Aqueous Electrolytes and Organic Solutes under Industrial Steam

Generator Conditions

Presentation to IAPWS Canadian National Committee

May 23, 2003

Peter TremaineDepartment of Chemistry and Biochemistry

Current Projects in High Temperature Water Chemistry at the

University of Guelph

• Tools:– Calorimetry and densimetry– Spectroscopy– Pressure vessels

• Equilibrium constants and pH at high T and p • Amines, organic acids and amino acids• Metal-ammine complexes• Phosphate Hideout chemistry

Steam Saturation Pressure as a Function of Temperature

Experimental Tools

Equilibrium Constant as a Function of Temperature

ln lnK KR T

HTo= − −

298 298

1 1 1298

∆

+ ∫ − ∫1 1

298 298RCT

dTRT

C dTpoT

po

T∆∆

− ∫1

1RTV dP

po∆

∆G RT KoR = − ln

∂∆∂

HT

CRo

P

P Ro

= ∆ ,

∂∂ln KP

VRTT

Ro

=

− ∆

U-Tube High TemperatureDensimeter

Picker Calorimeter

UV-Visible High Temperature Cell

ll HPLC pump Gilson 305HPLC pump Gilson 305ll Manometric Module Gilson 8Manometric Module Gilson 8ll Cary 50 SpectrophotometerCary 50 Spectrophotometerll Scan softwareScan software

UV- Visible HighTemperature Flow Cell

Trevani et al., J. Sol. Chem. 30, 585 (2001)

Hydrothermal pH Measurements

• Platinum/Hydrogen electrodes in pressure vessels

• Time consuming

• Difficult

Equilibrium Constants and pH

Amines, Organic Acids and Amino Acids

Hydrothermal pH IndicatorsJohnston and Chlistunoff

J. Supcrit. Fluid 12, 155 (1998)

N+

H

N

+ H+ºKHIn

KHIn = [H+]

[AcrH+]

Yields experimental pH

[Acr]

Determined from Spectral Fit

AcrAcrH+

γ γγH Acr

AcrH

+

+

Glycine Buffers

Glycine Buffers and Data Fit

250oC Acridine

λ (nm)

300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470

Abs

orba

nce

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Glycine R=0.1

Glycine R=0.5Glyc ine R=1NaOH

Triflic Acid

Abuffer = F1AHIn,Acid + F2 AIn-,Base

pK1 Results for Glycine

1 / T (K)0.0018 0.0020 0.0022 0.0024 0.0026 0.0028 0.0030 0.0032

pK

0

1

2

3

4

5

6

7

250oC

25oC

Acr

AcrH+

H2Gly+ » HGly" + H+

“Equations of State” for Aqueous Species

Amines, Organic Acids and Amino Acids

Equilibrium Constant as a Function of Temperature

ln lnK KR T

HTo= − −

298 298

1 1 1298

∆

+ ∫ − ∫1 1

298 298RCT

dTRT

C dTpoT

po

T∆∆

− ∫1

1RTV dP

po∆

∂∆∂

HT

CRo

PP Ro

= ∆ ,

∂∂ln KP

VRTT

Ro

=

− ∆

Standard Partial Molar Heat Capacity of AlCl3 (aq) and the HKF Model

Xiao et al., J. Chem. Thermodynamics 31, 1055 (1999)

Morpholine: Vo vs T

T / 0C

0 50 100 150 200 250 300

V20

/ (cm

3 m

ol-1

)

0

20

40

60

80

100

120

" n"= 20

T / 0C

0 50 100 150 200 250 300

V20 /

(cm

3 m

ol-1

)

80859095

100105110115120125130135

Experimental resultsHKF ModelDensity Model

" n" = -11

N

O

HN+

O

HHCl-

Tremaine et al., J. Phys. Chem. B 101, 409 (1997)

Standard Partial Molar Properties of Proline vs Temperature

T / (K)

288 324 360 396 432 468 504 540

V o /

(cm

3 mol

-1)

81

82

83

84

85

86

87

88

Vo

30 MPa

10 MPa

T / (K)

280 320 360 400 440 480 520

Cpo /

(J m

ol-1

K-1)

144

160

176

192

208

224

240

256

CPo

30 MPa

10 MPa

Clarke et al., J. Phys. Chem. B 104. 11781 (2000)

“Equations of State” for Group AdditivityModels of Organic Solutes

• Density Model– Marshall and Mesmer, J. Solution Chem. 13, 383 (1984)

• Krichevskii Parameter– Harvey, Ind. Eng. Chem. Res. 37, 3080 (1998)

• Solution Fluctuation Theory– Sedlbauer, O’Connell and Wood, Chem. Geol., 163,43 (2000)

Equilibrium Constantsations for Aqueous Metal Complexes

Copper-Ammonia Complexes under Feed-train Conditions

Cu(II)-NH3 Spectra as a Function of Temperature

0

0.5

1

1.5

2

450 550 650 750 850 950

W/nm

Abso

rban

ce

Increasing pH

0

0.5

1

1.5

2

400 500 600 700 800 900 1000

W/nm

Ab

sorb

ance

2525ooCC

150150ooCC

Cu(II)-NH3 System

Cu2+ + NH3 º Cu(NH3)2+

8 Cu(NH3)2+ + NH3 º Cu(NH3)22+

8 Cu(NH3)22+ + NH3 º Cu(NH3)3

2+

8 Cu(NH3)32+ + NH3º Cu(NH3)4

2+

1000*[1/Tr-1/T]

