Lesson 1 Feedback Exercises

Question 1

What is the purpose of the 636 HDS Unit?

Answer 1

Improve feed quality of gas oils that are used as FCCU feed. Feed quality is improved by removing sulfur & nitrogen, adding hydrogen and removing lighter fractions from the oil.

Question 2

In the Reaction subsystem, what are olefins and aromatics in the feed saturated with?

Answer 2

Hydrogen

Question 3

The reaction Subsystem uses either _______ or Cobalt Molybdenum catalyst.

Answer 3

Nickel Molybdenum

Question 4

Wash water is injected into the reactor effluent stream to absorb __________ and remove it from the process.

Answer 4

Ammonia (NH3)

Question 5

The Compression Subsystem provides ________ ________ to the Reaction System.

Answer 5

Combined Hydrogen

Question 6

Hydrogen from the Plant Hydrogen Header or the _______ ________ provides make-up hydrogen to the 636 HDS System.

Answer 6

633 Unit

Question 7

Make up hydrogen to the 636 HDS is compressed in how many stages?

Answer 7

3

Question 8

In the Compression Subsytem, lean amine from the SRC is used to absorb _____ in the recycle hydrogen stream from the Reaction Subsystem.

Answer 8

Hydrogen Sulfide (H2S)

Question 9

The Stripping Subsystem uses _______ _____ to strip entrained H2S, NH3, hydrogen, and light hydrocarbons from the hydrocarbon liquid streams from the Reaction Subsystem.

Answer 9

125 steam

Question 10

In the Stripping Subsystem, the stripper overhead off-gas is released to?

Answer 10

The Stripper Off Gas Scrubber

Question 11

The Fractionation Subsystem separates the Stripper Bottoms stream into _________, ________, _______, sour off gas, and sour water streams.

Answer 11

FCCU Feed, Diesel, and Naphtha

Question 12

In the Fractionation Subsystem, the Product Fractionator bottoms stream is cooled via heat exchange with BFW, which generates ________and ________ steam.

Answer 12

550pisg and 125psig steam

Question 13

In the Fractionation Subsystem, the Diesel Stripper removes ___________ _______ _______ from the diesel side-draw stream.

Answer 13

Light ends, (naphtha)

Question 14

List the Inputs in the 636 system.

Answer 14

536 HVGO
537 AGO, HVGO and MVGO
732 LGO
736/737 Coker HGO
Cold Feed 
Make up Hydrogen
Lean Amine
Wash Water

Question 15

List the Catalysts used the 636 system.

Answer 15

Nickel or Cobalt Molybdenum (Hydrotreating catalyst)

Question 16

List the chemicals used the 636 system.

Answer 16

Corrosion Inhibitor

Question 17

List the outputs produces the 636 system.

Answer 17

FCCU Feed, Diesel Product, Naphtha, Recycle Hydrogen, Scrubbed off gas, Sour off gas, purge gas and rich amine.

Question 18

List the waste streams in the 636 system.

Answer 18

Sour water and Boiler Feed Blowdown

Question 19

List the Utilities required in the 636 system.

Answer 19

125 psig steam, 20 psig steam, boiler feed water, cooling water, condensate, stripped sour water, fuel gas, natural gas, plant air, instrument air, nitrogen, and electricity

Question 20

List the Utilities produced in the 636 system.

Answer 20

550 psig steam and 125 psig steam