POWERPART 2: WATER TREATMENT STRATEGIES FOR FOSSIL-FIRED POWERPLANTS

n Part 1, we examined howcorrosion can be a majorcause of equipment failures in

power plants. One aspect to improvefacility operations is internal surfacepassivation where operators controlwater chemistry on the waterside of theboilers to encourage magnetite forma-tion, which can effectively control corro-sion.

However, in utility superheaters themagnetite formation is different becauseofthe temperatures that are above 662°F.In these cases, the magnetite is lessstable and it can break down in the

cooling and heating cycles associatedwith boiler shutdowns. Magnetite parti-cles can then be carried to the super-heater and into the turbine with the steamafter a shutdown and cause excessive

wear on the nozzles in the high-pres-sure turbine.

Part 1 also reviewed corrosion mech-

anisms that can be caused by oxygen,flow-accelerate corrosion, heat recov-ery steam generator (HRSG) metal lossin economizer tubes, deposit-inducedcorrosion, caustic corrosion, deposition,and stress corrosion cracking. In thisarticle, we will review water treatmentstrategies and monitoring in fossil-firedutility plants.

Minimizing CorrosionInconventionalfossilpower plants, high-purity water is used as the working fluid

By Douglas I. Bain, Ph.D.,Bain & Associates Consulting Ltd.and Joe BatesiSagacity Inc.

Editor's note: Part I appeared in the December 2005issue,

ISSN:0747-8291. COPYRIGHT (C) Tall Oaks Pub-lishing, Inc. Reproduction in whole, or in part,including by electronic means, without permissionof publisher is prohibited. Those registered with theCopyright Clearance Center (CCC) may photocopythis article for a flat fee per copy.

ULTRAPUREWATER@OCTOBER 2006

for producing electricity by the Rankinecycle. The water is purified using ionexchange, filtration and other process-es to remove the impurities before thewater is added to the steam cycle. How-ever, occluded regions such as the ar-eas underneath deposits, can lead tothe accumulation of trace levels of im-purities, resulting in aggressive envi-ronments.

Operators of power plants must bediligent in controlling the water chemis-try to ensure that any problems thatdegrade water quality are correctedquickly. Organic and inorganic addi-tives are used to provide further corro-sion protection. Oxygen is one of themain corrosion agents in the steam cy-cle. Adding an oxygen scavenger, suchas hydrazine directly to the condensatewater is a useful apfYroach to removeresidual oxygen. Ammonia or organicamines are added to the feedwater tocontrol the pH. Maintaining alkalineconditions throughout the steam cyclecan minimize the general corrosion rateof carbon steels that are widely used inpiping systems. Corrosion inhibitors,dispersants, and other chemicals arealso used in some power plants to con-trol corrosion and to minimize fouling ofheat transfer surfaces. Sodium phos-phate is currently used in many smallerfossil plants to buffer the pH because ofimpurity ingress excursions.

Buffering with phosphate salts gener-ally follows either a 'coordinated phos-phate' or 'congruent phosphate' regi-men. In the coordinated phosphate/pHcontrol regimen sodium phosphate saltsare added to the boiler water in anattempt to maintain a sodium-to-phos-

phate ratio of 3:1. In the congruentphosphate/pH control regimen, a sod i-um-to-phosphate ratio of between 2.4and 2.8:1 is maintained. The ratio is

held closely to 2.6: 1 in most congruentphosphate/pH control programs. Leak-age of sodium from deionizer systemscan create difficulties with maintainingthe sodium-to-phosphate ratio in coor-dinated or congruent phosphate/pHcontrol programs. In traditional fossil-fired power plants where the deionizereffluent is polished using mixed-bedpolishing units, sodium leakage is min-imized. However, a relatively small pro-portion of utility systems use phosphate/pH control treatment programs.

Most use all-volatile treatment (AVT)programs based on hydrazine with am-monia addition in some cases. Amines

are also used in a relatively small num-ber of units. Phosphate-based pro-grams are commonly found in cogener-ation systert;ls operating at lower pres-sures and in smaller utility units.. Morerecently, under deposit corrosion asso-ciated with the presence of acidic phos-phate salts has been recognized. Thishas lead to the development of an alter-

nate ~pproach called equilibrium phos-phate control, which uses lower phos-phate residuals with appropriate pHcontrol to minimize the potential for un-der deposit acid phosphate corrosion.

