Overview - French Creek Softwarefrenchcreeksoftware.com/chemtech/chemtech-fall-2011-seminar.pdf · French Creek Training ... 10/17/2011 12 Analytical Values or Free Ions? ... Chemistry”

10/17/2011

1

French Creek Training October 18, 2011

1

• Chemistry & Theory

• Putting French Creek to Work • WaterCycle

• DownHole SAT

• hyd-RO-dose

• WatSIM

• MineSAT

Overview

2

• Cooling Water

• Reverse Osmosis

• Municipal

• Oilfield

• Mining & Waste

Scale & Corrosion Software Sales & Service Tools

3

• Standard off the shelf

• Customized versions

• Windows Libraries

web applications

• Unix Libraries

controllers

Scale & Corrosion Software Sales & Service Tools

4

10/17/2011

2

Copyright 2011 French Creek Software

• Maximize Cycles

• Optimize and Compare

Treatments

• Optimize Formulations

• Troubleshoot Operating

Range

WaterCycle Rx® cooling water

5

• Maximize Cycles

• Optimize and Compare Treatments


• Troubleshoot Operating Range


6

• Maximize Cycles


7



HEDP

PBTC Untreated

8

10/17/2011

3



9



10



11



12

10/17/2011

4



13

• Maximize Cycles





14

• Maximize Recovery

• Optimize & Compare

Treatments



Range

hyd-RO-dose® reverse osmosis

15

• Maximize Recovery


16

10/17/2011

5



17

• Lead and Copper Minimization

• Blend Waters

• Optimize & Compare Treatments



WatSIM™ potable/wastewater

18


• Blend Waters

• Optimize & Compare Treatments




19



20

10/17/2011

6



21

• Blend Waters


22



23

• Produced Waters

• Injection Wells

• Frac’ing & Flowback

• Water Flood

• Blend Waters

DownHole SAT ™ Oilfield/geothermal

24

10/17/2011

7

• Produced Waters


25

• Injection Wells


26

• CO2 Corrosion


27

• Blend Waters

• Optimize and Compare

Treatments



Range

MineSAT™ mine chemistry

28

10/17/2011

8

• Programs “Talk”

• Maximize Water Reuse

• Minimize Discharge

Version 7 Suites

29

• Call FCS from your in-

house software

• Controller Calculations

• Web Calculations

French Creek DLL’s

Unix Libraries

30

Copyright 2011 French Creek Software 31

• Your logos, addresses, products

• Batch input from analytical files

Custom Software

32

10/17/2011

9

Part 1 – Theory understanding the chemistry behind French Creek Software

33

• Solubility product

• Solubility relationships for common

scales

• Solubility and simple indices

• Thermodynamics versus kinetics (or when will it come out?)

The Concept of Saturation

34


(Ca)(CO3) = Ksp


35


(Ca)(CO3) = Ksp


Where:

•(Ca) is the calcium activity

•(CO3) is the carbonate activity

•Ksp is the solubility product for calcium

carbonate at the temperature under study.

36

10/17/2011

10


scales


Calcium carbonate

SL= (Ca)(CO3)

Ksp’

_________

37


scales


Barium sulfate

SL= (Ba)(SO4)

Ksp’

_________

38


scales


Calcium sulfate

SL= (Ca)(SO4)

Ksp’

_________

39


scales


Calcium phosphate

SL= (Ca)3(PO4)2

Ksp’

_________

40

10/17/2011

11


scales


Calcium fluoride

SL= (Ca)(F)2

Ksp’

_________

41


scales


Magnesium hydroxide

SL= (Mg)(OH)2

Ksp’

_________

42


scales


Ferric hydroxide

SL= (Fe)(OH)3

Ksp’

_________

43


Software Examples

44

10/17/2011

12

Analytical Values or Free Ions?

• All ions are not free to form scale

• Analytical values are the total of

“free” and “bound” ions


45

Activity Coefficient Example

46


47


48

10/17/2011

13

• Free versus total ions

• Distribution of species

• Ion pairs used by WaterCycle

• Practical impact of incomplete

analyses upon saturation level

calculations

Ion Association Models

49

Free Ions Calculated From

Distribution of Species

• French Creek programs setup full

equilibria for a water

• Calculate most likely distribution


50

Free Ions Calculated From

Distribution of Species

• French Creek programs setup full

equilibria for a water

• Calculate most likely distribution


51

CALCIUM EQUILIBRIA

[Calcium] = [Ca+II] + [CaSO4] + [CaHCO3

+I] +

[CaCO3] + [Ca(OH)+I] + [CaHPO4] +

[CaPO4-I] + [CaH2PO4

+I]


