Aspen Physical Property System - Physical Property Models

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ai bi kij 50 2 Thermodynamic Property Models = = = The model has option codes which can be used to customize the model, by selecting a different alpha function and other model options. See Peng- Robinson Alpha Functions for a description of the alpha functions. See Option Codes for Equation of State Models (under ESPRSTD) for a list of the option codes. For best results, the binary parameter kij must be determined from regression of phase equilibrium data such as VLE data. The Aspen Physical Property System also has built-in kij for a large number of component pairs in the EOS- LIT databank. These parameters are used automatically with the PENG-ROB property method. Values in the databank can be different than those used with other models such as Soave-Redlich-Kwong or Redlich-Kwong-Soave, and this can produce different results. Parameter Name/Element Symbol Default MDS Lower Limit Upper Limit Units TCPRS T ci TC x 5.0 2000.0 TEMPERATURE PCPRS p ci PC x 10 5 OMGPRS � i PRKBV/1 k ij (1) PRKBV/2 k ij (2) PRKBV/3 k ij (3) 10 8 OMEGA x -0.5 2.0 — 0 x - - - PRESSURE 0 x - - TEMPERATURE 0 x - - TEMPERATURE PRKBV/4 T lower 0 x - - TEMPERATURE PRKBV/5 T upper 1000 x - - TEMPERATURE References D.-Y. Peng and D. B. Robinson, "A New Two-Constant Equation-of-state," Ind. Eng. Chem. Fundam., Vol. 15, (1976), pp. 59–64. Peng-Robinson-MHV2 This model uses the Peng-Robinson equation-of-state for pure compounds. The mixing rules are the predictive MHV2 rules. Several alpha functions can be used in the Peng-Robinson-MHV2 equation-of-state model for a more accurate description of the pure component behavior. The pure component behavior and parameter requirements are described in Standard Peng- Robinson, or in Peng-Robinson Alpha Functions. The MHV2 mixing rules are an example of modified Huron-Vidal mixing rules. A brief introduction is provided in Huron-Vidal Mixing Rules. For more details, see MHV2 Mixing Rules.
Predictive SRK (PSRK) This model uses the Redlich-Kwong-Soave equation-of-state for pure compounds. The mixing rules are the predictive Holderbaum rules, or PSRK method. Several alpha functions can be used in the PSRK equation-of-state model for a more accurate description of the pure component behavior. The pure component behavior and parameter requirements are described in Standard Redlich-Kwong-Soave and in Soave Alpha Functions. Note: You can choose any of the available alpha functions, but you cannot define multiple property methods based on this model using different alpha functions within the same run. The PSRK method is an example of modified Huron-Vidal mixing rules. A brief introduction is provided in Huron-Vidal Mixing Rules. For more details, see Predictive Soave-Redlich-Kwong-Gmehling Mixing Rules. Peng-Robinson-Wong-Sandler This model uses the Peng-Robinson equation-of-state for pure compounds. The mixing rules are the predictive Wong-Sandler rules. Several alpha functions can be used in the Peng-Robinson-Wong-Sandler equation-of-state model for a more accurate description of the pure component behavior. The pure component behavior and parameter requirements are described in Peng- Robinson, and in Peng-Robinson Alpha Functions. Note: You can choose any of the available alpha functions, but you cannot define multiple property methods based on this model using different alpha functions within the same run. The Wong-Sandler mixing rules are an example of modified Huron-Vidal mixing rules. A brief introduction is provided in Huron-Vidal Mixing Rules. For more details see Wong-Sandler Mixing Rules., this chapter. Redlich-Kwong The Redlich-Kwong equation-of-state can calculate vapor phase thermodynamic properties for the following property methods: NRTL-RK, UNIFAC, UNIF-LL, UNIQ-RK, VANL-RK, and WILS-RK. It is applicable for systems at low to moderate pressures (maximum pressure 10 atm) for which the vapor-phase nonideality is small. The Hayden-O'Connell model is recommended for a more nonideal vapor phase, such as in systems containing organic acids. It is not recommended for calculating liquid phase properties. The equation for the model is: p = Where: 2 Thermodynamic Property Models 51
Page 1 and 2: Aspen Physical Property System Phys
Page 3 and 4: Contents Contents..................
