Which distillation calculation model assumes constant molal vaporization and constant molal overflow ?
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Answer: A. McCabe-Thiele method
Explanation
The McCabe-Thiele graphical method assumes constant molal vaporization and constant molal overflow throughout column sections. This fundamental assumption means every mole of vapor condensed in the rectifying section generates a mole of liquid reflux. It simplifies energy balances by allowing linear operating lines to be constructed on binary equilibrium diagrams. Developed in 1925, the McCabe-Thiele method remains a cornerstone educational and preliminary design tool for distillation. Constant molal overflow requires that component molar latent heats of vaporization are approximately equal. Deviations from this assumption occur when components have vastly different latent heats or high feed enthalpies.
Option B is incorrect because the Ponchon-Savarit method does not rely on constant molal overflow assumptions. Option C is incorrect because the enthalpy concentration method incorporates complete energy balances for variable latent heats. Option D is incorrect because plate absorption columns involve gas absorption rather than binary fractional distillation.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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