Deck 24: Distillation

Question 1

What type of tray design is designed with perforated openings, typically circular, in the tray deck?

A) Sieve tray
B) Valve tray
C) Bubble cap tray
D) Overhead tray

Answer 1

A
Explanation: A) Correct. A sieve tray is designed with perforated openings, typically circular, in the tray deck.
B) Incorrect. A valve tray contains valve lifters, similar to those in a car engine. The valve is lifted, or opened, as the vapor rate increases.
C) Incorrect. A bubble cap tray is designed with risers in the deck area of each tray.
D) Incorrect. A sieve tray is designed with perforated openings, typically circular, in the tray deck.

Question 2

Which method of distillation occurs when materials with similar volatility points are more difficult to separate and require that the boiling point of one of the materials be changed?

A) Binary distillation
B) Azeotropic distillation
C) Extractive distillation
D) Reactive distillation

Answer 2

B
Explanation: A) Incorrect. Binary distillation occurs when some materials are easily separated because their boiling points are far enough apart that the lower boiler of the material is easily separated from the high boiler.
B) Correct. Azeotropic distillation occurs when materials with similar volatility points are more difficult to separate and require that the boiling point of one of the materials be changed.
C) Incorrect. Extractive distillation is a method of separating materials that have close boiling (or volatility) points is to add a solvent with a high boiling point to form a miscible mixture with the high boiler in the material.
D) Incorrect. In reactive distillation, the reaction process and the distillation process are combined in the same unit.

Question 3

Which of the following is the symbol for a trayed tower?

A)
B)
C)

Answer 3

B
Explanation: A) Incorrect. This is the symbol of a tower.
B) Correct. This is the symbol of a trayed tower.
C) Incorrect. This is the symbol for a tower with packing.

Question 4

Which of the following should process technicians look for when maintaining and monitoring distillation systems?

A) Leaks
B) Reboiler shell pressure
C) Column pressure
D) All of the above

Question 5

What component of distillation systems are used to apply additional heat to the base to begin boiling the bottoms liquid?

A) Column
B) Preheater
C) Condenser
D) Reboiler

Question 6

What is the material used in a distillation column to maximize the contact area between the liquid and gas to effect separation?

A) Packing
B) Fraction
C) Heavy ends
D) Light ends

Question 7

Which improper operation can lead to air in column?

A) Rapid changes in column control and set points
B) Opening a bleed valve on a vacuum column
C) No cooling liquid on condenser
D) Operation of column bottoms level too high or too low

Question 8

Where does the separation process take place during distillation?

A) Column
B) Preheater
C) Condenser
D) Reboiler

Question 9

Which improper operation does not lead to exposure to chemicals?

A) Tower not vented
B) No cooling liquid on condenser
C) Rapid changes in column control and set points
D) Opening a bleed valve on a vacuum column

Question 10

Which method of distillation occurs when some materials are easily separated because their boiling points are far enough apart that the lower boiler of the material is easily separated from the high boiler?

A) Binary distillation
B) Azeotropic distillation
C) Extractive distillation
D) Reactive distillation

Question 11

What is the distillation component where the separation of materials takes place?

A) Preheater
B) Tower
C) Condenser
D) Reflux drum

Question 12

What must the packing support used in a packed distillation column be designed for?

A) Evaporation of liquids
B) Free flow of air
C) Free flow of liquid and gas
D) Minimal storage space

Question 13

What is one component of the distillate that has a particular boiling point that is different from the boiling point of the other fractions in the column?

A) Overhead
B) Fraction
C) Flash zone
D) Reflux

Question 14

How could distillation be used in the water treatment industry?

A) To introduce additives to the water
B) To remove contaminants from the water
C) To separate the hydrogen from the water
D) All of the above

Question 15

In what type of distillation operation are materials fed to the system and the operation and production continue day and night for long periods of time?

A) Periodic
B) Batch
C) Continuous
D) Intermittent

Question 16

What section of the distillation column is the section located between the rectifying and stripping sections in a distillation column?

A) Rectifying
B) Flash zone
C) Stripping section
D) Feed tray

Question 17

What type of tray design is designed with stationary risers in the deck area of each tray?

A) Sieve tray
B) Valve tray
C) Bubble cap tray
D) Overhead tray

Question 18

Which of the following improper operation is least likely to extend start-up time and increase start-up cost?

A) Tower not vented
B) No cooling liquid on condenser
C) Opening a bleed valve on a positive pressure column
D) Introduction of steam to reboiler during startup

Question 19

What types of columns are filled with specialized material instead of trays?

A) Tray towers
B) Packed towers
C) Specialized towers
D) Feed towers