itk-234 termodinamika teknik kimia ii dicky [email protected] vle calculations for nonideal...
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ITK-234 Termodinamika Teknik Kimia II
Dicky Dermawanwww.dickydermawan.net78.net
VLE Calculations for Nonideal Mixtures
Modified Raoult’s Law K-value MethodVLE using Equation of States
Dicky Dermawan
satkkkkk PxPy
TR
PPVexp
ˆ
ˆ satkk
satk
kk
1ˆˆ satkk
Incorporation of fugacity and activity coefficient to vle criteria results:
Modified Raoult’s Law:
where
However, at low pressure (up to at least 1 bar):
The Poynting Factor 1
satkkkk PxPy
Modified Raoult’s Law:Wilson Equation for calculating
a. Prepare a P-x-y diagram at 80oC
b. Prepare a t-x-y diagram at 101,33 kPa
Modified Raoult’s Law:Wilson Equation for calculating (Cont’)
Use your diagram to answer there questions:
Given P = 70 kPa, T = 80oC & overall composition, z1=30%
Find the fraction of system which is liquid (L) & vapor (V) and their respective compositions xi & yi
Modified Raoult’s Law:Wilson Equation for calculating
a. Prepare a P-x-y diagram at 80oC
b. Prepare a t-x-y diagram at 101,33 kPa
Modified Raoult’s Law:Wilson Equation for calculating (Cont’)
Use your diagram to answer there questions:
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:Wilson Equation for calculating
Modified Raoult’s Law:NRTL Equation for calculating
a. Prepare a P-x-y diagram at 80oC
b. Prepare a t-x-y diagram at 101,33 kPa
Modified Raoult’s Law:NRTL Equation for calculating
VLE Calculation Using No Diagram
Answer the questions (a) through (e) from12.6 to 12.13 but don’t use the phase diagram to obtain the answers
Estimating Azeotrophic Condition,Use No Diagram
K-Value Method:Using De Priester Charts for light hidrocarbons
satkkkkk PxPy )P,T(f
P
P
x
yK
k
satkk
k
kk
iii xKy
The nomographs K = f(T,P) prepared by De Priester provide easy application of this approach to practical problem
TR
PPVexp
ˆ
ˆ satkk
satk
kk
K-Value Method:
Using De Priester Charts for light hidrocarbons
HighTemperatureRange
K-Value Method:
Using De Priester Charts for light hidrocarbons
LowTemperatureRange
Type of Phase Equilibria CalculationsBUBL P calculation:
Given T & liquid composition xi,Find the bubble point Pb & vapor composition
DEW P calculation:Given T & vapor composition yi,Find the bubble point Pb & vapor composition
0xK ii
Assume P, find Ki satisfying:
0K
y
i
i
Assume P, find Ki satisfying:
Type of Phase Equilibria Calculations
BUBL t calculation:Given P & liquid composition xi,Find the bubble point Pb & vapor composition
DEW t calculation:Given P & vapor composition yi,Find the bubble point Pb & vapor composition
0xK ii
Assume t, find Ki satisfying:
0K
y
i
i
Assume t, find Ki satisfying:
K-Value Method:Using De Priester Charts for light hidrocarbons
K-Value Method:Using De Priester Charts for light hidrocarbons
Type of Phase Equilibria Calculations
FLASH calculation:Given P, T & overall composition,Find the fraction of system which is liquid (L) & vapor (V) and their respective compositions xi & yi
1V1K1
zx
i
ii
Make sure P located between Pb dan Pd, i.e.Perform BUBL P for zi =xi andPerform DEW P for zi = yi
Find Ki ; assume V satisfying:or:
or: The General Solution Procedure
1
V1K1
Kzy
i
iii
0
V1K1
)1K(z
i
ii
K-Value Method:Using De Priester Charts for light hidrocarbons
K-Value Method:Using De Priester Charts for light hidrocarbons
K-Value Method:Using De Priester Charts for light hidrocarbons