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Our hydrocracking unit is cycle length limited by the pressure drop build up in pretreating reactor. The pressure drop build up is caused by a deposition of iron sulfide at the top of the reactor. I want to know what can be done to solve this problem?
 
Answers
07/10/2008 A: Samuel Sinanan, IPSL, Samuel.Sinanan@ipsl.co.tt
(1) Improve bed grading to mitigate pressure drop build up
(2) Consider feed filters or a scale catching tray (reactor internals)
(3) Reduce process upsets such as power failures, etc
15/10/2007 A: Randy Alexander, EURECAT, randy.alexander@eurecat.com
You should also talk to Crystaphase (www.crystaphase.com) about their Cat-Trap support material. This is a very porous top-bed support that traps scale and particulate. Cat-Trap is now on the best practices list for several large refining companies. ......
06/09/2007 A: Lindsay McRae, Pall Corporation, Lindsay_McRae@ap.pall.com
An external feed filter using sintered stainless steel mesh filter elements can prevent dP build up in HCU reactor and also in the pretreating reactor. The feed filter is backwashed periodically using gas assisted backwash to regenerate the filter dP. A feed characterisation study is usually recommended as first step to check particle size distribution, solids loading, diene number and OCT (Oil Compatibility Test). Pall Corp undertakes such studies with refinery customers globally to troubleshoot problematic HCU's in order to be able to provide a long term solution. ......