Q&A

ABIGAIL SLATER (HollyFrontier)
Salting typically occurs in the reactor effluent exchangers (shell and tube and fin fans), recycle and net gas compressors, and product stabilizer overhead system (top trays, overhead condenser, etc.). Common monitoring practices on exchangers and fin fans can be

DAVINDER MITTAL (HPCL Mittal Energy)
Chlorides have been a long standing issue in catalytic reformer operation. Until a few years ago, the focus on preventing operational problems from the chloride compounds in the catalytic reformer product stream was to remove HCl.  More recently, a growing

BILL KOSTKA (AXENS NORTH AMERICA)
Metal-catalyzed coke (MCC) formation typically occurs on 3d valence transition metals such as iron and nickel.  Under CCR-like conditions of low hydrogen partial pressure (less than about 620 kpa), high temperature (more than about 480 °C) and low or stagnant flow

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

GRUBB (Chevron USA, Inc.) I’ve consulted Gary Ash, the Pascagoula local expert, and Steve Mather, who is the corporate expert. They relayed to me that acid is still the biggest problem and not really necessarily the contaminants; but where the feed contaminants come in, they can make the acid more

KAISER (Delek Refining Ltd.) With respect to alkylate yield and T90, the short answer to the question is, yes. When T90 increases, your alkylate yield is going to go down. And if that’s all you care about alkylation, you can go to sleep for the next five minutes and Jeff will wake you up when we get

METKA (Sunoco, Inc.) We operate a cat poly and sulfuric alkylation unit within the same refinery. The configuration offers flexibility and synergies that allow various operating and business demands to be met. In our configuration, the cat poly debutanizer overhead feeds the alkylation unit to

QUINTANA (Valero Energy Corporation) The spent Isom regenerant will contain butanes that are attractive to recover. They can come from generally any of three sources: either the treated normal butane feed downstream of the on-stream dryer, the fractionated isobutene from the Deisobutanizer fractionator overhead, or the isomerate product is used as the regenerant source. The spent regenerant also contains all of the sulfur and oxygenate impurities that were previously accumulated on the sieve; and after the spent regenerant coalescer, it will also be saturated with water.

KAISER (Delek Refining Ltd.) In my experience, the cooling water exchangers in an HF alkylation unit are really no more problematic than any other exchanger in the refinery when you’re looking at the waterside only. If you have an exchanger in the HF alkylation unit that suffers from low flow or it’s at the end of a header, trapped scale, and there are certainly critical exchangers inside the alkylation unit that you want to keep clean, it’s really no different if it’s in the alkylation unit or in some other unit in the refinery. You’re going to have water problems and that’s going to generate issues for you.

KAISER (Delek Refining Ltd.) Again, just to re-emphasize, I’m not currently on an HF unit so part of this response will rely on some former colleagues of mine. I would not make a blanket recommendation to change the material specification for carbon steel in HF alkylation units. To me, the risk is too great. I understand that there are certain times when things are tight and you might need immediate material delivery and there’s no other option, but I would not make a blanket relaxation in the material specifications.