Page 5 and 6: General Pure Component Solid Molar
Page 7 and 8: 1 Introduction This manual describe
Page 9 and 10: Pure Component Temperature- Depende
Page 11 and 12: the Properties Parameters Pure-Comp
Page 13 and 14: 2 Thermodynamic Property Models Thi
Page 15 and 16: Property Model Model Name Phase(s)P
Page 17 and 18: Property Model Model Name 2 Thermod
Page 19 and 20: Where: Parameter Name/Element 2 The
Page 21 and 22: critical temperature, the critical
Page 23 and 24: Where the ideal-gas contribution
Page 25 and 26: , where � For polar, associating
Page 27 and 28: Parameter Name/ Element 2 Thermodyn
Page 29 and 30: The denominator of equation 8 is gi
Page 31 and 32: V. V. De Leeuw and S. Watanasiri, "
Page 33 and 34: References M. Benedict, G. B. Webb,
Page 35 and 36: References L. Haar, J.S. Gallagher,
Page 37 and 38: Parameter Name/Element NTHDDH 0 †
Page 39 and 40: Gibbs free energy departure: The fo
Page 41 and 42: For a block copolymer, there is onl
Page 43 and 44: Copolymer PC-SAFT Dispersion Term T
Page 45 and 46: The association-site number of the
Page 47 and 48: Then I2(�) and I3(�) are comput
Page 49 and 50: A databank called PC-SAFT contains
Page 51: Parameter Name/Element PRKBV/1 k ij
Page 55 and 56: ka,ij kb,ij = = For best results, b
Page 57 and 58: J. Schwartzentruber and H. Renon, "
Page 59 and 60: Redlich-Kwong-Soave-MHV2 This equat
Page 61 and 62: ‡ RKUC0, RKUC1, and RKUC2 are tre
Page 63 and 64: Parameter Name/ Element SRKLIJ/3 l
Page 65 and 66: Parameter Name/ Element Symbol Defa
Page 67 and 68: Association Equilibria Every associ
Page 69 and 70: and respectively. For the reactions
Page 71 and 72: R. W. Long, J. H. Hildebrand, and W
Page 73 and 74: Where the L, M, and N are parameter
Page 75 and 76: Alpha function Model name First Opt
Page 77 and 78: mi = Computed by equation 6 Equatio
Page 79 and 80: Parameter Name/Element 2 Thermodyna
Page 81 and 82: standard RKS alpha function, except
Page 83 and 84: These mixing rules are discussed se
Page 85 and 86: Where both Ai* and Am are calculate
Page 87 and 88: Like Huron and Vidal, the limiting
Page 89 and 90: Model Type Wilson Local composition
Page 91 and 92: Therefore, the simplified Pitzer eq
Page 93 and 94: Parameter Name/Element Symbol Defau
Page 95 and 96: Where: �i 2 Thermodynamic Propert
Page 97 and 98: The electrolyte NRTL model uses the
Page 99 and 100: Parameter Symbol No. of Name Elemen
Page 101 and 102: with Where: xi = Mole fraction of c
Page 103 and 104:
It should be understood that equati
Page 105 and 106:
The reference Gibbs energy is deter
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Where: j and k can be any species (
Page 109 and 110:
The pure component dielectric const
Page 111 and 112:
2 Thermodynamic Property Models 109
Page 113 and 114:
�I *PDH = Pitzer-Debye-Hückel te
Page 115 and 116:
Where: �i Vi = Activity coefficie
Page 117 and 118:
Recommended cij Values for Differen
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Parameter Name/ Element 2 Thermodyn
Page 121 and 122:
NRTL-SAC Reference States The NRTL-
Page 123 and 124:
Page 125 and 126:
For an anionic component, we have M
Page 127 and 128:
For a molecular segment, the activi
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Specifically, The long range intera
Page 131 and 132:
where and are activity coefficients
Page 133 and 134:
and Y+, are used to reflect the wid
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Parameter Name/ Element Symbol Defa
Page 137 and 138:
Reference C.-C. Chen and Y. Song, "
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Parameter Name GMPTPS, GMPTP1, GMPT
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zi = Charge of ion i Subscripts c,
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For option code = 0 (default), the
Page 145 and 146:
and for n-m electrolytes: 2 Thermod
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= 0.00979 Perform the necessary con
Page 149 and 150:
Pitzer, K.S., J.R. Peterson, and L.
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A4,ij = gij / T + hij A5,ij = mij /
Page 153 and 154:
Symmetric and Unsymmetric Electroly
Page 155 and 156:
Parameter Symbol No. of Name Elemen
Page 157 and 158:
Reference state for ionic component
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with 2 Thermodynamic Property Model
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G for these pairs is calculated the
Page 163 and 164:
with 2 Thermodynamic Property Model
Page 165 and 166:
Page 167 and 168:
Activity Coefficient Basis for Henr
Page 169 and 170:
Where is the liquid Gibbs free ener
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Ionic components 2 Thermodynamic Pr
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the pure fused salts. Applying Eq.