Water Treatment StrategiesIt must always be recognized that watertreatment can mitigate but not correctcorrosion due to improper design orincompatible metallurgies. The primaryapproach to protecting a steam gener-ator system is by minimizing impurity

TABLE AQuality Standards for HRSGs

Sample PointMake up

Condensate pump discharge

Main steam

Parametersilica (ppb)specific conductivity /Js/cmsodium (ppb)cation conductivity /Js/cmsodium (ppb)cation conductivity /Js/cm

Limit<20<0.15<6<0.25<6<0.25

19

TABLE BSolubility Product Constants and Additional Information for Iron-Containing Species

LOG KspCompound (25°C)Fe(OH)2 -14

-15.1

CrystallographicSystemColor

White(brucite)

Fe(OH)3 -38.7

FeO(wustite)

black cubic(NaCI)

Fe3O4(magnetite)

black cubic(inverse spinel)

-14-18

Alpha FeO(OH)-39.1(goethite)

yellow orthorhombic

ffiamma FeO( OH)(Iepidocrocite)

-39.1 orange

, <,

Alpha Fep3 -42.7(hematite)

red toblack

trigonal(hexagonal

unit cell)

Other Possible Iron Forms

Beta FeO(OH) lightbrown

Gamma Fe2O3(maghemite)

brown cubic (spinel)

Comments

1. decomposes @ 100°C to Fep 4 + H22. dehydrates to FeO

3. at room temperature + O2 can form goethitelepidocrocite and magentite.

Unstable iron form rapidly dehydrates tooxide form.

Decomposes to Fe and Fep4

Oxide typical of "0" oxygen systems.Found in utility condens.ate systems usinghydrazine.

Dehydrates to hematite at 200°C. Formshematite at lower temperatures in

presence of Hp. This form is favoredat high pH and has been identified bycolor in condensate systems.

6:>rthorhombic Dehydrates to hematite at 200°C. In

tne presence of HP corlVerts to hematite atIQwer temperatures. Has been identifiedbased on color in systems where .ironslugging is a problem. Has beenmistaken for copper contamination.

Decomposes to magnetite at 1,457°C. Mostcommon iron form in industrial system.Hematite formation favored by low pHand increasing temperatures.

Dehydrates to hematite at 230°C.Presence of water enhances dehydration.

Transforms to hematite above 250°C.

Presence of HP enhances transformation.

~- ...~ 1." ~...""----4P~ ..;!"":- -

7P.=~~ -~~. Soft8MIS\

.. '.. - ---'- -1 ~"\... ,~Stan""",Reverse Osmosis Systems ~"'-- ~:::::-=-==-- ":::~.;;:-.:..' ~.===:;-~.. . ~

Pre-engineered and CustomWater Treatment Systems

.Leading-edge technology

.Experienced design engineers

.Manufacturing & Service

Integrated Separation Solutions

Madison,WI .~

_.Sharon,WI ~262-736-4211

www.isepsol.com ~.

20

ingress. Sources of impurities include:condenser cooling water, process con-densate, pretreatment/make-up water,chemical feed impurities, condensatepolishers, regenerant chemicals, auxil-iary heating steam, and sample coolers.

Recording instruments for sodium, sil-ica, chloride, dissolved oxygen, andorganic carbon contamination are com-monly used in plants to monitor make-up water, condensate, boiler feedwater,boiler water, and steam samples on acontinuous basis to ensure that excur-

sions are quickly identified and correct-ed by minimizing ingress of contami-

ULTRAPUREWATER@OCTOBER 2006

nants.The primary objectives of the chemi-

cal treatment program are to minimizedeposition and corrosion on internalsurfaces in the boiler unit. The first stepinvolvesminimizing contamination intheboiler feedwater. Contaminants canenterthefeedwater eitherfromthe make-up water or the condensate. Make-upwater pretreatment systems commonlyuse filtration, reverse osmosis, anddeionization to minimize the ingress ofcontaminants. lron- and copper-basedcorrosion products are common con-taminants in the condensate. In addi-tion, hardness salts, silica, chloride,sulfate, and sodium can contaminatecondensate as a result of condenserleaks. Condensate polishers are veryhelpful in removing this contamination.Additional contaminants such as oil orother organic materials are often foundin cogeneration systems because ofcontamination of process condensate.In these systems, additional purificationsteps such as activated carbon filtersare used ahead of the condensate pol-ishers to minimize condensate contam-ination.

The treatment approaches used inmost conventional fossil-fired utility boil-ers are based on either AVT or oxygen-ated treatment. In lower-pressure drum-type units, phosphate treatment ap-proaches are also used.

