A distillation column with N plates is being operated under normal conditions. At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped). At the new steady state,

A Composition of vapors and that of liquid do not vary throughout the column
B Reboiler load and condenser load are minimum
C The top and bottom compositions are unchanged with and without total reflux
D The top and bottom compositions correspond to the maximum enrichment available

Correct Answer: The top and bottom compositions correspond to the maximum enrichment available

Bissoy MCQ
#Chemical Engineering #Mass Transfer

Related Questions

In a continuous distillation column, the optimum reflux ratio ranges from __________ times the minimum reflux ratio.
A 1.1 to 1.5
B 1.6 to 2
C 2.2 to 2.6
D 2.7 to 3
For the same feed, feed quality and separation (in a distillation column), with the increase of total pressure, the number of ideal plates will
A Increase
B Decrease
C Remain same
D Data insufficient, can't be predicted
At what value of reflux ratio, number of theoretical plates in a distillation column is minimum?
A 0
B 1
C ∞
In leaf springs, the maximum bending stress developed in the plates is (where W = Load acting on the spring, $$l$$ = Span of the spring, n = Number of plates, b = Width of plates and t = Thickness of plates)
A $$\frac{{{\text{W}}l}}{{{\text{nb}}{{\text{t}}^2}}}$$
B $$\frac{{3{\text{W}}l}}{{2{\text{nb}}{{\text{t}}^2}}}$$
C $$\frac{{2{\text{W}}l}}{{{\text{nb}}{{\text{t}}^2}}}$$
D $$\frac{{3{\text{W}}l}}{{{\text{nb}}{{\text{t}}^2}}}$$
For the same process conditions, the reflux ratio of an unlagged distillation column
A Decreases in winter
B Increases in winter
C Increases in summer
D None of these
At __________ reflux, theoretical number of plates in a distillation coloumn is calculated using Fenske-Underwood equation.
A Operating
B Total
C Minimum
D Maximum permissible
For a fixed number of ideal stages in a distillation column, as the reflux ratio is increased, the difference in composition between the top and bottom product streams
A Increases
B Decreases
C Remains unaffected
D Passes through a maximum
Total reflux in a distillation operation requires minimum
A Reboiler load
B Number of plates
C Condenser load
D All of the above
What is the reflux ratio at total reflux?
A Zero
B Infinity
C Unity
D Data insufficient
In batch distillation with constant reflux, overhead product composition __________ with time.
A Increases
B Decreases
C Does not vary
D May increase on decrease, depends on the system

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