Via Federal Express & Electronic Mail

.OCT 17 2008

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION 8

1595 Wynkoop Street

DENVER, CO 80202-1129

Phone 800-227-8917

http://www.epa.gov/region08

Ref: 8ENF-L

Mr. Terry O'Clair

. Director, Air Quality Division

North Dakota Department of Health

918 E. Divide Avenue

Bismarck, ND 58501-1947

Re: Transmittal ofEPA'B Response to

Minnkota's Letter on Public Comments

Received for the North Dakota Department

ofHealth's Preliminary NOxBACT

Determination for Milton R. Young Station

Dear Mr. O'Clair:

This letter responds to a letter from Minnkota Power Cooperative, InyorPorated (Minnkota)

addressed to the North Dakota Department of Public Health (NDDH) dated September 22, 2008.

Minnkota'g letter and enclosure were, in part, a response to comments submitted by the United

States Environmental Protection Agency's ("EPA") to NDDH on the Preliminary Best Available

Control Technology (BACT) Determination for Nitrogen Oxides (NOx) for Milton R. Young

Station (MRYS), Units 1 and 2' (the NDDH preliminary BACT determination). EPA received

an electronic versioJ! of Minnkota's letter on September 26,2008. Although Minnkota submitted

its comments nearly two months after the public comment period closed, EPA understands that

NDDH intends to include Minnkota's response in the administrative record for the final BACT

detennination.

EPA understands that NDDH needs to close the record so that a final BACT determination

can be made, but some portions ofMinnkota's letter need to be clarified and corrected. To assist

. NDDH in developing an accurate administrative record for the final BACT determination and as

part ofthe EPA-NDDH consultation process described in paragraph 66 ofthe Consent Decree

(Civil Action No. 1:06-CV-034, United States ofAmerica and State ofNorth Dakota v.

Minnkota Power Cooperative, Inc. and Square Butte Electric Cooperative),2 EPA is submitting

1 Per July 8, 2008 letter from NDDH to EPA, the public comment period closed on August 1,2008.

2 "After consultation with EPA, NDDH shall provide to the Parties its BACT Determination for NOx emissions

from each existing coal-fired Unit at the Milton R. Young Station."
J;:PA Response to Minnkota's

September 22, 2008 Letter

this response and additional information. I respectfully request that this information be included

in the administrative record for NDDH's final BACT determination.

EPA provided NDDH significant evidence that selective catalytic reduction (SCR) as a

control option is technically feasible, particularlyin a tail-end configuration. Minnkota and its

contractors failed to address this point or provide any additional data or facts substantiating the

claim that SCR is technically infeasible.' In fact, in Appendix A to Minnkota's letter, Burns &

McDonnell's subcontractor, Mr. Volker Rummenhohl ofTackticks LLC, never states that SCR

would be technically infeasible at MRYS. In addition, Minnkota's dismissal ofthe statements

made by catalyst vendors and SCR system suppliers provided by EPA regarding performance

guarantees for tail-end SCR is tenuous and inconsistent with EPA's "Top-Down" BACT

procedure, as outlined under Chapter B ofthe "New Source Review Workshop Manual---

Prevention of Significant Deterioration and Nonattainment Area Permitting," (Draft October

1990), (EPA's NSR Manual).3 Vendor responses and actual operating examples4 related to tailend SCR presented by EPA strongly indicate that SCR is a technically feasible option.

Therefore, EPA continues to beli'eve that the NDDH's preliminary BACT determination of

technical infeasibility for SCR is not supported by the record.

Enclosed is a detailed response, prepared by Mr. Hartenstein, Principal and Co-owner of

E&EC, an energy and environmental consulting firm, correcting inaccurate information and

refuting the conclusions submitted by Minnkota. Thank you for considering the information and

clarifications to the administrative record enclosed herein in the final NDDH BACT

determination~ If you would like to discuss any ofthese matters, please call Cynthia Reynolds at

(303) 312-62006 or Brenda Morris at (303) 312-6891.

Sincerely,

~T~

Andrewr:M. Gaydosh

Assistant Regional Administrator

Office ofEnforcement, Compliance and

Environmental Justice

Enclosures: Hartenstein Report & References (2 copies on cd)

3 "Vendor guarantees may provide an indication of commercial availability and technical feasibility of a control

technique and could contribute to a detennination oftechnical feasibility or technical infeasibility, depending on the

circumstances." (see page B.20)

4 According to EPA's NSRManual, available control options include "technologies in application outside the

United States to the extent that the technologies have been successfully demonstrated in practice on full scale

operations." (see page B.I 1-12)

-2-
cc: David Glatt, NDDH (w/o Enclosure),

Dean Haas, NDDH (w/o Enclosure),

Jerry MacLaughlin,USDOJ (w/o Enclosure),

JeffKodish, OECA, (w/o Enclosure),

Ron Rutherford, EPA (w/o Enclosure),

Cindy Reynolds, EPA (w/o Enclosure)

Brenda Morris, EPA

Hans Buenning, EPA

-3-

EPA Response to Minnkota's

September 22, 2008 Letter
Remarks to the "Comments and Responses to NDIllI Regarding U.S. EPA Region"

8's July 31,2008 Comments and Plains Justice July 30, 2008 Comments on NDIllI

Preliminary NOx BACT Determination for Milton R. Young Station (MRYS)"

dated September 22, 2008

by Hans Hartenstein

ON BEHALF OF THE

UNITED STATES DEPARTMENT OF JUSTICE

October 2008

page 10f24
General Remarks

This report was prepared after reviewing the "Comments and Responses to NDHH Regarding

U.S. EPA Region 8'sJuly 31, 2008 Comments and Plains Justice July 30, 2008 Comments on

NDHH Preliminary NOx BACT Determination for Milton R. Young Station (MRYS)" prepared

by Bums & McDonnell dated September 22,2008 (referred to hereafter as the "Document").

Even though many detailed comments, corrections, rectifications, clarifications and remarks are

being provided in this report, I would like to offer a few general comments. The Document does

not provide any new, previously unknown facts or offer any new technical arguments. Again, the

majority ofthe Document is directed at HDSCR and still doesn't adequately substantiate the

claim why TESCR is considered technically infeasible. While the Document discusses the

various types of deactivation mechanisms in minute scientific detail, which were never disputed

per se, it fails to address the rate ~t which this catalyst deactivation occurs in a TESCR system.

This however is the most critical issue and no data is provided to answer this fundamental

question.

Bums & McDonnell, who claims extensive SCR experience and expertise, retained an additional

SCR consultant (Tackticks LLC) in order to provide technical comments concerning the SCR

technology. Unfortunately, Bums & McDonnell's SCR consultant only provided one reference

for the numerous claims and statements made in Appendix A ofthe Document.

Interestingly enough, Bums & McDonnell's SCR consultant - contrary to Bums & McDonnelldid not arrive at the same conclusion, namely that SCR is technically infeasible for MRYS, but

correctly concluded that "the possible application of any SCR technology at Milton R. Young is

not standard, due to special considerations pertaining to lignite, boiler operating temperatures,

flue gas reheating, among others." I agree with the statement that this SCR application is not

"standard" in the sense that it exactly replicates the standard type ofHDSCR used up to now in

-the U.S. However, this by no means supports the Document's ultimate claim that SCR is

technically infeasible for MRYS as proven by the wide varieties of SCR applications and

extensive experience worldwide.

Specific Comments to the Document's Section "Corrections, Clarifications and Omissions

of Hartenstein and EPA Comments":

My comments to the statements made in the Document are offered in the following, each of

which is preceded by the statements presented in the Document for easier reference.

I _ H*ll1eiTlSfe:in Implies dial li.f9\h~~flrOO ~ilers *lite .s:ignifi(;andy repres('41te<,l arr~l't.g fhe 30,000

MW ofSCR S)"Stemsitl$i:alled to E~, ThilS is misleadin,glmd substanriallyinoorreci.

VeJ.'Y few Qihhe nml1Y seasretrofit in EUfQpe were inst~tUed on hg)lite~J1red utiUty boilet'$.

Tacktkh tUI$ a<tv~d thallQ d:t<: bestQfdteir' knO\\>tedg;e,they area\\'ate 'OfSCR being.

(y1'iginaUy anstaUed.at ()j}lylwo pl!l!Ilts, andl'H~ither ofthese plants is o;t:Jc.fatlonal tt>day..

page 2 of24
I. My report is not intended to imply that "lignite-fired boilers are significantly represented

among the 30,000 or so MW ofSCR systems installed in Europe." The fact ofthe matter

is that Europe has over 62,00o.MW ofSCRs installed, ofwhich approximately 35,000

MWare in Germany. Again about 40% ofthese 35,000 MW are TESCRs. At least five

HDSCRs were installed on lignite fired units, namely: Bayer Dormagen Unit 7, E.ON

SchwandorfUnits B, C and D andVoitsberg 3. All units were operated for between 10

and 16 years and four ofthem were decommissioned in the early 2000s for purely

economic reasons resulting from deregulation ofthe German utility market1. Voitsberg 3

was temporarily shut down in 2006 as the supplying lignite mine ran out of coal. It is

currently being converted to a blend of bituminous coal and biomass and is expected to

start up again in the near future with the same HDSCR2..

