Engineering Questions with Answers - Multiple Choice Questions
Distillation Design MCQ’s – Reflux Stage Relationships
1 - Question
Fenske’s Equation can be written as
a) Nmin = S/ ln α
b) Nmin = ln S/ ln α
c) Nmin – 1 = ln S/ ln α
d) Nmin + 1 = ln S/ ln α
View Answer
Answer: b
Explanation: The Fenske’s equation is given by this equation Nmin = ln S/ ln α, where N is the number of trays and alpha is the relative volatility.
2 - Question
The term S in the Fenske’s equation, is given as
a) (xLKxHK)D(xLKxHK)B
b) (xLKxHK)D(xLKxHK)L(xLKxHK)R
c) (xLKxHK)L(xLKxHK)V
d) (xLKxHK)HK(xLKxHK)LK
View Answer
Answer: a
Explanation: The term S in the Fenske’s equation is given as (xLKxHK)D(xLKxHK)B, representing High and Low keys of the gas and liquid phases.
3 - Question
N√αN this equation is called as
a) Sorel’s Method
b) Polson Equation
c) Fenske’s Equation
d) Gilliland Equation
View Answer
Answer: c
Explanation: Fenske’s Equation that is rigorous, Gilliland Equation are used and based on the trial and error basis
4 - Question
Calculate ln S? If XLK=0.41 and XHK = 0.005 and XL= 0.417 and XH= 0.01, then
a) 9.45
b) 8.90
c) 8.137
d) 7.98
View Answer
Answer: c
Explanation: As ln (0.41/0.005) (0.417/0.01) = 8.137.
5 - Question
A non-key component may be distributed if
a) Close to that of one key
b) The Specified separation is sloppy
c) Intermediate between keys
d) Intermediate one key
View Answer
Answer: b
Explanation: For distributed systems the Specified separation is sloppy, while for the distributed system it is close to that of one key
6 - Question
In a distillation operation, the reflux ratio may vary between
a) Zero and one
b) Zero and infinity
c) Minimum and infinity
d) One and two
View Answer
Answer: a
Explanation: L0/D Varies from zero to one, as the ratio cannot be more than one because that will cause the failure of the column.
7 - Question
Most distillation columns are designed for reflux ratio between
a) 3 to 5 Rmin
b) 1.2 and 1 .7 Rmin
c) 2 to 10 Rmin
d) 0.2 to 0.7 Rmin
View Answer
Answer: b
Explanation: This is the most suitable for 1.2 and 1.7 Rmin times reflux ratio, this also reduces the operating and the final cost of the system.
8 - Question
If Component is non-distributed, then
a) DR >1
b) DR<1
c) DR=0
d) DR=∞
View Answer
Answer: a
Explanation: If component is non-distributed then DR >1 contained entirely distillate, while if components are distributed they are entirely withdrawn.
9 - Question
If Component is distributed, then
a) 0< DR> 1
b) 0< DR< 1
c) DR= 0
d) DR < 0
View Answer
Answer: b
Explanation: If Component is distributed then 0< DR< 1, DR is recovery component, if DR = 0 then there exists no distributed components in the systems.
10 - Question
Underwood’s equation can be used to find
a) Distributed components
b) Non distributed components
c) Reflux for components
d) Non reflux components
View Answer
Answer: a
Explanation: Underwood’s equation can be used to find Distributed components (n) including key.