Hydrotreating Unit

1.

1 point

During operation, the hydrotreating catalyst gradually loses some of its activity. In order to maintain the desired quality of the products at the design feed rate, the operator must: (page 23 textbook)

Increase temperature

Decrease pressure

Decrease temperature

Increase pressure

2.

1 point

To improve the octane number of treated product, the Hydrotreating unit must convert the feed that contain:

Low concentration of aromatics

None of these are correct

Low concentration of n-paraffins

Low concentration of n-oleﬁns

3.

1 point

In HDT process, how to increase the purity of recycle hydrogen?

Remove methane in recycle gas

Remove hydrogen sulﬁde in recycle gas

Remove water in recycle gas

None of these are correct

4.

1 point

In HDT process, ___________ is a measure of change of reaction rate
over time. (page 23 textbook)

rates of reaction

none of these are correct

product quality

catalyst stability

5.

1 point

In NHT, the temperature cause the recombination re action to form mercaptan is around: (page 35 textbook)

343 C

130 C

30 C

230 C

6.

1 point

During the normal operation of HDT process, an increase in the end point of feed will make the sulfur and nitrogen removal ____________, thus requiring _______ reactor temperatures which, in turn, __________ coke formation. (page 26 textbook)

Easier/ higher/ reduce

Easier/ lower/ reduce

More difficult/ lower/ accelerate

More difficult/ higher/ accelerate

7.

1 point

Nitrogen compound is mostly found in:

All of these are correct

Gas fraction

Light naphtha

Residue fraction

8.

1 point

During the normal operation of HDT process, which is NOT a permanent poison of catalyst? (page 18 textbook)

Metals deposition

Coke deposition

Catalyst support sintering

All of these are correct

9.

1 point

In HDT process, “LHSV" stands for:

Liquid Hydrogen Space Velocity

Liquid Hourly Space Velocity

Liquid Hourly Speed Velocity

Liquid Hourly Space Volume

10.

1 point

In NHT, the minimum hydrogen to feed ratio is dependent on:

Feed characteristics

Desired product quality

All of these are correct

Hydrogen consumption

11.

1 point

The denitrogenation in which the impurities compounds are converted to: (page 5 textbook)

hydrogen sulﬁde

water

ammonia

metal sulﬁdes

12.

1 point

In HDT, the best performance catalyst for denitrogenation is: (page 16 textbook)

NiCoMo

CoMo

NiW

NiMo

13.

1 point

In HDT, the hardest to remove is: (page 7 textbook)

Dibenzo-thiophenes

Mercaptans

Sulfides

Thiophenes

14.

1 point

In NHT process, the reactor section can be divided into ____ systems.

8

6

4

2

15.

1 point

During the normal operation of HDT reactor (page 24 textbook)

The operator could control directly the catalyst activity

The operator could control directly the reactor inlet temperature

All of these are correct

The operator could control directly the reactor outlet temperature

16.

1 point

In HDT process, to prevent the exchanger fouling: (page 29 textbook)

The ammonia injected into the reactor effluent dissolves the ammonium bisulﬁde and prevents exchanger fouling

The water injected into the re actor effluent dissolves the ammonium bisulﬁde and prevents exchanger fouling

The NaOH injected into the reactor effluent dissolves the ammonium bisulfide and prevents exchanger fouling

None of these are correct

17.

1 point

In HDT process, which type of reaction is more dependent on the pressure?

all of these reactions are same

denitriﬁcation

saturation

desulfurization

18.

1 point

In HDT process, the aromatic saturation reaction is: (page 12 textbook)

strongly favored by low hydrogen partial pressure and low temperature

strongly favored by high hydrogen partial pressure and low temperature

strongly favored by high hydrogen partial pressure and high temperature

strongly favored by low hydrogen partial pressure and high temperature

19.

1 point

In general, the HDT reactions are:

None of these are correct

Favorable at low pressure

Endothermic

Exothermic