2. Tbe EPAQf'l$'1.l~d1:11tNDI)H:'Si preliminary BACTDeterminl$Qll doest\Of p!(ipeJ'lycomp~re

the emiS$:i..ms:Frciim odier ooa',.firoo bQilers\\i'hh hj~ t\ilel ~~ium (i4,):iltietlt t(~ olher bt)ilen~ thftf

&1,l~"SnJ1ly ol)~~tlI1e SCRst'biil1! PowdefRiverBlIl$i!n (PRB)<;OID with hi;gh dUSl SCRs in :dte

Ui)hed St~l'¢S ,and ~re (;~1itble 'to dIe Y0'1,l!tl:,g SmdO'fi OOilel\S. fQt their' ny;l'tsll alkali OOl1tent'i.

TheE?A i~Qr¢'l,i theDepartmenf$ supporting detll:U-ed inf-Offitatklfl hy HERe l!Il~t e;'q)latll$

'why S("'R$ ,iU'C not ~.ble to tolerate the big~' lev'ds of mk~i :species Cl).rtt~dJ:l,ed In fhie ,~IS'

:such at;; eXhatl$tie-dlf.'ronl the :MRY$ br:;:tifteJ.'$,~. C'<)mpareQt(9 theP:RB oortl Ilredbt)i~er$ ..

2. EERC's outline as to "why SCRs are not able to tolerate the higher levels of alkali

species contained in flue gas such as exhausted from MRYS boilers" is based on the

assumption that HDSCR is used where significantly more fly ash gets into contact with

the catalyst than in a TESCR installation. No data substantiating thecHlirrts for catalyst

deactivation in a TESCR application, where virtually no residual fly ash is present, is

presented by the Department.

). In J~ddidQIl, theEPA ~ld H~rtens~ltl <ltd .f~m provid.e My $'l;lbst$tlti~l techtlk:a11n~)iTt1latil,)tl

tht:lf demonstmt-es 'du~t ,effective s.olutioosw1)1'eveni Of remove fXl1'e pfugg.q;,geand b~h'j,dtng 'Of

SCR c.-u;alyst fl'Qhl $odhuf.1"" ;ifi(i J>-O'~iu.m,.;rl'Chspecies present in tile flue- ga.~ stre<llm

exh~llstetJ FrOfna NQif~b Dakota lignite"'fired cyclone ooile.r", wbethel' ~ilsWled til a

..x)lY\''elJtionild hm"'Side Qt' t(lld~side applicatioo !.'kw.iTtstre.llm .ofa. \\l'et SiCruhber, bave been

deve!(lped hy c~talysf vendors.

! Co-firing of biomass - evaluation offuel procurement and handling in selected existing plants and exchange of

information (COFIRlNG) - Part 2, Kraftwerk Schwandorf, Germany, Alterne ABV-NET V, Ruth Brokeland,

C.A.R.M.E.N. .

6 http://www.wirtschaftsblatt.atlhome/oesterreich/unternehmen/steiermark/337197!index.do

page 30f24
3. My report is not directed towards demonstrating effective solutions to prevent pore

pluggage and blinding ofHDSCR catalyst from sodium- and potassium-rich species

present in the flue gas stream exhausted from North Dakota lignite-fired cyclone boilers.

The only data presented by the Department showing such pore pluggage was obtained

during the Coyote Pilot Testing. This, however, was an HDSCR arrangement and not a

TESCR arrangement, which means that the data does neither properly represent the types

ofdeactivation mechanisms nor the rate of catalyst deactivation that can be expected in a

TESCR, where virtually no residual fly ash is present anymore. Therefore, the amount of

particles available for pore pluggage and the formation of a surface blinding layer as well

as the amount ofsodium- and potassium rich ash particles is greatly reduced, which in

return greatly reduces the catalyst's deactivation rate. The Document misses the point

that only the rate of catalyst deactivation remains in question rather than the undisputed

fact that among other physical and chemical deactivation mechanisms pore pluggage and

surface blinding can cause catalyst deactivation.

TESCRs have a proven track record of very little to no pore pluggage and/or surface

blinding occurring. Initially, isolated events ofsilicon fluoride (SiF4) blinding in

bituminous coal-fired units were reported but only persisted for a very short period of

timeJ. Several mitigation methods were quickly developed and SiF4 blinding has not been

an issue for more than a decade in TESCRs. Furthermore, extensive experience has been

gathered with the removal of pore pluggage and blinding of SCR catalyst from sodiumand potassium rich species by means ofin-situ, on-site as well as off-site regeneration of

HDSCR catalyst exposed to flue gases from i.e. 100% biomass .combustion containing

high quantities ofsodium- and potassium-rich species. Simple catalyst washing either insitu or on site is an effective method to quickly remove alkali poisoning from the catalyst.

This has been demonstrated for more than a decade and is currently regularly used for

units with HDSCRs burning biomass in Europe (i.e. Elsam's Avedoere Unit 2)1, 2.2.1.

.1 Personal discussion with plant personnel at Evonik's Herne, LUnen, Marl, Walsum and Voerde Generating

Stations

1 Cleaner Fossil Fuel For Sustainable Development. CO-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energie E2 until 07/01/2006 ), Denmark

i Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, 2007 NOx Round Table, Cincinnati,

Ohio

§ Considerations for Catalyst Deactivation and Regeneration When Firing Biomass, Dr. Greg Holscher, CERAM

and Mark Ehrnschwender, Evonik Energy Services, 2008 NOx Round Table, Richmond, Virginia

1 Mobile Katalysatorregeneration in der praktischen Bewahrung, Dr. Herwig Maier et. aL EnBW Kraftwerke AG,

VGB Konferenz Chemie im Kraftwerk, 2006

page 4 of24
4. Hartenstein did nQt demonSl'rnt-e be Imd an undel~nding:()fCeiltet Hgtlit-e ehai~rerlstics: ,j\nd

vm't~bmtjf issues. SpecIfically> he did notij~la:tld how SQluble sodium is used to define

tile a1:mndlmee oforg,llfiiCldly ~iated ~um in U~ite- and how sodium \\>ill vary be~e

of1he ~Utld!mce ofotller ronnitls c~ntpOllefilS inChe ~a1. Tbe ;abundance ofSQdhun

mld otJler $h furmlng \-~ dr,nmaucall)' tUbduniqueiy in NQrU. Dakota (Fort

Union region} lignhe eO@l-and resmt in ·operation~l clmtlen,ges. H~S$efn does not

uM-erstand the dHl'eoonces betiWeet1l FOtt.Untofi Hgfiite and Texi!\S Usni.e. He~:ndiCl\tes tbfft

theifi$mUatJQtl$ ofSCR ()1'IiPo\\>'d¢r River B~in (PRB} sl;lbbimrmnous eoal Md testing Qfi

T;»:U$ lignite indi-cat<e: f~ibHhy for sell 00 ND lignite even diOl;lgh the levds of$Odium in

typka& PRa eoo:ll4l'idTex:fi$ IlSfti.es M'e v~· low (0.1 «l' J.5% NatOJ as CQil1lfh'U'ed to 4,4 %

NazO tor Cente4' lignite. The .llimO~i1ft.~ f(Jrtn of al14'l11 ~cj~ in Uleo- ooal .ng wid!

combustion pr~ infh)eJl\~d1eif abHity 'to be eudched in dlieae.t'Osol .and fme ~rti(;le

fraction (Jfthe 'fly Mil, The :siz.-e: ~d oomposWon (if'~ patti<:;le ;altmgwi!ih vclocity

d~tet'mttl~ their a.;1>Hit)f to pene{mte :lind depo~l on SCR -cattdy:st i~~~g¢$; and in P~)iI'e$ ~d

(;""""'1:} n4ulill'htcl' LHnA,j:fi( .....dn.<W"Oiliii" . .. "'''''''.. r "'=-":;>' I} ,~ g. ""'. ..-"." . . Pi

4. The Document seems to erroneously assume that the purpose ofmy report was to

demonstrate my understanding ofCenter lignite characteristics and variability issues.

Again, the arguments presented are solely directed towards HDSCR. Organically

associated sodium and potassium compounds are also present in high quantities in flue

gases from biomass combustion in Europe either in combination with coal or without.

HDSCRs have been successfully applied for such flue gases from boilers firing ufo to

100% biomass (i.e. Elsam's Avedoere Unit 2~ 2, Wienstrom's Simmering Unit l~.

