Pick out the correct relationship. (Where, Ri = internal reflux ratio Ro = external reflux ratio.) ?

Related Mcqs:

1. In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as_____________________?

   A. Ri = Re/(1 – Re)
   B. Ri = (1 – Re)/Re
   C. Ri = Re
   D. Ri = Re/(1 + Re)

2. In a distillation operation, what is the effect of the temperature of the reflux stream (given below) on the condenser and reboiler loads? Reflux conditions: (i) Reflux stream is completely liquid and is at its bubble point. (ii) Reflux stream is below its bubble point ?

   A. Condenser and reboiler loads are the same in both the cases
   B. Reboiler load is the same in both the cases but condenser load is higher in case (ii)
   C. Condenser load is the same in both the cases but reboiler load is higher in case (ii)
   D. Both condenser and reboiler loads are higher in case (ii) as compared to case (i)

3. If Rm is the minimum reflux ratio, the optimum reflux ratio may be around _________________ Rm ?

   A. 1.2 to 1.5
   B. 2.5 to 3
   C. 3 to 4
   D. 5

4. The reflux to a distillation column is 100 moles/hr, when the overhead product rate is 50 moles/hr. The reflux ratio is____________________?

   A. 2
   B. 0.5
   C. 50
   D. 150

5. What is the reflux ratio at total reflux ?

   A. Zero
   B. Infinity
   C. Unity
   D. Data insufficient

6. Minimum reflux ratio in a distillation column results in_____________________?

   A. Optimum number of trays
   B. Minimum reboiler size
   C. Maximum condenser size
   D. Minimum number of trays

7. A distillation column separates 10000 kg/hr of a benzene-toluene mixture as shown in the figure below: In the figure xF, xD and xW represent the weight fraction of benzene in the feed, distillate and residue respectively. The reflux ratio is_______________ ?

   A. 0.5
   B. 0.6
   C. 1.0
   D. 2.0

8. 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

9. If xD = overhead product molal composition and RD = reflux ratio, then slope and intercept of the operating line for rectifying section are respectively ?

   A. [xD/(RD + 1)], [RD/(RD + 1)]
   B. [RD/(RD + 1)], [xD/(xD + 1)]
   C. [xD/(RD + 1)], [(RD + 1)/RD]
   D. None of these

10. For the same process conditions, the reflux ratio of an unlagged distillation column___________________?

    A. Decreases in winter
    B. Increases in winter
    C. Increases in summer
    D. None of these