Combined Cycle HRSGsModern HRSGs are built in a wide vari-

ety of designs. Traditional two-drumunits had low-pressure (15 to 50 poundsper square inch gauge (psig) sectionsand high-pressure (600 to 1,500 psig)sections. In the three drum designs,intermediate pressure (50 to 400 psig)sections were added and the high-pres-sure sections operated at pressures upto 2,200 psig. Some modern designsemploy once-through steam generatorsand combinations of once-throughsteam generating sections with one ortwo drum steam generating sections.

The treatment approaches used gen-erally involve either AVT or oxygenatedtreatment at the higher pressures withconventional phosphate treatment orequilibrium phosphate treatment in theintermediate pressure range. In someunits, polymer-based treatment pro-grams are used at the lower end of thepressure range (600 to 700 psig). Foronce-through steam generator designs,an all-AVT approach, or an oxygenatedtreatment approach is required.

ULTRAPUREWATER@OCTOBER 2006

KEEPING ANIONRESIN QUALITY?

See what cleanrea.Hy looks like.

.)

f,t'f~

InventedbyRecircul&tionTechnologiesInc.,ReStore+ issorevolutionarythatwe'repatentingit.Thisfast,

thorol!lghcleaningj3rocesspestares anionresinsf~ lik~ .

newcondition,makingtliletime-cansuming"BrineSqueeze"obsolete.

Brought to your site by the leader in mobile resincleaning services, ReStore +:.Rel;llovesanddestroysasmuchas90percentofthe.l:ncreasesthrol:lgh~utby[;Ipto 50percent.Decreasesoperatingcasts'byupto 50 f:Je~cent

.eli,minatesdisposalof fouled"resins

.Reeuces C6Stby nearly

II:

II

r ABLE CQptilTlum"Sodiumand Phosphate Values

at Various Operating Pressures'~

I OperatingPressure(psig)2,2001,800*,5001,2001,000700

OptimumPhosphate Value

(ppm)<4.5<7<10<12<15<20

OptimumSodium Value

(ppm)<4.5<6<8<9<13<15

TABLED

Guidelines for Various;Qp~~ating "Pressures

Drum Pressure(psig)2,7002,5001,9001,5001,000

Silica(ppm)<0.08<0.15<0.35<0.7<1.0

Chloride(ppm)<0.5<1.0<2.0<2.5<3.5

Sulfate(ppm)<1.5<1.7<2.5<2.7<3.5

'f'ASLEEBoilerFeedwaterGuidelinesfor AVTChemistry,

'il

ParameterCation conductivity (fJs/cm)Oxygen (ppb)pHIron (ppb)Hydrazine (ppb)

Sample

conti n!J~9jJscontinuouscontinuous

weeklycontinuous or shift

TABLe:,FBoilerlieedwaterGuidelinesfor OT

ParameterCation Conductivity (lJs/cm)Oxygen (ppb)pHIron (ppb)

SamplecontinuouscontinuouscontilillJJouS

weekly

TABLE GDowncomer Chemistry GuideliJ;les

Parameter

Sodium (ppm)Chloride (ppb)Sulfate (ppb)Silica (ppb)pHCation conductivity (IJS/cm)Oxygen (ppb)

22

Samplecontinuous or shiftcontinuous or shift

dailycontinuous or shiftcontinuouscontinuouscontinuous

Target Value<0.21 10

9.2- 9.6<5<20

Target Value<0.15

30 - 509.0- 9.6

<5

Target Value< 0.7< 30<30<100

8.8 - 9.2<1~.5<5

Optimizing boiler feedwater purity isthe first step toward minimizing corro-sion and deposition in the HRSG. Thosesteps can include guidelines for specif-ic areas (Table A) or a general overview(Table B). Table B provides guidelinesfor make up water, condensate andsteam purity for HRSGs in utility service.

In phosphate control programs, thephosphate concentration range usedvaries, depending on the operating pres-sure of the unit. Using equilibrium phos-phate control, the equilibrium phosphateco~entration must be determined foreach individual unit. The Electric Power

Research Institute (EPRI) has publisheda method for the determination of the

equilibrium phosphate concentration.Table A provides guidelines for the con-centration of sodium and phosphate inboiler water over a range of operatingpressures. The actual sodium-to-phos-phate ratio used in any specific case willdepend on the boiler design and oper-ating conditions and on the feedwaterquality attainable with the equipmentinstalled. It should be noted that 1.38

parts per million (ppm) of phosphateper ppm of sodium is required to obtaina sodium-to-phosphate mole ratio of 3to 1. It should ~Iso be noted that in manyindustrial units operating in the lowerpressure range, higher phosphate con-centrations are used to maintain buffer-

ing capacity in the presence of elevatedconcentrations of sodium in make-up

water bes::ause of sodium leakage from, deionizer units.

