Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
Center for Environmental Microplastics Studies, Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China; Research Center of Low Carbon Economy for Guangzhou Region, Key Laboratory of Philosophy and Social Science in Guangdong Province of Community of Life for Man and Nature, Jinan University, Guangzhou 510632, China.
J Hazard Mater. 2022 Aug 5;435:129037. doi: 10.1016/j.jhazmat.2022.129037. Epub 2022 Apr 30.
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.
生物基塑料在实现碳中和方面具有独特的优势，是减少大气温室气体的关键步骤，因为它具有稳定性、高碳含量和光合作用来源的碳。在此，我们评估了生物基塑料作为一种替代碳库的作用和潜力，这种碳库是完全人工的，因为大多数塑料聚合物是合成的，并且是在 20 世纪 50 年代之后大量生产的。模型模拟表明，在使用、埋藏和乱扔垃圾的情况下，塑料会形成一个不断增长的碳库，在 2020 年封存了 68.2 亿吨碳。在各种生产情景下，预计到 2060 年，塑料形成的碳将积累到 194-232 亿吨。然而，储存在塑料中的碳只有 18-40%是生物基碳，相当于大约 31-48 亿吨二氧化碳。如果没有低碳能源升级，即使使用 90%的生物基塑料替代和 50%的回收比例，也很难实现碳中和。因为随着垃圾产生量的增加，越来越多地使用焚烧作为后处理策略，导致额外的温室气体排放，因此，在生物基塑料替代和塑料回收达到上限后，年度净温室气体排放继续反弹。因此，需要采取额外的策略来实现完全的碳中和。
