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Flashcards in B questions/ other random questions Deck (25)
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1
Q

What is the main purpose of the demister pad?

A

to separate out entrained liquid

2
Q

What transfers the Stripper Overhead Liquid to Utilities?

A

The product stripper overhead liquid pumps transfer the hydrocarbon liquid from the product stripper accumulator to 586 drips tank in refinery Utilities

3
Q

What type of catalyst is used in the 634 Reactor?

A

Nickel Molybdenum in the top bed

Nickel Molybdenum/cobalt molybdenum in the bottom bed

4
Q

What are the two undesirable components in the feed?

A

Hydrogen sulfide and ammonia compounds

5
Q

The feed pumps transfer the feed to what piece of equipment?

A

The Hot flash vapor/ fresh feed Exchanger

6
Q

The reactor effluent goes through what piece of equipment before entering the Hot flash drum?

A

Reactor feed/ Reactor effluent exchanger

7
Q

The hot flash drum vapors go through what piece of equipment before entering the cold flash drum?

A

Hot flash vapor air coolers

8
Q

What is a possible cause for the Heater SIS system to trip?

A

low-low feed flow, low-low hydrogen flow, high-high fuel gas pressure, low-low fuel gas pressure, high-high furnace pressure, low-low furnace pressure (low pressure trip of pilot and fuel gas is bypassed when ID fan is off), Stack damper fail to open in natural draft (50%), Forced draft air door fail to open in natural draft (50%)

9
Q

The Stripper Overhead Accumulator vent gas can go to the Low line and the _________?

A

high line

10
Q

What best describes the Amine contactors operation?

A

The recycle gas contactor uses lean amine from the SRC to absorb H2S from the Cold flash Drum overhead stream and vents recycle hydrogen overhead.

11
Q

Where does the 636 makeup hydrogen enter the 634 hydrogen stream?

A

Downstream of the compressor discharge.

12
Q

What is the purpose of the compressor Lube Oil Rundown Tank?

A

To maintain a constant flow of lube oil to the compressor, motor, and gearbox lubrication points if normal oil flow is interrupted.

13
Q

What is a consequence of a low H2 flow to the Reactor?

A

The potential effects of this variable is not controlled are catalyst deactivation and insufficient hydrogen for desired reations to come to completion, resulting in off-spec prouct. Low combined hydrogen flow can also result in compressor damage due to surge. Additionally, low combined hydrogen flow can initiate the interlock to shut down the reactor feed heater. This can increase the temperature of the catalyst causeing an increase in coking of the lines.

14
Q

What variable is used to adjust the Heater outlet temperature?

A

adjusting the fuel gas pressure

15
Q

What is a consequence of low low pilot gas pressure?

A

pilot gas trips

16
Q

What is a consequence of a high level in the stripper?

A

The potential effect if this variable is not controlled is excessive level in the stripper, causing off spec product and lifting the PSV, which relieves to the flare resulting in an environmental release. Additionally if feed continues into the tower, there is a potential for liquid to fill the vapor line (not designed for liquid weight) resulting in line failure, potential fire. Fire can be immediately hazardous to personnel and has the potential to contact other materials increasing the potential for serious injury to personnel.

17
Q

What is a consequence of a low level in the stripper?

A

The potential effects if this variable is not controlled is a loss of level resulting in bottoms pump cavitation and a possible process upset at the FCCU. If the pump seal fails due to cavitation, there is the possibility of an environmental release and a potential fire. with potential contact with hydrocarbons that can cause severe, possibly disabling, personnel injury. Additionally a low deviation can cause hydrogen to be released through the tower bottoms to tankage potentially sinking of the tank roof, resulting in an environmental release.

18
Q

What is a consequence of a high high level in the Recycle KO drum?

A

The potential effect if this variable is not controlled is restriction of the Reactor effluent flow, which can create a high-pressure condition in the Reactor, resulting in lifting the unit PSV. Lifting of the PSV relieves to the flare, resulting in an environmental release. A high level and also flood the cold flash drum causing a possible hydrocarbon carry-over to the Recycle gas contactor. The Hydrocarbons could contaminate the amine and be released to the SRC with rich amine, upsetting the SRC. Hydrocarbons in the amine can also cause improper treating of the recycle hydrogen resulting in high H2S content in the recycle hydrogen. Uncontrolled high level will result in compressor damage causing a unit shutdown and a loss of containment. This loss of containment can lead to a fire potential, exposure and potential for personnel to come into contact with material that can cause severe possibly disabling, personnel injury.

19
Q

What is a possible response to high sulfur content in Product?

A
  1. Check fee lineup to ensure feed isn’t the cause
  2. sample intake and out take of suspected leaking exchanger to ensure an exchanger isn’t leaking
  3. increase the Reactor WABT because the reactor temperature is too cold
  4. Notify the engineer of the reduced catalyst activity
  5. increase the pressure because you have low pressure
  6. because the hydrogen is impure, increase the hydrogen purity
20
Q

What is a consequence to a high level in the Amine contactor?

A

The potential effect if this variable is not controlled is liquid to the recycle gas knockout drum and possible amine carry over to the Recycle hydrogen compressor. Lifting of the unit PSV

21
Q

What is used for the primary seals on the compressor?

A

Hydrogen

22
Q

What are the possible cuases for excessive smoke coming from teh heater stack?

A

Low oxygen or possible leaking or ruptured tubes

23
Q

What are possible causes for flashbacks and backfires?

A

Low fuel pressure at the burner, firebox under pressure or low furnace draft

24
Q

What are the feed streams to 634?

A

533 Reside, 536/37 Crude HVGO, 536/37 Crude LVGO, 537 Crude MVGO, 736/37 Coker HGO

25
Q

What are the 634 Utilities?

A

Cooling water, 550 psig steam, 125 Steam, plant air, instrument air, nitrogen, electricity, natural gas, fuel gas