Su Hongcai, Li Tian, Zhu Lingjun, Wang Shurong
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Zheda Road 38, Hangzhou, 310027, P. R. China.
ChemSusChem. 2021 Oct 5;14(19):4270-4279. doi: 10.1002/cssc.202100913. Epub 2021 Jun 30.
The thermal degradation and conversion of waste polyethylene (PE) using a two-step process including hydrothermal oxidation (HO) and aqueous phase reforming (APR) were investigated. The objective of this study was to achieve efficient disposal of waste PE and generate H in a mild and green way. The effects of various HO conditions on both HO and APR processes were studied. A high H O concentration caused overoxidation of PE resulting in more CO . Decreasing the H O concentration weakened the overoxidation. The process using diluted H O exhibited the highest selectivity for acetic acid among the produced carboxylic acids. When the HO temperature exceeded 200 °C, there was an increase in the CO yield during the HO process and a decrease in the H yield during the APR process. In addition, the effects of various monometallic and bimetallic catalysts on the reforming of the aqueous phase from the HO of PE were discussed. The highest H mole fraction (51.52 %) in gaseous products from the APR process was obtained with Ru/mesoporous carbon. Nevertheless, Ru-Ni exhibited a higher stability than the monometallic Ru catalyst.
研究了采用包括水热氧化（HO）和水相重整（APR）的两步法对废聚乙烯（PE）进行热降解和转化。本研究的目的是以温和且绿色的方式实现废PE的高效处置并产生氢气。研究了各种HO条件对HO和APR过程的影响。高浓度的H₂O会导致PE过度氧化，从而产生更多的CO₂。降低H₂O浓度可减弱过度氧化。使用稀释的H₂O的过程在所产生的羧酸中对乙酸表现出最高的选择性。当HO温度超过200℃时，HO过程中CO₂产率增加，而APR过程中H₂产率降低。此外，还讨论了各种单金属和双金属催化剂对PE的HO水相重整的影响。使用Ru/介孔碳时，APR过程气态产物中的H₂摩尔分数最高（51.52%）。然而，Ru-Ni比单金属Ru催化剂表现出更高的稳定性。