The silica concentration in the boilerwater must be controlled to minimize the

potential for silica volatilization in thesteam and chloride and sulfate concen-trations must be controlled in order to

minimize the potential for boiler water-side corrosion. Table C provides guide-lines for the concentrations of silica,chloride, and sulfate in the boiler water

with phosphate treatment over a rangeof operating pressures.

In the AVT approach, only volatilechemical additives are used normallyan oxygen scavenger such as hydra-zine with either ammonia, or in manycases amines at lower pressures. High-purity boiler feedwater is critical in theoperation of AVT chemistry programs.Table 0 provides a review of the criticalparameters monitored in boiler feedwa-ter with guidelines for limiting values.

Generally, the application of oxygen-ated treatment in drum HRSGs is advis-

able only if very pure feed water is avail-able in the unit with all ferrous metallur-

ULTRAPUREWATER@OCTOBER 2006

gy in the system. Table E provides areview of the critical parameters moni-tored in boiler feedwater with guidelinesfor limiting values.

Conventional Utility BoilersOxygenated treatment has been usedwith much success in fossil-fired utilityunits. It has been helpful in reducingiron contamination in both the feedwa-ter and the boiler water and in minimiz-

ing the need for chemical cleaning.Some basic conditions must be met to

ensure successful application of theoxygenated treatment regimen to drumfired utility boiler units. Here is a sum-mary:

1. It is important that no copper or cop-per alloy components be present inthe feedwater system.

2. It is advisable to have a sample pointavailable at the downcomers as wellas at the economizer inlet.

3. Feedwater and steam cation con-

ductivity must be maintained at lessthan 0.15 microsiemens per centi-meter (flS/cm).

4. It is essential that feedwater purity bemaintained to prevent corrosion inthe system. Full-flow condensatepolishers are recommended to en-sure removal of impurities resultingfrom condenser leaks.

Table F provides a review of the criti-cal parameters monitored in boiler feed-water with guidelines for limiting values.Table G provides guidelines for the con-centrations of sodium, silica, chloride,sulfate, pH, cation conductivity, andoxygen in the boiler water at the down-comers. Table H provides guidelinesfor the concentrations of sodium, silica,chloride, sulfate, pH, cation conductiv-ity, and oxygen in the superheatedsteam.

Oxygenated treatment has been usedwith great success in once-through util-ity units. It has been helpful in reducingiron contamination in both the feedwa-ter and the boiler water and in minimiz-

ing the need for chemical cleaning. Theguidelines for critical contaminant con-

TABLE HSuperheated Steam Guidelines

ParameterSodium (ppb)Chloride (ppb)Sulfate (ppb)Silica (ppb)pHCation conductivity, jJS/cmOxygen (ppb)

Samplecontinuous or shiftcontinuous or shift

daily .(ycontinuous or shiftcontinuous'continuouscontinuous

TABLE IReheat Steam Guidelines

Parameter

Sodium (ppb)Chloride (ppb)Sulfate (ppb)Silica (ppb)

Samplecontinuous or shiftcontinuous or shiftdailycontinuous or shift

Target Value<3<3<3<10

8.8 - 9.2<0.15

30 - 50

~.

Target Value<3<3<3<10

TABLE JBoiler Feedwater for OTSG Guidelines

ParameterCation cOJ'ilductivitY(jJS/cm)Oxygen (ppb)pH ferrous metallurgYJ'Copper (ppb) , ,Iron (ppb) .Hydrazine (ppb)

f

Samplecontinuouscontinuouscontinuousweeklyweeklycontinuous or shift ."

Target Value<0.151 - 10

9.2- 9.6<2<5

<20

TABLE KBoiler 'Feedwater for Economizerlrilet Guidelines

ParameterCation conductivity (jJs/cm)Oxygen (ppb)pH ferrous metallurgySodium(ppb)Iron(ppb)Ammonia (ppm)

Sample

c°t!J!nuouscontinuouscontinuouscOrc1tinuousweeklydaily

TABLE LControl Parameters for Reheat Steam

ParameterSodium (ppb)Cnloride(~ppb')Sulfate (ppb)Silica (ppb)Cation conductivity (jJS/cm)Oxygen (ppb)

SampleContinuousDailyDailyShiftcontinuouscontinuous

Target Value<0.15

50 - 1508.3 8.5

<3<5

0.04 ~ 0,05

Target Value<3<3<3<10<0.2

50 - 150 ~ .

centration limits in boiler feedwater boil-er water and superheated steam are monia or in many cases amines at lower boiler water in drum units at the down-essentially the same as those listed in pressures. High-purity boiler feedwater comers.