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�k is the activity coefficient of
Page 177 and 178:
References U. Weidlich and J. Gmehl
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ti' = �ij 2 Thermodynamic Propert
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Wagner Interaction Parameter The Wa
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References G.M. Wilson, J. Am. Chem
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Extended Antoine Equation Parameter
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IK-CAPE Vapor Pressure Equation The
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Harlacher and Braun, "A Four-Parame
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Parameter Name/Element 2 Thermodyna
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General Pure Component Heat of Vapo
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IK-CAPE Heat of Vaporization Equati
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Where: xp = Mole fraction of pseudo
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Parameter Name/Element VLBROC/1 V i
Page 201 and 202:
Where: Vm l,t = Liquid volume per n
Page 203 and 204:
Debye-Hückel Volume The Debye-Hüc
Page 205 and 206:
DIPPR DIPPR equation 105 is the def
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Rackett The Rackett equation is: Wh
Page 209 and 210:
Rackett/Campbell-Thodos Mixture Liq
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Zm RA Zi *,RA Vcm 2 Thermodynamic P
Page 213 and 214:
General Pure Component Solid Molar
Page 215 and 216:
Liquid Volume Quadratic Mixing Rule
Page 217 and 218:
If THRSWT/6 is This equation is use
Page 219 and 220:
Parameter Symbol Default MDS Lower
Page 221 and 222:
General Pure Component Ideal Gas He
Page 223 and 224:
(Other DIPPR equations may sometime
Page 225 and 226:
General Pure Component Solid Heat C
Page 227 and 228:
Parameter Name/Element 2 Thermodyna
Page 229 and 230:
The expression for the liquid mole
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� Entropy: � Heat capacity: �
Page 233 and 234:
Parameter Name † /Element CPIXPn/
Page 235 and 236:
Option Codes for Electrolyte NRTL E
Page 237 and 238:
Parameter Name Applicable Component
Page 239 and 240:
For subcritical components: Hm l -H
Page 241 and 242:
The vapor enthalpy is calculated fr
Page 243 and 244:
Where: 2 Thermodynamic Property Mod
Page 245 and 246:
Correlation algorithms for ionic sp
Page 247 and 248:
Model Model name Phase(s) Pure Mixt
Page 249 and 250:
Model Type Aspen Liquid Mixture Vis
Page 251 and 252:
(Other DIPPR equations may sometime
Page 253 and 254:
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�i = Viscosity of component i (N-
Page 257 and 258:
Parameter Name/Element 3 Transport
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Where: The Stockmayer or Lennard-Jo
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Where: Vcij = �ij = 0 (in almost
Page 263 and 264:
Where: Vcij = �ij = 0 (in almost
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Jones-Dole Electrolyte Correction T
Page 267 and 268:
Letsou-Stiel The Letsou-Stiel model
Page 269 and 270:
Where: The parameter is the mole fr
Page 271 and 272:
Reference C.H. Twu, "Internally Con
Page 273 and 274:
Vcij 3 Transport Property Models 27
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You must provide parameters for the
Page 277 and 278:
Linear extrapolation of � *,l ver
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If TRNSWT/4 is This equation is use
Page 281 and 282:
Page 283 and 284:
Page 285 and 286:
Page 287 and 288:
Page 289 and 290:
References R.C. Reid, J.M. Prausnit
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The mixture surface tension is then
Page 293 and 294:
Page 295 and 296:
Where: �solv = Dielectric constan
Page 297 and 298:
4 Nonconventional Solid Property Mo
Page 299 and 300:
wij = Mass fraction of the jth cons
Page 301 and 302:
The oxygen and organic sulfur conte
Page 303 and 304:
Parameter Name/Element Symbol Defau
Page 305 and 306:
The complete oxidation of carbon is
Page 307 and 308:
Parameter Name/Element Symbol Defau
Page 309 and 310:
The equation for �i dm is good fo
Page 311 and 312:
5 Property Model Option Codes The f
Page 313 and 314:
Model Name Option Code 5 Property M
Page 315 and 316:
Model Name Option Code 5 Property M
Page 317 and 318:
Soave-Redlich-Kwong Option Codes Th
Page 319 and 320:
Model Name Option Code HLRELNRT and
Page 321 and 322:
Model Name Option Code GLRELNRT, GL
Page 323 and 324:
Index A activity coefficient models
Page 325 and 326:
ideal gas/DIPPR heat capacity model
Page 327 and 328:
S Sato-Riedel/DIPPR thermal conduct
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Aspen Physical Property System - Physical Property Models

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