Question

You are comparing distillation column designs at 1 atm and 3 atm total pressure for a particular separation. You have the same feed in both cases, and the feed is a saturated liquid in both cases. The product specifications do not change, and the same reflux ratio is used in both cases.
Compared to the design at 3 atm, the design at 1 atm will have: (Select one)a) more stages, fewer stages, the same number of stagesb) a larger diameter, a smaller diameter, the same diameterc) a higher reboiler temperature, a lower reboiler temp, the same reboiler temp

Answer 1

Answer:

more number of stages will be required , a smaller diameter , a higher reboiler temperature

Explanation:

It is stated in the question that the product specifications and the reflux ratio do not change.

The pressure in a distillation column varies:

• directly as the diameter of the distillation column
• inversely as the number of stages required for the design
• inversely as the temperature of the reboiler

Based on the theory stated above, the distillation column design at a pressure of 1 atm requires a more number of stages than the design with 3 atm, it has a smaller diameter than the design at 3 atm. It also has a higher reboiler temperature than the design with 3 atm.