Mass Transfer Operation - II — Summer 2022

Explain Raoult’s Law and Relative Volatility

Discuss the factor on which the rate of drying depends

Arectification column is feed with 100 kmol/h of a mixture containing 50 mol % hexane and 50 mole % octane at 101.325 kPa absolute pressure. The feed is at its boiling point. The distillate is to contain 90 mole % hexane and the bottoms 10 mole % hexane. The reflux ratio used is 3. Calculate the kmol/h distillate and kmol/h bottoms, and number of theoretical trays needed for this separation. The equilibrium data for this system is given below x 1.0 0.69 0.4 0.192 0.045 0 y 1.0 0.932 0.78 0.538 0.1775 0

List assumptions of McCabe-Thiele method and its limitations.

Given the importance of providing reflux in distillation column and how it affects the purity of the product obtained.

Define quantity ‘q’. Derive equation for q -line and discuss location of ‘q’ line for typical feed condition in brief.

Explain Differential Distillation and derive Rayleigh’s Equation

Discuss about various types of adsorption

Write short note on desirable characteristics of Packing material used in packed distillation column.

Write and explain Freundlich equation. Write material balance for a single stage adsorption and apply Freundlich equation in it.

Briefly explain about Adsorption hysteresis

Discuss about ion exchange process used in softening of water.

With reference to breakthrough curve of adsorption in a fixed bed, deduce the expression to calculate the degree of saturation of the adsorbent bed.

Discuss the concept of Pressure Swing Adsorption (PSA)

Compare forced draft and induced draft cooling tower.

Derive equation for Adiabatic Saturation Curve.

Define: Free Moisture, Humidity, Blowdown

Discuss about range and approach with reference to cooling tower.

Give detailed classification of cooling towers and discuss about any one in detail with neat sketch.1

Briefly explain freeze drying

Explain with the sketch, the principle and working of rotary drier.

Derive the equation for time required in constant and falling rate period of the batch drying operations.

Explain with the sketch, the principle and working of spray drier.

Define and explain followings: a) Equilibrium moisture b) Bound moisture c) Unbound moisture d) Critical moisture content

Awet solid is to be dried from 35% to 10% moisture under constant drying conditions in five hours. If the equilibrium moisture content is 4% and the critical moisture content is 14%. All moisture content data is on wet basis. How long it will take to dry solids to 6% moisture under the same conditions.