OLI Simulation Conference 2016

Conference organization by

Advances in Electrolyte Thermodynamics

Peiming Wang, Margaret Lencka, Ronald Springer, Jerzy Kosinski, Jiangping Liu, Ali Eslamimanesh, Gaurav Das, and Andre Anderko

Scope

• Structure of OLI’s thermodynamic models

• Progress in thermodynamic modeling • Results for selected chemistries

• How predictive can we be?

• Dielectric constant

• Status of databanks

• Plans for the future

Structure of Thermophysical Property Frameworks

Electrical conductivity

Viscosity

Aqueous (AQ) Framework Mixed-Solvent Electrolyte (MSE) Framework

Self-diffusivity

Thermal conductivity

Surface tension

Interfacial tension

Dielectric constant

MSE thermodynamics

Standard state: HKF EOS (direct)

GEX: MSE No concentration limit

Solids: Thermochemical

properties

Gas phase: SRK equation of state

2nd liquid phase: MSE GEX model (same as for

aqueous phase)

Interfacial phenomena: Ion exchange, surface

complexation, molecular adsorption

AQ thermodynamics Standard state: HKF

EOS (via fitting equations as default)

GEX: Bromley-Zemaitis I < 30 m; xorg < 0.3

Solids: Equilibrium constants

for SLE

Gas phase: SRK equation of state

2nd liquid phase: SRK EOS (same as for gas

phase)

Interfacial phenomena: Ion exchange, surface

complexation, molecular adsorption

Other properties Other properties

Electrical conductivity

Viscosity

Self-diffusivity

Progress in Thermodynamic Modeling: Inorganic systems

• Actinide chemistry • U(IV, VI), Np(IV, V, VI), Pu(III, IV, V, VI), Am(III), Cm(III)

• Oxides, hydroxides, carbonates, chlorides, nitrates

• Redox

• Surface complexation on MnOx

• Rare-earth element chemistry • REE chlorides, sulfates, carbonates, phosphates,

hydroxides, acetates, citrates, gluconates

• Transition metal chemistry • Ru, Rh, Tc fundamental chemistry

• Ag nitrate, sulfate systems

• Ni sulfate systems

Progress in Thermodynamic Modeling: Inorganic systems

• Post-transition metal chemistry • Pb silicate, molybdate, tungstate, acetate, formate, nitrate • Al nitrate and sulfate with corresponding acids • AlF3 - NaF

• Tellurium chemistry • Oxides, hydroxides, nitrates, compounds with Na, Zr, Mo

• Silicate chemistry • Na aluminosilicates, Ca, Mg, Zn, Al, Pb silicates

• Sodium phosphate chemistry

• Chemistry of solutes in CO2 environments • S0, NOx, SOx in CO2

• High-pressure, high-temperature scaling • BaSO4, CaCO3

Progress in Thermodynamic Modeling: Inorganic systems

• C – N – H chemistry • Melamine, melam, ammeline, ammelide, cyanuric acid • Cyanate chemistry

• Chelant chemistry • EDTA and IDA

• Potash chemistry • K2SO4 – KCl • Li2SO4

• Other salts • NaBr • Revisions of Sr – SO4 – CO2 chemistry • Revisions of FeS and FeCO3 chemistry

Progress in Thermodynamic Modeling: Organic systems

• Hydrocarbon chemistry • PVT properties of hydrocarbons • Methanol-hydrocarbon systems • CO2 – hydrocarbon – H2O systems • H2S – hydrocarbon – H2O systems • Methane – higher hydrocarbon systems • Methane – H2O – salt mixtures

• Organic acid chemistry • Maleic acid and anhydride • Acetic and formic acids with hydrocarbons

• Monoethylene glycol chemistry refinements • PVT properties • Effect on SrSO4, FeSO4, FeCO3