My report is directed towards the SCR technology and its technical applicability. No data

substantiating the claims for catalyst deactivation in a TESCR application, where

virtually no residual fly ash is present, is presented in the Document.

Cleaner Fossil Fuel For Sustainable Development, CO-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energie E2 until 07/0112006), Derunark

2 Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, 2007 NOx Round Table, Cincinnati,

Ohio

!Q Considerations for Catalyst Deactivation and Regeneration When Firing Biomass, Dr. Greg Holscher, CERAM

and Mark Ehmschwender, Evonik Energy Services, 2008 NOx Round Table, Richmond, Virginia

page 5 of24
:;. Hartenstein dtd tlotaddress the issue ofthe partitioolng of ask,...rormifig :speeles- bet\:....een fhe

$!agand fly ~. oompo;aents in CYl,.1one~nred S)':s.tems .nat result in Wil elU'id'nnenlofsodium

@nd omerflOOte"ivoBadlized $peeles- ju the flue ,g~s. These f1Mte~v{datilil.ed SP~t~ wm

oolldense h()mogeneoosly to produce abWlool1t sodium ood potasstum~rieh t!erQ$()L" beeal.l~e

ofthe lQ'wer level of'entrainea soHdasb parti~les in (ycl~ combustioo..uerived flue S{;$e$

relative to pulve.J'~1 coal oomlmsf!otl dertved flue gas.

5. The purpose of my report was not to discuss the partitioning of ash-forming species

between the slag and fly ash components in cyclone-fired systems that result in an

enrichment ofsodium and other flame-volatilized species in the flue gas. Again the

arguments presented are solely directed towards HDSCR. No data substantiating the

claims for catalyst in a TESCRapplication is presented. Since virtually no residual fly

ash remains in the flue gas downstream of an ESP and wet scrubber, these issues are of

little if any relevance for the deactivation ofTESCR catalyst by fly ash particle-bound

compounds.

6. I;htrt-enSlelilldid tKlt 41iddress the l'(tfioottOiil ()if' 41ie;f()$()Js .ana bow that eM imp~t.et SCR

p-ert~()rnn£tl'l.t';ec The key isstlie lbrkliigh :sodhun Fort Un10tl (North Dakota ligl1ihe:~ cc-als ftred in

C){d01H.:~fbred bciBet'S.l$ die abUtidfiftCf:c (if alkali-ricb .lierosuls itlthe flue ga;s that CM pet1Jeu'ate

into ~:te pt)res QfSCR calmlys¢, ¢a.l~$i:ng blinding and. poii;onins. This is an. iZi$~e Jbr til;gh diUS.l

:and tow d~t 1mH~-end S(1t ~.Pl)ficC~lti()[lj$. f{e $li'PewfS. tt} not be ntmmar v,idl the' diffU;$ktfl

ulecJl$filsmofti'attSilJQft ot'aei'O'So·ls deep into the OCR (41taiyst:s dmt can ,cause ~thtgand

,)ll.ig.gin~. Hartenstein 4lppears 1() OOftftlSe the importance (lif' camlyst pitch r·elativeto fmfe

pluggitb[g ;JSw bHndin:g. Hei:nco~a~y Sl;l~~tsitt.al (::~.my~ pitch wLH solve lhe PQfe

liluggi,fig llnd bHndJng pll)ibJem. Using \\~der pitdt c_lyst doe:s not eBhnin~etbe :penetration

t}f ~kaU-ridl ae:t'(l$o~s de-ep tntQ ;sell Cl'~h'ilystc~ntStng pore pl~g~l1! blinding probBe.nus.

l'he lrrtpact ()fs:ooltael\.)So!s that p6;'S$ thf'Ollih the eleetf(tSt~e precil~imt(ir (ESP) on the

p-ertbrmance of ktW IIm;t SC:R appHc!tttOOS WID>: not discussed by I1arteflstetrl This: fine ash

that ~apes fi"Otll the ESP is fifleJ' tbanlhe butkflyash and has ahi8Jllef catlitJ)'st plug,~ng

pcttential due to a bigher ti~t(k:ncy toagg,lo~'atec In addidQll,. liartenstein dtd not OOfL~def

inrormatiil)r1 provided Q.ilPQ\vef>:Sf)ati b~rtet' ~atl-e tleilctQf pHQt-$.lipstt~mt$tnz d:tm

sno\..'ed alkali rkh ilC(:ltti'iiul~ttons dtwillStl"eam (}fthe Ullttl ESP at the 1\mY statton.

6. The Document erroneously claims that I suggested that "catalyst pitch will solve the pore

plugging and blinding problems." However, the fact remains and was reiterated also by

catalyst suppliers and SCR system vendors that proper catalyst selection is a critical issue

in order to avoid or at least minimize problems. No data was presented that shows any

page 6 of24
such pore plugging and blinding problems ofcatalyst in a TESCR application. As a

matter offact, absolutely no data was offered to substantiate the claimed impact of

aerosols on TESCR catalyst. No representative data quantifying and/or characterizing

such aerosols downstream of an ESP and wet scrubberwas provided (see also pages A 41

- A 45 ofmy original report). The data referenced from the Powerspan barrier discharge

reactor pilot slipstream testing is not relevant for TESCR as it was obtained on MRYS

Unit 1 downstream ofthe ESP rather than on MRYS Unit 2 downstream ofthe wet FOD.

Even though I never disputed that these aerosols will impact the catalyst in a TESCR, the

quantity ofsuch aerosols entering a TESCR must be expected to be extremely small,

which means their deactivation effect will most likely be rather slow. Therefore, it can be

expected with a very high degree of confidence that the catalyst lifetime in a TESCR will

most certainly exceed 10,000 hours, which was randomly defined by the Department as a

minimum time for successful operation.

7. l'i~.enstein~s ~edge{ngM~~\:JJid reaction uuecbanlsrras to fortn su:ltate and py1'Qi.SUlfate

.pib~ in.situ in SCR tatatystsap~)~rs 'to be very Htrtii~ed w:td WM nQ't adequ~~clyad~se,l

7. The gas-solid reaction mechanisms to form sulfate and pyrosulfate phase in-situ were not

addressed since no data was provided that such formation Ofsulfates and pyrosulfates

takes place in-situ in significant quantities in the catalyst in a TESCR.

:8. Hartensrein <ltd not dil$Cussd've r,ev.;:tlil Ht'el~wre (til -c(Jlt~~)'stp{)isortinsst.1.tdies in E.urope

associtwed "ddt cC!lir:fii}@. Ifdgb mhH (Na $!l(~ K) c.Oitlta:ifJit'!l~ bto~. This t~titlgh:a$ sbowed

sigltlitt£!Utt poJ:so:;mins of c:at:aiysfs due roa~btl nt:rorol :penetra~<m tinro. cat'lliysts and die

$.tlbsequettt reaa...'tlOii1 \vithcSitl1llys~' ~tive ,tOtlll)(Jfiefit:s CAus:ing pi';'loonin@..

8. Catalyst poisoning studies in Europe associated with co-firing high alkali (Na and K)

containing biomass have clearly shown an accelerated catalyst deactivation in HDSCRs

compared to European bituminous coal-fired unitslL!l. However, neither did this lead to

the conclusion that HDSCR is technically or economically infeasible nor did such

accelerated catalyst deactivation occur in TESCRsU, 11. Units firing 100% biomass (I.e.

wood and/or straw) with organically bound sodium and potassium contents as high or

II Cleaner Fossil Fuel For Sustainable Development, CO-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energie E2 until 07/0112006 ), Denmark

n Washing Your Own Catalyst a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007,'Cincinnati,

Ohio

11 Sobolewski, H, H. Hartenstein, H. Rhein, "STEAG's Long Term SCR Catalyst Experience and Cost", The 2005

EPRI Workshop on Selective Catalytic Reduction, Louisville, KY, 2005

H Considerations for Catalyst Deactivation and Regeneration When Firing Biomass, Dr. Greg Holscher, CERAM

and Mark Ehmschwender, Evonik Energy Services, 2008 NOx Round Table, Richmond, Virginia

page 7 of24
even higher than Center lignite have successfully operated even HDSCRs]2, l§. Wet

bottom boilers equipped with TESCRs have experienced no effect on catalyst

deactivation as a result ofco-firing biomass in Europe1L ll.

