超临界水氧化处理鲁奇炉气化废水的研究

Treatment of Lurgi gasifier coal gasification wastewater by supercritical water oxidation

采用240 L/d的连续式超临界水氧化(SCWO)装置对鲁奇炉气化废水进行试验研究,通过实验室设计的高压连续加氧系统和在线温度测量装置,系统研究了废水的反应温度、停留时间、质量浓度等对废水COD、NH3-N和挥发酚去除率的影响,并对氧化自热过程进行了初步探索。结果表明:升高温度和延长反应时间均可促进废水中有机物的分解;随着废水质量浓度的升高,COD去除率增加而挥发酚和NH3-N的去除率有所下降;当温度超过500℃、压力23 MPa、停留时间为68 s时,经处理的废水COD、NH3-N和挥发酚去除率均超过了99.8%。通过高质量浓度鲁奇废水的氧化试验,证明在现有的试验装置上实现过程自热操作是可行的,为过程开发和放大提供基础数据。

The treatment of Lurgi gasifier coal gasification wastewater was performed by using 240 L/d continuous supercritieal water oxidation reactor. The effects of reaction temperature, residence time and wastewater mass concentration on COD, volatile phenol and NH3-N removal rates were examined. The results show that higher temperature and longer residence time both can promote the decomposition of organic matter in wastewater. With the increase of wastewater mass concentration, COD removal rate increases while volatile phenol and NH3-N removal rates decrease slightly. The COD, volatile phenol and NH3-N removal rates can be over 99.8% in the condition of temperature 500 ℃, pressure 23 MPa, and residence time 68 s. The autothermal oxidation of wastewater was also investigated on the test device. These data provide the important information for the development of economically viable supercritical water oxidation process.