B questions/ other random questions

Question 1

What is the main purpose of the demister pad?

Answer 1

to separate out entrained liquid

Question 2

What transfers the Stripper Overhead Liquid to Utilities?

Answer 2

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

Question 3

What type of catalyst is used in the 634 Reactor?

Answer 3

Nickel Molybdenum in the top bed

Nickel Molybdenum/cobalt molybdenum in the bottom bed

Question 4

What are the two undesirable components in the feed?

Answer 4

Hydrogen sulfide and ammonia compounds

Question 5

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

Answer 5

The Hot flash vapor/ fresh feed Exchanger

Question 6

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

Answer 6

Reactor feed/ Reactor effluent exchanger

Question 7

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

Answer 7

Hot flash vapor air coolers

Question 8

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

Answer 8

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%)

Question 9

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

Answer 9

high line

Question 10

What best describes the Amine contactors operation?

Answer 10

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.

Question 11

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

Answer 11

Downstream of the compressor discharge.

Question 12

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

Answer 12

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

Question 13

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

Answer 13

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.

Question 14

What variable is used to adjust the Heater outlet temperature?

Answer 14

adjusting the fuel gas pressure

Question 15

What is a consequence of low low pilot gas pressure?

Answer 15

pilot gas trips

Question 16

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

Answer 16

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.

Question 17

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

Answer 17

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.

Question 18

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

Answer 18

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.

Question 19

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

Answer 19

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

Question 20

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

Answer 20

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

Question 21

What is used for the primary seals on the compressor?

Answer 21

Hydrogen

Question 22

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

Answer 22

Low oxygen or possible leaking or ruptured tubes

Question 23

What are possible causes for flashbacks and backfires?

Answer 23

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

Question 24

What are the feed streams to 634?

Answer 24

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

Question 25

What are the 634 Utilities?

Answer 25

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