Aspen Physical Property System - Physical Property Models

More documents

Recommendations

Info

Aij = aij + bij / T Subscripts i and j are component indices. The choice of model and parameters can be set for each binary pair constituting the process mixture by assigning the appropriate value to the ICHNUL parameter. The Regular Solution and Scatchard-Hamer models are regained by substituting in the general expression (ICHNUL = 1 or 2). Vji = Sji = Vj *,l / Vi *,l Where: Vj *,l 90 2 Thermodynamic Property Models = Liquid molar volume of component i The Chien-Null activity coefficient model collapses to the Margules liquid activity coefficient expression by setting (ICHNUL = 3): Vji = Sji = 1 The Van Laar Liquid activity coefficient model is obtained when the V and S parameters in the Chien-Null models are set to the ratio of the cross terms of A (ICHNUL = 4:) Vji = Sji = Aji / Aij Finally, the Renon or NRTL model is obtained when we make the following susbstitutions in the Chien-Null expression for the liquid activity (ICHNUL = 5). Sji = RjiAji / Aij Aji = 2�jiGji Vji = Gji The following are defined for the Non-Random Two-Liquid activity coefficient model, where: �ij = aij + bij / T Cij = cij + dij (T - 273.15 K) cji = cij dji = dij The binary parameters CHNULL/1, CHNULL/2, and CHNULL/3 can be determined from regression of VLE and/or LLE data. Also, if you have parameters for many of the mixture pairs for the Margules, Van Laar, Scatchard-Hildebrand, and NRTL (Non-Random-Two-Liquid) activity models, you can use them directly with the Chien-Null activity model after selecting the proper code (ICHNUL) to identify the source model and entering the appropriate activity model parameters.
Parameter Name/Element Symbol Default Lower Limit 2 Thermodynamic Property Models 91 Upper Limit ICHNUL — 3 1 6 — CHNULL/1 a ij 0 — — — CHNULL/2 b ij 0 — — — CHNULL/3 V ij 0 — — — Units The parameter ICHNUL is used to identify the activity model parameters available for each binary pair of interest. The following values are allowed for ICHNUL: ICHNUL = 1 or 2, sets the model to the Scatchard-Hamer or regular solution model for the associated binary; ICHNUL = 3, sets the model to the Three-Suffix Margules activity model for the associated binary; ICHNUL = 4, sets the model to the Van Laar formalism for the activity model for the associated binary; ICHNUL = 5, sets the model to the NRTL (Renon) formalism for the activity model for the associated binary. ICHNUL = 6, sets the model to the full Chien-Null formalism for the activity model for the associated binary. When you specify a value for the ICHNUL parameter that is different than the default, you must enter the appropriate binary model parameters for the chosen activity model directly. The routine will automatically convert the expressions and parameters to conform to the Chien-Null formulation. Constant Activity Coefficient This approach is used exclusively in metallurgical applications where multiple liquid and solid phases can coexist. You can assign any value to the activity coefficient of component i. Use the Properties Parameters Unary Scalar form. The equation is: �i = ai Parameter Name/Element Symbol Default MDS Upper Limit Lower Limit GMCONS a i 1.0 x — — — COSMO-SAC Units Cosmo-SAC is a solvation model that describes the electric fields on the molecular surface of species that are polarizable. It requires a fairly complicated quantum mechanical calculation, but this calculation must be done only once for a particular molecule; then the results can be stored. In its final form, it uses individual atoms as the building blocks for predicting phase equilibria instead of functional groups. This model formulation provides a considerably larger range of applicability than group-contribution methods. The calculation for liquid nonideality is only slightly more computationally intensive than activity-coefficient models such as NRTL or UNIQUAC. Cosmo-
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 and 52: Parameter Name/Element PRKBV/1 k ij
Page 53 and 54: Predictive SRK (PSRK) This model us
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: Therefore, the simplified Pitzer eq
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
Page 107 and 108: 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
Page 119 and 120: Parameter Name/ Element 2 Thermodyn
Page 121 and 122: NRTL-SAC Reference States The NRTL-
Page 123 and 124: 2 Thermodynamic Property Models 121
Page 125 and 126: For an anionic component, we have M
Page 127 and 128: For a molecular segment, the activi
Page 129 and 130: 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
Page 135 and 136: Parameter Name/ Element Symbol Defa
Page 137 and 138: Reference C.-C. Chen and Y. Song, "
Page 139 and 140: Parameter Name GMPTPS, GMPTP1, GMPT
Page 141 and 142: zi = Charge of ion i Subscripts c,
Page 143 and 144:
For option code = 0 (default), the
Page 145 and 146:
and for n-m electrolytes: 2 Thermod
Page 147 and 148:
= 0.00979 Perform the necessary con
Page 149 and 150:
Pitzer, K.S., J.R. Peterson, and L.
Page 151 and 152:
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
Page 159 and 160:
with 2 Thermodynamic Property Model
Page 161 and 162:
G for these pairs is calculated the
Page 163 and 164:
with 2 Thermodynamic Property Model
Page 165 and 166:
2 Thermodynamic Property Models 163
Page 167 and 168:
Activity Coefficient Basis for Henr
Page 169 and 170:
Where is the liquid Gibbs free ener
Page 171 and 172:
Ionic components 2 Thermodynamic Pr
Page 173 and 174:
the pure fused salts. Applying Eq.
Page 175 and 176:
�k is the activity coefficient of
Page 177 and 178:
References U. Weidlich and J. Gmehl
Page 179 and 180:
ti' = �ij 2 Thermodynamic Propert
Page 181 and 182:
Wagner Interaction Parameter The Wa
Page 183 and 184:
References G.M. Wilson, J. Am. Chem
Page 185 and 186:
Extended Antoine Equation Parameter
Page 187 and 188:
IK-CAPE Vapor Pressure Equation The
Page 189 and 190:
Harlacher and Braun, "A Four-Parame
Page 191 and 192:
Parameter Name/Element 2 Thermodyna
Page 193 and 194:
General Pure Component Heat of Vapo
Page 195 and 196:
IK-CAPE Heat of Vaporization Equati
Page 197 and 198:
Where: xp = Mole fraction of pseudo
Page 199 and 200:
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
Page 207 and 208:
Rackett The Rackett equation is: Wh
Page 209 and 210:
Rackett/Campbell-Thodos Mixture Liq
Page 211 and 212:
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
Page 231 and 232:
� 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:
Page 255 and 256:
�i = Viscosity of component i (N-
Page 257 and 258:
Parameter Name/Element 3 Transport
Page 259 and 260:
Where: The Stockmayer or Lennard-Jo
Page 261 and 262:
Where: Vcij = �ij = 0 (in almost
Page 263 and 264:
Where: Vcij = �ij = 0 (in almost
Page 265 and 266:
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
Page 275 and 276:
You must provide parameters for the
Page 277 and 278:
Linear extrapolation of � *,l ver
Page 279 and 280:
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
Page 291 and 292:
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
show all

Aspen Physical Property System - Physical Property Models

Create successful ePaper yourself

Delete template?

Save as template?