Aspen Properties Tutorial

Chen CL 0

Luyben: Distillation Design and Control Using ASPEN Simulation

ASPEN SimulationScenarios-Based Tutorial – 1

Physical Properties

Cheng-Liang Chen

PSELABORATORY

Department of Chemical EngineeringNational TAIWAN University

1

Chen CL 2

OutlinePart 1:

➢ Start-up ASPEN Plus

➢ Physical Properties of Pure Components (Benzene and Toulene)

➢ Binary Vapor-Liquid Equilibrium (Benzene and Toulene)

Part 2:

➢ Distillation Short-cut Design: DSTWU (Benzene and Toulene)

➢ Rigorous Distillation Simulator: RadFrac

☞ Ex: Benzene and Toluene Separation☞ Ex: Propane and iso-Butane Separation

Part 3:➢ Simulation of Multicomponent Nonideal Systems

☞ Ex: Methyl Acetate / Methanol / Water☞ Ex: Ethanol Dehydration☞ Ex: Heat-integrated Columns (Methanol / Water)

Chen CL 3

Start Up

ASPEN Plus

Chen CL 4

Start Up ASPEN Plus

Chen CL 5

Start Up

Chen CL 6

Start Up

Chen CL 7

Physical Properties

of Pure Components

Chen CL 8

Physical Properties of Pure ComponentsBenzene and Toulene

Chen CL 9


Int. system units (SI); English eng. units (ENG); Metric eng. units (MET)

Chen CL 10


Chen CL 11


Chen CL 12


Chen CL 13


Chen CL 14


Chen CL 15


Chao-Seader Pure Component Liquid Fugacity Model

➢ The Chao-Seader model calculates pure component fugacity coefficient, forliquids. It is used in the CHAO-SEA property method.

➢ This is an empirical model with the Curl-Pitzer form. The general form of themodel is:

ln (ϕi) = ln(ν0

i

)+ ωi ln

(ν1

i

)ν0

i , ν1i = fcn (T, Tci; p, pci)

➢ ReferencesK.C. Chao and J.D. Seader, “A General Correlation of Vapor-Liquid Equilibriain Hydrocarbon Mixtures,” AIChE J., Vol. 7, (1961), p. 598.

Chen CL 16


Chen CL 17


Chen CL 18


Chen CL 19


Chen CL 20


Chen CL 21


Chen CL 22


Chen CL 23


Chen CL 24


Chen CL 25


Chen CL 26

Pure Component Properties

➢ On the Pure Component Properties Analysis dialog box, most of the requiredinformation is set to defaults, including:

Item Information

Property Method The global property method is used, as specified on the PropertiesSpecifications Global sheet.You can select any Property Method that appears on the PropertiesSpecifications form.

Temperature The default is a temperature range from 0 to 25oC.You can enter a new range by modifying lower and upper temperatures, oryou can change from a temperature range to a temperature list, and specifya list of discreet temperature values.

Number of pointsto be tabulated

The default is 41 points.You can change the number of points, or enter a temperature increment

Pressure The default is 1 atm.You must change the default for vapor properties, for liquid properties nearthe critical point, and properties generated from EOS property methods

Chen CL 27

Available Thermodynamic/Transport Properties

Item Property Item PropertyAVAIL Availability, H − T0S GIG (Ideal gas) Free energyCP Constant pressure heat capacity H EnthalpyCPCV Heat capacity ratio PHI Fugacity coefficientCV Constant volume heat capacity PHIPC Fugacity coef, pressure cor.DG Free energy departure PL Vapor pressureDGPC Free energy dep, pressure cor. RHO DensityDH Enthalpy departure S EntropyDHPC Enthalpy dep, pressure cor. V VolumeDHVL Enthalpy of vaporization SONVEL Sonic velocityDS Entropy departure U Internal energyK Thermal conductivity SIGMA Surface tensionMU Viscosity

Chen CL 28

Physical Properties of Pure ComponentsBenzene

Chen CL 29


Chen CL 30


Chen CL 31


ln(PS

)= C +

D

T

Chen CL 32

Physical Properties inAspen Physical Property System

The following properties may be required by Aspen Physical Property Systemcalculations:

➢ Thermodynamic Properties

➢ Fugacity coefficients (for K values)

➢ Enthalpy

➢ Entropy

➢ Gibbs energy

➢ Molar volume

➢ Transport Properties

➢ Viscosity

➢ Thermal conductivity

➢ Diffusion coefficient

➢ Surface tension

Chen CL 33


➢ The properties required by unit operation models in the Aspen Physical PropertySystem are called major properties and are listed in the table labeled MajorProperties in Aspen Physical Property System.

