Question

A mixture of ethyl alcohol and water with equimolar concentration is to be distilled in a seven-plate column as a batch distillation with a reboiler at atmospheric pressure. If we neglect the residue liquid in the condenser and reboiler, calculate:

A) State-1 (Constant (x_D)):
The amount of distilled ((D)) and the amount of heat required for (100 kmole of feed) to get (x_D = 80) mole%, if (R) (reflux ratio must be increased till it reaches (6.0)).

a) 50 kmole, Heat = (2 times 10^5 , textJ)
b) 80 kmole, Heat = (1.5 times 10^5 , textJ)
c) 70 kmole, Heat = (2.5 times 10^5 , textJ)
d) 90 kmole, Heat = (1 times 10^5 , textJ)

B) State-2 (Constant reflux ratio (R)):
The average value of (x_D) (top product) & the amount of heat if the concentration in the boiler must not be less than (10) mole% ethanol if (R) is constant at (4.0).

a) (x_D = 15) mole%, Heat = (3 times 10^5 , textJ)
b) (x_D = 10) mole%, Heat = (2.5 times 10^5 , textJ)
c) (x_D = 20) mole%, Heat = (2 times 10^5 , textJ)
d) (x_D = 25) mole%, Heat = (3.5 times 10^5 , textJ)

Answer 1

In a batch distillation process, the amount of distilled and heat required can be calculated using the equimolar concentration of the mixture and the reflux ratio.

Step-by-step explanation:

In a batch distillation process, the amount of distilled and the heat required can be calculated using the equimolar concentration of the mixture and the reflux ratio.

For State-1 (constant xD), the amount of distilled and the heat required can be determined using the reflux ratio of 6.0 and xD = 80 mole%.

The correct answer is a) 50 kmole, Heat = 2 x 10^5 J. For State-2 (constant reflux ratio R), the average value of xD and the amount of heat can be calculated using a reflux ratio of 4.0 and a minimum concentration of 10 mole% in the boiler. The correct answer is b) xD = 10 mole%, Heat = 2.5 x 10^5 J.