Use of packed towers for distillation is generally limited to the (A) Small sizes (B) Multi-component distillation (C) High pressure operation (D) Vacuum distillation

Use of packed towers for distillation is generally limited to the

(A) Small sizes

(B) Multi-component distillation

(C) High pressure operation

(D) Vacuum distillation

by

1 Answer

Answer :

(A) Small sizes

by

Related questions

Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the possibility of tower wall collapse (B) Packed towers are preferred over plate towers for handling corrosive and foamy liquids (C) Diameter of randomly packed tower is normally more than 1.2 metres (D) Due to uneven supply and improper distribution of liquid, problem of channelling, loading & flooding is generally encountered in packed towers

Description : Pick out the wrong statement. (A) Packed towers are preferred for vacuum operation, because the pressure drop through the packing is less and they (packings) also lessen the ... of liquid, problem of channelling, loading & flooding is generally encountered in packed towers

Last Answer : (C) Diameter of randomly packed tower is normally more than 1.2 metres

The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives (A) Low pressure drop and high hold up (B) High pressure drop and low hold up (C) Low pressure drop and low hold up (D) High pressure drop and high hold up

Description : The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives (A) Low pressure drop and high hold up (B) High pressure drop and low hold ... C) Low pressure drop and low hold up (D) High pressure drop and high hold up

Last Answer : (C) Low pressure drop and low hold up

Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given ‘L/V’ ratio (B) The extraction per unit of total height for a short packed column is more effective than for a tall column, in case of liquid-liquid extraction(C) Natural draft cooling towers are made of ferroconcrete and its cross￾section is wider at the bottom(D) Vander wall adsorption is also called chemisorption

Description : Pick out the wrong statement. (A) With decrease in feed temperature, the number of plates required for binary distillation decreases for a given L/V' ratio (B) The extraction per unit ... and its cross￾section is wider at the bottom (D) Vander wall adsorption is also called chemisorption

Last Answer : (D) Vander wall adsorption is also called chemisorption

A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Description : A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Last Answer : (A) Incurs smaller pressure drop

The main reason for dividing a tall packed tower into series of small towers is to (A) Minimise the overall pressure drop (B) Avoid flooding (C) Reduce liquid hold up (D) Avoid channelling

Description : The main reason for dividing a tall packed tower into series of small towers is to (A) Minimise the overall pressure drop (B) Avoid flooding (C) Reduce liquid hold up (D) Avoid channelling

Last Answer : (D) Avoid channelling

Packed column distillation is limited to the column __________ metres. (A) Height < 6 (B) Diameter < 0.6 (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : Packed column distillation is limited to the column __________ metres. (A) Height < 6 (B) Diameter < 0.6 (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments (B) Pressure drop in the equipment will be very high (C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments

Very tall packed towers are divided into series of beds to (A) Reduce the overall pressure drop (B) Avoid channelling (C) Reduce liquid hold-up (D) Avoid flooding

Description : Very tall packed towers are divided into series of beds to (A) Reduce the overall pressure drop (B) Avoid channelling (C) Reduce liquid hold-up (D) Avoid flooding

Last Answer : (B) Avoid channelling

Which of the following unit operations makes use of Thiele-Geddes equation? (A) Liquid-liquid extraction (B) Solid-liquid extraction (C) Multi-component absorption with chemical reaction (D) Multi-component distillation

Description : Which of the following unit operations makes use of Thiele-Geddes equation? (A) Liquid-liquid extraction (B) Solid-liquid extraction (C) Multi-component absorption with chemical reaction (D) Multi-component distillation

Last Answer : (D) Multi-component distillation

Langmuir equation is associated with (A) Leaching (B) Adsorption (C) Steam distillation (D) Multi-component absorption

Description : Langmuir equation is associated with (A) Leaching (B) Adsorption (C) Steam distillation (D) Multi-component absorption

Last Answer : (B) Adsorption

Fenske equation for determining the minimum number of theoretical stages in distillation column holds good, when the (A) Relative volatility is reasonably constant (B) Mixture (to be separated) shows negative deviation from ideality (C) Mixture (to be separated) shows positive deviation from ideality (D) Multi-component distillation is involved

Description : Fenske equation for determining the minimum number of theoretical stages in distillation column holds good, when the (A) Relative volatility is reasonably constant (B) Mixture (to be separated) ... (to be separated) shows positive deviation from ideality (D) Multi-component distillation is involved