9. H~rtenstein did no~ offer infoil'ftta.iQft that mQre dl;tm 20.000£\.f\V oftiig:nite fired ,mi1$ .n

Germany were nQt required to i~1 SOt in Q1'&er ro c:-omp~y wrth the national f-e£.ulation, or

that even new H~ite..fired U!l1its bein¥ ittstaJled t~f in OermMy ate not equipped \.Vidi SCR

ofany type, fie didool sUlite duu Oen1\llt'lY' ltad only one -cycLQl»"nred boiler operating. wid~

~\. LDSCR (WalSUtl\ Unit 7), or that die unit bums btt!,tmiriO'tt$ ooal; nor' did he advise that

Voit.rg.Unit 3,3 boUer in Alwia t1:dng U;gtule OOQt; oo1y r,at~ fut 3 short time with a high-

&1:11Si SCR and '\,~ SUD.ljequenrl» $hutoo,,,,n 1\00 demo:Hshed. He statesthat TESCR

tet.'bf1(}k~mr was "genermly ~dopled $ a ~rrtiveJ'SaUy ~}f)1k..\lib~e SCR SQ~t1rit)tl for all types...;.

bu.t f-ailedro men~iQtl dlU!tdie,re has never been a!tl('lther TESCR bl,1Ht at):er Si'~'$dr;u:f; (which

\~ finisbedin e!lldy 1991 and bassl1b$equentlybeeJl deCOltlitllis$i;ot'ie<S), in the United States

(w EtJf(jipe. To the best of <,)U'J' lrn.~)\\4e-d.ge.thelfe is ftO TESCR ally'''~tere in the world on a

Hgllite--fircd ut1lhy b(~iler. lie crtes: "Cenl.t'fi'$ extensive experierlic-e'I~lith Hgt'litl:C.::, htlt ~ll!S l(l

l'Cl'OI'. d:J:aIi this oo~s of·001)' ;()1'/ie plant \vidt Ccrom CI'!Ualyst having op~'a'led Tt;u' ~t ~h(l':rt

1J'eriod oftime 00 Hpit:e a few p:ilQl'pro~raJllI$, S(~ that it i$; <tub.ii.)~lS to S'!.¥'j tbat this v~r

has ex:ti2iJlsh~ experiefice Qtl .i~lite fired. b()l1er SOtplants(see Appeooix A). TI'let'e are

nUlnerOli!S othcJ' ~~~ o:f1fti$h'i8 Of' factuallyinc,o:rret;J!: iflform~ltit)rc attributed lO Mr

H~lensteindise!(,l~ in Appendii A,

9. The lignite-fired units in Germany have to comply with the same NOx emission limit as

all other fossil-fired units, namely 200 mg/Nm3 @ 6% O2 (approximately 100 ppm)12· ~.

li Cleaner Fossil Fuel For Sustainable Development Co-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energie E2 until 07/0112006), Denmark

J..§ Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati,

Ohio

11 Sobolewski, H, H. Hartenstein, H. Rhein, "STEAG's Long Tenn SCR Catalyst Experience and Cost", The 2005

EPRI Workshop on Selective Catalytic Reduction, Louisville,KY, 2005

11 Considerations for Catalyst Deactivation and Regeneration When Firing Biomass, Dr. Greg Holscher, CERAM

and Mark Ehrnschwender, Evonik Energy Services, 2008 NOx Round Table, Richmond, Virginia

12 Dreizehnte Verodrnung zur DurchfUhrung des Bundes-Immissionsschutzgesetzes (Verordnung iiber

GroBfeuerungsanlagen) - 13. BlmSchV. Bundesdrucksache Bundersrepublik Deutschland, 1983

http://www.zittu-darmstadt.de/cipp/tudzitilib/alI/lob!returndownload.ticketguestlbid.]]79!checktable.it

chap downl embed/-iumwelttechnik.pdf

page 8 of24
Due to the specifics oflignite combustion, this limit could be met by most lignite-fired

units (exceptions listed under 1. above)without the addition ofSCRs. However, currently

the regulations are under review and it is expected that the emission limit will be reduced

to 100 mgINm3 @ 6% O2 (approximately 50 ppm), which will most likely require the

majority ofthe lignite-fired units to retrofit SCRs.

The statement that "Germany had only one cyclone-fired boiler operating with a LDSCR

(Walsum Unit 7)" is incorrect. Walsum Unit 7 is a U-fired wet bottom boiler rather than a

cyclone-fired boileril.

The statement that "Voitsberg Unit 3, a boiler in Austria firing lignite coal, only ran for a

short time with a high-dust SCR and was subsequently ·shutdown and demolished" is .

incorrect. Voitsberg Unit 3 operated with a HDSCR from 1990 to 2006, when it was

temporarily shutdown as the lignite mine supplying the fuel ran out of coal. Voitsberg 3

is currently being converted to burning a blend of biomass and bituminous coal and is

expected to restart operation in the near futurt#.

The statement that "there has never been another TESCR built after Siersdorf, (which

was finished in 1991 and has subsequently been decommissioned)" is incorrect as i.e.

VEB's Rudow Unit 2 was started up in 1994ld, 24. Legislation25 had required all units to

meet the new NOx emission limit of 200 mgINm3 by 1991, which is the reason why the

vast majority ofthe utility boilers including Siersdorf were retrofitted with SCRs by

1991. Nevertheless, additional utility units such as Rudow Unit 2 in Berlin were

retrofitted with TESCRs later. Additionally, a vast variety of other combustion processes

were retrofitted with TESCRs between 1991 and today due to the universal applicability

ofTESCRs.

The statement that CERAM's experience with lignite "consists of only one plant with

CERAM catalyst having operated for a short period oftime on lignite" is insofar

interesting as it probably refers to Voitsberg Unit 3. However, what is considered a "short

period oftime" seems to be very relative, since Voitsberg Unit 3's HOSCR was initially

l!. Personal conversation with plant personnel at Evonik's Walsum Generating Station

II http://www.wirtschaftsblatt.at/home/oesterreich/unternehmen/steiermark!337197/index.do

II SCR Reference List, Fisia Babcock Environment GmbH

M http://64.233.169.104/search?g=cache:zdIt5N-ngCwJ:www.stadtentwicklung.berlin.de/umwelt/umweltatlas!e

tab /1301e02.xls+Kraftwerk+Rudow+DeNOx&hl=de&ct=clnk&cd=8&gl=us

II Dreizehnte Verodmung zur Durchfiihrung des Bundes-Immissionsschutzgesetzes (Verordnung tiber

GroBfeuerungsanlagen) - 13. BlmSchV. Bundesdrucksache Bundersrepublik Deutschland, 1983

page 9 of24
equipped with CERAM catalyst and in operation for 16 years between 1990 and 2006

while the unit burned Austrian lignitJ.2.

10. Ag:ai:n, the EPA fails to r~)gfitzeconcll,lsive.y that ash Chetn1C~ and pnysk{d pr'Operties of

tbe Te;'i{as lignite (Wilcox f'Otmattofi) that TXU proPR~.e.~ t() burn at the new Oak Grove

po\vetplant where SCR. is being installed (but b8i$l)(}t yet begun oper-ati"itl) do oot repl'e:rent

\,iiat is fired! in North Dalwta, and theref{,rc:: techtlical feastbIHty and exp~ed performance in

it. TeXa$1igtihe~!lfed pulverized coal boitet SCR appHcntioo is notltall$feJ'nbie 10 North

D~kota Hgurre-fited qq::too.e burtleil' units du;e to the Si,gfi~fk:nnt differe1)~s in tlue ,gasMd ash

cheitl:uealand pbysietd properties. The CQfU)>,oshtolii Qfthe Texas Hgnit:etfred ,at Martinuke,

\\ibet'e S(1t mtni";sCRpUot resting has been OOfidu<.1ed, is typical i;)fdie oomposiUtltl of

lt~nite fired at Salld()!\\~, \\lith $odh.ttn (;Ktde levels ill 'me Tex8i$ Hgnite ash equtlil to O.'?k. The

le..'eJs of$odlurEl (),,'{~de in Center li:gn.he .frver;at~ 4,4% and c:Julbe a:sl~ith as 13% itli.lls",iired

sal't'!pte1l,Ham~;eifl (2.008) notptQvtde inf!ormattot\ on clletni'C~ (X)mpostrion OfM)'

:lfu;efis that are COlilJW,aWe 't{; high sodtum NO fitil1te \".''here SCR it'k~tlitllli1liotl have beef~

it~-'wd1ed and t~teod (fl' SiU~'UUY.oper~too.

10. The fact that various units firing Texas lignite are being equipped with HDSCRs shifts

the arguments to the different compositions between Texan and North Dakotan lignite.

