Mass Transfer Operations I — Summer 2021

What are different methods of conducting mass transfer operations at commercial scale?

With reference to concept of equilibrium, Explain the principles for interphase mass transfer between two insoluble phases.

State different theories used to explain the meaning of mass transfer coefficients. Explain any one in detail.

Draw classification chart of mass transfer operations.

Explain the temperature and pressure dependency of diffusivity of gases and liquid.

State and explain Fick’s first law of diffusion Also, differentiate between flux Nand J . Additionally, Prove that for unidirectional A A binary diffusion J = - J . A B

Calculate the rate of diffusion of Acetic acid (A) across a film of non- diffusing water (B) solution 1 mm thick at 17oC when the concentrations on opposite sides of the film are respectively 9 and weight % acid. The diffusivity of acetic acid in the solution is 0.95 x 10-9 m2/s. Density of 9 and 3 weight % aqueous solutions is 1012 kg/m3 and 1003.2 kg/m3 respectively. M = 60, M = 18. A B

Classify gas-liquid equipment based on phases being dispersed with examples.

Define the terms : (i) Flooding (ii) Coning (iii)Weeping (iv)Dumping

Write a short note on minimum liquid gas ratio in case of gas absorption.

Define absorption factor Aand Stripping factor S.

Explain HETP, HTU and NTU for packed bed absorption column.

Differentiate between Tray tower and Packed tower.

Define ideal and non-ideal solutions with reference to multi-component absorption and state the characteristics of ideal solution.

Enlist different industrial liquid extraction equipment and explain any one in detail.

Discuss the system of three liquids- one pair partially soluble and the effect of temperature on these ternary equilibria in case of liquid extraction.

Explain gas absorption with chemical reaction in brief.

Discuss various factors to be considered in making choice of solvent for liquid extraction.

150 kg of nicotine-water solution containing 1% nicotine is to be extracted with 250 kg of kerosene at 20oC. Water and kerosene are essentially immiscible in each other, Determine the % extraction of nicotine after single stage. The equilibrium relationship is Y*=0.798 X, where Xand Y* are expressed as kg nicotine/kg kerosene and kg nicotine/kg water respectively.

State different types of packing materials and explain their selection criterion.

What is crystallization? Discuss effect of temperature on solubility.

Discuss the preparation of solids in leaching and also explain rate of leaching.

Write a note on Ventury scrubber.

Explain any one crystallization equipment in detail.

Explain Shanks system for leaching.