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
With increase in the reflux ratio for a fixed production from a continuous binary distillation column, the __________ decreases.
A Fixed charges initially
B Running cost of cooling water for condenser
C Vapour & liquid load both
D Running cost of steam for reboiler
Optimum reflux ratio in a continuous distillation column is determined by the
A Maximum permissible vapour velocity
B Flooding limit of the column
C Total cost consideration (fixed cost of the column plus the cooling water & steam cost)
D None of these
In case of binary distillation, increasing the reflux ratio above optimum does not result in the increase of
A Area between operating line and 45° diagonal x-y diagram
B Condenser and reboiler surfaces
C Tower cross-section
D None of these
In a distillation column, with increase in the reflux ratio, the heat removed in the cooler
A Increases
B Decreases
C Remains unaffected
D And the heat required in reboiler decreases
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 At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped).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
Minimum reflux ratio in a distillation column results in
A Optimum no. of trays
B Minimum reboiler size
C Maximum condenser size
D Minimum number of trays
The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is
A 0
B ∞
C 1
D Minimum
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 what value of reflux ratio, number of theoretical plates in a distillation column is minimum?
A 0
B 1
C ∞

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