干煤粉气化黑水处理药剂的选择和应用

Selection and application of black water treatment agent in dry pulverized coal gasification

基于干煤粉气化装置的黑水处理工艺及其循环灰水的特性,分析了絮凝剂和分散剂对气化黑水、循环灰水的作用机理和作用效果;通过不同种类的絮凝剂和分散剂的添加效果对比,筛选出了适合干煤粉气化工艺的絮凝剂和分散剂;在试验确定的两种添加剂适宜的添加量条件下,处理后的循环灰水总溶固质量浓度<3500 mg/L,总硬度(以CaCO3计)<1500 mg/L,全碱度<10 mmol/L,悬浮物质量浓度<40 mg/L;气化装置运行周期延长至200 d以上,检修周期缩短至18 d,降低了药剂的消耗成本。

Based on the black water treatment process of dry pulverized coal gasification unit and the characteristics of its circulating ash water,the action mechanism and effect of flocculants and dispersants on gasification black water and circulating ash water were analyzed.By comparing the addition effects of different kinds of flocculants and dispersants,the flocculant and dispersant suitable for the dry pulverized coal gasification process were selected.Under the condition of appropriate addition volume of the two additives determined by the test,the total dissolved mass concentration of circulating ash water after the treatment was less than 3500 mg/L,the total hardness(in terms of CaCO3)was less than 1500 mg/L,the total alkalinity was less than 10 mmol/L,and the suspended matter was less than 40 mg/L.The operation cycle of the gasification device was extended to more than 200 days,the overhaul cycle was shortened to 18 days.And the consumption cost of the agent was reduced.