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(2008) Question 94: In monitoring catalytic reformer operation, how often do you perform a feed/product analysis and what analytical methods do you use? How often do you perform a mass balance and what is the acceptable mass balance closure? What is a typical mass balance closure?

Question 94: In monitoring catalytic reformer operation, how often do you perform a feed/product analysis and what analytical methods do you use? How often do you perform a mass balance and what is the acceptable mass balance closure? What is a typical mass balance closure? Michael Newton (Roddey Engineering) Units were the feed properties are relatively constant need to be monitored much less than those were the properties change often. For material balances during performance evaluation, accuracy should be within +/-1%. For daily monitoring, +/-2% is acceptable. All balances and monitoring require good data from the lab and making sure that meter data is input and calculations performed correctly.
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(2008) Question 95: How often do you perform CCR and cyclic reformer turnarounds? What determines the turnaround interval? What actions can you take to extend the turnaround cycle?

Question 95: How often do you perform CCR and cyclic reformer turnarounds? What determines the turnaround interval? What actions can you take to extend the turnaround cycle? Javier Quintana (Valero Energy) Valero’s best practice guideline for reformer turnarounds is currently 4-6 years, but eventually we will target 10 years. With the longer turnaround horizon, catalyst condition in a CCR unit can be managed with on-the-fly change out, which has been demonstrated several times in practice, while in cyclic units, a reactor can be changed out while the remainder of the unit is operating.
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(2008) Question 96: How do you manage sulfur in the feed to a catalytic reformer? What is the minimum allowable sulfur for CCR, semi-regen, and cyclic reformer feeds? What are your sampling frequencies and allowable ranges? What is your experience with carburization and/or metal-catalyzed coking?

Question 96: How do you manage sulfur in the feed to a catalytic reformer? What is the minimum allowable sulfur for CCR, semi-regen, and cyclic reformer feeds? What are your sampling frequencies and allowable ranges? What is your experience with carburization and/or metal-catalyzed coking? Joe Zmich (UOP LLC) UOP has extensively researched the tendency of metal surfaces to promote coke formation. UOP will provide specific recommendations on operating guidelines based on unit design and operating conditions. We are aware of two fixed bed units that have each operated with feed sulfur below 0.05 wppm and experienced coke growth in the reactors. Subsequent operation with a target of 0.15 wppm S successfully prevented repeat coke growth. Most fixed bed reforming catalyst systems must be properly sulfided following regeneration to attenuate the catalyst metal function.
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(2008) Question 97: What technologies and adsorbents are you using for net hydrogen off gas chloride traps and what operating problems have you experienced? What are the criteria for changing out the adsorbents and how often are the beds changed?

Question 97: What technologies and adsorbents are you using for net hydrogen off gas chloride traps and what operating problems have you experienced? What are the criteria for changing out the adsorbents and how often are the beds changed? Javier Quintana (Valero Energy) There are various adsorbents available for effective chloride treating of the hydrogen-rich net gas stream, including activated aluminas, promoted aluminas, and zeolites. Valero has moved away from the alumina products towards a best practice of using the zeolite products, not only for reasons of cost per quantity of chloride removed, but also for ease of changeout and completeness of chloride removal.
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(2008) Question 98: What metallurgy are you using for mesh pads in reformer compressor suction knockout drums? How often are the mesh pads inspected and how often are they replaced? Are the same criteria used for mesh pads in product separators?

Question 98 What metallurgy are you using for mesh pads in reformer compressor suction knockout drums? How often are the mesh pads inspected and how often are they replaced? Are the same criteria used for mesh pads in product separators? Rick Grubb (Chevron USA) We typically use 304 SS demister pads in the refinery and inspect them every 10 years. In reforming service we have been using Tefzel demister pads and have been replacing them approximately every dump and screen due to separator internal inspections. If we go into the vessel we go ahead and inspect the mesh pad, but assume before opening the vessel that the pad will need replacing. The Tefzel pads have greatly increased the reliability such that we don’t find mesh pad pieces in the compressors anymore. We have been contemplating using co-knit pads (synthetic fiber inter-woven with a SS fiber), but have not done so yet.
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