美国弗吉尼亚理工大学Guoliang Liu团队报道了聚乙烯、聚丙烯和及其混合物化学回收为高附加值表面活性剂。相关研究成果发表在2023年8月11日出版的《科学》。

将塑料垃圾转化为脂肪酸是补充这些高价值、高容量化学品来源的一种有吸引力的手段。

研究人员报道了一种在约80%转化率下将聚乙烯（PE）和聚丙烯（PP）转化为数均摩尔质量分别高达约700和670道尔顿的脂肪酸的方法。该工艺适用于城市PE和PP废物及其混合物。温度梯度热解是可控制地将PE和PP降解为蜡并抑制小分子产生的关键。蜡通过在硬脂酸锰上氧化和随后的加工而上循环为脂肪酸。PP裂解比PE裂解产生更多的烯烃蜡，并产生更高的酸值脂肪酸。

研究人员进一步将脂肪酸转化为高价值、市场需求大的表面活性剂。工业规模的技术经济分析表明，在不需要补贴的情况下，经济是可行的。

附：英文原文

Title: Chemical upcycling of polyethylene, polypropylene, and mixtures to high-value surfactants

Author: Zhen Xu, Nuwayo Eric Munyaneza, Qikun Zhang, Mengqi Sun, Carlos Posada, Paul Venturo, Nicholas A. Rorrer, Joel Miscall, Bobby G. Sumpter, Guoliang Liu

Issue&Volume: 2023-08-11

Abstract: Conversion of plastic wastes to fatty acids is an attractive means to supplement the sourcing of these high-value, high-volume chemicals. We report a method for transforming polyethylene (PE) and polypropylene (PP) at ~80% conversion to fatty acids with number-average molar masses of up to ~700 and 670 daltons, respectively. The process is applicable to municipal PE and PP wastes and their mixtures. Temperature-gradient thermolysis is the key to controllably degrading PE and PP into waxes and inhibiting the production of small molecules. The waxes are upcycled to fatty acids by oxidation over manganese stearate and subsequent processing. PP -scission produces more olefin wax and yields higher acid-number fatty acids than does PE -scission. We further convert the fatty acids to high-value, large–market-volume surfactants. Industrial-scale technoeconomic analysis suggests economic viability without the need for subsidies.

DOI: adh0993

Source: https://www.science.org/doi/full/10.1126/science.adh0993