加氢处理系统NH_4Cl结晶沉积预测及优化防控  

Prediction of NH_4Cl Crystalline Deposition and Optimized Prevention Method in Hydrotreating Unit System

作　　者：金浩哲[1] 偶国富[1,2] 王宽心[1] 张文彪[1] 程福星 

机构地区：[1]浙江理工大学流动腐蚀研究所,浙江杭州310018 [2]杭州富如德科技有限公司,浙江杭州310018

出　　处：《石油学报（石油加工）》2014年第4期662-667,共6页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家科技支撑计划项目(2012BAK13B03-02);国家基金委与神华集团联合资助项目(U1261124);浙江理工大学科研启动基金项目(1202825-Y)资助

摘　　要：通过热力学计算获得NH4Cl结晶反应的平衡曲线,分析冷换设备中NH4Cl结晶沉积机理;针对某石油化工厂典型加氢反应流出物冷却分离工艺,运用Aspen仿真软件建立多相平衡体系,计算获得气相中Kp即pHCl×pNH3随温度的变化曲线;结合二者建立加氢反应流出物冷却分离系统NH4Cl结晶预测模型,计算获得含不同N、Cl质量分数进料的NH4Cl结晶温度,并提出基于NH4Cl结晶沉积预测的冷却分离系统注水优化方案。结果表明,冷换设备中NH4Cl结晶沉积存在自加速过程,典型工况下NH4Cl结晶温度在155~205℃范围,主要发生在热高压分离高压换热器和空冷器内;根据进料N、Cl的质量分数预测NH4Cl结晶温度,并及时移动注水位置和调节注水量,可有效防止NH4Cl结晶沉积及垢下腐蚀。Based on the thermodynamic calculation, the NH4Cl crystallization equilibrium curve was obtained. The deposition mechanism of NH4Cl crystals in the heat exchanger was analyzed. The multiphase equilibrium model of typical cooling and separation system for hydrogenation reaction effluent was established by Aspen simulation software, and the Kp-T curve （i. e. （ PHCI × PNH3 ）-T curve） was obtained. Based on the above, the NH4Cl crystalline prediction model of cooling and separation system for hydrogenation reaction effluent was established and the NH4Cl crystalline temperatures in the feedstock with different N, Cl mass fractions were calculated. The water injection optimization in cooling and separation system for hydrogenation reaction effluent was proposed, according to NH4Cl crystalline prediction results. The results showed that, the NH4Cl crystalline deposition in exchangers was a self-acceleration process. The NH4Cl crystalline temperature ranged from 155℃ to 205℃, which were the operation temperatures of hot and highpressure heat exchangers and air coolers. By moving injection position and adjusting the amount of wash water promptly, based on the NH4Cl crystalline prediction results, NH4Cl deposition and under-deposit corrosion could be effectively restrained.

关 键 词：加氢系统 NH4Cl结晶 沉积 热力学计算 Aspen模拟 

分 类 号：TQ026.5[化学工程]