Tables E through G. is critical in the operation of AVT chem- Table I provides guidelines for theistry programs. Table H provides a concentrations of sodium, silica, chlo-

All-volatile teatment. In the AVT ap- review of the critical parameters moni- ride, sulfate, pH, cation conductivity,proach, only volatile chemical additives tored in boiler feedwater for drum units and oxygen in the superheated steam.are used normally an oxygen scaven- with guidelines for limiting values. The table also gives guidelines for re-ger such as hydrazine with either am- Table G also provides uidelines for heat steam quality. Table J provides a

ULTRAPUREWATER@OCTOBER2006 23

--

-.

!. I

I I

II

I!

review of the critical parameters moni-tored in boiler feedwater for once-

through units with guidelines for limitingvalues.

II'

Field experience. In recent years, thetreatment approach has changed fromAVT to oxygenated treatment in a con-siderable number of utility units. Inmany cases, significant reductions iniron contamination in boiler feedwaterhave been reported along with a re-duced requirement for chemical clean-ing. One such case involves Unit Num-ber 2 at MerrimackStation - PublicService of New Hampshire

Merrimack Station Unit Number 2 is auniversal pressure cyclone-fired unitburning a blend of high British thermalunits (BTU) bituminous coals. The unitproduces 2.3 million pounds per hour ofsteam at 2,620 psig at the throttle valve.The main steam and reheat steam tem-perature is 1,005°F. The unit was oper-ated with AVT chemistry for approxi-mately 30 years and changed over tooxygenated treatment in 1994. Full-flowcondensate polishing is employed toremove impurities from the condensatestream. Oxygenated treatment is em-ployed only under normal load condi-tions. Full deaeration is used duringstart-up and shut-down operations.Under normal operating conditions us-ing oxygenated treatment, the pH iscontrolled between pH 8.0 to 8.5 at thedeaerator inlet. Under start-up and shut-down conditions without oxygen addi-

III

tion, the pH is elevated to pH 9.1 to 9.3.Table K illustrates the control param-

eters utilized for boiler feedwater at theeconomizer inlet. Table L illustrates thecontrol parameters utilized for reheatsteam.

Prior to 1994 using the AVT program,Unit 2 was chemically cleaned every 2to 3 years, based on an increase inboiler feed pump discharge pressure.Fouling of the orifice valves in the lowerheader system caused the increase indischarge pressure. Waterwall tubesamples taken at regular intervals didnot show any appreciable deposit ac-cumulation. Following the change tooxygenated treatment in 1994, the unithas not required cleaning in a period ofmore than 7 years. Again, waterwalltube samples have not shown any sig-nificant deposit accumulation.

Advanced Monitoring TechniquesTechnology advances over the past twodecades have led to an outpouring of

'varioys digital/computerized data log-ging systems that have the ability tocontrol, trend, and monitor power plantprocesses. Water treatment and co.rro-sion control softwqre are plentiful in to-day's power market. Often, the ability tomonitor and store data greatly exceedsthe resources required to analyze andassess that data in a timely fashion. Thisis a direct contrast to the purpose ofcollecting data, and thus the whole pro-cess can become a mere act of elec-

tronic cataloging of numbers.

_mmn.~'@)J~ib~!_~

. Low prices. Fast service

. Huge selection of RO membranes

1-877-854-LESSConsolidated Equipment Company. 10100 J Street. Omaha, NE68127

Integrating chemicals and equipment for water treatment solutions:industrial ROsystems. membranes. chemicals. filters. membrane cleaning services

24

Data requirements. The first consider-ation for data requirements is potentialproblems. Data are needed to assurethat the power plant is operating withina certain set of criteria. As listed previ-ously, corrosion and deposition are twomain problems in a power plant that canoccur from a variety of situations. Thereare measurement techniques that canbe used to monitor and assess theseproblems both on and off line. Table Agives an example of common powerplant c<11cernsalong with some datathat are used to diagnose the condition.

Locations in the plant for data monitor-ing are chosen based on the area ofconcern, the ability to sample, and theability to accurately analyze for that spe-cies based on expected concentrationlevels. Algorithms and modeling can beused to calculate the corrosion or chem-istry environment of an area that is notaccessible to direct measurement. Aswith all data collection, the error in mea-surement or calculated measurementmust be considered in evaluating theoverall result.