Even though biomass such as wood and straw have very similar if not higher sodium and

potassium contents than ND lignite and are burned in boilers, which are equipped with

HDSCRs and have successfully operated in Europe for some timell, Th~, it is not

necessarily relevantto provide such "information on chemical composition of any fuels

that are comparable to high sodium ND lignite where SCR installation have been

installed and tested or successfully operated." It would be much more relevant to properly _

characterize the flue gas downstream ofthe wet scrubber ofMRYS Unit 2 so that it could

be compared to similar flue gases upstream ofsuccessful TESCR installations. However,

such data properly characterizing the flue gas for a possible TESCR installation at MRYS

was never provided.

http:.!/www.wirtschaftsblatt.at/home/oesterreich/unternehmen/steiermark/337197/index.do

n Cleaner Fossil Fuel For Sustainable Development. Co-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energfe E2 until 07/0112006), Denmark

Washing Your Own Catalyst a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati,

Ohio

£2 Considerations for Catalyst Deactivation and Regeneration When Firing Biomass, Dr. Greg Holscher, CERAM

and Mark Ehmschwender, Evonik Energy Services, 2008 NOx Round Table, Richmond, Virginia

page 10 of24
IL No eX!Ulipjes were prov~ded of oo~Hne cmeamng medlods tlOfvaialyst that w'()Uld pi'Ove

resistant tQ dtun~e from Sllcl1 mertuxfs.hat ,"VQuid be etie\.'tiYe itl fem<JVit\£ surface blinding

~tld pore pt~ttg det)o$~ ~uch dtose seen in the Co)rqte pilot test cat~lyet even \'lith the

su~ed e~e erqst<m pr,evention il1:l'ellSureStfi place. H~$ Hartenstein doos nqt addteiis d~1S

j;ssue in his (;omtnen~ Hattenste!n implies in hisrqxt:rt (2008). 'Chat (:ntatyst that bas been

.,.'Ol$QI:ted by oodium compounds can be l'egene'-r~red in..itru, @tld that thiste'Cbnique is weU

(feveIOtl;l;ed. There tseoctt'Cmely lhuited experience wifhin~tu ,catalysit clel'ming Ot1 c:.ooI·fil'ed

u.rrt~s. n hais-ne\"ef been used f:err blinded Qf themicanypoi~onet,1catfat~~$t; lmt oo1y t~)f

mecb.ant~ly p1uft~ ~.a1Y$l (see Ap'peubdix A).

11. The statements that "there is extremely limited experience with in-situ catalyst cleaning

on coal-fired units" and that "it has never been used for blinded or chemically poisoned

catalyst, but only for mechanically plugged catalyst" are both incorrect. In-situ catalyst·

regeneration for chemically (mostly sodium and potassium) poisoned catalyst has been

successfully used in Europe since 1996JQ,;u, and is still used today. On-site ex-situ as well

as in-suit catalyst washing is being regularly performed i.e. in Avedoere 2 in Denmark in

orderto reverse the alkali poisoning, pore pluggage and surface blinding layers resulting

from the biomass combustion32• In-situ regeneration forthe removal ofsurface blindin~

layers has been used in Europe successfully even in TESCRs for several years nown., L

35 as this process is ideally suited to remove highly water soluble constituents including

alkali (sodium and potassium) and sulfate compounds from the catalyst.

Specific Comments to the Document's Section "SCR Technology Review and Update":

The statement that "the reports provided by Hartenstein were notpeer reviewed and were derived

primarily from companies who have vested interests in the SCR technology and typically do not

JQ Entwicklung und Einsatz eines Regenerationsverfahrens fUr SCR-Katalysatoren, Dr. Herwig Maier et. aI., VGB

Kraftwerkstechnik 1998

11 Reference List Catalyst Regeneration Integral Umwelttechnik GmbH

II Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati,

Ohio

n Stadtwerke DiisseldorfAG, Miillverbrennungsanlage, a presentation by Uwe Behrendt SWD, Wildeshausener

Katalysatortage 2008, Wildeshausen, Gennany

Ji Regeneration von Katalysatoren im Rahmen einer Kapazitatssteigerung, a presentation by Dr. Jiirgen Boseke,

2008 Wildeshausener Katalysatortage, Wildeshausen, Gennany

11 Was kann die Katalysatorregeneration zur Temperaturabsenkung beitragen?, a presentation by. Dr. Alexander

Schuttig, Wildeshausener Katalysatortage 2008, Wildeshausen, Germany

page II of24
discuss problems and challenges" is incorrect. The reports and literature cited was mostly

authored or co-authored by utilities, EPRI, and other reputable industry organizations. Also, the

majority ofHartenstein's publications were presented at reputable industry conferences such as

the DOE SCR Conference, the EPRI SCR Workshop, the NOx Roundtable, the Mega

Symposium, etc. most ofwhich require peer reviews ofthe paper prior to acceptance.

The mini-survey I conducted among the exact same experienced and knowledgeable SCR system

suppliers and catalystmanufacturers contacted by Bums & McDonnell was obviously derived

"from companies who have vested interests in the SCR technology." Also, the depth ofthe

survey was not significant as time didn't permit a more detailed interrogation ofthe companies.

However, the depth ofthe survey conducted by Bums & McDonnell among the exact same

companies concerning HDSCR was not much greater either. It is therefore most interesting to

note that the responses ofthese same SCR system suppliers and catalyst manufactures to the

survey conducted Bums & McDonnell concerning HDSCR were considered unquestionably

valid and indisputably correct by Bums & McDonnell for inclusion in their initial report while

the responses by the same companies and often even the same individuals concerning TESCR

are attempted to be disqualified as coming from people who "typically do not discuss the

problems and challenges." This gives the distinct impression that the credibility and iptegrity of

the companies and individuals, whose responses and technical comments were initially used by

Bums & McDonnell's attempt to prove the technical infeasibility ofHDSCR, is now only being

questioned because theirresponses concerning the technical feasibility ofTESCR don't seem to

fit the agenda.

The entire section concerning the blinding and poisoning mechanisms including popcorn ash

pluggage caused by large particle ash, pore pluggage potentially caused by very small fly ash

particles, masking ofthe marcosurface and poisoning ofthe active sites as elaborated on pages 9

through 26 is certainly not being disputed concerning its scientific correctness. However, these

arguments are all directed to catalyst installed in a HDSCR system and therefore largely

irrelevant for catalyst installed in a TESCR system as the flue gas composition and

characteristics are fundamentally different. Furthermore, even though correct, they don't prove

by any means what the catalyst deactivation rate would be neither in an HDSCR nor in a

TESCR. A much better approximation for the catalyst deactivation rate to be expected can be

derived from full scale HDSCR data of units burning biomass with similar alkali contents. These

units equipped with HDSCRs are successfully operated in Europe and some actual full scale

catalyst deactivation data has been published. Units equipped with TESCR co-firing biomass are

operated successfully in Europe and some actual full scale catalyst deactivation data has also

been pUblishedJQ•

As valid as all the described mechanisms and the presented data may be for scientifically

explaining the various types of deactivation they do not allow any definitive conclusions

concerning the exact deactivation rate of catalyst installed in an HDSCR and even less so in a

TESCR. More broadly worded, the presented arguments and data certainly support the

Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati,

Ohio

page 12 of24
expectation that catalyst deactivation in a HDSCR will be more rapid than typically observed for

most sub-bituminous coals in HDSCR. Also, it is an indisputable fact that the combustion of

many bituminous coals, particularly many Southern Illinois Basin coals containing high

quantities of arsenic and little calcium, result in much more rapid catalyst deactivation in

HDSCRs than observed for most sub-bituminous coals37• Several units in the U.S. burning

Southern Illinois Basin coal. are known to have exchanged, regenerated or added catalyst in their

HDSCRs well before an operating time of 10,000 hours was reached, which was randomly

defined by the Department as a minimum time for successful operation. Just because the arsenic

poisoning ofthe catalyst was more rapid than initially expected, this doesn't mean the HDSCR

operation ofthese units has been unsuccessful and these plants continue to operate this way..

The most obvious solution for the stated problem ofthe claimed catalyst deactivation rate

resulting from burning ND lignite results from various fly ash particle-bound mostly alkali

compounds would be to remove as much ofthe fly ash particles as possible upstream ofthe SCR.

This can easily be accomplished by means ofan ESP or baghouse and a wet scrubber in order to

minimize the effect ofthese fly ash particle-bound compounds. The result is a TESCR.

The biomass data provided in the Document is very useful as it offers some insight into the

possible deactivation rates ofa HDSCR that could be eXRected at MRYS. Since HDSCRs have

been in operation on biomass fired boilers since 2001 38, --.2, this allows some composition

comparison ofbiomass (Le. wood)and ND lignite. The fuels listed in Tables 2through 5 ofthe

Document are mostlywbods of various types. A comparison to ND lignite is shown in the table

below. As stated in the Document, wood is similar to ND lignite in its composition and

variability.

