Vapor liquid equilibrium using hysys
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August 25, 2010 1 Vapor / Liquid Equilibrium Using HYSYS Prepared by: A.N.Tabish Lab. Engineer / Lecturer Department of Chemical Engineering UET, City Campus, Lahore sat i i i i i P x P y [email protected]
Transcript of Vapor liquid equilibrium using hysys
August 25, 2010 1
Vapor / Liquid Equilibrium Using HYSYS
Prepared by:
A.N.Tabish
Lab. Engineer / Lecturer
Department of Chemical Engineering
UET, City Campus, Lahore
sat
iiiii PxPy
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For the system methanol (1) / methyl acetate (2) , the following
equations provide a reasonable correlation for the activity coefficient
Example # 10.3:*
* J.M.Smith, H.C.Van Ness and M.M.Abott (2005), “Introduction to Chemical
Engineering Thermodynamics”, Ed. 7, pp. 359, McGraw Hill
2
21 Axn l2
12 Axn l
TA 00523.0771.2 Where,
In addition following equations provide vapor pressures:
424.33
31.364359158.161
TnP
satl
424.53
51.266525326.142
TnP
satl
Where T is in kelvin and the vapor pressure are in kPa.
August 25, 2010 [email protected]
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CALCULATE:
1. P and {y1}, for T = 318.15 K and {x1}= 0.25
2. P and {x1}, for T = 318.15 K and {y1}= 0.60
3. T and {y1}, for P = 101.33kPa and {x1}= 0.85
4. T and {x1}, for P = 101.33kPa and {y1}= 0.40
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Solution Strategy:
Start a new case in HYSYS.
Define components
Select Thermodynamic model.
Draw the PFD (material streams)
Define
1. Composition
2. Vapor fraction
3. Mole/mass flow rate
4. Temperature / Pressure
Determine BUBL/DEW Pressure/Temperature
Determine composition using K-Value information
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Start a new case in HYSYS.
Define components (Methanol + Methyl Acetate).
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Vapor Pressure of Methanol
Vapor Pressure of Methyl Acetate
44.51kPa using
Antoine Equation
65.64kPa using
Antoine Equation
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BUBL Pressure:
73.50 kPa in manual
calculations
1. P and {y1}, for T = 318.15 K and {x1}= 0.25
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Vapor compositions:
y1 = 0.282
y2 = 0.718
y1 = 0.278
y2 = 0.722i
ii
x
yK
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DEW Pressure:2. P and {x1}, for T = 318.15 K and {y1}= 0.60
62.89 kPa in manual
calculations
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Liquid compositions:
x1 = 0.8169
x2 = 0.1831
x1 = 0.8099
x2 = 0.1901i
ii
x
yK
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3. T and {y1}, for P = 101.33kPa and {x1}= 0.85
BUBL Temperature:
331.20K = 58 oC in
manual calculations
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Vapor compositions:
y1 = 0.670
y2 = 0.330
y1 = 0.671
y2 = 0.329i
ii
x
yK
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4. T and {x1}, for P = 101.33kPa and {y1}= 0.40
DEW Temperature:
326.70K = 53.7 oC in
manual [email protected]
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Liquid compositions:
x1 = 0.4602
x2 = 0.5398
x1 = 0.4517
x2 = 0.5483i
ii
x
yK
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VLE Plot:
Download registry files from
http://people.clarkson.edu/~wilcox/Design/EqPlots.dll
http://people.clarkson.edu/~wilcox/Design/EqPlots.edf
and save them to your computer at some safe place.
Create a case containing the components of interest and choose a suitable
fluid package.
Go to the Simulation Environment
Go to Tools/Preferences/Extensions and Click on Register an Extension.
Find EqPlots.dll and open it. This will remain part of HYSYS or UniSim
on your machine until it is Unregistered. Close Preference.
Go to Flowsheet/Add Operation. Select the Extensions category and Add
Equilibrium Plots. This should open the equilibrium plots extension.
For a Binary plot, click the Binary tab at the bottom of the Equilibrium
Plots menu, and select the components and the type of plot desired.
For an XY plot, specify either T or P, and click on Plot.
For a TXY plot, specify P. For a PXY plot, specify T.
August 25, 2010 [email protected]
August 25, 2010 [email protected]
August 25, 2010 [email protected]
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Example # 10.4:*
* J.M.Smith, H.C.Van Ness and M.M.Abott (2005), “Introduction to Chemical
Engineering Thermodynamics”, Ed. 7, pp. 364, McGraw Hill
For a mixture of 10 mol-% methane, 20 mol-% ethane, and 70 mol-%
propane at 50 (oF), determin:
1. The dew point pressure
2. The bubble point pressure
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Home Work Task:
1. Assuming the validity of Raoult's law, do the following calculations
for the benzene (l)/toluene (2) system:
2. For the system ethyl ethanoate (1) and n-heptane (2) at 343.15 K
(70"C)
BUBL P calculation for T = 343.15 K (70°C), x1 = 0.05.
DEW P calculation for T = 343.15 K (70°C), y1 = 0.05.
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Home Work Task Contd….
3. Make the following VLE calculations for the methane (l) / ethylene (2) /
ethane (3) system:
