Billion tons of post-consumer Tetra Pak cartons are discarded annually as land and ocean wastes, creating significant environmental problems and resource losses. Recycling of the carton wastes is hindered by its multi-material compositions and low values of the recycled products. In this study, a novel upcycling of the cartons was investigated. A post-consumer carton consisting of paper, polyolefin, and polyamide was directly converted in 210–230 °C tetrahydrofuran containing 10–20 mM acid to produce up to 19.2% of levoglucosenone and 8.6% of furfural by selectively decomposing paper fraction. The remaining solids containing mostly intact polyethylene and polyamide but also a smaller fraction of paper-derived char were separated using a solvent-dissolution method. The xylene-soluble fraction was a recycled polymer similar to the original polyethylene, which was verified by its functional groups, the composition of the pyrolysis products, and the melt rheology results. The xylene-insoluble fraction was a mixture of polyamide and paper-derived char. Upon pyrolysis, caprolactam was produced as the only major vapor product. The remaining, thermally stable paper-derived char could be used as a high-quality solid fuel. Overall, the demonstrated recycling method could potentially maximize the values of the products recovered from carton wastes.

每年有 10 亿吨消费后的利乐纸盒作为陆地和海洋垃圾被丢弃，造成了严重的环境问题和资源损失。纸箱废料的回收受到其多材料成分和回收产品的低价值的阻碍。在这项研究中，研究了一种新型的纸箱升级改造。由纸、聚烯烃和聚酰胺组成的消费后纸箱在 210-230 °C 的四氢呋喃中直接转化，该四氢呋喃含有 10-20 mM 酸，通过选择性分解纸部分，产生高达 19.2% 的左旋葡萄糖酮和 8.6% 的糠醛。剩余的固体主要包含完整的聚乙烯和聚酰胺，但也包含较小部分的纸衍生炭，使用溶剂溶解方法进行分离。二甲苯可溶部分是类似于原始聚乙烯的回收聚合物，这通过其官能团、热解产物的组成和熔体流变学结果得到证实。二甲苯不溶部分是聚酰胺和纸衍生炭的混合物。在热解时，己内酰胺作为唯一的主要蒸气产物产生。剩余的热稳定纸衍生炭可用作高质量的固体燃料。总体而言，所展示的回收方法有可能最大限度地提高从纸箱废物中回收的产品的价值。己内酰胺作为唯一的主要蒸汽产品生产。剩余的热稳定纸衍生炭可用作高质量的固体燃料。总体而言，所展示的回收方法有可能最大限度地提高从纸箱废物中回收的产品的价值。己内酰胺作为唯一的主要蒸汽产品生产。剩余的热稳定纸衍生炭可用作高质量的固体燃料。总体而言，所展示的回收方法有可能最大限度地提高从纸箱废物中回收的产品的价值。