➢ A major property may depend on other major properties.In addition, a major property may depend on other properties that are not majorproperties. These other properties can be divided into two categories:

subordinate properties and intermediate properties.

➢ Subordinate properties may depend on other major, subordinate or intermediateproperties, but are not directly required for unit operation model calculations.

➢ Examples of subordinate properties are enthalpy departure and excess enthalpy.

➢ The table labeled Subordinate Properties in Aspen Physical Property Systemlists the subordinate properties.

Chen CL 34


➢ The properties required by unit operation models in the Aspen Physical PropertySystem are called major properties and are listed in the table labeled MajorProperties in Aspen Physical Property System.

➢ A major property may depend on other major properties.In addition, a major property may depend on other properties that are not majorproperties. These other properties can be divided into two categories:

subordinate properties and intermediate properties.

➢ Intermediate properties are calculated directly by property models, rather thanas fundamental combinations of other properties.

➢ Common examples of intermediate properties are vapor pressure and activitycoefficients.

➢ The table labeled Intermediate Properties in Aspen Physical Property Systemlists the intermediate properties.

➢ Major and subordinate properties are obtained by a method evaluation.Intermediate properties are obtained by a model evaluation.

Chen CL 35

Major Properties inAspen Physical Property System

Prop Name Symbol Description

PHlV ϕ∗,vi Vapor pure component fugacity coefficient

PHIL ϕ∗,li Liquid pure component fugacity coefficient

PHlS ϕ∗,si Solid pure component fugacity coefficient

PHlV ϕvi Vapor fugacity coefficient of a component in a mixture

PHlLMX ϕli Liquid fugacity coefficient of a component in a mixture

PHlSMX ϕsi Solid fugacity coefficient of a component in a mixture

HV H∗,vi Vapor pure component molar enthalpy

HL H∗,li Liquid pure component molar enthalpy

HS H∗,si Solid pure component molar enthalpy

HVMX Hvm Vapor mixture molar enthalpy

HLMX Hlm Liquid mixture molar enthalpy

HSMX Hsm Solid mixture molar enthalpy

GV µ∗,vi Vapor pure component molar Gibbs free energy

GL µ∗,li Liquid pure component molar Gibbs free energy

GS µ∗,si Solid pure component molar Gibbs free energy

GVMX Gvm Vapor mixture molar Gibbs free energy

GLMX Glm Liquid mixture molar Gibbs free energy

GSMX Gsm Solid mixture molar Gibbs free energy

SV S∗,vi Vapor pure component molar entropy

SL S∗,li Liquid pure component molar entropy

SS S∗,si Solid pure component molar entropy

SVMX Svm Vapor mixture molar entropy

SLMX Slm Liquid mixture molar entropy

SSMX Ssm Solid mixture molar entropy

Chen CL 36

Major Properties inAspen Physical Property System


VV V∗,vi Vapor pure component molar volume

VL V∗,li Liquid pure component molar volume

VS V∗,si Solid pure component molar volume

VVMX V vm Vapor mixture molar volume

VLMX V lm Liquid mixture molar volume

VSMX V sm Solid mixture molar volume

MUV η∗,vi Vapor pure component viscosity

MUL η∗,li Liquid pure component viscosity

MUVMX µv Vapor mixture viscosity

MULMX µl Liquid mixture viscosityKV λ

∗,vi Vapor pure component thermal conductivity

KL λ∗,li Liquid pure component thermal conductivity

KS λ∗,si Solid pure component thermal conductivity

KVMX λv Vapor mixture thermal conductivity

KLMX λl Liquid mixture thermal conductivityKSMX λs Solid mixture thermal conductivityDV Dv