52

10/17/2011

14

MAGNESIUM EQUILIBRIA

[Magnesium] = [Mg+II] + [MgSO4] + [MgHCO3+I] +

[MgCO3] + [Mg(OH)+I] +[MgHPO4]

+ [MgPO4-I]+[MgH2PO4

+I]+[MgF+I]


53

BARIUM & STRONTIUM EQUILIBRIA

[Barium] = [Ba+II] + [BaSO4] + [BaHCO3+I]

+ [BaCO3] + [Ba(OH)+I]

[Strontium] = [Sr+II] + [SrSO4] + [SrHCO3+I]

+ [SrCO3] + [Sr(OH)+I]


54

BARIUM & STRONTIUM EQUILIBRIA

[Barium] = [Ba+II] + [BaSO4] + [BaHCO3+I]

+ [BaCO3] + [Ba(OH)+I]

[Strontium] = [Sr+II] + [SrSO4] + [SrHCO3+I]

+ [SrCO3] + [Sr(OH)+I]


55

SODIUM EQUILIBRIA

[Sodium] = [Na+I] + [NaSO4-I] + [Na2SO4] +

[NaHCO3] + [NaCO3-I] +

[Na2CO3] + [NaCl]+[NaHPO4-I]


56

10/17/2011

15

POTASSIUM EQUILIBRIA

[Potassium] = [K+I] + [KSO4

-I] + [KHPO4-I] + [KCl]


57

IRON EQUILIBRIA

[Iron] = [Fe+II] + [Fe+III] + [Fe(OH)+I] + [Fe(OH)+II] +

[Fe(OH)3-I] + [FeHPO4+I] + [FeHPO4] +

[FeCl+II] + [FeCl2+I] + [FeCl3] + [FeSO4] +

[FeSO4+I] + [FeH2PO4

+I] + [Fe(OH)2+I] +

[Fe(OH)3] + [Fe(OH)4-I] + [Fe(OH)2] +

[FeH2PO4+II]


58

ALUMINUM EQUILIBRIA

[Aluminum] = [Al+III] + [Al(OH)+II] + [Al(OH)2

+I] +

[Al(OH)4-I] + [AlF+II] + [AlF2

+I] +

[AlF3] + [AlF4-I] + [AlSO4

+I] +

[Al(SO4)2-I]


59


Software Examples

• High Sulfate

• When [OH] is significant

60

10/17/2011

16

• Langelier

• Ryznar

• Puckorious (Practical)

• Stiff-Davis

Simple Scale Indices

61



Calcium carbonate

SL= (Ca)(CO3)

Ksp’

SL = 1.0 at equilibrium

_________

Take the log of both sides

Log(SL)= Log(Ca)+Log(CO3)-Log(Ksp’)

Log(1.0)= Log(Ca)+Log(CO3)-Log(Ksp’)

Log(Ca)+Log(CO3)-Log(Ksp’) = 0.0

62



Calcium carbonate

SL= (Ca)(CO3)

Ksp’

_________

Substituting


Log(Ca)+Log(CO3)+p(Ksp’) = 0.0

63



Calcium carbonate

SL= (Ca)(CO3)

Ksp’

_________

Substituting


Log(Ca)+Log(CO3)+p(Ksp’) = 0.0

-pCa – pKsp + log(CO3) = 0.0

64

10/17/2011

17



Calcium carbonate

SL= (Ca)(CO3)

Ksp’

_________

(H)(CO3)

(HCO3)

_______ K2 =

65

• Estimating CO3 in LSI Derivation


(H)(CO3)

(HCO3)

_______ K2 =

Log(K2) = log(H) + log(CO3) – log(HCO3)

66



(H)(CO3)

(HCO3) _______

K2 = Log(K2) = log(H) + log(CO3) – log(HCO3)

-Log(K2) = -log(H) - log(CO3) + log(HCO3)

pK2 = pH + log(CO3) + log(HCO3)

67

Estimating CO3 in LSI Derivation


(H)(CO3)

(HCO3) _______

K2 =

Log(K2) = log(H) + log(CO3) – log(HCO3)

-Log(K2) = -log(H) - log(CO3) + log(HCO3)

pK2 = pH + log(CO3) + log(HCO3)

Assume HCO3 is Approximately Equal to “M” Alkalinity

pK2 = pH + log(CO3) + log(Alkalinity)

68

10/17/2011

18



(H)(CO3)

(HCO3)

_______ K2 =

pK2 = pH + log(CO3) + log(Alkalinity)

-log(CO3) = pK2 - pH -log(Alkalinity)

