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OLI’s Mixed Solvent Electrolyte with Aspen PLUS. OLI Systems, Inc. Agenda. OLI’s basic history OLI’s history with Aspen Technologies Advantages/disadvantages of Aspen PLUS OLI Architecture of the Aspen PLUS OLI interface Introduction to MSE Overview of Aspen PLUS OLI (with MSE)
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OLI’s Mixed Solvent Electrolyte with Aspen PLUS OLI Systems, Inc.
Agenda • OLI’s basic history • OLI’s history with Aspen Technologies • Advantages/disadvantages of Aspen PLUS OLI • Architecture of the Aspen PLUS OLI interface • Introduction to MSE • Overview of Aspen PLUS OLI (with MSE) • Demonstration
OLI’s basic history • Company founded in 1971 by Marshall Rafal • First electrolyte simulator (ECES) 1973 • Developed for OLIN Chemical • First commercial sale of ECES 1975 • Dupont • The Environmental Simulation Program developed in 1991 • Linkage to simulators in 1995 • Windows program (Analyzers) became commercial in 2000 • Mixed-Solvent Electrolytes commercially available 2005 • Windows based process simulator (OLI Pro) to be available in 2007
OLI’s history with Aspen Technologies • That “Other” chemical company that has a “D” in its name. • 25 years of process simulation experience with electrolyte • 1995 switched to Aspen PLUS as their process simulator • Wanted OLI’s electrolytes in Aspen PLUS • 1996 first Aspen PLUS OLI interface created • No model manager, version 8.2 • 1997 Aspen PLUS OLI linked to model manager • Version 9.0 • 2006 Aspen PLUS OLI updated for Aspen ONE 2006 • Included change in concentration basis • Included MSE • 2007 Aspen PLUS OLI updated for Aspen ONE 2006.5 • General release of MSE for all Aspen PLUS OLI clients
Advantages of Aspen PLUS OLI • User Interface • Learn one flow sheeting system • Multiple Property Options in same flowsheet • Different Non-electrolyte capability • Sizing • Costing • Two Software Venders
Disadvantages of Aspen PLUS OLI • No Corrosion • No advanced OLI technology • No Ion-exchange • No Surface Complexation • No Bio-kinetics • No Scaling Tendencies • Two Software Venders
Architecture of the Aspen PLUS OLI interface OLI Chemistry Generator A+ Model Manager .BKP OLI Databases .ASP/.INP .DBS OLI/A+ XREF OLI Numerical Solver/Engine A+ Simulation Engine Electrolyte Flash or Property
Architecture of the Aspen PLUS OLI interface • Aspen Unit Operations available with the OLI Property Set • MIXERS • FSPLIT • SEP • SEP2 • HEATER • FLASH2 • FLASH3 • HEATX • MHEATX • RADFRAC • RSTOIC • RYIELD • RCSTR • RPLUG • PUMP • COMPR
Architecture of the Aspen PLUS OLI interface • Thermodynamic Properties from OLI used by Aspen PLUS (OLI propset)
Architecture of the Aspen PLUS OLI interface • The OLI-Aspen Plus Cross Reference File (partial listing) • Full listing is available on your computer: • C:\Program Files\OLI Systems\Alliance Suites\Aspen OLI 2006\Databanks\OLIAspenPlusCompXRef.lis ESP-NAME DB 8-CHAR ASP-ALIAS ASP-NAME ================ = ====== ========= ===================================== AR P AR AR ARGON 7440-37-1 Ar ABIETICAC P ABIETICA C20H30O2 ABIETIC-ACID 514-10-3 C20H30O2 ACENAPHTHN P ACENAPHT C12H10-D0 ACENAPHTHENE 83-32-9 C12H10 ACENITRILE P ACENTL C2H3N ACETONITRILE 75-05-8 C2H3N ACET2 P ACET2 ........... C4H8O4 ACETACID P ACETACID C2H4O2-1 ACETIC-ACID 64-19-7 C2H4O2 ACETAL P ACETAL C6H14O2-D1 ACETAL 105-57-7 C6H14O2 ACETALDEHD P ACEALD C2H4O-1 ACETALDEHYDE 75-07-0 C2H4O ACETAMIDEPPT P ACETAM-S 60-35-5 C2H5NO ACETAMIDE P ACETAMD C2H5NO-D1 ACETAMIDE 60-35-5 C2H5NO ACETANHYD P ACETAHYD C4H6O3 ACETIC-ANHYDRIDE 108-24-7 C4H6O3 ACETANILID P ACEANILD C8H9NO ACETANILIDE ACETATEION P ACET- CH3COO- CH3COO- ........... C2H3O2-1 ACETBR P ACETBR 506-96-7 C2H3BrO ACETCL P ACETCL C2H3CLO ACETYL-CHLORIDE 75-36-5 C2H3ClO ACETONE P ACETONE C3H6O-1 ACETONE 67-64-1 C3H6O ACETPHENON P ACEPHEN C8H8O METHYL-PHENYL-KETONE 98-86-2 C8H8O ACETYLENE P ACETYLN C2H2 ACETYLENE 74-86-2 C2H2 ACRIDINE P ACRIDINE 260-94-6 C13H9N ACROLEIN2 P ACROLIN2 C3H4O ACROLEIN 107-02-8 C3H4O ACRYLAMIDEPPT P ACRAMI-S 79-06-1 C3H5NO ACRYLAMIDE P ACRYAMID C3H5NO-D1 ACRYLAMIDE 79-06-1 C3H5NO