ij Vapor binary diffusion coefficient

DL Dlij Liquid binary diffusion coefficient

DVMX Dvi Vapor diffusion coefficient of a component in a mixture

DLMX Dli Liquid diffusion coefficient of a component in a mixture

SIGL σ∗,li Pure component surface tension

SIGLMX σl Mixture surface tension

Chen CL 37

Subordinate Properties inAspen Physical Property System


DHV H∗,vi −H

∗,igi Vapor pure component molar enthalpy departure

DHL H∗,li −H

∗,igi Liquid pure component molar enthalpy departure

DHS H∗,si −H

∗,igi Solid pure component molar enthalpy departure

DHVMX Hvm −H ig

m Vapor mixture molar enthalpy departure

DHLMX Hlm −H ig

m Liquid mixture molar enthalpy departure

DHSMX Hsm −H ig

m Solid mixture molar enthalpy departureDHVPC H

∗,vi (p)−H

∗,vi (p∗i ) Vapor pure component molar enthalpy departure pressure correction

DHLPC H∗,li (p)−H

∗,li (p∗i ) Liquid pure component molar enthalpy departure pressure correction

DHSPC H∗,si (p)−H

∗,si (p∗i ) Solid pure component molar enthalpy departure pressure correction

DGV µ∗,vi − µ

∗,igi Vapor pure component molar Gibbs energy departure

DGL µ∗,li − µ

∗,igi Liquid pure component molar Gibbs energy departure

DGS µ∗,si − µ

∗,igi Solid pure component molar Gibbs energy departure

DGVMX Gvm −Gig

m Vapor mixture molar Gibbs energy departure

DGLMX Glm −Gig

m Liquid mixture molar Gibbs energy departure

DGSMX Gsm −Gig

m Solid mixture molar Gibbs energy departureDGVPC µ

∗,vi (p)− µ

∗,vi (p∗i ) Vapor pure component molar Gibbs energy departure pressure correction

DGLPC µ∗,li (p)− µ

∗,li (p∗i ) Liquid pure component molar Gibbs energy departure pressure correction

DGSPC µ∗,si (p)− µ

∗,si (p∗i ) Solid pure component molar Gibbs energy departure pressure correction

DSV s∗,vi − s

∗,igi Vapor pure component molar entropy departure

DSL s∗,li − s

∗,igi Liquid pure component molar entropy departure

DSS s∗,si − s

∗,igi Solid pure component molar entropy departure

Chen CL 38

Subordinate Properties inAspen Physical Property System


DSVMX svm − sig

m Vapor mixture molar entropy departure

DSLMX slm − sig

m Liquid mixture molar entropy departure

DSSMX ssm − sig

m Solid mixture molar entropy departureHNRY HiA Henry’s constant of supercritical component i in subcritical component A

HLXS HE,lm Liquid mixture molar excess enthalpy

HSXS HE,sm Solid mixture molar excess enthalpy

GLXS GE,lm Liquid mixture molar excess Gibbs energy

GSXS GE,sm Solid mixture molar excess Gibbs energy

PHILPC θ∗,l Pure component liquid fugacity coefficient pressure correctionPHISPC θ∗,s Pure component solid fugacity coefficient pressure correction

GAMPC θE Liquid activity coefficient pressure correction, symmetric convention

GAMPC1 θ∗E Liquid activity coefficient pressure correction, asymmetric convention

HNRYPC θPciA

Henry’s constant pressure correction for supercritical component iXTRUE xt True composition. in subcritical component AMUVLP η

∗,vi (p = 0) Pure component low pressure vapor viscosity

MUVPC η∗,vi (p)− η

∗,vi (p = 0) Pure component vapor viscosity pressure correction

MUVMXLP ηv(p = 0) Low pressure vapor mixture viscosityMUVMXPC ηv(p)− ηv(p = 0) Vapor mixture viscosity pressure correctionKVLP λ

∗,vi (p = 0) Pure component low pressure vapor thermal conductivity

KVLP λv(p)− λv(p = 0) Pure component vapor thermal conductivity pressure correctionKVMXLP λ

∗,vi (p = 0) Low pressure, vapor mixture thermal conductivity

KVMXPC λv(p)− λv(p = 0) Vapor mixture thermal conductivity pressure correction

Chen CL 39

Intermediate Properties inAspen Physical Property System


GAMMA γ Liquid phase activity coefficientGAMUS γ∗ Liquid phase activity coefficient, unsymmetric conventionGAMMAS γs Solid phase activity coefficientWHNRY w Henry’s constant mixing rule weighting factor

PL p∗,li Liquid pure component vapor pressure

PS p∗,si Solid pure component vapor pressure

DHVL ∆vapH∗i Pure component enthalpy of vaporization

DHLS ∆fusH∗i Pure component enthalpy of fusion

DHVS ∆subH∗i Pure component enthalpy of sublimation

VLPM V li Partial molar liquid volume

Chen CL 40

Vapor Pressure Models for Pure Liquids

➢ The Aspen Physical Property System has several submodels for calculating vaporpressure of a liquid.

