UOP连续重整装置催化剂循环故障分析及处理
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摘要
介绍了UOP连续重整装置再生器或反应器中因催化剂颗粒间隙中气体线速发生变化而对催化剂颗粒移动产生的影响,并对几种异常现象进行分析,包括:1气体线速过高会造成催化剂贴壁或空腔现象,引起还原段料位和分离料斗料位突然降低;2再生剂和待生剂下料管线中,气体流动方向与颗粒移动方向相反,气体流速过高导致催化剂无法向下移动,引起催化剂循环中断;3对于闭锁料斗来说,如果闭锁区的下料管中催化剂料封被高压差破坏,气体就会互串导致闭锁区与缓冲区之间连通,且闭锁料斗的催化剂循环中断。通过对以上3种案例进行分析可知,分离料斗补充氮气量、氮封罐补充氮气量、闭锁料斗的补偿气流量异常增加均意味着输送故障已经发生。使连续重整两器的各处流量保持在正常范围是催化剂稳定输送的前提。当装置出现异常现象导致输送停止或波动后,需采取针对性措施加以解决和恢复。
The negative impacts of changes of gas velocity between the catalyst particles on the movement of catalyst particles in the regenerator or reactor of UOP's continuous catalytic reforming unit are described.Several abnormal phenomenons are studied,including( 1) "pinning and caving"of catalysts due to excessive gas velocity and sudden level lowering in reduction section and separation hopper,( 2) the flow direction of gas is opposite to the direction of particles' movement in the regenerated and spent catalyst transfer lines.Higher velocity of gas will stop the movement of catalyst and absolutely result in the stoppage of catalyst circulation and( 3) for the lock hopper,the change of the pressure difference between these two zones will adjust the gas velocity between particles in the standpipe in the lock zone. If the"catalyst sealing"in the standpipe is destroyed by the excessive high pressure difference,the lock zone and surge zone will be connected and lock hopper circulation will stop. It can be known from above 3 analyses that the abnormal increases of nitrogen in separation hopper,nitrogen addition of nitrogen sealing tank,flow of gas addition in lock hopper will lead to accidents. Therefore,the control of flowrates within the normal operating range for the different parts of CCR reactor and regenerator is the guarantee for the normal stable transfer of catalysts. Corresponding effective measures should be taken to restore to the normal flow after occurrence of stoppage and fluctuation of catalyst transfer.
The negative impacts of changes of gas velocity between the catalyst particles on the movement of catalyst particles in the regenerator or reactor of UOP's continuous catalytic reforming unit are described.Several abnormal phenomenons are studied,including( 1) "pinning and caving"of catalysts due to excessive gas velocity and sudden level lowering in reduction section and separation hopper,( 2) the flow direction of gas is opposite to the direction of particles' movement in the regenerated and spent catalyst transfer lines.Higher velocity of gas will stop the movement of catalyst and absolutely result in the stoppage of catalyst circulation and( 3) for the lock hopper,the change of the pressure difference between these two zones will adjust the gas velocity between particles in the standpipe in the lock zone. If the"catalyst sealing"in the standpipe is destroyed by the excessive high pressure difference,the lock zone and surge zone will be connected and lock hopper circulation will stop. It can be known from above 3 analyses that the abnormal increases of nitrogen in separation hopper,nitrogen addition of nitrogen sealing tank,flow of gas addition in lock hopper will lead to accidents. Therefore,the control of flowrates within the normal operating range for the different parts of CCR reactor and regenerator is the guarantee for the normal stable transfer of catalysts. Corresponding effective measures should be taken to restore to the normal flow after occurrence of stoppage and fluctuation of catalyst transfer.
引文
[1]徐承恩.催化重整工艺与工程[M].北京:中国石化出版社,2009:421-422.
[2]邢祖远.连续重整反应再生设备技术问答[M].北京:中国石化出版社,2006:11-12.
[3]Alsaggaf R M,Padmanabhan S,Abuduraihem H Z,et al.Innovative approach solves CCR regeneratior pinning problem[J].Hydrocarbon processing,2008(10):94-96.
[4]闫遂宁,李朝发,全民.连续催化重整闭锁料斗的研究[J].炼油技术与工程,2004,34(4):27-30.
[5]金涌,祝京旭,汪展文,等.流态化工程原理[M].北京:清华大学出版社,2001:361-365.
[6]何文全.连续重整催化剂再生系统问题分析及对策[J].高桥石化,2004,19(6):12-17.
[2]邢祖远.连续重整反应再生设备技术问答[M].北京:中国石化出版社,2006:11-12.
[3]Alsaggaf R M,Padmanabhan S,Abuduraihem H Z,et al.Innovative approach solves CCR regeneratior pinning problem[J].Hydrocarbon processing,2008(10):94-96.
[4]闫遂宁,李朝发,全民.连续催化重整闭锁料斗的研究[J].炼油技术与工程,2004,34(4):27-30.
[5]金涌,祝京旭,汪展文,等.流态化工程原理[M].北京:清华大学出版社,2001:361-365.
[6]何文全.连续重整催化剂再生系统问题分析及对策[J].高桥石化,2004,19(6):12-17.