-log(CO3) = pK2 - pH +pAlkalinity

log(CO3) = -pK2 + pH -pAlkalinity

69

• Substitute CO3 into LSI Derivation


(H)(CO3)

(HCO3)

_______ K2 =

log(CO3) = -pK2 + pH -pAlkalinity

0.0 = –pCa + pKsp + log(CO3)

0.0 = -pCa + pKsp - pK2 + pH -pAlkalinity

70

• LSI Derived From Definitions KSP & K2


LSI = pH – ( pCa + pAlk + pK2 – pKsp)

Calcium carbonate

1.0 = SL= (Ca)(CO3)

Ksp’

_______

Calcium carbonate

_______ K2 =

(H)(CO3)

(HCO3)

71

• LSI is log(SL) Based Upon Analytical Values

& Assumption That (HCO3) ≈ “M” Alkalinity


LSI = pH – ( pCa + pAlk + pK2 – pKsp)

Calcium carbonate

1.0 = SL= (Ca)(CO3)

Ksp’

_______

Calcium carbonate

_______ K2 =

(H)(CO3)

(HCO3)

72

10/17/2011

19

In Langelier’s original paper,

He recommended that a chemist:

• Should correct for non-carbonate alkalinity

• Should use a rigorous method for carbonate

calculation

• Should calculate “Free” ion concentrations and not

use analytical values for calculations.

Lack of computers made manual calculation

a 2 week affair


73

Thermodynamics versus kinetics

(or when will it come out?)

• The higher the temperature, the faster the

reaction, all things equal.

• The higher the saturation level, the faster the

reaction, all things equal.

• Refer to Stumm and Morgan, “Aquatic

Chemistry” for an overview of the kinetics of

scale formation.


74

Thermodynamics versus kinetics

(or how much will come out?)

• The higher the saturation level, the faster the

reaction will approach equilibrium, all things

equal.

• Momentary Excess indicates how much to

expect, if the water reaches equilibrium.

• Momentary Excess tends to overesitmate.


75

• Calculations

• Interpretation

• Other uses

Momentary Excess

76

10/17/2011

20

Definition of Solubility at Equilibrium

(Ca)(CO3) = Ksp

Definition of Momentary Excess

(Ca - X)(CO3 - X) = Ksp

where X is Momentary Excess

the precipitation required to return a

water to equilibrium

Momentary Excess

77

CHARACTERISTICS

• Developed as a driving force for scale.

• Not a quantative prediction.

• Inherent error in prediction due to change

in pH, CO3/HCO3 ratio as precipitation

occurs.

• A free ion version of CCPP from potable

Momentary Excess

78

CHARACTERISTICS

• Used in DownHole SAT as an indication

of scale to expect per 1000 barrels

• Used in WatSim as a refined CCPP

Momentary Excess

79

• Correcting for non carbonate alkalinity

• Does a system conserve alkalinity? Molar

Carbon?

• How WaterCycle handles alkalinity

• Choosing WaterCycle Alkalinity to match

the system

Alkalinity

80

10/17/2011

21

• Correcting for non carbonate

alkalinity

• The classic definition:

“M”=HCO3- + 2CO3

= + OH- - H+

Alkalinity

81


alkalinity

• The classic definition:

“M”=HCO3- + 2CO3

= + OH- - H+

• When other alkalis are present:

“M”=HCO3- + 2CO3

= + OH- - H+ +A-

Alkalinity

82


alkalinity

When other alkalis are present:

“M”=HCO3- + 2CO3

= + OH- - H+ +A-

Where A is the sum of phosphate alkalinity,

contribution, silicate contribution, and any other

alkalis that may be present

Alkalinity

83


alkalinity

HCO3- + 2CO3

= = “M”- OH- + H+ - A-

Alkalinity

84

10/17/2011

22

• Estimating carbonate

K2 = {H}{CO3}/{HCO3}

CO3=K2{HCO3}/{H}

HCO3- + 2CO3

= = “M”- OH- + H+ - A-

Alkalinity

85

• Does a system conserve alkalinity?

Molar Carbon?

