheric greenhouse gases, due to its stability, high carbon content, and origin of carbon by photosynthesis. Herein we evaluate the role and potential of biobased plastic as an alternative carbon reservoir which is completely artificial, since most plastic polymers are synthetic and massively produced after the 1950 s. Model simulation indicates that plastic, under usage, burial, and littering, forms a growing carbon reservoir, sinking 6.82 gigatons of carbon (GtC) in 2020. Plastic-formed carbon is estimated to stack up to 19.4–23.2 GtC in 2060 under various production scenarios. However, only 18–40% of carbon stored in plastic is biobased carbon, equivalent to approximately 31–48 gigatons of carbon dioxide. Without any low carbon energy upgrade, carbon neutrality is difficult to achieve even with 90% biobased plastic substitution and 50% recycling ratio. Because extra GHG emissions are generated as a result of increasingly using incineration as a post-treatment strategy in response to increasing waste generation, the annual net GHG emission continues to rebound after the bio-based plastic substitution and plastic recycling approach their upper limits. Additional strategies are therefore needed to achieve complete carbon neutrality. [Display omitted] •An anthropogenic carbon reservoir is formed with plastic production, usage, and accumulation.•Carbon neutrality can be achieved with proper biobased plastic substitution and recycling under current production trends.•Carbon neutrality is difficult to maintain without low carbon energy upgrades.•Incineration should be carefully used from carbon neutrality point of view, especially if plastic is fossil-originated.