火电厂脱硝用尿素水解中试试验

Pilot experimental study of urea hydrolysis for deNO_x in coal plant

为降低火电厂NO_x排放造成的环境污染,采用尿素水解法制备烟气脱硝还原剂,在自主研发尿素水解反应器和尿素水解制氨工艺的基础上,搭建产氨量10kg/h规模的尿素水解中试试验台。结果表明,尿素水解反应速率是由温度控制的单调递增函数,蒸汽耗量随反应压力的增加而增加,当反应压力大于0.6MPa时加剧,装置经济性降低。提高进料浓度可减少过量水吸热造成的能量损失,有益于降低装置运行成本。多批次测试期间,进料浓度为40%~60%,操作压力与温度为0.6MPa、160℃,装置最大产氨量为16kg/h,水解率均大于98%,产品气氨气质量分率22.6%~34%(体积分率28.5%~48%),装置性能良好。

Based on the domestically developed urea hydrolysis reactor and urea hydrolysis ammonia process,apilot test of urea hydrolysis with 10kg/h ammonia production for the flue gas denitration reductant was established,to reduce pollution of NO_x emission from coal plant.The results showed that urea hydrolysis reaction rate was controlled by the temperature monotonically.Steam consumption increases with the increase of pressure,intensifies when pressure is greater than 0.6MPa and brings about lower economy.The higher feed concentration,the lower energy loss for the water latent heat of vaporization,and the lower operation cost of device.The maximum ammonia production is 16kg/h,the hydrolysis rate is greater than 98%,and the ammonia mass fraction of product gas is 22.6%~34%(volume fraction of 28.5%~48%)during the tests,at the feed concentration of 40%~60%,and the operate pressure and temperature of 0.6MPa and 160℃.