Abstract Hydrothermal treatment (HTT) is able to remove chlorine effectively from polyvinyl chloride (PVC), however, the reaction temperature is critical in practical application. Less energy-intensive hydrothermal dechlorination condition with cupric ion (Cu2+) has been proposed in this study. In particular, Cu2+ was applied in HTT of PVC at temperature ranging from 200 °C to 240 °C. It has been found that the introduction of Cu2+ distinctly accelerated PVC decomposition and dechlorination at 220 °C. When Cu2+ concentration was increased from 0.01 mol/L to 0.20 mol/L, the dechlorination efficiency was significantly improved from 15.46 %–67.89 %. Dramatic dechlorination occurred as residence time was longer than 15 min during HTT. Besides, both elimination and substitution dominated the HTT dechlorinaton. The facilitated dechlorination after the addition of Cu2+ was mainly due to the enhanced dispersion and formation of micropores in hydrochar. On the whole, HTT could be a promising pretreatment technology for copper-containing PVC in electronic wastes to prepared chlorine free hydrochar for combustion or pyrolysis applications, the optimal HTT condition would be 220 °C, 60 min with 0.1 mol/L Cu2+.

中文翻译：

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铜离子水热处理脱氯聚氯乙烯

摘要 水热处理（HTT）能够有效地去除聚氯乙烯（PVC）中的氯，但在实际应用中反应温度很关键。本研究提出了使用铜离子 (Cu2+) 的低能耗水热脱氯条件。特别是，Cu2+ 在 200 °C 至 240 °C 的温度范围内应用于 PVC 的 HTT。已经发现，Cu2+ 的引入在 220 °C 时明显加速了 PVC 的分解和脱氯。当Cu2+浓度从0.01 mol/L提高到0.20 mol/L时，脱氯效率从15.46%~67.89%显着提高。由于在 HTT 期间停留时间超过 15 分钟，因此发生了剧烈的脱氯。此外，消除和替代都主导了HTT脱氯。添加Cu2+后促进脱氯主要是由于水炭中微孔的分散和形成的增强。总的来说，HTT 是一种很有前景的电子废物中含铜 PVC 的预处理技术，以制备用于燃烧或热解应用的无氯氢碳，最佳 HTT 条件是 220°C，60 分钟，0.1 mol/L Cu2+。