Q&A

(2010) Question 91: Assuming the FCCU already has a third stage separator, what are the various options you consider for further reduction of particulate emissions (PM) and what is the expected level of PM to be achieved?

The first thing to consider is the fourth stage collector. For designs that re-introduce the collected fines downstream of the expander, a fourth stage collector with fines removal and filter on the TSS underflow gas will aid in reducing PM.

(2019) Question 38: What are your guidelines for cleanliness of reactor vessel and overhead lines during Turnaround?  Do you have limits on reactor temperatures during dry-out to prevent the ignition of coke in the reactor?  What actions do you take if coke starts to burn?

What are your guidelines for cleanliness of reactor vessel and overhead lines during Turnaround?  Do you have limits on reactor temperatures during dry-out to prevent the ignition of coke in the reactor?  What actions do you take if coke starts to burn?

(2019) Question 39: What are your best practices for transferring FCC catalyst into/from pneumatic trailers and rail cars to ensure personnel safety and catalyst containment?

These trailers are often referred to as pneumatic, dry bulk, or pressure differential (PD) trailers. On-road trailers and railcars have similar functionality although railcars are not usually rated for vacuum, nor do they usually have a filter system. Both types of transport vessels have multiple hoppers.

(2019) Question 43: What are your best practices when shipping ecat, fines, feed, and slurry to suppliers for testing?  Please also comment on some best practices for sampling equilibrium catalyst.

When shipping ecat or fines, an appropriate sample container should be used. Catalyst suppliers will typically provide refiners with sample containers if needed. Catalyst shipping containers should be made of plastic or metal.

(2019) Question 44: What is your recommended back up options for slide valve / plug valve Hydraulic Power Units? Are electric actuators an option? What are the response times?

What is your recommended back up options for slide valve / plug valve Hydraulic Power Units? Are electric actuators an option? What are the response times?

(2018) Question 1: What are the benefits of alumina treating in sulfuric acid alkylation and HF alkylation? Has this technology been proven commercially?

In the sulfuric acid alkylation process, droplets of acid are found in the effluent stream from the reactor. These droplets, which are formed primarily from the alkylation chemistry itself and the formation of intermediates, are small and stable and cannot be removed by gravity settling and / or coalescing alone.

(2018) Question 2: What metallurgy works well and does not work well for use in alkylation units? In what applications does the alternate metallurgy perform better/worse?

The standard metallurgy for use throughout HF alkylation units is carbon steel. Showing a high degree of corrosion resistance in both low and very high acid concentrations, carbon steel is also useful for its relatively low cost compared to more exotic materials.

(2018) Question 3: What type of release mitigation safety systems do you use for sulfuric acid and HF alkylation units?

Sulfuric acid alkylation units do not require the robust safety systems as the HF Alky units since sulfuric acid is a liquid at atmospheric conditions. The release mitigation safety systems typically used are curbed and/or diked areas to contain the liquid sulfuric acid in event of a leak.

(2018) Question 44: Describe your procedures for placing and operating the FCC in hot standby/safe park mode. What safety concerns do you consider and what safeguards should be in place?

If the air blower is not running, things you should consider are ensuring all ignition sources are shutdown, bypassed or isolated (ESP, torch oil, DFAH, CO Boiler). Verify all hydrocarbon sources to the reactor, riser and regenerator are closed (fresh feed, any recycles, torch oil, fuel gas purges, LCO quench, etc.) and all sources of air are not being injected (main air, plant instrument air, fluffing air, etc.).

(2018) Question 45: What are the safe and reliable options for rodding out plugged bleeders such as hydraulic ram pumps, packing gland / drill assemblies or tangential bleeders? How are these options used in a best practice for ensuring piping is hydrocarbon free and ready for maintenance?

Rod out tools or bleeder cleaners are safe and effective at clearing clogged drain, vent and instrument valves to be cleaned during normal operations. Most include some type of drill bit and local pressure gauge and are designed to handle high temperature and pressure applications.

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