高NO_(x)浓度低空速下SCR系统的工艺优化  

The Process Optimization for SCR System at High NO_(x)and Low Space Velocity

作　　者：樊航 Fan Hang(Shanghai Branch,SINOPEC Catalyst Co.,Ltd.,Shanghai 201208)

机构地区：[1]中国石化催化剂有限公司上海分公司,上海201208

出　　处：《中外能源》2025年第1期97-102,共6页Sino-Global Energy

摘　　要：在丙烯腈催化剂的生产过程中,由于硝酸盐的高温分解,有大量高浓度的NO_(x)烟气产生。选择性催化还原法(SCR)是使还原剂氨(NH_(3))与氮氧化物反应后生成氮气(N_(2))与水(H_(2)O)。为使NO_(x)达标排放,生产单位采用选择性催化还原法(SCR)NO_(x)环保处理工艺。该工艺使用尿素[(NH_(2))_(2)CO]水溶液热解取得还原剂NH_(3),相较于直接使用NH_(3)更为安全、环保。通过对丙烯腈催化剂生产装置SCR系统进行工艺条件试验,取得了在低空速工况下去除高浓度NO_(x)的优化工艺条件。试验结果表明,反应温度控制在325~335℃,入口NO_(x)浓度控制在3000μL/L以下,氨氮比保持在1.1~1.4,空速保持在620~700h^(-1)(对应尿素热解风的风量在320~370m^(3)/h),SCR系统的NO_(x)去除率保持在95%及以上且NO_(2)的去除率也保持在90%左右的高水平上。试验结果得到了实际运行的验证。在本文观察范围内,NO的去除率在各种工况下均能保持97%以上的高水平,影响NO_(x)去除率的主要因素是NO_(2)的去除率。In the production process of acrylonitrile catalyst,due to the high temperature decomposition of nitrate,a large number of high concentration NO_(x)gas is produced.Selective catalytic reduction(SCR)is the reaction of reducing agent ammonia(NH_(3))with nitrogen oxide to produce nitrogen(N_(2))and water(H_(2)O).In order to meet NO_(x)emission standards,the production unit adopts the selective catalytic reduction(SCR)NO_(x)environmental treatment process.This process uses urea[(NH_(2))_(2)CO]aqueous solution pyrolysis to obtain reducing agent NH_(3),which is safer and more environmentally friendly than using NH_(3)directly.Through the process condition test of SCR system of acrylonitrile catalyst production unit,the optimized process condition of removing high concentration NO_(x)at low space speed was obtained.The test results show that the reaction temperature is controlled at 325~335℃,the inlet NO_(x)concentration is controlled below 3000μL/L,the ammonianitrogen ratio is maintained at 1.1~1.4,and the space velocity is maintained at 620~700h^(-1)(corresponding to the urea pyrolysis wind flow is 320~370m^(3)/h).The NO_(x)removal rate of SCR system is maintained at 95%or above and the NO_(2)removal rate is also maintained at a high level of about 90%.The test results have been verified by actual operation.In the observation range of this paper,the removal rate of NO can maintain a high level of more than 97%under various working conditions,and the main factor affecting the removal rate of NO_(x)is the removal rate of NO_(2).

关 键 词：NOx SCR 丙烯腈催化剂 空速 工艺优化 

分 类 号：X783[环境科学与工程—环境工程] TQ426[化学工程]