masakazu sasaki toyo engineering corporation toyo engineering corporation sse-02 a study of pro/ii...

© 2012 TOYO ENGINEERING CORPORATION

　　　　 Masakazu Sasaki 　　　　　　 Toyo Engineering Corporation

SSE-02A Study of PRO/II® Liquid Density

Models for Effective Usage of Thermo.

SSE-02A Study of PRO/II® Liquid Density

Models for Effective Usage of Thermo.

1

NA 2012 User Group Series: SimSci-Esscor, IntelaTrac & Tech Support Symposium

Houston, USAOctober 14-16, 2012

© 2012 TOYO ENGINEERING CORPORATION 2

　　 Backgrounds and Objectives for This Study

Summary for Major Liquid Density Estimation Models

provided by PRO/II Thermo Package

Validation of PRO/II Model for Pure Hydrocarbons

and Hydrocarbon Mixture

Validation of PRO/II Model for Pure Methanol, Pure

Water and those Mixtures

Conclusion

Agenda

© 2012 TOYO ENGINEERING CORPORATION 3- 3 -

Backgrounds and Objectives for This Study

This study is a fundamental study to confirm prediction accuracy of liquid density of the commercial simulator, PRO/II®. Density is one of key physical property for equipment sizing. In addition, actual liquid density is related to calculation of hydraulic head and power of pump as the below. , , w : mass flow rate Therefore, we may say that liquid density is related to not only equipment sizing, but also power consumption and mass & heat balance calculation. The following applications were taken as the assumed target business applications for this study. I) Mixtures of hydrocarbon liquid, water liquid, and additional chemicals like gas hydrate equilibrium inhibitors. The assumed operation pressure range is high. II) Chemical Applications. In this study, Purification section of methanol plant was assumed as the application. The assumed pressure range is low and or moderate.


Summary for Major Liquid Density Estimation Models provided by PRO/II Thermo Package

　　 Applied for User Tuning Parameters

　　Hydrocarbon Non-H/C Excess Volume Pure Mixture

EOS

CubicPeneloux Volume Shift possible probably possible possible available available

Virial Expansion

LKP possibleunknown but

doubtful partially possibleIn general, user shall not modify the parameters.

available

BWRS possible partially possible partially possible available available

Reference EOSREFPROP, IAPWS IF-97 possible possible possible

In general, user shall not modify the parameters.

Generalized

API possible partially possibleunknown but no tuning params. available NA

Rackett, COSTALD (HBT correlation) possible partially possible

possible but no tuning params. available NA

LK possibleunknown but

doubtfulunkown but no tuning params.

In general, user shall not modify the parameters.

NA

LibraryTemperature Polynomial Correlation

possible possibleunknown but no tuning params. available NA

OthersAPI correlation (API Technical Data Book)

Applied for petroleum pseudo components mixture


Applied Ｔｏｏｌｓ in This Study

PRO/II 9.0.1 (main tool for this evaluation work) NIST REFPROP 8.0 (as bench mark) PRO/II 9.1.1 (confirmation of Invensys’s update for Peneloux model for water density)


Validation of PRO/II Model for Pure Hydrocarbons and Hydrocarbon Mixtures

Remarks : 5 – 90 degC ( 0.752 <Tr < 0.982) for propane

Testing of Pure Hydrocarbons

Remarks : 5 – 230 degC (0.548<Tr<0.992) for n-hexane

0.750 0.800 0.850 0.900 0.950 1.000 250

300

350

400

450

500

550

Fig. Saturated Liquid Density of Propane

RACKETT

COSTALD

LK

API

Peneloux

BWRS

SRKM

REFPROP V8.0

Tr [-]

Den

sity

[kg

/m3]

0.550 0.600 0.650 0.700 0.750 0.800 0.850 0.900 0.950 1.000 250

300

350

400

450

500

550

600

650

700

750Fig. Saturated Liquid Density of n-Hexane

RACKETTCOSTALDLKAPIPenelouxBWRSSRKMREFPROP V8.0

Tr [-]

Den

sity

[kg

/m3]



Propane For light hydrocarbon (liquefied gas), LK (probably LKP also) would be better choice as we had understood so. BWRS would be alternative choice instead of LK(LKP). COSTALD also showed good results. API shows good agreement up to 0.9 of Tr, but it is recognized that API shows poor results at lower chilled temperature range.n-Hexane API, BWRS and COSTALD showed good agreements. But , LK shows poor agreements. It was my surprise because LKP (probably LK also) used nC8 as a reference component in its thermodynamic framework.

Summary for Pure HydrocarbonsAgreements with REFPROP V.8.0 (Bench Mark)

　　　　 C3 nC6COSTALD GOOD GOOD

APIGOOD (up to

Tr=0.9)GOOD (up to Tr=0.9)

BWRS GOOD - FAIR GODD (Up to Tr=0.93)LK (including LKP)

GOOD - FAIR POOR

Peneloux FAIR - POOR POOR

RackettBAD (above

Tr=0.75)GOOD (up to Tr=0.75)

SRKM BAD BAD



For both compounds, PRO/II Rackett shows far from bench mark above Tr=0.75. It is due to calculation formula of T i for Tri >0.75 the above second equation. This formula is not described in the original paper of Dr. Cal Spencer. In addition, other major simulators do not show such strange behavior. Therefore, Invensys should confirm the original source of this formula and add kill option of this equation from Rackett model.

