This set of Bioseparation Processes Multiple Choice Questions & Answers (MCQs) focuses on “Supercritical Fluid Extraction”.
1. What is supercritical fluid?
a) Properties of both solid and liquid
b) Properties of both liquid and gas
c) Properties of both gas and solid
d) Properties of solid, liquid, gas
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Explanation: The supercritical fluid are the material which have the properties of both gas as well as liquid. The substance which can be considered as supercritical fluid have critical temperature above the actual temperature of the substance and the critical pressure above the actual pressure.
2. What is the significance of the given diagram?
a) Pressure temperature phase diagram
b) Pressure solubility phase diagram
c) Temperature solubility phase diagram
d) Extraction phase diagram
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Explanation: A supercritical fluid can be obtained by increasing the temperature as well as pressure of a pure substance which is above the critical temperature and the critical pressure which is explained in the above diagram.
3. How can we change the density of the supercritical fluid?
a) By continuously changing the temperature
b) By continuously changing the pH
c) By continuously changing the pressure
d) By changing the pressure
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Explanation: The continuous change in pressure will help in changing the density of the supercritical fluid. It combines the gaseous properties of being able to penetrate substances easily with the liquid property of being able to dissolve the substance easily.
4. What is the advantage of use of supercritical fluid?
a) Economical
b) Alternative to organic solvent
c) Less eco-friendly
d) Alternative to biological solvent
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Explanation: The supercritical fluid is advantageous because it offers an alternative to the organic solvent as well as it is ecologically friendly to the environment. The dissolving power is safe and the pharmaceutical products, food products etc. are safe using supercritical fluid.
5. What is the basic use of supercritical fluid?
a) Removal of oil, Purification of essential oil
b) Removal of grease, Processing of beverages
c) Purification of essential oil, Removal of oil
d) Processing of beverages, Purification of essential oil, Removal of grease, Removal of oil
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Explanation: The basic use of supercritical fluid are separation and purification of essential oils and medicinal components, removal of grease and other fouling material from process equipment, food and beverage processing e.g. production of ‘decaf coffee and alcohol-free beer.
6. What is the significance of the given diagram?
a) Solubility curve of supercritical fluid
b) Pressure curve of supercritical fluid
c) Temperature curve of supercritical fluid
d) pH curve of supercritical fluid
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Explanation: The solubility of the substance in a supercritical fluid increases with the increase in the pressure of the supercritical fluid as shown in the diagram of solubility curve of supercritical fluid.
7. A supercritical fluid can be used only for the solid supercritical fluid extraction.
a) True
b) False
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Explanation: A supercritical fluid can be used for both liquid supercritical fluid extraction and solid supercritical fluid extraction. The supercritical fluid is produced by pressurizing a gas such as carbon dioxide using a compressor.
8. The adiabatic compression increases __________
a) Temperature and pH
b) pH and pressure
c) Solubility and temperature
d) Pressure and temperature
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Explanation: The Adiabatic compression increases both pressure and temperature of the substance above its critical values. The generators of supercritical fluid is an additional heat exchanger also used in series with the compressor.
9. Which kind of arrangement is required in the extractors used for supercritical fluid extraction?
a) Minimal mechanical contact arrangement
b) Minimal electrical contact arrangement
c) Extreme mechanical contact arrangement
d) Extreme electrical contact arrangement
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Explanation: The minimal mechanical contacting arrangement is required in extractors used for supercritical fluid extraction. It is used due to the high penetrability of the supercritical fluid and the solid-supercritical fluid type extraction in the batch mode may be efficiently achieved using a packed bed extractor.
10. What is the significance of the given diagram?
a) Ternary phase diagram
b) Ethanol-water ternary phase diagram
c) Ethanol-water-supercritical carbon dioxide ternary phase diagram
d) Ethanol-supercritical carbon dioxide ternary phase diagram
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Explanation: It is the ternary phase diagram of Ethanol-water-supercritical carbon dioxide system using partially miscible liquids are also used in liquid-SF extraction. It is evident from the phase diagram that the supercritical carbon dioxide is not suitable for breaking water-ethanol azeotrope.
11. What is the advantage of using membrane as a porous barrier between the feed and the extracting solvent?
a) Efficient segregation, compactness
b) Compactness, large area
c) Large area, constant area, compactness, efficient segregation
d) Constant area, large area, compactness
View Answer
Explanation: The advantage of using a membrane as a porous barrier between the feed and the extracting solvent are efficient segregation of raffinate and extract, compactness of apparatus, large interfacial area, constant interfacial area which is independent of the fluid velocity. The use of membranes is more successful in liquid supercritical fluid extraction than in liquid-liquid extraction since the supercritical fluid can easily penetrate through the membrane into the feed phase, extract the solute and diffuse back with it to the extract side.
Sanfoundry Global Education & Learning Series – Bioseparation Processes.
To practice all areas of Bioseparation Processes, here is complete set of 1000+ Multiple Choice Questions and Answers.
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