Architecture of the Aspen PLUS OLI interface • OLI added user blocks to Aspen PLUS • EFRACH • EFLASH • Available during Aspen PLUS Installation • Must be enabled at run-time
Architecture of the Aspen PLUS OLI interface EFLASH (Four outlet material streams) Vapor (1) Feeds Aqueous (2) Organic (3) Solid (4) Heat Heat • EFLASH
Architecture of the Aspen PLUS OLI interface Vapor or Liquid Heat Heat 1 DECANTER Organic Feeds Products 2 3 Heat Heat Heat Heat N Bottoms • EFRACH
Introduction to MSE • Why develop a new thermodynamic model? • The Bromley-Zemaitis model (a/k/a Aqueous Model-AE) had limitations • Water was required as a solvent • Mole fraction of all solutes was limited to approximately 0.35 • Limited in temperature (Approximately 300 oC) • LLE predictions exclude critical solution points (limited to strongly dissimilar phases) • A Mixed Solvent Electrolyte model (MSE) has advantages • Water is not required • Mole fraction of solute can approach and be equal to 1.0 • Temperature can be up to 0.9 Tc of solution • Full range of LLE calculations including electrolytes in both phases
MSE model Model advantages: No composition limitations Reliable predictions for multicomponent concentrated solutions Full range of LLE calculations including electrolytes in both phases Methodological advantages Multi-property regressions Consistent use of thermochemical properties (no shortcuts like KFITs) Rigorous quality assurance Disadvantages: A smaller in-place databank but it is continuously extended Introduction to MSEAdvantages and disadvantages between AE and MSE • AE Model • Advantages: • Larger existing databank • The only model available for rates of corrosion • Disadvantages: • Limitations with respect to composition (30 m with respect to electrolytes, x=0.3 with respect to nonelectrolytes • LLE predictions exclude critical solution points (limited to strongly dissimilar phases)
Introduction to MSE • Overview of species coverage between AE and MSE models. 8000 6000 AE Growing with each build 4000 Components 2000 MSE Build 7.0.54 0 1.0 0.0 Solute Mole Fraction
Structure of the thermodynamic model • Definition of species that may exist in the liquid, vapor, and solid phases • Excess Gibbs energy model for solution nonideality • Calculation of standard-state properties • Helgeson-Kirkham-Flowers equation for ionic and neutral aqueous species • Standard thermochemistry for solid and gas species • Algorithm for solving phase and chemical equilibria
Outline of the model:Solution nonideality Excess Gibbs energy LR Debye-Hückel theory for long-range electrostatic interactions LC Local composition model (UNIQUAC) for neutral molecule interactions II Ionic interaction term for specific ion-ion and ion- molecule interactions
Outline of the model:Chemical equilibrium calculations For a chemical reaction: At equilibrium with Standard-state chemical potential of i • Infinite-dilution properties • Thermochemical databases for aqueous systems • Helgeson-Kirkham-Flowers model for T and P dependence
Outline of the model:Constraints • Activity coefficients are converted to unsymmetrical normalization to work with infinite-dilution properties • Constraining the parameters of the GE model to reproduce the Gibbs energy of transfer Activity coefficient of ion i in solvents R and S in unsymmetrical, mole-fraction based convention
Mixed-solvent electrolyte model:Applicability • Simultaneous representation of multiple properties • Vapor-liquid equilibria • Osmotic coefficient/water activity and activity coefficients • Solid-liquid equilibria • Properties of electrolytes at infinite dilution, such as acid-base dissociation and complexation constants • Properties that reflect ionic equilibria, e.g., solution pH and species distribution • Enthalpy (Hdil or Hmix) • Heat capacity • Density
Validity range • Concentrations from infinite dilution to saturation or fused salt or pure solute limit • Temperatures up to 0.9Tc of mixtures • This translates into 300 C for H2O – dominated systems • For concentrated inorganic systems, substantially higher temperatures can be reached • Solvents: water, various organics or solvent mixtures