Center lignite Biomass /woods)

Historical Future Range average

Heating value [lOt> Btu/lb] 13.2 13.4 6.8 - 9.1 8.3

Ash content [%wt.] 9.6 7.8 0.3 - 20.4 6.0

CaO [%wt. in ash] 13.2 17.0 5.8 - 49.9 20.9

K20 f%wt. in ash1 1.3 1.0 0.2 - 22.4 7.7

MgO [%wt. in ash] 4.0 5.1 1.8 - 18.4 4.3

Na20 [%wt. in ash] 4.4 5.6 0.1-23.5 3.1

Likewise is the association ofalkali and alkaline earth elements in Center lignite similar to the

associations found in biomass. Thus, it seems to be not unreasonable to expect that the catalyst

TI Kramer, M., C. Gerlach, H. Hartenstein, "As,03 and S03 Testing at Hoosier Energy's Merom Generating

Station", The 2007 EPR! Workshop on Selective Catalytic Reduction, Pensacola, FL, 2007

Cleaner Fossil Fuel For Sustainable Development. Co-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energie E2 until 07/0112006), Denmark

:l2 Washing Your Own Catalyst a presentation Nathan White, Haldor Topsoe, NOx RoundTable 2007, Cincinnati,

Ohio

page 13 of24

, '.,
deactivation in HDSCRs installed on units burning 100% biomass ofsimilar composition and

variability should be similar to the one of catalyst in a HDSCR burning ND lignite.

The deactivation rate ofthe HDSCR catalyst at Elsam's Avedoere Unit 2 was found to be about

25% per 8,000 HDSCR operating hours when burning 100% biomass (mostly wood and some

straw) while it was found to be only about 10- 11% per 8,000 HDSCR operating hours when

burning 100% bituminous coal4o• Thus, the catalyst deactivation was found to be about 2.5 times

higher for biomass than for bituminous coal. However, a catalyst deactivation of around 25% per

8,000 HDSCR operating hours has also been observed for several units in the U.S., particularly

for those burning high arsenic coal without limestone mitigation. In other words the full scale

HDSCR catalyst deactivation experience of a unit burning 100% biomass, which is very similar

and therefore directly comparable to ND lignite, was found to be virtually identical with the full

scale HDSCR catalyst deactivation ofmany U.S. units burning high arsenic bituminous coal.

Needless to say that the catalyst deactivation to be expected in a TESCR where virtually all of

the fly ash associated particle-bound compounds have been removed upstream ofthe catalyst

will be considerably less.

There is no question that the flue gases from combusting ND lignite will cause a relatively rapid

catalyst deactivation of a HDSCR catalyst. However the rate ofcatalyst deactivation is

indisputably a function ofthe mass flow of catalyst poisons, which is dramatically reduced in a

TESCR compared to a HDSCR.

Specific Comments to the Docnment's Section "Variability of Lignite":

The Document incorrectly quotes me and my "experience with German Ruhr Brown coal as

described in a paper by Hartenstein and others (1999):" Besides the fact that German Ruhr·coal

is bituminous coal and not brown coal or lignite as incorrectly indicated in the Document, the

paper describes the effect of alkali compounds on the adhesiveness offly ash, which in

combination with the incorrect catalyst selection resulted in physical pluggageproblems.

Catalyst deactivation due to these alkali compounds occurred only during start-up and shut down

ofthe units when the flue gas went through the dew point. This results in the mobility ofthese

highly water soluble compounds and the reaction with in water dissociated alkali ions (Na+, K+)

with the catalyst's active compounds V20s.

Neither ofthese two issues, however, caused the technical or economical feasibility ofHDSCR

to be questioned. The pluggage issue was resolved by the selection ofthe correct catalyst type

and pitch and the catalyst deactivation was mitigated by limiting the number oftimes the flue gas

inside SCR reactor went through the dew point. Both issues were already pointed out in my

report.

1Q Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati,

Ohio

page 14 of24
Specific Comments to the Document's Section "Results of the Coyote Pilot Testing":

The Document quotes me as describing the Coyote Pilot Testing as "ill-designed." This quote is

certainly correct but only repeats me quoting the Department who characterized the Coyote Pilot

Testing as "ill-designed" (page 7 second line) and concluded that it "didn't provide much useful

data" (page 7, first line). This view was confirmed by catalyst suppliers such as CERAM and

SCR system suppliers such as Babcock Power. I· agree with this view regardless <;>fwho was all

involved in or reviewed the design ofthe test reactor and the test. The fact alone that the catalyst

was too plugged for Haldor Topsoe to perform activity testing proves that not much useful data

could be derived from the test. In essence the only useful result ofthe Coyote Pilot Tests seem to

have been that it was recognized that a 6 mm pitch catalyst is not suitable for a HOSCR

application featuring highly adhesive fly ash. Not surprisingly, this is a very similar result as

described in my 1999 paper for E.ON's (not RWE's as erroneously claimed in the Document).

Staudinger Generating Station Units 1 and 2 where the pluggage problem was solved by either a

different coal blend or by installation of a 10 mm pitch catalyst as shown in Figure 11 ofsaid

pape.-4l.

Specific Comments to the Document's Section "Soluble Sodium":

This section describes in detail the effects ofsoluble sodium on catalyst in a HDSCR installation.

While these described effects are not disputed, the section, however, fails to provide any data

that allows for estimating a catalyst deactivation rate in a HOSCR. Furthermore, it doesn't even

address the issue in a TESCR as most water soluble sodium compounds will be removed in the

wet scrubber upstream of a TESCR and therefore are unlikely to pose a rapid deactivation threat

for TESCR catalyst.

Specific Comments to theDocument's Section "Differences in Flue Gas Composition":

The Document fails to allude to what differences there may be between flue gases from

combusting ND lignite and flue gas from combusting biomass. As a matter offact the Document

states that "the abundance ofrich alkali aerosols is similar to that found in biomass combustion

systems." As described earlier, HDSCRs have been in successful operation for several years in

units burning 100% biomassQ 11, which renders the Document's claim invalid that no examples

exist of a fuel fired in a boiler that produces a flue gas that is characteristic offlue gases

produced from NO lignite where SCR has been installed and successfully operated.

i!. Hartenstein, H., H. Gutberlet, "Utility Experience with SCR in Gennany", DOE Conference on SCR/SNCR, .

Pittsburgh, PA, USA 1999

g Cleaner Fossil Fuel For Sustainable Development, Co-Firing Coal and Biomass, a presentation by Henrik

Noppenau, Elsam (Energie E2 until 07/01/2006), Denmark

Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati,

Ohio

page 15 of24
Specific Comments to the Document's Section "Catalyst Poisoning, Blinding and Plugging"

and Applicability ofSCR Development for Texas Lignite":

Again, both ofthese sections refer only to HDSCR and entirely ignores that these issues are

much less if not irrelevant in a TESCR application.

Specific Comments to the Document's Section "SCR Catalyst Erosion and Cleaning":

This section refers also only to HDSCR and ignores TESCR. However, it also incorrectly claims

that catalyst does not withstand highly erosive flue gas and/or on-line cleaning measures such as

aggressive sootblowing. HDSCR systems are successfully operated on boilers burning coals with

up to 30% ash, which not only creates a highly erQsive flue gas but also requires very aggressive

sootblowing. Properly selected catalyst has been shown to withstand this without major erosion

damage for many years41.

The Document also claims incorrectly that EnBW in Germany developed an in-situ cleaning

technique, which has never been a commercial success. As pointed out earlier, simple catalyst

washing either in-situ or on site is an effective method to quickly remove alkali poisoning from

the catalyst. This has been demonstrated for more than a decade~ 1§, 41, 49 and is currently

re~ularly used for units with HDSCRs burning biomass in Europe (i.e. Elsam's Avedoere Unit

2).....Q. In-situ regeneration is also used within the EdF group including EnBW and numerous

operators of various smaller SCRs i.e. in waste-to-energy plantsll, TI..

11 Personal conversations with plant personnel at Evonik's Fenne, Herne and Walsum Generating Stations

Entwicklung und Einsatz eines Regenerationsverfahrens fUr SCR-Katalysatoren, Dr. Herwig Maier et. aI., VGB

Kraftwerkstechnik 1998 .

12 Successful experience with In.situ Regeneration ofSCR Catalyst in Coal-Fired Applications, Dr. Herwig Maier

et. al., EnBW, 2000 DOE Conference on SCR / SNCR, Pittsburgh 2000

11 Recent Experience with SCR Catalyst Regeneration, Dr. Herwig Maier et. aI., EnBW, 2001 DOE Conference on

SCR / SNCR, Pittsburgh 2000

Reference List Catalyst Regeneration Integral Umwelttechnik GmbH

.42 Mobile Katalysatorregeneration in der praktischen Bewahrung, Dr. Herwig Maier et. al. EnBW Kraftwerke AG,

VGB Konferenz Chemie im Kraftwerk, 2006

2Q Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, NOx Round Table 2007, Cincinnati;

Ohio

21. Stadtwerke DUsseldorfAG. Miillverbrennungsanlage, a presentation by Uwe Behrendt SWD, Wildeshausener

Katalysatortage 2008, Wildeshausen, Germany

page 16 of24
Specific Comments to the Document's Section "Pilot Testing for SCR Catalyst":

It is interesting that Bums & McDonnell disagrees with all the catalyst suppliers and SCR

vendors that pilot testing is not needed for TESCR atMRYS while Bums & McDonnell in its

attempt to prove the technical infeasibility ofHDSCR at MRYS relied heavily on exactly the

same catalyst suppliers and SCR vendors.