Alkalinity

86

• Alkalinity

“M” = [HCO3] + 2 * [CO3]+ [OH] – [H]

• Molar Carbon

Ct = [H2CO3] + [HCO3] + [CO3]

Alkalinity

87

Alkalinity (OPEN SYSTEM)

• “M” = [HCO3] + 2 * [CO3]+ [OH] – [H]

• Free CO2 exchange with the atmosphere

• Cooling Tower is classic open system

• Recarbonation of Cold Lime Softened

Water

• Flashing of CO2 from Deep Well Water

Alkalinity versus Ct

88

10/17/2011

23

Molar Carbon (CLOSED SYSTEM)

• Ct = [H2CO3] + [HCO3] + [CO3]

• No CO2 exchange with atmosphere

• “Tight” unvented Reverse Osmosis Unit

Alkalinity versus Ct

89

How hyd-RO-dose handles alkalinity

CLOSED pH CALCULATION

Default Conserve Ct

VENTED pH CALCULATION

Conserve Alkalinity

Alkalinity and Ct

90

Carbonic acid Distribution of Species

Carbonic acid and dissolved CO2

Bicarbonate

Carbonate

91

Closed System – Acid Added To Decrease pH


Bicarbonate

Carbonate

Equilibrium shifts toward CO2 – carbonic acid

Ct constant, alkalinity changes

92

10/17/2011

24

Open System – Acid Added To Decrease pH


Bicarbonate

Carbonate

Equilibrium shifts toward CO2 – carbonic acid

Ct decreases, alkalinity changes

93


Software Examples

hyd-RO-dose - Closed versus

Open pH prediction and control

94

• Choose the appropriate WaterCycle

carbonic acid calculation method to

match the system

“Closed” for once through

“Open” for cooling towers

Alkalinity and Ct

95

• Choose the appropriate MineSAT

carbonic acid calculation method to

match the system

“Closed” for unvented mixing,

once through systems

“Open” for mixing, pH adjustment

in vented systems

Alkalinity and Ct

96

10/17/2011

25

• Kunz Curve: pH versus Alkalinity for Great Lakes

Water

• Translate Source pH: Kunz curve slope with

source water as intercept

• Manufacturer’s Calculation: classic alteration to

CO3/HCO3 or HCO3/H2CO3 ratio based upon acid

addition

• User Defined Curve

Predicting pH

97

Predicting pH

Software Examples

How many points does it take

to define a line?

98

Predicting pH

How many points does it take

to define a line?

y = mx + b

y pH

m slope

x alkalinity

b intercept

99

We Digress…

Why is the pH at 1.0 cycle different than

the make-up water pH?

Two Examples:

Cold lime softened make-up pH 10+

recarbonates as it circulates. pH drops to

8 something.

100

10/17/2011

26

We Digress…

Why is the pH at 1.0 cycle different than

the make-up water pH?

Example 2:

Deep well water. High pCO2. pH mid 6’s.

CO2 flashes like a soda bottle. pH rises to

7’s.

101

• Free versus total ions

• Distribution of species

• Ion pairs used by WaterCycle



calculations


102



calculations


103

Untreated

> 1.0 Supersaturated

= 1.0 At Equilibrium

< 1.0 Undersaturated

Saturation Level Limits

104

10/17/2011

27

Zone of Supersaturation

A water can be supersaturated

for a finite period of time, with or

without treatment.


105

French Creek Color Coding

106


Red - Scale Expected

Magenta – How sure are you of your

operating range, analytical values

Yellow – Like a yellow light.

Green – Out of the safe range

Blue – Safe!

107


Brackets Indicate

[ 5.00]

Out-of-Range

108

10/17/2011

28

CaCO3

135 – 150 xSat HEDP, ATMP, PAA

200 – 225 xSat PBTC, Blends


109

Calcium sulfate. Gypsum? Anhydrite?

• CaSO4*2H2O Gypsum at lower

temperature

• CaSO4 Anhydrite at higher

temperature


110

Calcium sulfate

• 2.5 – 5.0 xSat HEDP, ATMP, PAA

• 5.0+ xSat PCA, Specialized

phosphonates

Very responsive to induction time extension


111

Calcium phosphate

Tricalcium phosphate? Hydroxyapatite?

Alkaline Phosphate Program 400 – 1200 xSat

Phosphate Scale Control 125,000 xSat


112

10/17/2011

29

Silica

Amorphous silica?

Stoichiometric?

Non-stoichiometric?

Saturation Levels

113

Silica

Amorphous silica? 1.2x Sat untreated

Stoichiometric? MgSiO3 high temperature

Non-stoichiometric? SiO2 adsorbs on

Mg(OH)2 “floc”

