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
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
=
− ∆
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
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+
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)
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 ∆
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
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