Specific Comments to the Document's Section "Vendor Guarantees":

Both seem to imply that vendors lightly guarantee anything without hesitation, which is

inconsistent with my experience. To the contrary in my experience vendors do not lightly and

without hesitation guarantee anything but carefully consider their process performance

guarantees. In my opinion, the vendors would not suggest TESCR as technically feasible and

available for this application ifthey would not be willing to provide the proper associated

process performance guarantees. What benefit would the queried vendors derive from suggesting

that TESCR would be technically feasible and available for MRYS ifthey would not be willing

to provide the proper associated process performance guarantees at the same time?

Specific Comments to the Document's Section "Temperature Variation for HDSCR":

As already stated in my report HDSCR will not work at MRYS without a solution for the

temperature variation problem such as for example adequately modifying the ~oiler' s

economizer sections.

Specific Comments to the Document's Sections "Burns & McDonnell's SCR Experience"

and·"Comments by Sargent and Lundy on SCR Experience:

Neither one ofthese two AlE firms disputes my claims that they have no SCR operating

experience and have never provided any SCR system or catalyst performance guarantees of any

kind.

Regeneration von Katalysatoren im Rahmen einer Kapazitiitssteigerung, a presentation by Dr. JUrgen Boseke,

2008 Wildeshausener Katalysatortage, Wildeshausen, Germany

21 Was kann die Katalysatorregeneration zur Temperaturabsenkung beitragen?, a presentation by Dr. Alexander

Schuttig, 2008 Wildeshausener Katalysatortage, Wildeshausen, Germany

page 17 of24
Specific Coinments to the Document's Section "Comments on Hans Hartenstein's

Qualification for Expert SCR Opinions":

No comment.

Specific Comments to the Document's Section "Fuel Switching":

No comment.

Specific Comments to the Document's Section "Non-SCR NOx Controls":

No comment.

Specific Comments to the Document's Section "Conclusions":

No comment.

Specific Comments to Appendix A "Qualifications"

The author erroneously claims that "all waste-to-energy plants in Europe have either activated

carbon injection or fixed activated carbon plants", which "take out all the poisons such as all

acidic components, arsenic etc. from the flue gas" upstream ofthe SCR. This statement is

incorrect since many waste-to-energy units in Europe have:

TESCRs directly. downstream of a wet scrubber and no activated carbon injection or

fixed bed activated carbon plants upstream ofthe SCR. The waste-to-energy plants AEZ

Asdonkshof, Germany and MVA Bielefeld-Herford, Germany may serve as examples for

this TESCR arrangement~ 55.

LDSCRs directly downstream ofthe ESP and upstream ofthe acid gas removal system.

The waste-to-energy plants KVA Basel, Switzerland and MVA WUrzburg, Germany may

serve as examples for this LDSCR arrangement2§, 21.

. http://w\.VW.aez-asdonkshof.de/mva.html

22 Regeneration von Katalysatoren im Rahmen einer Kapazitiitssteigerung, a presentation by Dr. Jiirgen Boseke,

2008 Wildeshausener Katalysatortage, Wildeshausen, Germany

2§ http://~.vw.iwb.chisite/rundgangirundgang.php

n http://www.zvaws.de/verbrennung.html

page 18 of24
HDSCRs directly downstream ofor even integrated in the boiler. The waste-to-energy

plant MHKW Mainz, Germany may serve as an example for this HGSCR arrangement~.

Specific Comments to Appendix A "Missing Information"

The author claims that "more than 20,000 MW oflignite fired units in Germany were not

required to install SCR in order to comply with the regulations." Even though this statement is

correct the following statement that "these units were exempted from the regulation despite the

fact that they would not achieve the required emission limit of 200 mgINm3

" is simply incorrect.

Correct is that the lignite-fired units have to meet the same NOx emission limit of200 mgINm3

,

however have been able to achieve this with primary measures only such as low NOx burners~.

The author erroneously claims that "Germany had only one cyclone-fired (slag tap) unit with a

SCR system. This unit is Walsum 7, the NOx control system is a LDSCR." Evonik's Walsum

Unit 7 a U-fired and not a cyclone fired wet bottom boiler. It is equipped with a LDSCR with

flue gas reheating downstream of a cold-side ESp§Q. However, numerous cyclone:fired units with

HDSCRs and TESCRs exist in Germany. At least two units, namely E.ON's cyclone fired

Staudinger Units 1 and 2 equipped with HDSCR should be known to the author as they are

extensively discussed in my 1999 paper21.

The author erroneously claims that one "cannot send saturated gas from the scrubber to the gasgas heat exchanger (GGH) for the TESCR." In the following paragraph the author continues to

erroneously claim that "there is no TESCR on any utility boiler anywhere in the world that uses

this configuration successfully downstream ofa wet FOD." Eyonik's Marl Units 3, 4 and 5 may

serve as one ofmany plants where exactly this has been successfully in operation for over 20

years now62• The flue gas from the wet scrubber enters an axial booster fan upstream ofthe

TESCR GGH. In order to avoid any CaS04 deposits on the fan blades, a small amount offlue

gas is recirculated from downstream ofthe TESCR back to upstream ofthe booster fan.

.However, many wet FGDs in Europe are equipped with GGH around the scrubber, thus cooling

the flue gas prior to entering the scrubber and reheating immediately afterleaving the scrubber.

In all ofthese GGHs the wet, saturated flue gases coming from the scrubber enter the GGH's

heating surfaces. Of course regular on-line washing is necessary to keep the heating surfaces

clean, which, however, is no different than on-line sootblowing in a boiler. These systems have

2!! http://wv..W.mhkw-mainz.de!anJagetechnik/index.php

22 Dreizehnte Verodmung zur DurchfUhrung des Bundes-Immissionsschutzgesetzes (Verordnung tiber

GroBfeuerungsanlagen) - 13. BImSchV. Bundesdrucksache Bundersrepublik Deutschland, 1983

QQ Personal conversation with plant personnel ofEvonik's Walsum Generating Station

§! Hartenstein, H., H. Gutberlet, "Utility Experience with SCR in Germany", DOE Conference on SCRiSNCR,

Pittsburgh, PA, 1999

g Personal conversation with plant personnel ofEvonik's Marl Generating Station

page 19 of24
been in successful operation for more than 25 years now so that this must be considered a well

proven concept. Interestingly enough the author acknowledges the existence ofthese FGD

GGHs, which are exactly the same piece of equipment as the TESCR GGH, however, he fails to

explain why the FGD GGHs work well and the TESCR GGHs wouldn't.

The author also erroneously states that "the required FGD removal efficiency was about 80%."

The fact ofthe matter is that the minimum required SOx removal efficiency has been 85%

regardless ofthe SOx concentration in the flue gas since 198363• Likewise the maximum

permissible SOx outlet concentration ,at the stack was 400 mgINm3 (~140 ppm) between 1983 .

and 2004 and 200 mgINm3 (~70 ppm) since 200464• This means that the SOx removal efficiency

at full load and design coal has typically been well above 90% and in many cases above 95%,

with a minimum of 85% even at very low SOx inlet concentrations.

Specific Comments to Appendix A "Incorrect Information"

My comments mostly address only issues that weren't addressed earlier already and are relevant

for the discussion.

The author claims that it is incorrect that no flue gas reheating is typically required for HDSCR

and LDSCR. Since the vast majority ofthe coal-fired units equipped with SCRs in North

America are base loaded units, they typically run at full or close to full load for the majority of

the time. In this operating mode typically no flue gas reheating is required. Also, economizer

bypasses or split economizers are commonly not considered as flue gas reheating since no .

additional heat energy is added to the flue gas but only the amount of heat energy extracted from

the flue gas is limited during low load operation.