Saturation Levels

114

BaSO4

80 xSat Phosphonates, PAA

Saturation Levels

R.O, Oil Field, Waste – coming soon to cooling

115

Interpreting saturation levels

< 1.0 Undersaturated

= 1.0 At Equilibrium

> 1.0 Supersaturated

Saturation Levels

116

10/17/2011

30

Rules of Thumb

A comparison of general guidelines

with ion association model results

117

SIMPLE INDICES

• Based Upon Analytical Values

• Simple Corrections for Temperature, TDS

• Ignore Ion Pairs, Bound Ions

• Estimate critical concentrations

Rules of Thumb

Simple Indices versus Rigorous Methods

118

RIGOROUS METHODS

• Correct Analytical Values

• Rigorous Corrections for Temperature, TDS

• Consider Ion Pairs, Bound Ions

• Base results on free ion

Rules of Thumb


119

SCALES DISCUSSED

• Amorphous Silica

• Magnesium silicate

• Calcium sulfate

• Calcium carbonate

Rules of Thumb


120

10/17/2011

31

SCALES DISCUSSED

•Amorphous silica

•Magnesium silicate

•Calcium sulfate

Rules of Thumb


121 Copyright 2011 French Creek Software

Water Treatment Rules of Thumb

Program Limit pH

Range

Temperature Comments

Acid Chromate

Acid Phosphate

120 ppm SiO2

5.8 – 7.2

1.0 x

Saturation at

77 oF

pH adjustment for CaCO3,

Ca3(PO4)2 control

Alkaline Zinc

Alkaline PO4

150 ppm SiO2

7.2 – 7.6

1.0 x

Saturation at

85 oF

Phosphonates/Polymers

for CaCO3, Ca3(PO4)2

control

No pH Control 180 ppm SiO2

8.6 – 9.0+ 1.0 x

Saturation at

85 oF

Phosphonates/Polymers

for CaCO3, Ca3(PO4)2

control

Silica Rules of Thumb Comparison

122

Copyright 2011 French Creek Software 123 Copyright 2011 French Creek Software 124

10/17/2011

32

Copyright 2011 French Creek Software 125

•Silica Rules of Thumb Correlate well

with 1.0 – 1.2 x Saturation at lower

temperatures in most systems.

•Exercise care when applying to systems

where temperatures can be lower than

85oF

•Rules of Thumb may be too conservative

in hotter systems.

126

Applicable

pH Range

Ion Product Limit

Mg as mg/L Mg,

SiO2 as mg/L SiO2

Comments

< 7.5 [Mg][SiO2 ] < 17,000

Stoichiometric magnesium silicate expected. Mg(OH)2

understatured. Unlikely.

7.5 – 8.5 [Mg][SiO2 ] < 12,000

Stoichiometric magnesium silicate expected.

Mg(OH)2 understatured except at extremes of

pH, temperature, Magnesium concentration.

> 8.5 [Mg][SiO2 ] < 6,000 May be superstaturated in Mg(OH)2. Silica

adsorbtion/adsorption within/upon

precipitating brucite {Mg(OH)2 mineral}

expected.

127

128

10/17/2011

33

129

130

131

Mag silicate Rules of Thumb Correlate well in

lower end of pH range where potential is low.

Exercise care when applying to systems where

pH is above 7.8

Rules of Thumb are confusing to apply.

Magnesium silicate and Magnesium hydroxide

saturation levels greatly preferred.

132

10/17/2011

34

Calcium sulfate

Rules of Thumb Comparison

MINERAL

FORM

UNTREATED RULE

OF THUMB

SATURATION

LEVEL AT

LIMIT

TREATED RULE

OF THUMB

SATURATION

LEVEL AT

LIMIT

GYPSUM

CaSO4*2H2O [Ca][SO4] < 50,000

Ca as mg/L Ca,

SO4 as mg/L SO4

0.96

(at 120 oF)

[Ca][SO4] < 10,000,000

Ca as mg/L Ca,

SO4 as mg/L SO4

4.98 X

Saturation

(at 120 oF)

ANHYDRITE

CaSO4

[Ca][SO4] < 50,000

Ca as mg/L Ca,

SO4 as mg/L SO4

0.99

(at 120 oF)

[Ca][SO4] < 10,000,000

Ca as mg/L Ca,

SO4 as mg/L SO4

3.10 X

Saturation

(at 120 oF)

133

134

Calcium sulfate Rules of Thumb Correlate well

with 1.0 – 1.2 x Saturation for Gypsum at 120oF.

Treated Rules of Thumb correlate loosely with

2.5 and 4.0 x Saturation level limits

Saturation levels for Gypsum preferred in lower

temperature systems.

Saturation levels for Anhydrite preferred in

higher temperature systems.

135

CALCIUM CARBONATE RULES OF THUMB Index Untreated

Limit

Treated

Limit

Stressed

Inhibitor

Limit

Comments

Langelier

Saturation Level

0.0 – 0.2 2.5 3.0 Use alkalinity corrected for

noncarbonate (e.g. NH3, CN, PO4, Si)

alkalinity.