Last Answer : (A) Relative volatility is reasonably constant

The Hatta number is important in (A) Multi-component distillation (B) Binary distillation (C) Gas absorption without chemical reaction (D) Gas absorption with chemical reaction

Description : The Hatta number is important in (A) Multi-component distillation (B) Binary distillation (C) Gas absorption without chemical reaction (D) Gas absorption with chemical reaction

Last Answer : (D) Gas absorption with chemical reaction

Flash distillation is (A) Same as differential distillation (B) Used for multi-component systems like crude refining (C) Same as simple distillation (D) Most useful for handling binary systems

Description : Flash distillation is (A) Same as differential distillation (B) Used for multi-component systems like crude refining (C) Same as simple distillation (D) Most useful for handling binary systems

Last Answer : (B) Used for multi-component systems like crude refining

Small dia distillation column can be a (A) Packed column (B) Sieve tray (C) Bubble cap (D) Any of these

Description : Small dia distillation column can be a (A) Packed column (B) Sieve tray (C) Bubble cap (D) Any of these

Last Answer : (A) Packed column

The main use of heavy gas oil produced by the vacuum distillation unit is as a (A) Blending component for kerosene (B) Blending component for petrol (C) Feedstock for fluid catalytic cracking unit (D) None of these

Description : The main use of heavy gas oil produced by the vacuum distillation unit is as a (A) Blending component for kerosene (B) Blending component for petrol (C) Feedstock for fluid catalytic cracking unit (D) None of these

Last Answer : (C) Feedstock for fluid catalytic cracking unit

Which of the following equipments is not used in liquid-liquid extraction? (A) Pachuka tank (B) Agitated vessels (C) Centrifugal extractors (D) Packed towers

Description : Which of the following equipments is not used in liquid-liquid extraction? (A) Pachuka tank (B) Agitated vessels (C) Centrifugal extractors (D) Packed towers

Last Answer : (A) Pachuka tank

Which of the following equipments is not used for liquid dispersion? (A) Wetted wall towers (B) Packed towers (C) Venturi scrubbers (D) Agitated vessels

Description : Which of the following equipments is not used for liquid dispersion? (A) Wetted wall towers (B) Packed towers (C) Venturi scrubbers (D) Agitated vessels

Last Answer : (D) Agitated vessels

Channelling 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

Description : Channelling 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

Last Answer : (A) In towers packed with stacked packing

Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes? (A) Packed towers(B) Plate towers(C) Spray towers(D) Wetted wall columns

Description : Which one of the following devices is not used for both the absorption as well as the liquid-liquid extraction processes? (A) Packed towers (B) Plate towers (C) Spray towers (D) Wetted wall columns

Last Answer : (D) Wetted wall columns

Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these

Description : Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the (A) High evaporation losses of water (B) High pressure drop of the gas (C) Difficulty in its fabrication (D) None of these

Last Answer : (B) High pressure drop of the gas

Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by __________ distillation. (A) Atmospheric (B) Vacuum (C) High pressure (D) None of these

Description : Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by __________ distillation. (A) Atmospheric (B) Vacuum (C) High pressure (D) None of these

Last Answer : (B) Vacuum

Pick out the wrong statement. (A) Critical moisture content is not a property of the material itself (B) A sharp increase in pressure drop gives an indication of the flooding in a distillation column (C) Separation of components is not possible in liquid extraction, if selectivity is unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Description : Pick out the wrong statement. (A) Critical moisture content is not a property of the material itself (B) A sharp increase in pressure drop gives an indication of the flooding in a ... unity (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Last Answer : (D) Dehydration of ethyl alcohol is most economically done by molecular distillation at very high vacuum

Out of two equilibrium curves, first one lies above the diagonal and the second lies below the diagonal in the x-y plot. It means that separation by distillation is(A) Not possible in the second case unless vacuum is applied(B) Not possible in the second case unless high pressure is applied(C) More readily done in the second case compared to first one(D) None of these

Description : Out of two equilibrium curves, first one lies above the diagonal and the second lies below the diagonal in the x-y plot. It means that separation by distillation is (A) Not possible in the second ... (C) More readily done in the second case compared to first one (D) None of these

Last Answer : (C) More readily done in the second case compared to first one

How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and humid inside air c) Due to the given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and humid inside air c) Due to the given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Description : How does the flow of air occur in natural draught cooling towers? a) Natural pressure head density between cold outside air and humid inside air b) Variation in pressure of both cold outside air and ... given air vents and vacuum ports d) Because of difference in the volume of both the of airs