Also, the frequency of measurementplays a large role in proper diagnosisand the amount of data logging that isrequire~ to assure plant integrity. On-line data acquisition can occur at fre-quencies greater than once per sec-ond. Manual, or grab data typicallyoccur once per shift, day,week, month...The frequency of data collection repre-s~nts a combination of importance anddynamics of the data. A high frequencyof data collection reflects an importantor dynamic data and a low frequency ofdata collection reflects a less importantor dynamic data. The reliance on in-linedata such as pH, conductivity, and cat-ion conductivity has,greatly enhancedthe ability to monitor plant chemistryspecifications for many power plantconditions.

Still, the diagnosis of these conditionsis often left to single-parameter condi-tions. Single-parameter diagnosis isreasonable for some conditions, suchas an elevated pH in the boiler, or a lackof amine in the feedwater. However,there are multiple conditions that cancontribute to a single data out-of-spec-ification occurrence. This leaves sin-gle-condition diagnosis at a loss.

Other technologies and algorithmshave been developed to assess multi-variable diagnostics. Some of thesetechniques include fuzzy logic, rule-based diagnostics, and pattern recog-nition techniques. Initial applications of

ULTRAPUREWATER@OCTOBER 2006

these techniques were used in the pow-er industry through EPRI member utili-ties (1, 2).

Further development of technologieshas lead to real time Internet-baseddiagnosis for systems, including a vari-ety of steam cycles and cooling towers.Advanced techniques have been em-ployed in the power industry to not onlydiagnose the condition of the plant inreal time, but also to give guidance topower plant personnel on correctiveactions and consequences of the cur-rent condition.

SummaryCorrosion in power plants is boundedby metallurgical susceptibility and de-sign, driven by heat and stress, andadvanced by the physical-chemicalenvironment. Because of these rela-tionships, chemistry programs havebeen developed to address a variety ofmetallurgies,temperatures,and designsin order to mitigate corrosion and en-sure equipment integrity. There aremany instrumentsand techniques avail-able to improve control of chemistryprograms and corrosion in fossil powerplants. These approaches have proven

0 Decisivelyhigherflowcapacities than competitiveregulators with much lowerpressure drop-off.

0 Protectsinstruments byconverting varyinginlet pressuresto presetdownstream

pressure.

ULTRAPUREWATER@OCTOBER 2006

valuable in mitigating corrosion issues,which would have seriously underminedequipment integrity if not addressed.Recent advances with on-line monitor-

ing. and diagnostic techniques are al-lowing power plant personnel to spendless time gathering and analyzing data,and more time proactively managing aprogram. Service providers with Inter-net based technologies are able to im-plement low cost, high value productsto power plant workers that improveoverall resource performance..

References1. "EPRISMARTchemWorksTM",TR-108739-

V1, Electric Power Research Institute(June 1998).

2. Smith, D.J. "Remote Monitoring", PowerEngineering (March 2004).

Author Douglas Bain, Ph.D., has morethan 33 years experience in the watertreatment industry, including 26 yearswith Dearbornand BetzDearbornandthe last six years as an independentconsultant. His work has involved allaspects of cooling systems, boilers,steam turbines, and ste~m/condensatesystemoperation. Dr. Bain has water

treatment experience in the refining,petrochemical, pulp and paper, electri-cal power generation, steel, and chem-ical plant utility operations. He receivedhis Ph.D. in chemistry from UniversityCollege Cardiff (The University of Wales)in Cardiff, Wales, Great Britain.

Coauthor Joe Bates is the vice presi-dent of engineering and a principal con-sultant at iSagacity. He has 22 years ofexperience with companies that includeCommonwealth Edison, Electric PowerResearch Institute (EPRI), and EPRISolutions. He is a recognized expert inwater treatment and corrosion control in

the power industry. He is a patent holderof a polymer dispersant for nuclear steamgenerators as well as a developer andimplementer of chemistry program opti-mizations at several power plants. Mr.Bates holds a B.S. in Chemical Engi-neering from the University of Illinois.

This paper was presented at the 24th Utility Chemis-try Workshop, which was conducted May 11-13,2004, in Champaign, III.

Key words: ALL-VOLATILE TREAT-MENT, BOILERS, CORROSION, FOUL-ING, OXYGEN, POWER, SCALING

II!

I!

i

III'Ii"

27