Representative applications of the MSE thermodynamic model • Strong acid systems • Simultaneous representation of phase equilibria and speciation • Salt systems • Prediction of properties of multicomponent systems • Organic – salt – water systems • Salt effects on VLE, LLE and SLE • Acid-base equilibria • pH of mixed-solvent systems
VLE for H2SO4 + SO3 + H2O • Phase equilibria are accurately reproduced from 0 C to 500 C
Speciation for H2SO4 + SO3 + H2O: • Predicted speciation in concentrated solutions agrees with spectroscopic data
Partial pressures in the H2SO4 + SO3 + H2O system • Partial pressures of H2SO4, SO3 and H2O are also correctly reproduced Partial pressures of H2SO4
Salt systems:Na – K – Mg – Ca – Cl – NO3 NaNO3 – H2O • Step 1: Binary systems – solubility of solids • The model is valid for systems ranging from dilute solutions to the fused salt limit Mg(NO3)2 – H2O
Step 1: Binary systems – solubility of solids Water activity decreases with salt concentration until the solution becomes saturated with a solid phase Modeling salt systems:Na – K – Mg – Ca – Cl – NO3
Step 2: Ternary systems • Solubility in the system NaNO3 – KNO3 – H2O at various temperatures • Activity of water over saturated NaNO3 – KNO3 solutions at 90 C: Strong depression at the eutectic point
Deliquescence data simultaneously reflect solid solubilities and water activities Step 3: Verification of predictions for multicomponent systems Mixed nitrate systems at 140 C
Electrolyte + organic systems:Examples • Effect of electrolytes on phase equilibria in nonelectrolyte – water systems • Salting out(in) effects • Liquid-liquid equilibria in aqueous systems containing water-soluble polymers and salts • Liquid immiscibility is induced by the presence of a salt
LLE results – salt effect Solubility of benzene in aqueous (NH4)2SO4 and NaCl solutions at 25ºC
Simultaneous representation of thermodynamic properties:NaCl-methanol-water P=1 bar 25°C ---- Salt-free —— Saturated NaCl Solubility VLE: salting-out effect
LLE in aqueous polymer – salt systems • PEG (MW=1000) + NaH2PO4 + H2O at 25 C • PEG (MW=4000) + (NH4)2SO4 + H2O at 25 C
Acid-base and phase equilibria: Treatment of pH in mixed solvents • Classical treatment • pH scale can be defined separately for each, pure or mixed, solvent • pH scales can be converted using the Gibbs energy of transfer of the proton • Such a conversion is inconvenient (availability of Gibbs energy of transfer, extrathermodynamic assumptions) • However, it opens the possibility of a uniform calculation of pH using an activity coefficient model as long as the model accurately reproduces activity coefficients of individual species and the Gibbs energy of transfer
Treatment of pH in mixed-solvents • Uniform treatment of apparent pH • Starting point: Aqueous definition of pH • Conversion to mole fraction scale and solvated proton basis • Activity coefficients are obtained directly from the model • Values can be compared with measurements using glass electrode • Does not require the presence of water – equivalent expressions can be obtained for other solvents
Speciation Effects Apparent (Mixed Solvent-Based) Ionization Constants Acetic Acid in EtOH-H2O Acetic Acid in MeOH-H2O Equilibrium constant obtained from aqueous solutions
Binary and principal ternary systems composed of the following primary ions and their hydrolyzed forms Cations: Na+, K+, Mg2+, Ca2+, Al3+, NH4+ Anions: Cl-, F-, NO3-, CO32-, SO42-, PO43-, OH- Aqueous acids, associated acid oxides and acid-dominated mixtures H2SO4 – SO3 HNO3 – N2O5 H3PO4 – H4P2O7 – H5P3O10 – P2O5 H3PO2 H3PO3 HF HCl HBr HI Parameters in the MSE Databank (1) • H3BO3 • CH3SO3H • NH2SO3H • HFSO3 – HF – H2SO4 • HI – I2 – H2SO4 • HNO3 – H2SO4 – SO3 • H3PO4 with calcium phosphates • H – Na – Cl – NO3 • H – Na – Cl – F
Inorganic gases in aqueous systems CO2 + NH3 H2S + NH3 SO2 + H2SO4 N2 O2 H2 Transition metal aqueous systems Fe(III) – H – O – SO4, NO3 Fe(II) – H – O – SO4, Br Sn(II, IV) – H – O – CH3SO3 Zn(II) – H – SO4, NO3, Cl Zn(II) – Li - Cl Parameters in the MSE Databank (2)
Transition metal aqueous systems - continued Cu(II) – H – SO4, NO3 Ni(II) – H – SO4, NO3, Cl Mo(VI, IV) – H – O – Cl, SO4, NO3 W(VI) – H - O - Na – Cl, NO3 Most elements from the periodic table in their elemental form Base ions and hydrolyzed forms for the majority of elements from the periodic table Hydrogen peroxide chemistry H2O2 – H2O – H - Na – OH – SO4 – NO3 Parameters in the MSE Databank (3)
