Gas Absorption Flashcards
For absorbing a sparingly soluble gas in a liquid, the
a.) gas side coefficient should be increased
b.) liquid side coefficient should be increased
c.) gas side coefficient should be decreased
d.) liquid side coefficient should be decreased
B
For contacting a highly soluble gas with a liquid
a.) bubble the gas through liquid
b.) spray the liquid on gas stream
c.) either a or b will suffice
d.) none of them
A
Wetted wall tower experiment determines
a.) molal diffusivity
b.) volumetric coefficient
c.) mass transfer coefficient
d.) none of these
C
Stacked packing compared to dumped packing
a.) provides poorer contact between the fluids
b.) gives lower pressure drop
c.) both (a) and (b)
d.) gives higher drop
C
Channeling is most severe
a.) in towers packed with stacked packing
b.) in towers packed randomly with crushed solids
c.) in dumped packing of regular units
d.) at very high liquid flow rate
A
Flooding results in
a.) High tray efficiency
b.) Low tray efficiency
c.) High gas velocity
d.) at very high liquid flow rate
B
Operating velocity in a packed tower is usually
a.) half the flooding velocity
b.) twice the flooding velocity
c.) equal to flooding velocity
d.) more than the flooding velocity
A
At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid
a.) is greater than that in a dry packed
b.) lower than that in drying packing
c.) is same as that in drying packing
d.) cannot be predicted as data are insufficient
A
Berl saddle made of carbon cannot be used
a.) for alkalis
b.) for SO2
c.) for H2SO4
d.) in oxidizing atmosphere
D
Carbon is not suitable coz it is itself an element that can be oxidized.
Flooding in a column results due to
a.) high pressure drop
b.) low pressure drop
c.) low velocity of the liquid
d.) high temperature
A
The operating line for an absorbed is curved when plotted in terms of
a.) mole fractions
b.) mole ratios
c.) partial pressure
d.) mass fraction
C
In case of an absorber, the operating
a.) line always lies above the equilibrium curve
b.) line always lies below the equilibrium curve
c.) line can be either above or below the equilibrium curve
d.) velocity is more than the loading velocity
A
- For an absorber, both equilibrium and operating line will be straight for
a.) concentrated solution and non-isothermal operation
b.) dilute solution and non-isothermal operation
c.) dilute solution and isothermal operation
d.) concentrated solution and isothermal operation
C
In case of desorber (stripper)
a.) the operating line always lies above the equilibrium curve
b.) the operating line always lies below the equilibrium line
c.) temperature remains unaffected
d.) temperature always increases
B
The minimum liquid rate to be used in an absorber corresponds to an operating line
a.) of slope = 1
b.) of slope = -1
c.) tangential to the equilibrium curve
d.) none of these
C