The author erroneously claims that "not a single coal-fired unit with a LDSCR or TESCR system

has a heat exchanger other than rotary." This statement is incorret and E.ON's Westerholt Power

Station Units 1 & 2, which had TESCRs equipped with Balcke-DUrr plate type cross flow GGHs,

may serve as an example. The 150 MW wet bottom boiler units were built in the early 1960,

retrofitted with wet FGDs and TESCRs in the late 1980s and decommissioned and demolished in

2006 after almost 45 years of servic~, QQ.

g Dreizehnte Verodmung zur Durchfiihrung des Bundes-Immissionsschutzgeseties (Verordnung Uber

GroBfeuerungsanlagen) - 13. BlmSchV. Bundesdrucksache Bundersrepublik Deutschland, 1983

M NovelIierung der Dreizehnten Verordnung zur Durchfiirhrung des Bundes-Immissionsschutzgesetzes

(Verordnung Uber GroBfeuerungs- und Gasturbinenanlagen - 13. BlmSchV, Bundesdrucksache Bundesrepublik

Deustchland,.2004

Press release 10108/200, Abschaltung des Kemkraftwerks Stade im Jahre 2003 geplant, E.ON Energie AG;

Hamlover, Germany

§!j https:/!www.etde.org/etdeweb/details.i~Q1osti id'=5422433

page 20 of24
The author obviously misunderstood my comment about the possible elimination ofthe heat rate

penalty in case of a turbine limited unit. It is certainly correct that the more heat input is

necessary for the same electrical output. What I meant to point out·is that incase ofturbine

limited units, it is often possible to maintain the same electrical output despite using steam for

reheating rather than having to reduce the electrical output ofthe unit as a result ofthe steam

consumption for reheating.

The author erroneously claims that "there has never been another TESCR built after Siersdorf,

which was finished in early 1991, in the U.S. or in Europe." As already pointed out previously,

VEB's Rudow Unit 2 was retrofitted with a TESCR in 199467. After that numerous TESCRs

were retrofitted to a wide variety of combustion process including at least one unit in North

America, namely the waste-to-energy plant KMS Peel Units 1 through 5 in Mississauga, Ontario,

which has been in successful operation since 200168•

It is also worth noting that even though Siersdorfwas shut down, the catalyst, which was

installed in these TESCRs still remains in operation today since no significant deactivation was

observed. The TESCR catalyst originally installed in Siersdorfwas installed in Evonik's Voerde

Generating Station's Units West 1 and 2~. .

Specific Comments to Appendix A "Vendor Guarantees"

No additional comment as this was already addressed previously.

Specific Comments to Appendix A "Catalyst Poisons and Pilot Projects"

No additional comment as this was already addressed previously.

References and Literature Considered

1. Cleaner Fossil Fuel For Sustainable Development, Co-Firing Coal and Biomass, a

presentation by Henrik Noppenau, Elsam (Energie E2 until 07/0112006 ), Denmark

2. Co-firing ofbioniass -evaluation offuel procurement and handling in'selected existing

plants and exchange ofinformation (COFIRING) - Part 2, Kraftwerk Schwandorf,

Germany, Alterne ABV-NET V, Ruth Brokeland, C.A.R.M.E.N.

§1 SCR Reference List, Fisia Babcock Environment GmbH

Chandler, 1., 1. Gallant, H. Hartenstein, A. Licata, "Retrofit of a WTE Facility with SCR for NOx and PCDDIF

Control and NaZS4 Injection for Mercury Control", DOE Conference on SCR/SNCR, Pittsburgh, PA, 1999

§2 Personal conversation with plant personnel at Evonik's Voerde Generating Station

page 21 of24
3. Considerations for Catalyst Deactivation and Regeneration When Firing Biomass, Dr. Greg

Holscher, CERAM and Mark Ehmschwender, Evonik Energy Services, 2008 NOx Round

Table, Richmond, Virginia

4. Dreizehnte Verodmung zur DurchfUhrung des Bundes-Immissionsschutzgesetzes

(Verordnung tiber GroBfeuerurrgsanlagen) - 13. BImSchV. Bundesdrucksache

Bundersrepublik Deutschland, 1983

5. Novellierung der Dreizehnten Verordnung zur DurchfUrhrung des BundesImmissionsschutzgesetzes {Verordnung tiber GroBfeuerungs- und Gasturbinenanlagen - 13.

BImSchV, Bundesdrucksache Bundesrepublik Deustchland,.2004

6. Entwicklung und Einsatz eines Regenerationsverfahrens fUr SCR-Katalysatoren, Dr.

Herwig Maier e~. aI., VGB Kraftwerkstechnik 1998

7. Katalytische DioxinzerstOrung fUr Abfallverbrennungsanlagen, Dr. R. Spahl et. al. BASF,

Sonderdruck aus EntsorgungsPraxis 5/93, 1993

8. Kramer, M., C. Gerlach, H. Hartenstein, "Asz03 and SOl Testing at Hoosier Energy's

Merom Generating Station", The 2007 EPRI Workshop on Selective Catalytic Reduction,

Pensacola,FL,2007

9. Landesamt fUr Umweltschutz Nordrhein-Westfalen, KHirschlammbericht 2003

10. Landtag Nordrhein-Westfalen Drucksache 13/6936, Antwort der Landesregierung auf die

Kleine Anfrage des Abgeordneten Reiner Priggen, GRONE, Drucksache 13/6716,2005

11. Mitverbrennung von KHirschlamm in kalorischen Kraftwerken, Umweltbundesamt GmbH,

Wien, ISBN 3-85457-614-5

12. Mobile Katalysatorregeneration in der praktischen Bewahrung, Dr. Herwig Maier et. al.

EnBW Kraftwerke AG, VGB Konferenz Chemie im Kraftwerk, 2006

13. Press release 10/08/200, Abschaitung des Kemkraftwerks Stade im Jahre 2003 geplant,

E.ON Energie AG; Hannover, Germany

14. Recent Experience with SCR Catalyst Regeneration, Dr. Herwig Maier et. aI., EnBW, 2001

DOE Conference on SCR / SNCR, Pittsburgh 2000

15. Reference List Catalyst Regeneration Integral Umwelttechnik GmbH

16. Reference List SCR, Fisia Babcock Environment GmbH

page 22 of24
17. Regeneration von Katalysatoren im Rahmen einer KapaziHitssteigerung, a presentation by

Dr. JUrgen Boseke, 2008 Wildeshausener Katalysatortage, Wildeshausen, Germany

18. Retrofit of a WTE Facility with SCR for NOx and PCDDIF Control and Na2S4 Injection for

Mercury Control, Chandler, J., J. Gallant, H. Hartenstein, A. Licata, DOE Conference on

SCR/SNCR, Pittsburgh, PA, 1999

19. Stadtwerke DUsseldorfAG, MUllverbrennungsanlage, a presentation by Uwe Behrendt

SWD, Wildeshausener Katalysatortage 2008, Wildeshausen, Germany

20. STEAG's Long Term SCR Catalyst Experience and Cost", Sobolewski, H, H. Hartenstein,

H. Rhein, The 2005 EPRI Workshop on Selective Catalytic Reduction, Louisville, KY,

2005

21. Successful experience with In.situ Regeneration of SCR Catalyst in Coal-Fired

Applications, Dr. Herwig Maier et. aI., EnBW, 2000 DOE Conference on SCR 1SNCR,

Pittsburgh 2000

22. Utility Experience with SCR in Germany, Hartenstein, H., H. Gutberlet, DOE Conference

on SCR/SNCR, Pittsburgh, PA, USA 1999

23. Washing Your Own Catalyst, a presentation Nathan White, Haldor Topsoe, 2007 NOx

Round Table, Cincinnati, Ohio

24. Was kann die Katalysatorregeneration zur Temperaturabsenkung beitragen?, a presentation

by Dr. Alexander Schuttig, Wildeshausener Katalysatortage 2008, Wildeshausen; Germany

25. Workshop VI SCR: Catalyst Poisoning, Jeff van Aaken, Argillon, 2007 NOx Round Table,

Cincinnati, Ohio

26. Website I1ttp://64.233. I 69.1 04/search?g=cache:zdIt5NngCwJ:www.stadtentwicklung.berlin.de/umwelt/umweltatlas/e tab

1130 1e02.xls+Kraftwerk+Rudow+DeNOx&hl=de&ct=clnk&cd=8&gl=us

27. Website http://ww\\..aez-asdonkshof.de/mva.html

28. Website http://www.eon-energie.com/pages/eea de/Presse/PressemitteilungenlAktuelle

Presse/PressemitteiIung.htm?id=49380

29. Website https:llwww.etde.org/etdeweb/details.jsp?osti id=5422433

30. Webiste http://www.iwb.ch/site/rundgang/rundgang.php

31. Website http://www.mhkw-mainz.de/anlagetechnik/index.php

page 23 of24
32. Website http://www.spiegel.de/politikJdeutschland/O. 1518.97338,OO.html .

33. Website http://l,vww.stmk.spoe.at/steiermarkJaktuelles/archiv/grose-chance-fur-neue-

.arbeitsplatze-durch-kovats-engagement-beim-kraftwerk-voitsberg

34. Website

http://w\\.W.wirtschaftsblatt.at/home/oesterreich/unternehmen/steiermark/337197/index.do

35. .Website http://www.zittu-danllstadt.de/cipp/tudzit/lib/al1/lob/return download,ticket,

guest/bid,1179/check table,it chap downl embed/~/umwelttechnik.pdf

36. Website http://www.zvaws.de/verbrennung.html

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