催化裂化装置分馏塔顶循环系统结盐倾向分析  

Tendency analysis of salt formation at the top circulation system offractionation column in FCC unit

作　　者：蔺峰涛 Lin Fengtao(SINOPEC Cangzhou Company,Cangzhou,Hebei 061000)

机构地区：[1]中国石油化工股份有限公司沧州分公司,河北省沧州市061000

出　　处：《炼油技术与工程》2024年第5期37-40,共4页Petroleum Refinery Engineering

摘　　要：催化裂化分馏塔顶循环部位结盐腐蚀,威胁装置的安全生产和长周期运行。用量化分析的方法可以更准确地说明结盐产生的条件,从而有助于采取有效措施来解决或缓解结盐问题。盐的主要成分是NH_(4)Cl,主要来源有两个:一是气相结晶,通过气相中NH_(3)和HCl的分压可以计算出NH_(4)Cl的沉积温度,计算的沉积温度越高,说明结盐的倾向性越大;二是水相溶解,塔内有水蒸气凝结时,气相中NH_(3)、HCl的溶解可以生成NH_(4)Cl溶液,塔内水蒸气露点温度与顶循环返塔温度之差可作为结盐倾向性判定指标,温差越大,结盐的倾向性越大。从分析结果看,使用分馏塔顶含硫污水作为终止剂,无论是从气相结晶还是水相溶解来看,都会明显增加结盐的倾向性。Salt formation corrosion at the top circulation system of FCC fractionator threatens safe production and long-term operation of the unit.The quantitative analysis method can explain the conditions of salt formation more accurately,thus helping to take more effective measures to solve or alleviate the salt formation problem.The main component of salt is NH_(4)Cl,and the main sources include two aspects:one is vapor phase crystallization,the deposition temperature of NH_(4)Cl can be calculated by the partial pressure of NH_(3) and HCl in the vapor phase,the higher the calculated deposition temperature,the greater the tendency of salt formation;another source is water phase dissolution,when there is water vapor condensation in the tower,NH_(3) and HCl dissolution in the gas phase can produce NH_(4)Cl solution,the difference between the dew point temperature of water vapor in the tower and the top circulation return temperature can be used as the judgment index of salt formation tendency,the greater the temperature difference,the greater the salt formation tendency.According to the analysis results,the use of sulfur-containing wastewater at the top of the fractionator as a terminator will obviously increase the tendency of salt formation,whether from the perspective of gas phase crystallization or water phase dissolution.It should be used with caution for the unit with serious salt formation corrosion problems in the top circulation system of the fractionator.

关 键 词：催化裂化装置 分馏塔 顶循环系统 结盐 气相分压 铵盐 露点温度 腐蚀 

分 类 号：TE962[石油与天然气工程—石油机械设备]