0.00 0.25 0.50 0.75 1.00

log

( βn

)

2

4

6

8

10

12

14

Modelling Copper Transport under Feedtrain Conditions

300oC and 200 bar25oC and 1 bar

1. Make-Up water2. Condenser3. Deaerator4. Low pressure heaters 5. High pressure heater 6. Boiler

NHNH33

11 22 33 44 6655

airair

waterwater

COCO22/O/O22

CuO(s)CuO(s)

slnslnsln

CuO(s)CuO(s)

Crevice and Under-Deposit Chemistry

Phosphate Hideout Chemistry in Thermal Power Stations

and at theLepreau Nuclear Generating Station

Magnetite Solubility

Fe3O4

Metal Oxide

Aqueous Solution

H2

Fe2+ W FeOH+ W Fe(OH)2o W Fe(OH)3

-OH-

Svedov and Tremaine, J. Sol. Chem. 29, 905 (2000)

Tremaine and Le Blanc, J. Sol. Chem. 9, 415 (1980)

Sodium Phosphate “Hideout” in Thermal Power Station Boilers

Sodium Iron (III) and Iron (II) PhosphateReaction Products

Bridson et al., Chem. Mater. 10, 763 (1998)

Conclusions

• Experimental know-how is in place for:- partial molar properties- equilibrium constants- spectroscopy

• Practical “equations of state” for Cpo, Vo

- Inorganic ions……..yes!- Organic….maybe?

• Equilibrium constants at high T and p- Amine, organic acid ionization- Metal-ammonia complexation

• Sodium and ammonium phosphate hideout models

Hydrothermal Chemistry Group at MUN• Postdoctoral Fellows and Graduate Students Present Position• Dr. H. Bianchi (1990-1991) PDF Comision Nacional de Energia

Atomica Argentina.• Dr. P. Pan (1992) PDF Assisant Res. Officer AECL Chalk

River Laboratories • Mr. C. Xiao (1992-1997) Ph.D. PDF, Oak Ridge National Laboratories• Mr. Y. Zhou (1992-1995) M.Sc. Analytical Chemist, Toronto• Mr. Sean Quinlan (1993-1996) M.Sc. Analytical Chemist, North Atlantic

Refinery • Ms. Jian Ping Zhao (1993-1996) M.Sc. Analytical Chemist, Toronto • Dr. Dimetri Shvedov (1995-1997) PDF Research Scientist, Alcan Research,

Kingston• Dr. Wolfram Rudolph (1995-1996) Res. Associate, on leave from Medical Academy,

Dresden• Mr. Z. Wang (1992-1999) M.Sc. Consultant, Waterloo• Mr. Wei Xie (1995-1999) M.Sc. Analytical Chemist, Glyco Design Inc.,

Toronto • Mr. Brent Hawrylak (1997-1999) M.Sc. Pharmacy Student, Memorial Univ.• Mr. Rodney Clarke (1996-2000) Ph.D. High School Teacher, Saskatchewan.• Dr. Liliana Trevani (1997-2000) PDF Oxford Fellowship, and Univ. Buenos

Aires• Ms. Kai Zhang (1998-2002) M.Sc. Laboratory Assistant, Memorial

University• Ms. Wanda Aylward (1999-2002) M.Sc. PhD Student, Memorial University• Ms. Rosemarie Harvey(1999-pres.) M.Sc. MUN, School of Grad. Studies Fellowship• Dr. R.Bartholomew (2000-pres.) PDF Research Associate University of

Guelph

• B.Sc. Theses: Chris Collins (2001), Jenene Roberts (2001)

Acknowledgements

Picker Calorimeter

φCC so C H O

mPP P=

−( ln) ( )2

Hydration Effects

Equation of StateHelgeson, Kirkham, and Flowers (1981)

Tanger and Helgeson (1988)

( )V ion cd

TVo

Borno= +

−+

228∆

( )C ion a bT

Cpo

po

Born= +

−+

( ) ,228 2 ∆

Apparent Molar Propertiesand Critical Behaviour

Apparent Molar Heat Capacities of Aqueous Solutes at Near-Critical Temperatures

Neutral Solutes

Experiment

t /oC

Cpo

or

Vo

KrichevskiiTerm

( )A im

PVRT

nn

T V n

12 02

2

1

=

→l∂

∂, ,

V A RTo2 12 1= κ

Krichevskii ParameterLevelt Sengers (1991)

Cpo and Vo

Electric Power Plants

Schematic Diagram of the Solvation Process

( )∆ solv Borno A

e

r

r

GZe N

r=

− −

( )2

081

πεε

ε

ION DIPOLE

( )( )

∆ solv dipoleo A

e

r

r

GNr

=− −

+

µπε

εε

2

034

12 1

Clarke and Tremaine, J. Phys. Chem. B 103, 5131 (1999)

Simulations

• Experiments are expensive

• Water is a more “normal” solvent

• Important advances in computational technology

High Temperature Vibrating Tube Densimeter

( ) ( )ρ ρ τ τ− = −o oK 2 2