Last Answer : Natural pressure head density between cold outside air and humid inside air

Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low interfacial tension (C) When Henry's law constant is very small, then the mass transfer rate is controlled by the gas film resistance (D) Taylor-Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers

Description : Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low ... Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers

Last Answer : (A) Mechanical agitation is required, if the system has low interfacial tension

High pressure at the bottom of a distillation tower handling heat sensitive materials results in (A) Thermal decomposition of bottoms (B) Increased relative volatility (C) Erosion of the tower (D) Very efficient operation

Description : High pressure at the bottom of a distillation tower handling heat sensitive materials results in (A) Thermal decomposition of bottoms (B) Increased relative volatility (C) Erosion of the tower (D) Very efficient operation

Last Answer : (A) Thermal decomposition of bottoms

Pick out the wrong statement: (A) Reboiler is not used in open steam distillation (B) The separation of solutes of different molecular sizes in a liquid solution by use of a suitable membrane is called dialysis (C) Freeze drying is used for the drying of fish (D) Fenske-Underwood equation is used for calculating theoretical number of plates in a distillation column at normal operating reflux condition

Description : Pick out the wrong statement: (A) Reboiler is not used in open steam distillation (B) The separation of solutes of different molecular sizes in a liquid solution by use of a ... is used for calculating theoretical number of plates in a distillation column at normal operating reflux condition

Last Answer : (D) Fenske-Underwood equation is used for calculating theoretical number of plates in a distillation column at normal operating reflux condition

Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the flooding velocity, generally (C) 'Elution' means the desorption of the adsorbed solute by a solvent (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Description : Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the ... (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Last Answer : (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Last Answer : (C) 0.7

Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low boiling products are prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Description : Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low ... prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Last Answer : (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose

Steam distillation is used to (A) Reduce the number of plates (B) Avoid thermal decomposition of a component (C) Increase the efficiency of separation (D) Increase the total pressure of distillation

Description : Steam distillation is used to (A) Reduce the number of plates (B) Avoid thermal decomposition of a component (C) Increase the efficiency of separation (D) Increase the total pressure of distillation

Last Answer : (B) Avoid thermal decomposition of a component

Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is important in problems involving gas absorption without chemical reaction (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion (D) Total reflux in case of distillation operation requires infinite number of plates for a binary system separation

Description : Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is ... reflux in case of distillation operation requires infinite number of plates for a binary system separation

Last Answer : (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion

When liquid and vapour phase of multi-component system are in equilibrium (at a given temperature and pressure), then chemical potential of each component is (A) Same in both the phases (B) Zero in both the phases (C) More in vapour phase (D) More in liquid phase

Description : When liquid and vapour phase of multi-component system are in equilibrium (at a given temperature and pressure), then chemical potential of each component is (A) Same in both the phases (B) Zero in both the phases (C) More in vapour phase (D) More in liquid phase

Last Answer : (A) Same in both the phases

For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases. (A) Chemical potential (B) Fugacity (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : For multi-component multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases. (A) Chemical potential (B) Fugacity (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Black liquor is converted into white liquor by (A) Evaporation and burning the concentrate followed by causticisation of products (B) Multi-effect evaporation only (C) Selective liquid extraction (D) Extractive distillation

Description : Black liquor is converted into white liquor by (A) Evaporation and burning the concentrate followed by causticisation of products (B) Multi-effect evaporation only (C) Selective liquid extraction (D) Extractive distillation

Last Answer : (A) Evaporation and burning the concentrate followed by causticisation of products

Vacuum is generally maintained in the vapour space of an evaporator mainly to (A) Get economical temperature difference by using moderate pressure steam (B) Facilitate forward feeding in multiple effect evaporation (C) Concentrate heat sensitive materials (D) Achieve very high concentration of the final product

Description : Vacuum is generally maintained in the vapour space of an evaporator mainly to (A) Get economical temperature difference by using moderate pressure steam (B) Facilitate forward ... (C) Concentrate heat sensitive materials (D) Achieve very high concentration of the final product

Last Answer : (A) Get economical temperature difference by using moderate pressure steam

Can I successfully freeze fresh, vacuum packed oysters?

Description : Can I successfully freeze fresh, vacuum packed oysters?

