Q&A

GRUBB (Chevron U.S.A., Inc.) My experience here is with the design of a new unit in Pascagoula. So we went to the other CCRs within the Chevron system and asked this question already on how to increase our reliability with that project. This is a roundabout answer arranged from all the different operating ones. On the valve types, I’ll just state that all of Chevron’s experience is with the UOP designs and what we do is we specify soft seat on the “V” notch ball valve wherever the catalyst flow must be stopped. We use a double-seated plug and globe “G” valves on the vents and spring loaded “B” ball valves for the gas tight seal on the catalyst transfer line.

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

It is quite important to optimize PERC injection in feed as guided by technology supplier as otherwise the HCl concentration in off gas can go too high (normal range 1500 - 2500 ppm). This will lead to rapid depletion of caustic strength due to neutralization effect, thereby requiring frequent fresh caustic make-up.

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

ABIGAIL SLATER (HollyFrontier)
Gasoline blending specifications are vast and different in various geographical areas. The common blending limit that taxes both summer and winter specifications are volatility specifications. Depending on the gasoline blend, Reid Vapor Pressure (RVP), Total vapor over

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

We would recommend ensuring that the acid knockout drum be sized large enough to allow the hydrocarbons to disengage in the drum.

Ammonium chloride salts are a common problem in both naphtha reforming and naphtha hydrotreating units.

The problem now comes from the oxygen ingress coming in with makeup hydrogen, with the culprit typically being CO and CO2.