大型硫黄装置液硫池废气回收技术应用分析

Application Analysis of Exhaust Gas Recovery Technology for Liquid Sulfur Pit of Large Sulfur Unit

按照新标准要求,硫黄回收装置二氧化硫排放浓度应小于400 mg/m^3,为此选择了克劳斯循环处理技术回收液硫池废气,从而降低装置烟气二氧化硫的排放浓度。装置新增1台空气加热器,将燃烧空气加热至140℃,降低废气对主燃烧炉温度的影响,避免含硫废气堵塞主燃烧炉风线;新增了联锁系统,在克劳斯系统异常停车工况,废气入主燃烧炉切断阀和中压蒸汽切断阀联锁关闭,以保证系统的本质安全。测试数据分析表明,克劳斯系统、加氢系统运行稳定,催化剂床层温度、硫比值数据、急冷塔出口气氢含量、急冷水pH值等硫黄单元工艺参数未见异常。硫黄单元在80%、100%负荷工况下,烟气二氧化硫减排超过100 mg/m^3,减排幅度达到50%。

Since according to the requirements of new standards,the SO2 emission concentration of sulfur recovery device should be less than 400 mg/m^3,the Claus recycling technology is selected to recover the exhaust gas of liquid sulfur pit according to the actual situation of factory,so as to decrease the fuel gas SO2 emission concentration of the device.A air heater is added to heat combustion air to140℃and reduce the influence of exhaust gas on the temperature of main combustion furnace,so as to avoid the wind line of the main combustion furnace being blocked by sulfur-containing exhaust gas.By adding an interlock system,under the abnormal shutdown condition of the Claus system,the cutoff valve of exhaust gas entering the main furnace and medium pressure steam cut-off valve are closed to ensure the intrinsic safety of the Claus system.According to the test data,it is found that the Claus system and hydrogenation system operate steadily,and the process parameters of sulfur unit such as catalyst bed temperature,sulfur ratio data,hydrogen content of quench tower outlet gas and pH value of quench water are not abnormal.With 80%and 100%load conditions of sulfur unit,the sulfur dioxide emission reduction in flue gas exceeds 100 mg/m^3,and the range of emission reduction reaches 50%.