Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States.
Systems Assessment Center, Energy Systems Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Environ Sci Technol. 2021 Oct 19;55(20):14215-14224. doi: 10.1021/acs.est.1c03654. Epub 2021 Oct 7.
Today, polyurethanes are effectively not recycled and are made principally from nonrenewable, fossil-fuel-derived resources. This study provides the first high-resolution material flow analysis of polyurethane flows through the U.S. economy, tracking back to fossil fuels and covering polyurethane-relevant raw materials, trade, production, manufacturing, uses, historical stocks, and waste management. According to our analysis, in 2016, 2900 thousand tonnes (kt) of polyurethane were produced in the United States and 920 kt were imported for consumption, 2000 kt entered the postconsumer waste streams, and 390 kt were recycled and returned to the market in the form of carpet underlayment. The domestic production of polyurethane consumed 1100 kt of crude oil and 1100 kt of natural gas. With the developed polyurethane flow map, we point out the limitation of the existing mechanical recycling methods and identify that glycolysis, a chemical recycling method, can be used to recycle the main components of postconsumer polyurethane waste. We also explore how targeting biobased pathways could influence the supply chain and downstream markets of polyurethane and reduce the consumption of fossil fuels and the exposure to toxic precursors in polyurethane production.
如今，聚氨酯实际上无法回收利用，主要由不可再生的化石燃料资源制成。本研究首次对美国经济中的聚氨酯流动进行了高分辨率的物质流分析，追溯到化石燃料，并涵盖了与聚氨酯相关的原材料、贸易、生产、制造、用途、历史库存和废物管理。根据我们的分析，2016 年，美国生产了 290 万吨聚氨酯，进口了 920 万吨用于消费，2000 万吨进入了消费后废物流，390 万吨以地毯衬垫的形式回收并返回市场。国内生产的聚氨酯消耗了 1100 万吨原油和 1100 万吨天然气。通过开发的聚氨酯流程图，我们指出了现有机械回收方法的局限性，并确定了化学回收方法——醇解，可以用于回收消费后聚氨酯废物的主要成分。我们还探讨了如何针对生物基途径，这可能会影响聚氨酯的供应链和下游市场，并减少对化石燃料的消耗和对生产过程中有毒前体物的暴露。