It uses parameter THRSWT/3 to determine which submodel is used.

If THRSWT/3 is Then this equation is used

0 Extended Antoine

200 BARIN

301 Wagner

302 PPDS Modified Wagner

400 PML

401 IK-CAPE

501 NIST TDE Polynomial

502 NIST Wagner 25

See Pure Component Temperature-Dependent Properties for details.

Chen CL 41

Vapor Pressure Models for Pure LiquidsExtended Antoine Equation

➢ Parameters for many components are available for the extended Antoine equationfrom the Aspen Physical Property System pure component databank.

➢ This equation can be used whenever the parameter PLXANT is available.

➢ The equation for the extended Antoine vapor pressure model is:

ln(p∗,li ) = C1i +C2i

T + C3i+ C4i + C5i ln(T ) + C6iT

C7i for C8i ≤ T ≤ C9i

➢ Default values are zero for C3i, . . . , C8i; 1000 for C9i

Chen CL 42

Thermodynamic Properties ModelModel Model Name Phase Properties

Antoine/Wagner PL0XANT L L1 L2 PLAPI liquid volume VL2API L VLMXAqueous Electrolyte NRTL Enthalpy HAQELC L HLMXAqueous Electrolyte NRTL Gibbs Energy GAQELC L GLMXASME Steam Tables ESH2O0, ESH2O V L +Brelvi O’Connell VL1BROC L VLPMBromley Pitzer GMPT2 L GAMMABromley Pitzer Enthalpy HAQPT2 L HLMXBromley Pitzer Gibbs Energy GAQPT2 L GLMXBWR Lee Starling ESBWR0, ESCSTBWR V L +,++Cavett Liquid Enthalpy Departure DHL0CVT, DHL2CVT L DHL,DHLMXChao Seader PHL0CS L PHILClarke Aqueous Electrolyte Density VAQCLK L VLMXConstant Activity Coefficient GMCONS S GAMMACostald Liquid Volume VL0CTD,VL2CTD L VL,VLMXCOSMO-SAC COSMOSAC L GAMMADebye Huckel Volume VAQDH L VLMXDIPPR Liquid Heat Capacity HL0DIP, DHL0DIP L HL, DHLElectrolyte NRTL GMENRTL L L1 L2 GAMMAElectrolyte NRTL Enthalpy HMXENRTL L HLMXElectrolyte NRTL Gibbs Energy GMXENRTL L GLMXENRTL-SAC (patent pending) ENRTLSAC L GAMMAGrayson Streed PHL0GS L PHILHayden O’Connell ESHOC0, ESHOC V +, ++

+ A pure component equation of state model calculates: PHIL,PHIV,DHL,DHV,DGL,DGV,DSL,DSV,VL,VV

++ A mixture equation of state model calculates:PHILMX,PHIVMX,DHLMX,DHVMX,DGLMX,DGVMX,DSLMX,DSVMX,VLMX,VVMX

+++ DHLMX,DHVMX,DGLMX,DGVMX,DSLMX,DSVMX,VLMX,VVMX

Chen CL 43


Henry’s constant HENRY1 L HNRY,WHNRYHF equation of state ESHF0, ESHF V +,++Ideal Gas ESIG0, ESIG V +,++Kent Eisenberg ESAMIN L PHILMX, GLMX, HLMX, SLMXLee Kesler ESLK V L +++Lee Kesler Plocker ESLKP0, ESLKP V L +,++Modified UNIFAC Dortmund GMUFDMD L L1 L2 GAMMANBS/NCR Steam Tables ESSTEAM0, ESSTEAM V L +,++Nothnagel ESNTH0, ESNTH V +,++NRTL (Non Random Two Liquid) GMRENON L GAMMANRTL-SAC (patent pending) NRTLSAC L GAMMAPeng Robinson Boston Mathias ESPR0, ESPR V L +,++Pitzer GMPT1 L GAMMAPitzer Enthalpy HAQPT1 L HLMXPitzer Gibbs Energy GAQPT1 L GLMXPolynomial Activity Coefficient GMPOLY L S GAMMAPredictive SRK ESRKSV10, ESRKSV1 V L +++Peng Robinson Wong Sandler ESPRWS0, ESPRWS V L +++Peng Robinson MHV2 ESPRV20, ESPRV2 V L +++