Thermodynamics of Actinides • Trivalent actinides

show similar phase behavior

• Weak complexation with Cl-

• Moderate increase in solubility due to Cl complexation

• Model is consistent with both solubility and TRLFS speciation data

Solubility of Am(OH)3

as a function of pH and Cl-

Speciation of Cm(III)

as a function of Cl-

Thermodynamics of Actinides • Dual effect of CO3/HCO3

• Strong complexation

• Formation of carbonate solids

Speciation of Cm(III) as a function of CO3/HCO3

Solubility of Am

as a function of pH and CO2

How does redox affect solubility? Behavior of Np(VI)

Np(VI) is unstable in acidic and neutral environments

May be easily reduced to Np(V) and Np(IV)

Solubility and speciation calculated by including redox equilibria

At near-neutral conditions, Np(V) predominates (red lines)

solubility of Np(VI) is governed by reductive dissolution

At alkaline conditions, Np(VI) predominates (blue lines)

Surface Complexation Np(V) on hausmanite (Mn3O4) in the presence of CO2

• Double-layer surface complexation model • Originally parameterized

for hydrous ferric oxide using AQ bulk thermodynamics

• Applied to actinide sorption on MnO2 (synthetic, biogenic), MnOOH, Mn3O4 using MSE bulk thermodynamics

• Explains relationship between bulk phase and surface speciation

NpO2-Mn3O4·OH0

NpO2+

NpO2OH

NpO2CO3-Mn3O4·OH2-

NpO2(CO3)2-Mn3O4·H2O3-

NpO2(CO3)2-Mn3O4·OH4-

NpO2CO3-

NpO2(CO3)23-

NpO2(CO3)35-

Thermodynamics of Rare Earth Elements

• DOE’s Critical Material Institute • Diversifying supply:

Improving methods to extract REEs from ores and waste

• Recycling and increasing efficiency of materials use

• OLI’s role • Provide tools for

predicting phase and chemical equilibria to optimize new or improved processes

0

2

4

6

8

10

12

14

16

18

20

-70 -40 -10 20 50 80 110 140 170 200

mL

aC

l3

t / oC

Sokolova (1988)Sokolova (1988)Sokolova (1988)Sokolova (1988)Friend (1940)Herkot (1989)Powell (1960)Nikolaev (1971/67/77/78/69)Zhuravlev (1972/74a)Tang (1982)Storozhenko (1988/86)Khutorskoi (1968/68a,b)Sheveleva (1973a,b/58/61/68)Chen, Y. G. (2003)Chen, J. X. (1990)Berecz (1990)Zelikman (1971)Volkov (1970)Zholalieva (1976/78)Alieva (1970)Brunisholz (1969)Petelina (1969)Sergeeva (1976)Voigt (1993)Cui (1997)Fischer (1968)Kost (1980)Li (1995)Liu (1999)Shi (1988)Shirai (1981)Sorokina (1977)Spedding (1977)Wang (2007)Zwietasch (1984)Voigt (1993)Voigt (1993)

LaCl3.H2O

LaCl3.7H2O

LaCl3.3H2O

LaCl3.9H2O

LaCl3.10H2O

Ice

Fundamentals: Phase behavior of LaCl3 – H2O

Thermodynamics of Rare Earth Elements: Application to Bioseparations

• Engineered cell surfaces used to separate REEs from aqueous solutions

• Lanthanide binding tags bind REEs

• Complexing agents are necessary to recover absorbed REEs

• What eluents will work?

* Park et al. Environ. Sci. Technol. 2016, 50 (5), 2735-2742.

Complexation of Tb

• Complexation is necessary to desorb REEs

• Predicted fraction of Tb uncomplexed in solution parallels the observed fraction of Tb that remains bound to the surface

0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50

Fra

cti

on

of

Tb

un

co

mp

lex

ed

Eluent (Na acetate) / mM

System:TbCl3 10 µm

CaCl2 0 or 150 mmNa acetate 0-50 mm

NaCl 10E-3 m

pH = 5

pH = 6.1

pH = 5 + CaCl2

pH = 6.1 + CaCl2

Ca competes with Tb for complexation with acetate.

