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(2015) Question 27: What is your experience with processing benzene in C5/C6 isomerization units? Have there been any issues with higher reactor exotherms associated with benzene saturation?

UOP’s general guideline is to limit the lead reactor ΔT to 100°F (55°C). This limit is based on our design margins or the heat exchangers around the reactors. That 100-degree limit corresponds to above 5 to 8% benzene in the feed. So, one way to get around that is to recycle or add something to dilute the benzene.
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(2015) Question 30: What factors influence your decision to conduct air versus inert reactor entry for catalyst changeout? For, what methods do you use to avoid stress corrosion cracking?

For us to enter a reactor that is under an inert atmosphere, the conditions need to warrant it, such as when there are large amounts of pyrophoric material still present, when a specific job is required, an old catalyst needs to be vacuumed out for sampling purposes, or if there is filtration material on top that requires removal in order to allow the catalyst below to dump freely.
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(2016) Question 70: What is your method for measuring naphthenic acid [TAN (total acid number)] in FCC feed? Is this method affected by VABP (volume average boiling point) or Concarbon (Conradson carbon) content? Do you have data that validates an appropriate integrity operating window (IOW) trigger level? If above the trigger level, what is your recommended corrective action (extra inspection, change crude/slate, etc.)?

In terms of TAN number, we typically recommend the standard test method UOP 565, which can be found through the ASTM (American Society for Testing and Materials) website.
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(2016) Question 71: In your experience, what factors affect NOx emissions for a partial-burn FCC with a CO boiler? How do you achieve 50 ppm CO emissions while simultaneously minimizing NOx emissions through the stack?

Combustor-or incinerator-style CO boilers can produce lower NOx emissions than direct burning CO boilers (COBs). COBs with cold planes where the CO is combusted (package boilers, as an example) require high firing rates to combust the CO to acceptable levels, thereby increasing the liberation and NOx contribution.
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(2016) Question 72: Recent drone technology advancements have enabled refiners and contractors to improve the efficiency of maintenance and inspection activities. With this, how are your hot work permits and general safety policies evolving to sustain adequate asset and personnel protection at all times? For instance, what additional safety permits or considerations would apply for drone use and aerial inspections?

In June 2016, the Federal Aviation Administration (FAA)announced that it had finalized the first operational rules for routine commercial use of small, unmanned aircraft systems (UASs) including “drones”. According to industry estimates, the rule could generate more than $82 billion for the U.S. economy and create more than 100,000 new jobs over the next 10 years.
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(2016) Question 73: What criteria do you use to justify sea-less pumps in place of conventional double-seal pumps in LPG services? What are the operational and reliability issues associated with these types of seal-less pumps?

Seal-less pumps can be either mag drive or canned motor. Seal-less pumps are now commonly used all over the refinery and petrochemical industries. The U.S.is quite a bit behind Europe in the use of seal-less pumps. Europe has been specifying seal-less for multiple services since the mid-1980s.
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