| American Fuel & Petrochemical Manufacturers

Question 20: What are the allowable limits/guidelines for water in feed to hydroprocessing units? Does the guidance change for activation vs normal operation? If so, how? What effective test methods do you use to measure water in feed? Do the limits change for different hydroprocessing units?

SUNHEIL ABDO and MICHAEL PEDERSEN (Honeywell UOP)

Question 19: In a hydrocracking unit, what methods do you use to determine the pretreat reactor operating temperature for optimum nitrogen slip to cracking catalyst?

AMIT KELKAR (Shell Catalysts & Technologies)

Question 18: What are your methods to mitigate bed 1 pressure drop without a unit skim? How would your approach be different if the pressure drop developed in a different bed, say bed 3?

JOE RYDBERG (CITGO)
Mitigation of elevated pressure drop first begins with identification the nature of the pressure drop. Is the DP a result of a more gradual buildup or a step change from a unit event or upset? Was an event related to hydrogen starving of the unit or loss of recycle compressor?

Question 17: What testing frequency and additional feed characterization (apart from bulk properties) should be used to accurately monitor catalyst performance on heavy feeds?

FERNANDO MALDONADO (Shell Catalysts & Technologies)
The type and frequency of tests performed are unit and refinery specific. When creating or modifying a unit’s laboratory test schedule some factors to be considered include:

1.   Unit objectives
2.   Past and/or current operational issues
3.   Refinery onsite laboratory’s capability and resources
4.   Catalyst vendor support

Question 16: What is required to achieve Safety Integrity Level 2 (SIL-2) rating on the hydrocracker depressuring system? For a hydrotreater that does not require SIL-2, what position should the depressurization valve fail to?

JOE RYDBERG (CITGO)
CITGO typically seeks process safety consultants to help with SIS design including SIL selection. Kenexis is such a company who has provided the following technical information regarding depressurization systems.

Question 15: What practices and modifications have you implemented in response to the new High Temperature Hydrogen Attack (HTHA) guidelines and updated Nelson curves?

JOE RYDBERG (CITGO)

Question 14: What are your strategies to reduce alky acid consumption?

ABIGAIL SLATER (HollyFrontier)
The most impactful parameter affecting alky acid consumption is feed quality. Reducing feed contamination will greatly reduce acid consumption. There are also operational changes that can be made to reduce acid consumption, but the biggest impact will be feed contaminants. Anything that will cause the alkylation reaction to reduce acid strength or polymerize will affect acid consumption.

Question 11: Where are your liquid-phase chloride treaters installed for reforming units? What are the advantages of each location?

BILL KOSTKA (AXENS NORTH AMERICA)
Liquid-phase Cl treaters are typically used in three locations for reforming units.

Question 10: What causes metal-catalyzed coking (MCC) that obstructs catalyst circulation in CCR reformers? What actions do you take to mitigate MCC formation?

BILL KOSTKA (AXENS NORTH AMERICA)

Question 9: How do you track chloride in liquid/gas/LPG? What are your criteria for replacing adsorbent in chloride treaters?

DAVINDER MITTAL (HPCL Mittal Energy)