0

0.2

0.4

0.6

0.8

1

0 5 10 15 20

Fra

cti

on

of

Tb

un

co

mp

lex

ed

Eluent (Na citrate) / µM

System:TbCl3 10 µm

CaCl2 0 or 150 mmNa citrate 0-50 mm

NaCl 10E-3 m

pH = 5 - No CaCl2

pH = 6.1 - No CaCl2

pH = 5 + CaCl2

pH = 6.1 + CaCl2

Ca does not effectively compete with Tb for complexation with citrate.

Acetate is inefficient for desorption and

Ca interferes with desorption

Small concentration of citrate is sufficient

for desorption

Modeling systems containing elemental sulfur

• What are the chemical transformations of SOx, NOx H2S, and O2 in CO2 transportation pipelines?

• Hence, what are the limits of safe operation?

• Part 1: Model the solubility of S0 in CO2-rich phases in order to predict whether solid S0 can drop out

• Systems analyzed: Pure S0, S0 – H2O, S0 – CO2

• Speciation of sulfur

• Species up to S020 have been detected

• S01 through S0

8 have been assumed • S0

8 is dominant at moderate conditions in gas phase

• Lower multimers become prevalent at higher temperatures

• In liquid phase, S08 predominates

• In CO2 phase, solvated S0 – CO2 species appears

S08

Solubility of S0 in CO2

• Two segments of solubility curves at each T corresponding to gas (or gas-like) and liquid (or liquid-like) CO2

• Transition is sharp for subcritical CO2 and gradual for supercritical CO2

1E-07

1E-06

1E-05

1E-04

1E-03

50 100 150 200 250 300 350 400 450

S8, m

ole

fra

cti

on

Pressure, atm

Kennedy and Wieland (1960)

Gu etal (1993)

Serin etal (2010)

Dugstad et al (2015)

Svenningsen et al (2016)

25C

45C

60C

90C

110C

120C

Pushing the Limits of Complexity: NaOH + H3PO4 + H2O

Temperature range:

to 350C

Chemical equilibria

• PO4-3, HPO4

-2,

H2PO4-1, etc.

• Association of

Na+/H2PO4-1

Phase equilibria

• Vapor-liquid

• Solid-liquid, sodium pyrophosphate (T

> 250C)

• Liquid-liquid (T >

270C)

Liquid-Liquid Equilibria at High Temperatures

• Increased ion pairing at high T drives liquid phase demixing

• Lower critical temperature

• LLE depends on the Na/P ratio

• If the solubility drops with T, LLE will not appear

How to Deal with Near-Critical Behavior?

• Classical models do not represent near critical behavior

• Crossover models would not be practical for highly speciated reactive systems

• A local model gives a fully quantitative representation of LLE in the high-T region

Modeling Silicates: Importance of Metastable Phases PbO – SiO2 – H2O

• Multiple competing silicate phases

• Both stable and metastable phases

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E-05 1.E-04 1.E-03 1.E-02

m S

iO2

m PbO

SiO2 amorphous

SiO2 quartz

PbSiO3 alamosite

Pb2SiO4

Pb11Si3O17

PbO yellow

PbO red

SiO2 (quartz)

SiO2 (am)

Pb2SiO4

PbSiO3

Pb11Si3O17

PbO red PbO yellow

25 C 300 C

Mixtures of Hydrocarbons with Acetic Acid

• Reproducing vapor-liquid and liquid-liquid equilibria

• Generalization of parameters for normal alkanes to handle pseudocomponents

-20

-10

0

10

20

30

40

50

60

70

0.2 0.4 0.6 0.8 1

t / °C

x acetic acid

C7

C9

C10

C11

C12

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 0.2 0.4 0.6 0.8 1

x a

ceti

c aci

d

x hexane

fuse&Iguchi (1970), 25°C

Rao&Rao (1957), 31°C

acetic acid + hexane + water

P=1atm.

LLE for HAc – hexane – H2O ternary LLE for HAc – hydrocarbon binaries: Miscibility gap increases with carbon number

How Predictive Is the Model?

