excess residue property.pdfv8yp98yb98yab

v4ypq98ybvpq89ybp

1. EXCESS AND RESIDUAL PROPERTIES

2. •Introduction to excess properties
•Excess volume and Excess Gibb's free energy
•Introduction to residual properties
•Applications
•Calculation methods and models
•Case Study
•Conclusion
Table of content

3. EXCESS PROPERTIES
The excess property is defined as the difference between actual property and the
property that would be calculated for same temperature, pressure and composition
for an ideal solution.
Where as:
M^E= Excess property
M = Molar property of solution,
M^id =Property of ideal solution
Excess property change of mixing is defined in similar way

4. Excess function may be positive or negative
Excess Function indicates the deviation from ideal solution behavior and are easily
related to activity coefficient.
Partial molar excess function is similar to the partial molar thermodynamic
property.
if is the partial molar property of component I. so, partial molar excess property
can be written as

5. Mathematically, Excess volume is defined as:
VE = Vactual - Videal
We can also write this equation in form of mass and density of the component or mixture.
it provides insights into molecular interactions and the behavior of the mixture under
different conditions, such as changes in temperature, pressure, and composition.
Excess Volume

6. For phase equilibrium studies the most useful excess property is the partial molar excess Gibbs free
energy which can be directly related to the activity coefficient.
The excess Gibbs free energy is defined as:
where, is excess chemical potential of component i.

= change in chemical potential of component i
Excess Gibbs free energy

7. The change in chemical potential for component when it is transferred from its standard state
to the solution at the same temperature and pressure is related to its fugacity in the solution
Since fugacity of ideal solution is , so can be written as:
The fugacity is related to activity coefficient so the equation becomes
The above equation can also be written in form

8. Residual properties are the differences between the actual properties of a real gas and the
properties it would have if it were an ideal gas at the same temperature and pressure.
These property help in quantifying how much the behavior of a real gas deviates from the
ideal gas law due to intermolecular interactions and the volume occupied by the gas
molecules.
Residual Properties

9. Excess Property Residual Property
Primarily used for liquid mixtures to describe
deviations from ideal solution behavior.
Mainly used for gases to describe deviations from
ideal gas behavior.
Apply to mixtures (liquid or gas) and quantify
deviations from ideal solution behavior.
Apply to single-component real gases and quantify
deviations from ideal gas behavior.
Crucial in models of liquid-phase equilibria (e.g.,
vapor-liquid equilibrium, liquid-liquid
equilibrium), particularly in predicting activity
coefficients.
Important in models of gas-phase thermodynamics,
such as calculating fugacity, compressibility factor,
and other properties where ideal gas assumptions
do not hold.
Difference in Excess and Residue properties

10. What is use of Residual property and Excess
property in thermodynamics?
Excess properties are used
to correct for non-ideal
behavior in liquid
mixtures, essential for
accurately designing and
optimizing separation
processes like distillation
and for phase equilibrium
calculations.
Residual properties are used
to adjust for non-ideal
behavior in gases, crucial for
accurately predicting
thermodynamic properties
and phase equilibria in
systems where the ideal gas
law does not hold, especially
under high pressure and low
temperature.
MR = M - Mig
ME = M - Mid

11. Experimental methods to determine Excess Property
Measurement of density of liquid & liquid mixture by
densimeter or by Rd bottle
Measuremnt of heat of mixture by calorimeter
Ultrasonic velocity by interferometry
Vapour pressure by isoteniscope
Ultrasonic interferometry

12. Case Study
THERMODYNAMIC PROPERTIES OF BINARY LIQUID MIXTURES OF
CYCLOALKANOL + n-ALKANES
Manager
Everest Cantu
Marketing
Drew Holloway
Business Head
Study focuses on the thermodynamic properties of binary liquid mixtures composed of cycloalkanols and
n-alkanes
It present here results of determination of excess enthalpies and excess volume at 298.15 K for
cyclopentanol and cyclohexanol with n-hexane ,n-heptane, n-octane, n-decane and n-dodecane.
The calorimeter and dilatometer used to measure excess enthalpies HE and excess Volumes VE .
The HE and VE results for each mixture were expressed as a
funcation of the mole fraction x of cycloalkanol by the
polynomials
The vaues of coefficients A, and the standard deviations HE
and VE obtained by the method of least squares with al points
weighted equally

13. Case Study
THERMODYNAMIC PROPERTIES OF BINARY LIQUID MIXTURES OF
CYCLOALKANOL + n-ALKANES
Remy
Marsh
Everest Cantu
Marketing
Drew Holloway
Business Head

14. Conclusion
Bridge Between Ideal and Real Behavior
Essential for Accurate Predictions:
Applicability in Process Design:
Insights into Molecular Interactions:
Foundation for Thermodynamic Calculations:

15. Refrances
K. V. Narayanan; A Textbook of Chemical Engineering Thermodynamics; Third Edition,
Prentice-Hall of India Pvt. Ltd.
1.
J. M. Smith, H. C. Van Ness, M. M. Abbott; Introduction to Chemical Engineering
Thermodynamics; Seventh Edition, McGraw-Hill
2.
Kaur, H., J. R. Khurma, and B. S. Mahl. "Thermodynamic properties of binary liquid
mixtures of cycloalkanol+ n-alkanes." Fluid phase equilibria 45, no. 1 (1989): 121-133.
3.

16. Thank you