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
An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii)
A Less number of trays are required
B Composition of the residue remains unchanged
C More number of trays are required but the residue composition remains unchanged
D More number of trays are required and the residue composition is more dilute in methanol
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 At some point of time, the operation is shifted to total reflux condition (i.e., no product and residue are being withdrawn and feed to the column is stopped).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
The feed to fractionating column is changed from saturated vapour to saturated liquid. If the separation and reflux ratio remains unchanged, the number of ideal stages will
A Increase
B Decrease
C Remains same
D Depend on saturated boiling point; may increase or decrease
The fixed cost of a distillation column at minimum reflux ratio is
A Minimum
B Infinite
C Optimum
D None of these
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
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
Reflux ratio variation in a distillation column is between
A Zero and infinity
B Zero and one
C Minimum and infinity
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 ∞
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

Next steps