• Desirable scenario: • Develop model parameters based on binary data

• Predict the behavior of multicomponent systems

• If the model is physically correct, this works • Caveat: As long as there is no chemistry change in a

multicomponent system

• Two cases to illustrate predictions

Case 1: Mixed Chloride - Sulfate

Systems • Binary systems

• Regressed parameters • Cation-anion interaction

parameters

• Thermochemical properties of solids

• Based on experimental data • Solubilities

• VLE/osmotic coefficients

• Activity coefficients

• Enthalpies of dilution

• Heat capacity

• Density

Na2SO4 (rhombic)

Na2SO4 (monoclinic) Na2SO4 ·10H2O

Ice

Ice

NaCl ·2H2O

NaCl

NaCl – H2O

Na2SO4 – H2O

Case 1: Mixed Chloride - Sulfate Systems

• Ternary system

• Regressed parameters • Cl- - SO4

2- interactions

• Second-order correction

• Binary in nature but obtained from ternary data

• Full complexity of ternary behavior is reproduced

NaCl - Na2SO4 – H2O

Case 1: Mixed Chloride - Sulfate Systems: Pure Prediction

KCl – K2SO4 – H2O • Behavior of ternary

system is accurately predicted without any further parameter adjustment

• Parameters are fully transferable

• No new ternary chemical effects

Case 2: Mixed Al and Na Salts

• Binary and ternary systems

• Interactions regressed • Cation-anion

parameters

• Al3+ - Na+ cation-cation parameters

NaF – H2O

AlF3 – H2O

AlF3

Case 2: Mixed Al and Na Salts

AlF3 – NaF – H2O

• Although NaF and AlF3 are fairly soluble, solubility in the ternary system AlF3 – NaF – H2O is dramatically lower

• Specific ternary chemistry effect: Formation of sparingly soluble double salts • Cryolite, Na3AlF6, and chiolite, Na5Al3F14

• Ternary chemical effects need to be incorporated but cannot be simply predicted from the properties of binary or other ternary systems

Na3AlF6

Na5Al3F14

AlF3.3H2O

NaF

Predicting Dielectric Constant of Mixtures

• Calculating polarization • Kirkwood theory

• Mixing rule for polarization

• Good approximation without binary parameters

kT

g

v

Np A

33

4

9

121 2

n

i

ii

n

i

n

j

ijji

m

vx

vpxx

p

1

ijjjiiij kpvpvvp 1

2

1

Monoethylene glycol – water

Predicting Dielectric Constant

• Effect of ionic components

• Predicts universal decrease with ionic composition

• Effect of ion pairs is more complex

ionsXiii

0ss

IB1xA1 )ln(

NaCl at 25 C

NaCl at various T

AQ and MSE Databanks: A Comparison Databank Aqueous model:

Number of species Mixed-solvent electrolyte model: Number of species

General-purpose (process chemistry) PUBLIC 5407 (5407 in 10/2014)

MSEPUB 2590 (2150 in 10/2014)

Geochemical (solids formed on a geological timescale)

138 135

Corrosion (corrosion-related solids) 367 321

Urea (enabling urea-related reactions) Not available 8

Surface complexation, double layer 120 57

Ion exchange 13 0

Ceramics (ceramic solids) 36 Not applicable – included in MSEPUB

Low temperature (extension to calculate properties below 0 C)

227 Not relevant (MSEPUB works below 0 C)

Plans for the Future • Thermodynamics of rare-earth elements

• Applications to diversifying the supply, separation and recycling

• High-pressure, high-temperature scaling • Solubility of ZnS, PbS and CaSO4 in produced water

environments

• Chemistry of CO2 transmission • Predicting formation of corrosive phases in dense-phase

CO2

• Chemistry of silicates • Application to silica removal processes including surface

complexation and kinetics

Plans for the Future

• Potash chemistry • K – Na – Li – Ca – SO4 – Cl systems

• Amines and amine hydrochlorides • Towards further improvement of predictions

• Finalizing improvements of hydrocarbon chemistry

• Mutual diffusivity • Applications to mass-transfer separations

• Future client-driven projects