Separation Processes Questions and Answers - FUG Method

1. What is true if debutanizer is placed first in sequence?
a) N-butane is LK and isobutane is HK
b) Isobutane is LK and n-butane is HK
c) Both are LK
d) Both are HK

Answer: a
Explanation: If the debutanizer is first placed in sequence then the specifications require that N-butane is LK and isobutane is HK.

2. Where is the separation more difficult?
a) Debutanizer
b) Deisobutanizer
c) Both are simple
d) Both are difficult

Answer: b
Explanation: separation is more difficult in deisobutanizer.

3. The light key split is ______ whereas high key split is _______
a) Not sharp, sharp
b) Sharp, sharp
c) Sharp, not sharp
d) Not sharp, not sharp

Answer: c
Explanation: The lightkey split is sharp whereas high key split is not.

4. Why is column pressure fixed after design problems are solved?
a) Because the answer of design problems is column pressure
b) The design problems are independent of column pressure
c) The design problems are difficult
d) The design problems do not use column pressure while solving

Answer: c
Explanation: Since there are no available algorithms for solving design problems, the design problems are difficult. Hence column pressure is decided later.

5. If the :
Component distillate rate for LK (di) = 20
Component distillate rate for HK (dj) = 30
Bottom flow rate for LK (bi) = 30
Bottom flow rate for HK (bj) = 10
Mean relative volatility is 2
What is the minimum number of stages required?
a) 1
b) 2
c) 3
d) 4

Answer: a
Explanation: Only 1 stage is required here.

6. If the :
Component distillate rate for LK (di) = 20
Component distillate rate for HK (dj) = 30
Bottom flow rate for LK (bi) = 30
Bottom flow rate for HK (bj) = 10
Mean relative volatility is 3
What is the minimum number of stages required?
a) 1
b) 2
c) 3
d) 4

Answer: a
Explanation:Only 1 stage is required here.

7. If the :
Component distillate rate for LK (di) = 40
Component distillate rate for HK (dj) = 30
Bottom flow rate for LK (bi) = 30
Bottom flow rate for HK (bj) = 10
Mean relative volatility is 3
What is the minimum number of stages required?
a) 1
b) 2
c) 3
d) 4

Answer: a
Explanation: Only 1 stage is required here.

8. If the :
Component distillate rate for LK (di) = 50
Component distillate rate for HK (dj) = 40
Bottom flow rate for LK (bi) = 30
Bottom flow rate for HK (bj) = 10
Mean relative volatility is 2
What is the minimum number of stages required?
a) 1
b) 2
c) 3
d) 4

Answer: a
Explanation: Only 1 stage is required here.

9. If the :
Component distillate rate for LK (di) = 80
Component distillate rate for HK (dj) = 30
Bottom flow rate for LK (bi) = 30
Bottom flow rate for HK (bj) = 10
Mean relative volatility is 2
What is the minimum number of stages required?
a) 1
b) 2
c) 3
d) 4

Answer: b
Explanation: Only 2 stages are required here.

10. If the :
Component distillate rate for LK (di) = 160
Component distillate rate for HK (dj) = 30
Bottom flow rate for LK (bi) = 30
Bottom flow rate for HK (bj) = 10
Mean relative volatility is 2
What is the minimum number of stages required?
a) 1
b) 2
c) 3
d) 4

Answer: d
Explanation:Only 4 stages are required here.