IGCC电站煤气化废水脱氨工艺的优化改造

Optimization of ammonia removal process for coal gasification wastewater of IGCC power plant

介绍了华能天津IGCC示范电站煤气化污水处理单元的工艺流程、常规脱氨工艺流程及原理。针对煤气化废水常规脱氨工艺流程存在的蒸汽消耗量较多、废水进入后续系统时水温较高、脱氨提升泵内易发生碱结垢等问题,进行了取消注入蒸汽、采取常温脱氨工艺、优化NaOH溶液添加流程等改造。改造后,常温脱氨工艺氨氮去除率仍可达到50%~65%,污水水温降低5℃~6℃,脱氨提升泵的故障率降低85%,可节约蒸汽24 t/d,2021年的排污费用较2020年改造前减少约47万元。

The process flow of coal gasification sewage treatment unit of Huaneng(Tianjin)IGCC demonstration power plant,conventional ammonia removal process and its principle were introduced.In view of the problems existed in the conventional ammonia removal process of coal gasification wastewater,such as high steam consumption,high water temperature when wastewater entered the subsequent system,and easy alkali scaling in the deamination lifting pump,the steam injection was cancelled,the normal temperature ammonia removal process was adopted,and the NaOH solution addition process was optimized.After the renovation,the removal rate of ammonia nitrogen by normal temperature ammonia removal process could still reach 50%-65%,the water temperature of the sew age could be reduced by 5℃-6℃,the failure rate of the deamination lifting pump could be reduced by 85%,and 24 tons of steam could be saved per day.The pollution discharge cost in 2021 was lowered by about 470000 yuan compared with that before the transformation in 2020.