Summary for Pure HydrocarbonsRackett

Peneloux

It does not match my prediction before the ending of this testing, Peneloux did not show good agreement with the bench mark. Peneloux might focus on lower temperature range. Invensys shall try to do more turning based on temperature dependency volume shift parameters, or users might need further tuning because thermodynamic framework of Peneloux volume shit methodology must not be bad.

Ref: PRO/II 9.0 reference Manual (Volume I)



Testing of Hydrocarbon Mixture

For this testing, the following conditions were taken.

System : Propane – n- Hexane Temperature : 80 degC and 120 degC Pressure : Saturated bubble point pressures Bench Mark : NIST23 on PRO/II 9.0.1 K value model (including bench mark model (NIST23 )) : SRKM EOS with Invensys default kij



0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1300

350

400

450

500

550

600

650

Fig. Saturated Liquid Density of C3-nC6 Mixture at 80degC

Rackett

COSTALD

LK

API

Peneloux

BWRS

Library

NIST23

molefraction of propane

Liqu

id d

ensi

ty [k

g/m

3]

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1250

300

350

400

450

500

550

600

Fig. Saturated Liquid Density of C3-nC6 Mixture at 120degC

Rackett

COSTALD

LK

API

Peneloux

BWRS

Library

NIST23

molefraction of propane

Liqu

id d

ensi

ty [k

g/m

3]



Summary for C3 – nC6 Mixture

API shows good results except near critical point at this testing conditions.The next favorite model might be LK and LKP. Probably, if temperature dependent volume shift parameter and temperature dependent interaction parameter of Peneloux would be introduced or disclosed to user, the accuracy of Peneloux could be increased.

Agreements with PRO/II NIST23 (Bench Mark)　　COSTALD FAIRAPI GOOD (except near Critical Point)BWRS FAIR - POORLK (including LKP) FAIR - POORPeneloux FAIR - POORRackett POORLibrary BAD



Intrinsic Trouble of Mixing Rule of HBT ( COSTALD) for Liquefied Hydrocarbon Mixture

Ref: Poling B.E. et al., The Properties of Gases and Liquids, 5 th Ed. (2001)

Unable to handle by HBT (COSTALD)


Validation of PRO/II Model for Pure Methanol, Pure Water and those Mixtures

Testing of Pure Methanol

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1400

500

600

700

800

900

1000

Fig. Saturated Liquid Density of Methanol (-90 ~ 230 degC)

LIB (DB=PROCESS)

COSTALD

RACKETT

API

LK

Peneloux

REFPROP V8.0 / NIST23

Tr [-]

De

nsi

ty [k

g/m

3]



Testing of Pure Methanol

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-20.00%

-15.00%

-10.00%

-5.00%

0.00%

5.00%

10.00%

15.00%

20.00%Fig. Percent Deviation to REFPROP / NIST23

COSTALDRACKETTAPILKPeneloux

Tr

Pe

rce

nt D

evi

atio

n to

NIS

T2

3

Agreements with PRO/II NIST23 / REFPROP V.8.0(Bench Mark)　　

COSTALDGOOD - FAIR (but, further user tuning was done for wide

range)

PenelouxGOOD - FAIR (but, further user tuning required for wide

range)API GOOD - FAIRLK (including LKP) POORRackett GOOD (up to Tr = 0.75)



COSTALD Parameter Tuning of Pure Methanol

-100 -50 0 50 100 150 200 250400

500

600

700

800

900

1000Fig. Liquid Density of Methanol at Satulated Conditions

REFPROPCorrelated results and Excel ResultsP2 with Modified PrametersP2 with Original Params

Temperature [degC]

Dens

ity [k

g/m

3]

Tc(HBT) 513.18 KVc 0.100717 m3/kgmolOmega -0.25911Mw 32.042Tc(True) 513.15

0.4 0.5 0.6 0.7 0.8 0.9 1-5.00%

-4.00%

-3.00%

-2.00%

-1.00%

0.00%

1.00%

2.00%

3.00%

4.00%

5.00%Fig. Percent Deviation to REFPROP / NIST23 of COSTALD

Original

Fitting

Tr [-]

Per

cent

Dev

iatio

n to

NIS

T23




Testing of Pure Water

0.4 0.5 0.6 0.7 0.8 0.9 1500

600

700

800

900

1000

1100Fig. Saturated Liquid Density of Water (5 - 350degC)

LIB

COSTALD

RACKETT

API

LK

Peneloux

REFPROP V8.0 / NIST23

Tr [-]

De

nsi

ty [k

g/m

3]



