How do you test maximum silicon capacity on Si trap in laboratory? I have difficulty in deciding the model silicon molecules and reaction conditions.

In DHDS unit, amine scrubber having foaming issue. Anti foam dosing was not yet commissioned from almost 20 years but suddenly foaming problem started , antifoam helps to control the problem but continuous dosing is also not suggested. What may be the reasons when we are maintaining other parameter and proper Delta T between Amine and process gas and how can we encounter this issue?

In Naphtha Hydrotreating Unit the Sulfur is removed, and than in CCR Platformer feed DMDS is dosed again. Why cant we maintain the required Sulfur level in CCR Platformer directly from NHT unit (suppose In NHT Unit feed Sulus is 786 wppm and we have to maintain 0.75 wppm in CCR PF Feed)? Why it is necessary to remove sulfur first and than add sulfur (DMDS) again?

We have Heavy Coker Gas oil Hydrotreating unit and its reactor MOC is 2.25 Cr, 1 Mo, 0.25 V. As per Licensor manual, the MPT (Minimum Pressurization temperature) is 93C. However, as per fabricator it is 38 C. The query is which MPT value will be governing and to be used during pressurization of the unit while start up.

If the steam turbine motive steam pressure becomes low than the actual pressure lets say 30bar operating pressure and dropped to 20 bar, can you please elaborate what is the effect of pressure on the governor, will it trip the compressor on what basis.

Are there options for online cleaning a preheat exchanger network?

We’ve increased the opportunity crude content of our feed and are experiencing high calcium issues. How can we best address this?

Please suggest ways of reducing steam demand in our sour water stripper.

For best product quality from vegetable oils should we hydrotreat them with conventional petroleum feed or use them as straight feed?

Our air compressor trips off immediately after it powers on. Is this a mechanical or process issue?

We’d like to produce less light naphtha and more liquid fuels from our hydrocracker. How do we go about it?

What is the best route for maximum propylene from a resid feed to the FCC?

We didn’t expect severe corrosion issues in the carbon steel of our amine unit. What is causing it?

The CDU boots water is red-orange color. It has been more than a week now. We are not sure where this problem comes from and how this can affect the process. (When we add corrosion inhibitor in the water, the part of it was turned into brown color.) Could anyone please share the knowledge regarding this issue?

For a crude tank with a capacity of 610,000 bbl capacity, what mechanised cleaning system would be required and how long would it take to clean the tank especially of sludge. This is a refinery cum petrochemical complex project to be undertaken and we are in the process of optimised tank sizing.

In our naphtha hydrotreating unit, stripper heater is being used to heat heavy naphtha coming from NHT reaction section to eliminate all the H2S, NH3, H2O by stripper column. But, currently the heater is not performing well and outlet temperature reduced down from 210°C to 203°C . So, need to know that in order to improve the heater performance, can we conduct only the steaming through the coil to strip out all the dirt layer/coke formed inside the coil surface ?

We are facing lots of solid formation in the quench tower circuit of our TGT Unit. What can be the reason and how are solids/salts formed in this circuit?

We are having a problem with the product fractionator bottoms pump (multistage centrifugal Pump turbine driven/standby motor driven)(inlet ~330 deg C) of a MHC unit; whenever the pump is taken in service and made ready after maintenance  and primed (previously used to prime from the suction valve, now try to prime with a warm-up line) the downstream fired heater (thermal cracker) trips due to low flow as soon as the suction valve is crack opened to take it in service.

Any suggestions on how to rectify this issue?

Is there any way to increase or improve the heat transfer rate of the Austenitic Stainless Steel tubes of the VGO hydrocracker reactor charge heater? Chemical cleaning or any mechanical means? Also ensuring temperature doesn't drop below 205C to avoid acid attack.

With gasoline demand picking up, are North American refineries tight on octane supply, and how do you manage an octane supply constraint?

What are impurities in alkylation spent sulphuric acid? Is there Chloride or Flouride in such spent acid?

What is hydrogen embrittlement, where could it occur in our refinery, and how do we avoid it?

In our DHDT unit (Axens licensor) one PV is given after the feed filter package to maintain a back pressure of 5kg/cm2. What is its importance? In the other DHDT unit (Haldor Topsoe) there is no PV given.

During precommissioning a diesel unit why we can not start the recycle gas compressor with 100 % hydrogen before catalyst sulfiding as per the licensor: 50% nitrogen with 50% hydrogen?

What is the most effective way to capture particulates in FCC flue gas?