For ethanol-water system, the lowering of distillate quality from 95% to 92% will cause __________ plate requirement.
A. No change in theoretical
B. Marginal decrease in the number of
C. Major decrease in the number of
D. None of these
Answer: Option B
This Question Belongs to Chemical Engineering >> Mass Transfer
Join The Discussion
Comments (1)
Related Questions on Mass Transfer
A. Chemical properties
B. Physical properties
C. Degree of turbulence
D. Interfacial area
A. No change in theoretical
B. Marginal decrease in the number of
C. Major decrease in the number of
D. None of these
The correct answer is: C. Major decrease in the number of
Explanation:
In a distillation column, the number of theoretical plates required increases non-linearly as the desired distillate purity increases—especially near azeotropic or high-purity regions.
For the ethanol-water system, the separation becomes very difficult near 95% ethanol, due to the presence of an azeotrope at around 95.6% ethanol.
Reducing the distillate purity from 95% to 92% means moving away from the azeotropic point, which significantly eases the separation.
This results in a major decrease in the number of required theoretical stages/plates.
Therefore, the correct choice is:
C. Major decrease in the number of