Miscellaneous inorganic systems in water NH2OH NH4HS + H2S + NH3 LiCl – KCl LiCl – CaCl2 Na2S2O3 LiOH – H3BO3 – H2O Organic acids in water, methanol and ethanol and their Na salts Formic Acetic (also K salt) Citric Adipic Nicotinic Terephthalic Isophthalic Trimellitic Parameters in the MSE Databank (4)
Organic components and their mixtures with water Hydrocarbons Straight chain alkanes: C1 through C30 Isomeric alkanes: isobutane, isopentane, neopentane Alkenes: ethene, propene, 1-butene, 2-butene, 2-methylpropene Aromatics: benzene, toluene, o-, m-, p-xylenes, ethylbenzene, cumene, naphthalene, anthracene, phenantrene Alcohols Methanol, ethanol, 1-propanol, 2-propanol, cyclohexanol Glycols Mono, di- and triethylene glycols, propylene glycol, polyethylene glycols Phenols Phenol, catechol Ketones Acetone, methylisobutyl ketone Aldehydes Butylaldehyde Parameters in the MSE Databank (5)
Organic solvents and their mixtures with water Carbonates Diethylcarbonate, propylene carbonate Amines Tri-N-octylamine, triethylamine, methyldiethanolamine Nitriles Acetonitrile Amides Dimethylacetamide, dimethylformamide Halogen derivatives Chloroform Aminoacids Methionine Heterocyclic components N-methylpyrrolidone, 2,6-dimethylmorpholine Parameters in the MSE Databank (6)
Polyelectrolytes Polyacrylic acid Complexes with Cu, Zn, Ca Mixed-solvent organic systems HAc – tri-N-octylamine – toluene – H2O HAc – tri-N-octylamine – methylisobutylketone – H2O HAc – MeOH – EtOH – H2O HAc – MeOH – CO2 – H2O Dimethylformamide – HFo – H2O Parameters in the MSE Databank (7)
Mixed-solvent inorganic/organic system Hydrocarbon – water – salt (Na, K, Ca, Mg, NH4, H, Cl, SO4, NO3) systems Mono, di- and triethylene glycols - H – Na – Ca – Cl – CO3 – HCO3 - CO2 – H2S – H2O Phenol - acetone - SO2 - HFo - HCl – H2O Benzene – NaCl and (NH4)2SO4 - H2O Cyclohexane – NaCl - H2O n-Butylaldehyde – NaCl - H2O LiPF6 – diethylcarbonate – propylene carbonate Ethanol – LiCl - H2O Methanol - H2O + NaCl, HCl Parameters in the MSE Databank (8)
Predictive character of the model • Levels of predictivity • Prediction of the properties of multicomponent systems based on parameters determined from simpler (especially binary) subsystems • Extensively validated for salts and organics • Prediction of certain properties based on parameters determined from other properties • Extensively validated (e.g., speciation or caloric property predictions)
What does it mean for the model to be predictive? MSE (no ternary fits) • Parameters were determined using only binary salt + H2O data • SLE for the ternary system was predicted without making any ternary fits • MSE is clearly superior even in the applicability range of the aqueous model • This can work only when the ternary system does not introduce a chemistry change (e.g., double salts) Aqueous model (no ternary fits)
Predictive character of the model • Levels of predictivity - continued • Prediction of properties without any knowledge of properties of binary systems • Standard-state properties: Correlations to predict the parameters of the HKF equation • Ensures predictivity for dilute solutions • Properties of solids: Correlations based on family analysis • Parameters for nonelectrolyte subsystems • Group contributions: UNIFAC estimation • Quantum chemistry + solvation: CosmoTherm estimation • Also has limited applicability to electrolytes as long as dissociation/chemical equilibria can be independently calculated
Transport properties in the OLI software • Available transport properties: • Diffusivity • Viscosity • Electrical conductivity • OLI was the first to develop transport property models for concentrated, multicomponent aqueous solutions • More recently, the models have been extended to mixed-solvent systems
Modeling diffusivity in electrolyte systems • Limiting diffusivity – • Long-range electrostatic interactions – Relaxation effect: • Short-range interactions – Hard-sphere contribution: • Combination of the two effects: MSA theory: Important in relatively dilute solutions Enskog theory: Significant for concentrated solutions