Presentation on

Vapor Liquid Equilibrium

Presented ByMd.Touhidul IslamStd no.-1202011Date: 19-12-15

Presentation outline

Objectives

Importance

Applications

Vapor-Liquid Equilibrium Concept

Theory included

Equilibrium data interpretation

Vapour liquid equilibrium

2

Presentation outline (Cont’d)

Experimental setup

Experimental results

Graphical representations

Discussion

Conclusion

3

Vapour liquid equilibrium

Objectives

To produce vapor-liquid equilibrium at atmospheric

pressure

To determine the equilibrium temperature and

compositions for a certain system

To compare the experimental results with the

theoretical data supplied

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Vapour liquid equilibrium

Importance

A knowledge of the vapor-liquid equilibrium is essential in the analytical treatment of a distillation problem

Azeotropic systems can be identified

Vapour liquid equilibrium

5

Applications

• Industrial Separation Processes

• Distillation of Crude Oil

• Distillation of Alcohols

• Design of Distillation Columns

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Vapour liquid equilibrium

Vapor-Liquid Equilibrium Concept

An isolated system consisting ofliquid and vapor phases in intimatecontact wherein

• The temperature, pressure & phase compositions reach final values

• The vaporization occurs at the same rate as the condensation

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Vapour liquid equilibrium

Theory included

At equilibrium condition,T liquid = T vapor

P liquid = P vapor

Chemical Potential liquid = Chemical Potential vapor

No change in composition

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Vapour liquid equilibrium

Equilibrium data interpretation

Gibb’s phase rule gives

F = C-P+2

For two component VLE, F=2-2+2=2

Thus by fixing any two of the three intensive variables will

automatically fix the remaining one.

Binary VLE data can be graphically represented in several

ways,

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Vapour liquid equilibrium

Equilibrium data interpretation (Cont`d)

y-x diagram

T-xy diagram

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Vapour liquid equilibrium

Experimental setup11

water out

water outwater in

water in

Vapour liquid equilibrium

cotton

condenser

stand

thermometer

insulationglass biddistillate collector

liquid phase separatorheater

ethanol water solutionround bottom flaskrecycle line

Experimental results

Equilibrium temperature = 80 oC

Equilibrium composition,

Liquid phase, x = 24 % mole ethanol

Vapor phase, y = 48 % mole ethanol

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Vapour liquid equilibrium

Graphical representationsT-xy Diagram

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Vapour liquid equilibrium

Graphical representations (Cont`d) yx Diagram

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Vapour liquid equilibrium

Discussion

• Sample had been taken from the system

• High volatility of ethanol

• Approximate readings of refractive index

• Supplied Refractive Index Vs. Composition curve at 300C

• Pressure could not be maintained constant

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Vapour liquid equilibrium

Conclusion

Temperature, pressure and composition of two phases does not change at equilibrium

The temperature and pressure of the liquid and vapor phases are equal but the compositions are not at equilibrium

The knowledge acquired from this experiment can be used for further calculations

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Vapour liquid equilibrium

THANK YOU ALL