Chen CL 44


Rackett / DIPPR Liquid Density VL0RKT, VL2RKT L VL VLMXRedlich Kister GMREDKIS L S GAMMARedlich Kwong ESRK0, ESRK V +,++Redlich Kwong Soave Boston Mathias ESRKS0, ESRKS V L +,++Redlich Kwong Aspen ESRKA0, ESRKA V L +,++RKS MHV2 ESRKSV20, ESRKSV2 V L +++RKS Wong Sandler ESRKWSWS0, ESRKSWS V L +++Schwartzentruber Renon ESRKU0, ESRKU V L +,++Scatchard Hildebrand GMXSH L GAMMASolids Heat Capacity Polynomial HS0POLY S HSSolids Volume Polynomial VS0POLY S VSStandard Peng Robinson ESPRSTD0, ESPRSTD V L +,++Standard Redlich Kwong Soave ESRKSTD0, ESRKSTD V L +,++Three Suffix Margules GMMARGUL L S GAMMAUNIFAC GMUFAC L L1 L2 GAMMAUNIQUAC GMUQUAC L L1 L2 GAMMAVan Laar GMVLAAR L GAMMAWagner interaction parameter GMWIP S GAMMAWatson / DIPPR DHVLWTSN L DHVLWilson GMWILSON L GAMMA




Chen CL 45

Thermodynamic Properties Model

Chen CL 46

Binary Vapor-Liquid Equilibrium

Phase Diagram

Chen CL 47

Vapor Pressure

➢ Vapor pressure is a physical property of a pure chemical component.

It is the pressure that a pure component exerts at a given

temperature when both liquid and vapor phases are present.

➢ Vapor pressure depends only on temperature.

Figure 1.1a gives vapor pressure curves for benzene and toluene.

([PS

]: mmHg; [T ] : Kelvin)

Chen CL 48

Vapor Pressure

➢ Vapor pressure is a physical property of a pure chemical component.

It is the pressure that a pure component exerts at a given

temperature when both liquid and vapor phases are present.

➢ Vapor pressure depends only on temperature.

Figure 1.1a gives vapor pressure curves for benzene and toluene.

([PS

]: mmHg; [T ] : Kelvin)

Chen CL 49

Binary VLE Phase DiagramBenzene and Toulene

Chen CL 50


Chen CL 51


Chen CL 52


Chen CL 53


Chen CL 54


Chen CL 55


Chen CL 56


Chen CL 57


Chen CL 58


Chen CL 59


Chen CL 60

VLE Nonideality

➢ Liquid-phase ideality (activity coefficients γj = 1) occurs only when thecomponents are quite similar.The benzene/toluene system is a common example.

➢ If components are dissimilar, nonideal behavior occurs.

➢ Consider a mixture of methanol and water.Water is very polar. Methanol is polar on the OH end of the molecule, but theCH3 end is nonpolar. This results in some nonideality.

Chen CL 61

VLE Nonideality

➢ Consider a mixture of ethanol and water.

➢ The CH3-CH2 end of the ethanol molecule is more nonpolar than the CH3 endof methanol.

➢ Note that the activity coefficient of ethanol at the x = 0 end (pure water) is verylarge (γEtOH = 6.75) and also that the xy curve crosses the 45o line (x = y) at∼ 90 mol% ethanol.This indicates the presence of an azeotrope.

➢ Note also that the temperature at the azeotrope (351.0 K) is lower than theboiling point of ethanol (351.5 K).

Chen CL 62

VLE Nonideality

➢ The ethanol/water azeotrope is a minimum-boiling homogeneous azeotrope.

➢ Step 1: Setup Property Analysis, Property Estimation (UNIFAC)

Chen CL 63

VLE Nonideality


➢ Step 2: Components Specification (find Water and Ethanol)

Chen CL 64

VLE Nonideality


➢ Step 3: Tools → Conceptual Design → Azeotrope Search

Chen CL 65

VLE Nonideality


➢ Step 4: Azeotrope → Report

Chen CL 66

Thank You for Your Attention

Questions Are Welcome

Documents

Aspen Properties Tutorial