Last Answer : I don’t see why not? I haven’t done it with oysters but I have with mussels and clams and it’s always worked fine.

How do I cook a 2.7 Kg beef eye of round in a vacuum packed plastic bag in one sitting?

Description : How do I cook a 2.7 Kg beef eye of round in a vacuum packed plastic bag in one sitting?

Last Answer : Do you have access to a propane grill?

The terminology used for the bottom most product from the vacuum crude distillation unit is (A) Residual crude (B) Residuum (C) Reduced crude (D) Petrolatum

Description : The terminology used for the bottom most product from the vacuum crude distillation unit is (A) Residual crude (B) Residuum (C) Reduced crude (D) Petrolatum

Last Answer : (B) Residuum

Vacuum maintained in the vacuum distillation column in oil refinery is in the range of about __________ mm Hg absolute. (A) 1 to 5 (B) 30 to 80

Description : Vacuum maintained in the vacuum distillation column in oil refinery is in the range of about __________ mm Hg absolute. (A) 1 to 5 (B) 30 to 80

Last Answer : (B) 30 to 80

Catalytic cracking compared to thermal cracking of residue of vacuum distillation of crude oil (A) Gives higher yield of petrol (B) Lower octane number of petrol (C) Higher sulphur content in the product (D) Higher gum forming material in petro

Description : Catalytic cracking compared to thermal cracking of residue of vacuum distillation of crude oil (A) Gives higher yield of petrol (B) Lower octane number of petrol (C) Higher sulphur content in the product (D) Higher gum forming material in petro

Last Answer : (A) Gives higher yield of petrol

Vacuum maintained in the vacuum distillation tower of the crude distillation plant is about __________ mm Hg (absolute). (A) 5-10 (B) 30-80 (C) 150-250 (D) 350-400

Description : Vacuum maintained in the vacuum distillation tower of the crude distillation plant is about __________ mm Hg (absolute). (A) 5-10 (B) 30-80 (C) 150-250 (D) 350-400

Last Answer : (B) 30-80

The vacuum maintained in vacuum distillation unit for reduced crude is about __________ mm Hg. (A) 1.2 (B) 12 (C) 120 (D) 700

Description : The vacuum maintained in vacuum distillation unit for reduced crude is about __________ mm Hg. (A) 1.2 (B) 12 (C) 120 (D) 700

Last Answer : (C) 120

In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be (A) At ground level (B) 2 metres above the ground (C) 5 metres above ground (D) 10 metres above ground

Description : In the layout plan for a vacuum distillation unit, operating at 60 mm Hg, supported by a barometric condenser, the appropriate place for the location of vacuum drum for collecting the distillate will be ... metres above the ground (C) 5 metres above ground (D) 10 metres above ground

Last Answer : (A) At ground level

Concentration of hydrogen peroxide is done by(A) Crystallisation(B) Vacuum crystallisation(C) Atmospheric distillation(D) Dehydration

Description : Concentration of hydrogen peroxide is done by (A) Crystallisation (B) Vacuum crystallisation (C) Atmospheric distillation (D) Dehydration

Last Answer : (B) Vacuum crystallisation

Glycerine is recovered from lye by (A) Evaporation followed by vacuum distillation (B) Liquid extraction technique (C) Extractive distillation technique (D) None of these

Description : Glycerine is recovered from lye by (A) Evaporation followed by vacuum distillation (B) Liquid extraction technique (C) Extractive distillation technique (D) None of these

Last Answer : (A) Evaporation followed by vacuum distillation

In distillation, overhead product contains (A) Only one component (B) Two components (C) Any number of components (D) Only saturated liquid

Description : In distillation, overhead product contains (A) Only one component (B) Two components (C) Any number of components (D) Only saturated liquid

Last Answer : (C) Any number of components

With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on system

Description : With lapse of time, the overhead composition of light component in case of batch distillation with constant reflux (A) Increases (B) Decreases (C) Remain same (D) May increase or decrease; depends on system

Last Answer : (B) Decreases

Design calculation for multiple component distillation is done by (A) Ponchon-Savarit method (B) McCabe-Thiele method (C) Enthalpy concentration method (D) Tray to tray calculations

Description : Design calculation for multiple component distillation is done by (A) Ponchon-Savarit method (B) McCabe-Thiele method (C) Enthalpy concentration method (D) Tray to tray calculations

Last Answer : (D) Tray to tray calculations