连续重整装置预加氢换热器内漏原因分析及对策  

Reason analysis and treatment measures of pre-hydrogenation heat exchanger leakage in continuous reforming unit

作　　者：张士元 赵景岩 杨勇辉 王伟 ZHANG Shi-yuan;ZHAO Jing-yan;YANG Yong-hui;WANG Wei(No 5 Refinery Joint Workshop,PetroChina Karamay Petrochemical Co Ltd,Karamay 834003,China)

机构地区：[1]中石油克拉玛依石化有限责任公司炼油第五联合车间,新疆克拉玛依834003

出　　处：《石化技术与应用》2022年第3期199-205,共7页Petrochemical Technology & Application

摘　　要：针对80万t/a连续重整装置出现的预加氢反应器(R 2101)压降、预加氢产物及重整进料中的硫含量、重整反应总温降等均超标的系列异常变化,经综合分析后预判为预加氢换热器(E 2101)管束腐蚀内漏所致,提出并实施了在该装置不停产条件下的检维修处理方案。结果表明:将45万t/a催化汽油加氢装置汽油与150万t/a柴油加氢装置重石脑油的混合进料作为短时期重整原料,并调控其含硫量在1μg/g以内,如此既维持重整装置生产运行,又对E 2101实施检维修的处理方案是可行的;E 2101管束内漏遭遇的是低温下管束中Fe与内流介质形成的H_(2)S-H_(2)O体系腐蚀,加上H_(2)S,HCl和NH_(3)形成相应的铵盐结晶及其垢下腐蚀;E 2101封堵消漏投运后,重整进料中的含硫量和含氮量从异常的1.7,0.4μg/g分别降至0.6,0.3μg/g,其待生催化剂的积炭质量分数从异常时的9.26%降至4.10%,催化活性得到提升,重整反应器总温降从异常时的270℃提高至300℃,R 2101压降不仅从异常时的120 kPa回升并达到320 kPa,且远高于维修前正常运行时的200 kPa,增幅为60%。A series of abnormal changes appeared in the 0.8 Mt/a continuous reforming unit,such as the pressure drop in pre-hydrogenation reactor(R 2101),the sulfur content in pre-hydrogenation products and reforming materials feed,and the total temperature drop of whole reforming reaction,were found to be caused by corrosion and internal leakage of pre-hydrogenation heat exchanger(E 2101).After the comprehensive analysis,it was predicted and anchored that the above abnormal changes resulted from the most possible internal leakage of tube bundle corrosion of E 2101,and the expedient inspection and maintenance treatment scheme was put forward and implemented along with the relevant unit makeshift continuous producing operation.The results showed that it was feasible to take the mixed feed of gasoline from the 0.45 Mt/a catalytic gasoline hydrogenation unit and heavy naphtha from 1.5 Mt/a diesel hydrogenation unit as the short-term reforming raw material substitute,along with regulating the sulfur content of the mixed feed within 1μg/g,so as to maintain the continuous production operation of the reforming unit and carry out the inspection and maintenance of E 2101 simultaneously.The internal leakage of E 2101 tube bundle was caused by H_(2)S-H_(2) system corrosion formed by Fe and internal medium flow at low temperature,together with the corresponding ammonium salt crystallization and scale corrosion are formed by H_(2)S,HCl and NH_(3).After E 2101 was fixed and put into operation,the sulfur and nitrogen contents in reforming feed decreased from 1.7 and 0.4μg/g in abnormal condition to corresponding 0.6 and 0.3μg/g,and the mass fraction of carbon deposition on spent catalyst also decreased from 9.26%in abnormal condition to 4.10%,and the catalytic activity was improved.Moreover,the total temperature drop of the reforming reactor increased from 270℃in abnormal condition to 300℃,and the pressure drop of R 2101 not only rose from 120 kPa in abnormal condition to 320 kPa,but also was much higher than 200 kPa in normal oper

关 键 词：连续重整 预加氢 硫含量 管壳式换热器 内漏 低温腐蚀 处理措施 

分 类 号：TE965[石油与天然气工程—石油机械设备] TE986