通过亚临界水-尿素处理从溴化环氧树脂废料中高效低温脱溴及高选择性产物回收。
Efficient low-temperature debromination and high selectivity products recovery from brominated epoxy resin waste by subcritical water-urea treatment.
机构信息
College of Geology and Environment, Xi'an University of Science and Technology, Xi' an 710054, China; Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi'an 710054, China.
College of Geology and Environment, Xi'an University of Science and Technology, Xi' an 710054, China.
出版信息
Waste Manag. 2020 May 15;109:171-180. doi: 10.1016/j.wasman.2020.05.001. Epub 2020 May 11.
In this study, a subcritical water-urea (SubCW-urea) process was developed for the treatment of brominated epoxy resin powder (BRP) waste. The SubCW-urea process had two significant advantages: efficient low-temperature debromination and highly selective products recovery. The NH and CO released from urea in the SubCW medium had a prominent enhancement effect on the decomposition and debromination of BRP waste when the SubCW temperature was below 300 °C. The debromination efficiency of SubCW-urea treatment was significantly enhanced in comparison with that of SubCW-NH and single SubCW treatments. The debromination efficiency of BRP could reach 38.21%, 85.3%, and 99.92% at 200 °C, 250 °C, and 300 °C, respectively. The debromination rate constant of BRP in SubCW-urea, SubCW-NH, and single SubCW system was 0.1363, 0.1254, and 0.0146 min, respectively. No brominated chemical compound could be detected in the oil phase products when the treatment temperature was higher than 250 °C. The decomposition products of BRP waste could be easily regulated by controlling the treatment temperature of SubCW-urea. 2-bromo-phenol with the purity of 72.5% could be selectively prepared from BRP by SubCW-urea process at 200 °C. The purity of the recovered phenol could reach as high as 81.5% at 250 °C. The selectivity of the products decreased greatly at 300 °C due to the secondary reactions. The SubCW-urea process has an application prospect in the safe treatment of BRP waste with the aim of high-efficiency debromination and high selectivity products recovery at low temperature.
在这项研究中，开发了一种亚临界水-尿素（SubCW-urea）工艺来处理溴化环氧树脂粉末（BRP）废物。SubCW-urea 工艺有两个显著的优点：高效低温脱溴和高选择性产物回收。当亚临界水温度低于 300°C 时，尿素在 SubCW 介质中释放的 NH 和 CO 对 BRP 废物的分解和脱溴具有显著的增强作用。与 SubCW-NH 和单一 SubCW 处理相比，SubCW-urea 处理的脱溴效率显著提高。在 200°C、250°C 和 300°C 下，BRP 的脱溴效率分别达到 38.21%、85.3%和 99.92%。在 SubCW-urea、SubCW-NH 和单一 SubCW 体系中，BRP 的脱溴速率常数分别为 0.1363、0.1254 和 0.0146 min。当处理温度高于 250°C 时，油相产物中检测不到溴化化学物质。通过控制 SubCW-urea 的处理温度，可以轻松调节 BRP 废物的分解产物。在 200°C 时，通过 SubCW-urea 工艺可以从 BRP 中选择性地制备纯度为 72.5%的 2-溴苯酚。在 250°C 时，回收的苯酚的纯度可高达 81.5%。由于二次反应，产物的选择性在 300°C 时大大降低。SubCW-urea 工艺有望在安全处理 BRP 废物方面得到应用，目的是在低温下实现高效脱溴和高选择性产物回收。
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