Testing of Pure Water

0.4 0.5 0.6 0.7 0.8 0.9 1-20.00%

-15.00%

-10.00%

-5.00%

0.00%

5.00%

10.00%

15.00%

20.00%Fig. Percent Deviation to REFPROP / NIST23

COSTALD RACKETT API

LK Peneloux

Tr [-]

Pe

rce

nt D

evi

atio

n to

NIS

T2

3

Agreements with PRO/II NIST23 / REFPROP V.8.0(Bench Mark)　　

COSTALDGOOD - FAIR (but, further user tuning was done for wide

range)Peneloux FAIR-POOR (However, accuracy was drastically impoved at PRO/II 9.1.1)

API FAIR - BADLK (including LKP) BADRackett FAIR (up tp Tr = 0.75)



COSTALD Parameter Tuning of Pure Water

0 50 100 150 200 250 300 350500

600

700

800

900

1000

1100Fig. Liquid Density of Water at Satulated Conditions

REFPROP / NIST23Correlated results and Excel ResultsP2 with Modified PrametersP2 with Original Params

Temperature [degC]

Dens

ity [k

g/m

3]


0.4 0.5 0.6 0.7 0.8 0.9 1-5.000%

-4.000%

-3.000%

-2.000%

-1.000%

0.000%

1.000%

2.000%

3.000%

4.000%

5.000%Fig. Percent Deviation to REFPROP V8.0 / NIST23

Original

Fitting

Tr

Per

cent

Dev

iatio

n to

NIS

T23




Testing of Methanol – Water Mixture

Author(s): Dizechi,M.; Marshall,E.Titel: Viscosity of Some Binary and Ternary Liquid MixturesJournal: J. Chem. Eng. DataLanguage: englishCODEN: JCEAAXISSN: 0021-9568Volume: 27published: 1982Pages: 358-363

Bench Mark : Experimental Data of Dizechi and Marshall (1982) at 30 and 50 degC



Extension of COSTALD Mixing Rule for Correlation of Excess Volume of Mixing

𝑇 𝐶𝑖𝑗=(1−𝒌𝒊𝒋 )¿

Original Mixing Rule of COSTALD : REF PRO/II Reference Help on PRO/II 9.1.1

The fitting parameter, kij was introduced as the below.



Correlation of Excess Volume of Mixing using COSTALD

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1750

800

850

900

950

1000

1050Fig. Liquid Density of Methanol Aqueous Solution at 323.15K

Dizechi et al. (1982)

COSTALD (kij=0)

COSTALD (kij=-0.2775)

mole fraction of Methanol [-]

Liqu

id D

ensi

ty [k

g/m

3]

Methanol WaterTc [K] 513.18 647.35 kij= -0.277502088Vc [m3/kgmol] 0.100717 0.038315 lij= 0Omega [-] -0.25911 -1.31616Mw [kg/kgmol] 32.042 18.015

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1750

800

850

900

950

1000

1050Fig. Liquid Density of Methanol Aqueous Solution at 303.15K

Dizechi et al. (1982)COSTALD (kij=-0.2775)

mole fraction of Methanol[-]

Liqu

id D

ensi

ty [k

g/m

3]

Methanol WaterTc [K] 513.18 647.35 kij= -0.277502088Vc [m3/kgmol] 0.100717 0.038315 lij= 0Omega [-] -0.25911 -1.31616Mw [kg/kgmol] 32.042 18.015



Correlation of Excess Volume of Mixing using Peneloux

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1700

750

800

850

900

950

1000

1050 Fig. Liquid Density of Methanol Aqueous Solution at 323.15K

Dizechi et al. (1982)

LIB

API

NIST23

Rackett

Peneloux without tune

Peneloux with mod params 1)

mole fraction of Methanol [-]

Liqu

id D

ensi

ty [k

g/m

3]

1) Peneloux Methanol : 0.007 m3/kgmol Water : 0.00336 m3/kgmol kij = -0.35


Conclusion

According to model framework and this study, Peneloux showed high flexibility and potential for mixture of hydrocarbons, mixture of water and chemicals and mixture of two phase liquids. However, temperature dependent Peneloux Volume Shift parameters and temperature dependent kij should be disclosed user and user may try to make tuning.

For chemical applications (non-hydrocarbons, relatively lower pressure range and relatively low amounts of dissolved gaseous compounds), COSTALD and Rackett might be good. Fitting binary parameter on those one fluid mixing rule is newly required for correlation of excess volume. Of course, the trouble on Rackett should be fixed.

For conventional hydrocarbon mixtures, API, LK, LKP and BWRS are better choices according to existing criteria for model selection.

NIST REPROP would be the most powerful tool if all of concerned pure compounds and those mixture were registered.

For describing excess volume, one idea is to add a simple and flexible mixing rule in Library method.

masakazu sasaki toyo engineering corporation toyo engineering corporation sse-02 a study of pro/ii...

Documents

study proii

tuning params

proii thermo packageapplied

bench mark proii

pure water

water density

pure methanol

pure hydrocarbons