Q&A

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.

NEWTON (Roddey Engineering Services, Inc.) As everyone knows, we’re not here to discuss how to make more gasoline; we’re here at the conference to learn how to make more diesel, so I just hope you people in here... But whenever you start to talk about maximizing diesel yield from most refineries, what you’re going to talk about is shifting the heavy end of the reformer feed to the diesel stream and so you lower your endpoint to the reformer.

METKA (Sunoco, Inc.) Typically, iron levels up to approximately 12,000 ppm can be tolerated before a change-out is required. Iron is a support modifier that can affect both the metal and acid sites. There is more of an impact on the acid sites, and iron can impede chloride pick-up and trap sulfur on the catalyst. Iron typically impacts the first reactor in a fixed-bed unit and is primarily a result of upstream corrosion in the naphtha hydrotreater.

NEWTON (Roddey Engineering Services, Inc. Engineering) I’m just going to deal with Roddey Engineering’s experience. I know some people on the panel have different experiences. But as far as feed effluent exchangers go, and especially Texas Towers, we have seen significant fouling on all that we’ve dealt with. Pretty much every refinery that has one, they do not clean the tower.

THOMAS PORRITT (Chevron U.S.A)
A selective hydrogenation unit or SHU converts diolefins to olefins in a stream before it feeds an alkylation unit.

Below is a basic flow scheme.

Figure Q2 - 1 Selective Hydrogenation Unit Flow Scheme

The typical composition of non-condensable gases and light

DAVINDER MITTAL (HPCL Mittal Energy)

The gas and liquid dryers perform important task of safeguarding the ISOM catalyst from water vapor and other impurities in the make-up hydrogen and hydrocarbon feed.
The dryer switching valves play an important role of directing the inlet/outlet gas streams

ABIGAIL SLATER (HollyFrontier)
The Tier 3 gasoline regulation partially took effect in 2017 and will be fully implemented in 2020. The Tier 3 gasoline regulation has impacted the refining industry in a myriad of ways as refiners reduce sulfur further. These impacts will be similar to most refineries

BILL KOSTKA (AXENS NORTH AMERICA)
Reported platinum recoveries from reforming catalyst following commercial utilization have typically ranged between 90 and 100 wt% and have rarely been less than 80 wt%.  The magnitude of this range is both frustrating and at least somewhat explainable.

How one

The answer to this question depends on the specific RTD technology.