Ryznar Stability

Index

6.0 – 5.8 4.0 3.5 Empirical rearrangement of pH and pHs

used to calculate Langelier Saturation

Index.

Practical

Scaling

Index

6.0 – 5.8 4.0 3.5 Interpretation similar to Ryznar. Index

applicable to NH3 or other alkali

contaminated waters. Calculates a pH

as if only carbonic acid based alkalinity

present.

Calcite

Saturation Level

1.2 – 2.5 135 – 150 200 - 225 Index corrects for ion pairing,

noncarbonate alkalinity, activity effects.

Reproducible results at the same index.

136

10/17/2011

35

L.S.I. 2.5 and Calcite 150 xSat at the Same C.R.

137

Treated Limit High Sulfate Makeup

L.S.I. 2.5 Underestimates Max Cycles

138

Calcium carbonate Rules of Thumb Correlate well

with 1.0 – 1.2 x Saturation for calcite.

Treated Rules of Thumb correlate loosely with 150

and 225 x Saturation level limits for common

inhibitors.

Saturation levels preferred, especially in higher

dissolved solids, high sulfate systems and systems

with non-carbonate alkalinity sources.

139

•Rules of Thumb, in general, were derived from

simplified saturation level calculations.

•Rules of Thumb provide quick-and-dirty

guidelines for troubleshooting, evaluating a

system.

•Ion Association model saturation levels are the

preferred method for evaluating scale potential,

establishing control limits.

•Be leery of Rules of Thumb at extremes of pH,

temperature, dissolved solids.

140

10/17/2011

36

Larson-Skold (Larson’s ratio)

epm Cl + epm SO4

epm Alkalinity

Indicates difficulty in maintaining film

Predicting Corrosion

___________________________ =

141

• Models Developed From Broad Database

• Blanks from Major Service Company Tests

• Chemistry Range pH 6.0 – 9.5 Temperature 25 – 70 OC

Cl 0 - 2000 SO4 0 – 2000

Ca 0 – 1200 “M” 0 - 1200

142

143

Most Models Based Upon Henry’s Law

Estimation of Water Phase CO2

Some Models Adjust Corrosion Rate

Based Upon FeCO3 FeS CaCO3

Saturation

CO2 Corrosion

144

10/17/2011

37

CO2 Corrosion

de Waard – Millams Method

CR = k pCO2m

Refined versions use fugacity rather than plain old pCO2

145

CO2 Corrosion

Oddo – Tomson Add a Scale Correction

CR = k pCO2m

Scor

Scor based upon ‘scaling temperature ‘

for FeCO3, FeS, CaCO3

146

CO2 Corrosion

Henan University and China National Petroleum Corporation Model

Adds the impact of H2S and a refined scale

factor to a modified de Waard – Millams

model

147

CO2 Corrosion


Fscale based upon scaling potential for FeCO3, FeS

Applies when T > Tscale

16010 Tscale = _______________________

0.6 * pCO2 + 5.0 pH2S -12.3

148

10/17/2011

38

CO2 Corrosion


Fscale based upon scaling potential for FeCO3, FeS

Applies when T > Tscale

16010 Ln(Fscale ) = _______ - 0.6 * pCO2 - 5.0 pH2S + 12.3

T

149

CO2 Corrosion

The French Creek Model Is a combination of Oddo – Tomson and the Henan University and China National Petroleum Corporation Model Uses CO2 fugacity rather than uncorrected pCO2

Uses FeCO3, FeS, and CaCO3 saturation for scale correction

Adds a %inhibition correction

150

Part 2 Putting French Creek to Work

151

• Windows VISTA

• Input units

• Printers

• Printer ports

• Printing to file

Installation & Setup Hints

152

10/17/2011

39

The Default Directory

WaterCycle \WATER

hyd-RO-dose \HYDRO

WatSim \MUNI

DownHole SAT \DHSAT

MineSAT \MINESAT

Restoring & Saving Work files

153

The Default Directory

WaterCycle \WATER\INHIB

hyd-RO-dose \HYDRO\INHIB

WatSim \MUNI\INHIB

DownHole SAT \DHSAT\INHIB

MineSAT \MINESAT\INHIB

Restoring & Copying

Products, Inhibitors

154

• Source analysis input

• Input specs

• Temperature profiles

• pH profiles

• 3D pH/temperature profiles

Once Through System Evaluation

155


• How WaterCycle varies pH/alkalinity

• Should you conserve Ct? Alk? what does that little box really mean?

• Printing reports

• Printing graphs

156

10/17/2011

40


• Exporting graphic files

• Printing in color

• Future once-through options

157

• Makeup water input

• System specs • Customizing your region

• What numbers should I use?

