湿法脱硝尿素吸收液析出物性质分析及研究  

Research on Properties of Precipitates from Urea Absorption Solution in Wet Denitrification Units

作　　者：胡海强 李柯志 苑志伟 任靖 张毅 赵保槐 史建公 Hu Haiqiang;Li Kezhi;Yuan Zhiwei;Ren Jing;Zhang Yi;Zhao Baohuai;Shi Jiangong(Institute of Engineering Technology,Sinopec Catalyst Co.,Ltd.,Beijing 110112)

机构地区：[1]中国石化催化剂有限公司工程技术研究院,北京110112

出　　处：《中外能源》2023年第11期73-78,共6页Sino-Global Energy

基　　金：国家自然科学基金项目“低温铁捕集废催化剂贵金属的多反应耦合及富集机理”(项目批准号:U2002212)。

摘　　要：尿素湿法脱硝技术具有成本低、操作简单、无污染等优点被广泛应用,但其副反应及其副产物的累积是其应用中的一大问题。通过使用X射线衍射仪、电感耦合等离子光谱发生仪、紫外分光光度计、总有机碳TOC分析仪、离子色谱等分析方法,首先,对工业湿法脱硝装置尿素吸收液中析出物进行了元素组成、氨氮、总氮、总有机碳及晶相分析,确定了析出物主要为硝酸脲,并且发现硝酸脲在120℃干燥下即可分解为硝酸铵;其次,研究了尿素溶液中尿素浓度、硝酸根浓度、氢离子浓度对硝酸脲析出的影响,阐明了硝酸脲的析出机理,确定了硝酸脲析出的边界条件;最后,通过对工业湿法脱硝装置吸收液组成的研究,明确了工业装置中硝酸脲析出的原因,为湿法脱硝技术在工业应用中避免硝酸脲析出提供了理论指导。Wet denitrification by urea has been widely used due to its advantages such as low cost,simple operation and no pollution,but its side reactions and the accumulation of by-products is a major problem in its application.In this paper,some analytical methods such as X-ray diffractometer,inductively coupled plasma spectrometer,ultraviolet spectrophotometer,total organic carbon(TOC)analyzer and ion chromatography are applied.Firstly,the elemental composition,ammonia nitrogen,total nitrogen,total organic carbon and crystal phase of the precipitates from the urea absorption solution of industrial wet denitrification unit are analyzed.It is determined that the main precipitates are urea nitrate,and it is found that urea nitrate can be decomposed into ammonium nitrate when dried at 120℃.Secondly,the effects of urea concentration,nitrate concentration and hydrogen ion concentration in the urea solution on the precipitation of urea nitrate are studied,the mechanism of urea nitrate precipitation is elucidated,and the boundary conditions for urea nitrate precipitation are determined.Finally,the reasons for the precipitation of urea nitrate in industrial units are clarified by analyzing the composition of the absorption solution in industrial wet denitrification units,providing theoretical guidance for avoiding the precipitation of urea nitrate in the industrial application of wet denitrification technology.

关 键 词：湿法脱硝 NO_(x) 尿素 吸收 硝酸脲 

分 类 号：X701[环境科学与工程—环境工程]