Mass Transfer Operation - II — Summer 2018

Explain characteristics of ideal solutions with Raoults’s law.

Discuss positive deviations from ideality with neat sketch.

With neat diagram explain the theory of wet-bulb temperature and derive the equation for wet-bulb temperature determination.

Write short note on flash distillation.

Write in brief on Azeotropic distillation.

Aliquid mixture of 50 mole% n-heptane (i) and 50 mole% n-octane (ii) were subjected to differential distillation at atmospheric pressure with 55 mole% of the liquid distilled. Compute the composition of the composite distillate and the residue. “x” 1.00 0.50 0.46 0.42 0.38 0.34 0.32 0.00 “y” 1.00 0.689 0.648 0.608 0.567 0.523 0.497 0.00

Acontinuous distillation column is to separate 50 Kmol/hr of feed mixture having 65% Benzene (A) and 35% Toluene (B). Top product contains 95% Benzene and Bottom product contains 95% Toluene (by mole).Feed is saturated liquid at its bubble point. Average relative volatility is 2.44. If reflux ratio R= 2.25 R , determine feed tray min location and number of theoretical stages by Mccabe-Thiele method.

Discuss applications of steam distillation.

Write short note on types of reflux ratio and its significance.

Derive Fenske’s equation for the minimum number of theoretical stages.

Discuss importance of vacuum distillation.

Explain the following terms:

Bound moisture ii) Free moisture iii) Equilibrium moisture iv) Critical moisture

Write Freundlich equation? How is it applied to two-stage cross current adsorption?

Write short note on adsorbents with their characteristics.

Derive the relation to determine the time needed for constant & falling rate period of the batch drying operations.

Explain construction, working, advantages & disadvantages of rotary dryer.

For adsorption operation, explain following:

Adsorption hysteresis ii) Nature of adsorbents

Explain rate of drying curve.1

Define: (1) Absolute humidity (2) Relative humidity (3) Dry-bulb temperature (4) Wet-bulb temperature (5) Humid volume (6) Humid Heat (7) Lewis relation

Explain relative volatility and derive its relationship equation with equilibrium compositions in vapor and liquid phases.

Compare and contrast physical adsorption and chemisorptions.

What do you mean by Ion Exchange? Describe techniques and application of ion exchange and list out the factors on which rate of ion exchange is dependent.

Explain adsorption isotherm with figure.

Qualitatively, explain the apparent adsorption of solute from solution.

Explain the various types of cooling towers and discuss their selection criteria.