High pressure at the bottom of a distillation tower handling heat sensitive materials results in____________________?

Related Mcqs:

1. 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

2. Heat sensitive materials with very high latent heat of vaporisation may be economically separated using__________________?

   A. Liquid extraction
   B. Distillation
   C. Evaporation
   D. Absorption

3. When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is _______________ distillation?

   A. Continuous
   B. Steam
   C. Azeotropic
   D. None of these

4. 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

5. Pressure drop through plate tower as compared to that through packed tower, for the same duty will be___________________?

   A. Less
   B. More
   C. Equal
   D. Either A. or B.; depends on the packing height

6. At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid _______________ that in dry packed tower ?

   A. Is greater than
   B. Is lower than
   C. Is same as
   D. Cannot be predicted as data are insufficient

7. A natural draft cooling tower is filled with wooden grids, which covers about _________________ percent of the tower height?

   A. 10-15
   B. 30-40
   C. 70-80
   D. 90-100

8. In a moderately sized packed absorption tower, channelling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter ?

   A. > 4 :1
   B. < 8 : 1
   C. > 8:1
   D. < 6:1

9. 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 streams

10. For a fixed number of ideal stages in a distillation column, as the reflux ratio is increased, the difference in composition between the top and bottom product streams__________________?

    A. Increases
    B. Decreases
    C. Remain unaffected
    D. Passes through a maximum