Preliminary selection for VLE (without azeotrope) methanol + water Model: NRTL with the following parameters: Non-randomness parameter: 0.1 Dimensionless interaction parameters (form: A + B/T): A B 1 9.23811 -2432.61 2 -5.70743 1538.74 0.1 MPa pressure as an example All pressure conditions: deviation plots Temperature / K 0 0.200 0.400 0.600 0.800 1.00 -4.00 -2.00 0 2.00 4.00 6.00 Percent deviation from equation / % Liquid mole fraction of methanol Phase boundary pressure [L, G] - NRTL/HOC: Percent deviation from equation methanol + water 0 0.200 0.400 0.600 0.800 1.00 -0.100 -0.0800 -0.0600 -0.0400 -0.0200 0 0.0200 0.0400 0.0600 Absolute deviation from equation (G) Liquid mole fraction of methanol Liquid mole fraction of methanol Temperature [L, G] - NRTL/HOC methanol + water Gas mole fraction of methanol - NRTL/HOC: Absolute deviation from equation methanol + water
Transcript
Preliminary selection for VLE (without azeotrope)
methanol + water
Model: NRTL with the following parameters: Non-randomness parameter: 0.1 Dimensionless interaction parameters (form: A + B/T):
A B 1 9.23811 -2432.612 -5.70743 1538.74
0.1 MPa pressure as an example
All pressure conditions: deviation plots
Tem
pera
ture
/ K
0 0.200 0.400 0.600 0.800 1.00
-4.00
-2.00
0
2.00
4.00
6.00
Perc
ent d
eviat
ion fr
om eq
uatio
n / %
Liquid mole fraction of methanolPhase boundary pressure [L, G] - NRTL/HOC: Percent deviation from equation
methanol + water
0 0.200 0.400 0.600 0.800 1.00
-0.100
-0.0800
-0.0600
-0.0400
-0.0200
0
0.0200
0.0400
0.0600
Abso
lute d
eviat
ion fr
om eq
uatio
n (G)
Liquid mole fraction of methanol
Liquid mole fraction of methanol
Temperature [L, G] - NRTL/HOC methanol + water
Gas mole fraction of methanol - NRTL/HOC: Absolute deviation from equation methanol + water
butane + propane Model: Peng-Robinson equation with the following parameters: Parameters: k12= k21= -0.00291821
A few literature examples:
T<250 K from Hirata, M.; Suda, S.; Hakuta, T.; Nagahama, K. Light hydrocarbon vapor-liquid equilibria. Mem. Fac. Technol., Tokyo Metrop. Univ., 1969, 19, 103-122
T=253-273 K from Skripka, V. G.; Nikitina, I. E.; Zhdanovich, L. A.; Sirotin, A. G.; Ben'yaminovich, O. A. Liquid-vapor phase equilibrium at low temperatures in binary systems formed by components of natural gas. Gaz. Prom., 1970, 15, 35-6
Phas
e bou
ndar
y pr
essu
re /
kPa
Phas
e bou
ndar
y pr
essu
re /
kPa
Liquid mole fraction of butanePhase boundary pressure [L, G] - Original Peng-Robinson (Non-translated)
butane + propane
Liquid mole fraction of butanePhase boundary pressure [L, G] - Original Peng-Robinson (Non-translated)
butane + propane
T=260-280 K from Clark, A. Q. ; Stead, K. (Vapor + Liquid) Phase Equilibria of Binary, Ternary, and Quaternary Mixtures of CH4, C2H6, C3H8, C4H10 and CO2. J. Chem. Thermodyn., 1988, 20, 413-427
T=270-310 K from Kayukawa, Y.; Fujii, K.; Higashi, Y. Vapor-Liquid Equilibrium (VLE) Properties for the Binary Systems Propane (1) + n-Butane (2) and Propane (1) + Isobutane (3). J. Chem. Eng. Data, 2005, 50, 579-582
Phas
e bo
unda
ry p
ress
ure /
kPa
Phas
e bo
unda
ry p
ress
ure
/ kPa
Liquid mole fraction of butanePhase boundary pressure [L, G] - Original Peng-Robinson (Non-translated)
butane + propane
Liquid mole fraction of butanePhase boundary pressure [L, G] - Original Peng-Robinson (Non-translated)
butane + propane
T=273-323 K from Seong, G.; Yoo, K.-P.; Lim, J. S. Vapor-Liquid Equilibria for Propane (R290) + n-Butane (R600) at Various Temperatures. J. Chem. Eng. Data, 2008, 53, 2783-2786
General statistics:
Pressure deviations: 2% on average above T=320K; 4% on average at 240 K (the points with larger deviations are from two unreliable sources) Gas mole fraction deviations: ±0.01 on average above T=320 K; 0.04 on average at T=240 K.