• % evaporation

• Leaks

• Drift

• Cycles

Cooling Tower Evaluation

158

• Predicting pH • Default curve

• Custom pH/alkalinity curves

• Should the makeup water pH equal the pH at

1.0 cycles?

• Are more sophisticated models necessary?

• Acid feed


159

• How WaterCycle “Concentrates”

makeup water • Should you: conserve alkalinity? Total molar

carbon?

• Alkalinity/sulfate or alkalinity/Cl changes due to

pH control

• Graph color coding

• Setting the range for tables


160

10/17/2011

41

• How WaterCycle “Concentrates”

makeup water • Should you: conserve alkalinity? Total molar

carbon?

• Alkalinity/sulfate or alkalinity/Cl changes due to

pH control

• Graph color coding

• Setting the range for tables


161

• Interpreting Tables: • Water Chemistry

• Deposition Potential


162

• Calcite saturation level • Calcite saturation 150 warning/action point

• Calcite saturation 200 warning/action point

• How high can you go?


163

• Tricalcium phosphate • What’s significant?

• Where do typical orthophosphate corrosion

inhibitor programs run?

• How high a saturation level can copolymers

handle?

• Why are Ca3(PO4)2 momentary excess values

so small?


164

10/17/2011

42

• Silica • Modeling pH/temperature effects upon silica

solubility

• Warning zones for Mg(OH)2: SiO2

• Do silica inhibitors work?

• Calcium sulfate saturation levels

– Gypsum?

– Anhydrite?


165

• 3D Profiles • Setting specs for the profiles

• Printing in black and white

• Color printing

• Exporting as a PCX file

• Showing the impact of SPC control limits

• Exporting the Data Points to an ASCII


166

• Bringing graphs and data into other

programs • Printing PCX files from Windows Paintbrush

Accessory

• Creating and printing multi graph pages in

CorelDraw

• Microsoft Word


167

Part 5 – Modeling Scale Inhibitors

168

10/17/2011

43

• The Concept of Induction Time • The Molecular waiting room

• Kinetics vs. thermodynamics

• The impact of phosphonates upon induction

time

• The impact of saturation level upon induction

time

• The impact of temperature upon induction time

Modeling Scale Inhibitors

169

…. they delay the inevitable.

Scale Inhibitors do NOT Prevent Scale….

[inhibitor]M

Induction Time = _______________

k [SR - 1]P-1

170

1

Induction Time = _____________________________

k [Saturation Level - 1]P-1

Where:

Induction Time is the time before crystal formation and growth occurs;

k is a temperature dependent constant;

Saturation Level is the degree of super-saturation;

P is the critical number of molecules in a cluster prior to phase change


171


172

10/17/2011

44


173


174

-Ea/RT

K = A e

Where:

k is a temperature dependent constant;

Ea is activation energy;

R is the Gas Constant;

T is absolute temperature.


175

HEDP excellent for lower temperature, lower saturation level calcium carbonate

ATMP for higher temperature, higher saturation

level calcium carbonate

PBTC for extreme saturation levels “stressed” systems

PAA performance improves as pH increases due to protonation state of functional groups

Blend smoothing effect over a wide range of saturation level and temperature

Inhibitor Niches

176

10/17/2011

45

Inhibitor Niches

0

1

2

3

4

5

6

7

8

9

0 50 100 150

HE

DP

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of HEDP

177

Inhibitor Niches

0

1

2

3

4

5

6

7

0 50 100 150

AT

MP

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of ATMP

178

Inhibitor Niches

0

5

10

15

20

25

0 50 100 150

PA

A D

os

ag

e (

mg

/L)

Saturation Level

Saturation Level Vs Dosage of PAA

179

Inhibitor Niches

0

1

2

3

4

5

6

7

8

9

0 50 100 150

PM

A D

os

ag

e (

mg

/L)

Saturation Level

Saturation Level Vs Dosage of PMA

180

10/17/2011

46

Inhibitor Niches

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150

PB

TC

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of PBTC

181

No Virginia, There is no Synergy…

Modeling Inhibitor Blends

Tuesday, September 21, 1897

The Sun Newspaper, New York, NY.

182

Synergy? 1 + 1 = 2.2 They help each other

Equality? 1 + 1 = 2.0 They ignore each other

Competitive 1 + 1 = 1.8 They get in each other’s way

Inhibition?

Modeling Inhibitor Blends


0

2

4

6

8

10

0 20 40 60 80 100 120 140

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of Common Inhibitors and Blends

ATMP

HEDP

PAA

PBTC

PMA

PBTC:PMA

HEDP:PMA

1:1 ATMP:HEDP

184

10/17/2011

47


0

1

2

3

4

5

6

7

8

9

0 50 100 150

PM

A D

os

ag

e (

mg

/L)

Saturation Level


0

1

2

3

4

5

6

7

8

9

0 50 100 150

HE

DP

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of HEDP 0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150

1:1

HE

DP

:PM

A B

len

d

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of 1:1 HEDP:PMA

Blend


0

1

2

3

4

5

6

7

8

9

0 50 100 150

PM

A D

os

ag

e (

mg

/L)

Saturation Level


0

0.5

1

1.5

2

2.5

3

0 50 100 150

1:1

PB

TC

:PM

A

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of 1:1 PBTC:PMA

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150

PB

TC

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of PBTC

186


0

1

2

3

4

5

6

7

8

0 50 100 150

1:1

AT

MP

:HE

DP

Ble

nd

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of 1:1 ATMP:HEDP

Blend

0

1

2

3

4

5

6

7

8

9

0 50 100 150

HE

DP

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of HEDP

0

1

2

3

4

5

6

7

0 50 100 150

AT

MP

Do

sa

ge

(m

g/L

)

Saturation Level

Saturation Level Vs Dosage of ATMP

187


Software Examples

Developing An Inhibitor Model

188

10/17/2011

48


Use Common Sense

Minimum of 3 Saturation Levels

Minimum of 3 Temperatures

Minimum of 3 Induction Times

Find the Failure Points

189

• Laboratory test methods • Static beaker tests

• Constant composition tests

• Pilot cooling systems

• Relating laboratory tests to field systems

• Notes on experimental design


190

• Putting it all together – The Models • Dosage = f (saturation level, temperature time)

• Dosage = f (saturation level, temperature, pH,

time)

• Dealing with interfering substances (e.g. Fe)


191

Modeling Corrosion Rates and Corrosion Inhibitors

192

10/17/2011

49

• Prior art for corrosion rate prediction • Simple indices as indicator

• Larson Skold

• Do calcium carbonate indices apply?

• Psigan and Singley

• Davis

• Boffardi

Modeling Corrosion Rates

193

• The Zisson Data Model • Laboratory Method

• Parameter Selection

• The Model

Modeling Corrosion Rates

194

• Experience based data (the Water

Treatment Company Manuals)

• Laboratory data

• The models • Dosage = f (water chemistry, target corrosion

rate)

• Corrosion rate = f (waster chemistry, inhibitor

dosage)

Modeling Corrosion Inhibitors

195

Control Corrosion Calculate Dosage to Achieve Target

Corrosion Rate

Compare Costs for Various Levels of Control

Compare Inhibitors

Control Inhibitor Caused Scales

196

10/17/2011

50

197

Belcor 575 Dosage vs

Target Corrosion Rate

0.8

0.9

1

1.1

1.2

1.3

1.4

0 1 2 3 4 5

Target Corrosion Rate (mpy)

mg

/L B

elc

or

575 (

acti

ve)

198

Corrosion Rate vs

Belcor 575 Dosage

0

1

2

3

4

5

6

0.9 1 1.1 1.2 1.3

Belcor 575 Dosage (mg/L active)

Co

rro

sio

n R

ate

(m

py

)

199

Optimizing Inhibitor Blends for a Specific Water

200

10/17/2011

51

• How WaterCycle evaluates a water • Corrosion inhibitor

• Problems caused by the inhibitor

• Other scale forming species


201

• Examples • The orthophosphate/copolymer/phosphonate

blend


202

Corrosion Inhibitor Dosages

• Solubility Controlled Dosage

• Performance Controlled Dosage

203

Dosage = f(water chemistry, temperature, corrosion target)

Corrosion Rate = f(water chemistry, temperature, inhibitor)

204

10/17/2011

52

205

Corrosion Inhibitor Models (solubility controlled)

• Orthophosphate

• Polyphosphate

• Zinc

206


10/17/2011

53


Blending

211 212

10/17/2011

54

213 214

215

100% Well Water, 120 oF

100% Well Water, 70 oF

216

10/17/2011

55

Workshop

217

• Optimize your own formulas

• Develop your own models

Workshop

218

• Call FCS from your in-house software

• Controller Calculations

• Web Calculations

French Creek DLL’s

Unix Libraries

219

• Your logos, addresses, products

• Batch input from analytical files

Custom Software

220

Documents

Overview - French Creek Softwarefrenchcreeksoftware.com/chemtech/chemtech-fall-2011-seminar.pdf · French Creek Training ... 10/17/2011 12 Analytical Values or Free Ions? ... Chemistry”