p.1 

OAR Box 1778 

Prepped by Ollie Stewart 

Document Number: 

236)11-1-16 

Docket Number: 

A-90-06 

Printed 10/28/2008 9:51:02 AM Sheet 236 of 276 
T P.2 

'^UG-16-9 0 THU 14:01 FAX N 

II-I-16 

,(3-16-99 TH U H':S 1 

Wisconsin 

Electric 

POWSA COMPANY 

23lWMteniQcaPO.0a2Ci«.Mliv^l<Ot5.Wi£32fl1 ('.vi} 221-2345 

August 15, 1990 

Mr. Paul 0. Yeung f~T~ 

Environmental Engineer i ,

 : 

Wisconsin Department of Natural Resources 

Bureau of Air Management 

P. 0. BOX 7921 . . . 

Madison, Wisconsin 53707-7921 * L 

I 

;l]il JUN I 2 1991 p\ 

Dear Mr. Yeung: 

) EPA AIR DC '•i^ j \ fr.3 

PROPOSED AIR POLLUTION CONTROL PERMIT FOR 

PORT WASHINGTON POWER PLANT (PERMIT NO. 90-POV-037) 

This is a follow-up to one of the items we discussed at our meeting 

of August 6, 1990. As we understand it, the DNR's proposed permit 

conditions for S03 control on Units 1 and 4 are being imposed to 

avoid triggering NSPS for S02 on these boilers. The proposed permit 

conditions would require the company to operate the S02 removal 

equipment (dry sorbent injection) on units l and 4 at all times, even 

when the units were operated at low loads. It has been the DNR's 

position, based on its understanding of EPA's position, that use of 

technology to reduce S02 emissions from the units after renovation, 

to or below those at current maximum capability, must be applied on a 

continuous basis. 

To get a more definitive explanation of the EPA position, we spoke to 

Mr. John Calcagni, Director of the Air Quality Management Division of 

EPA's Office of Air Quality Planning and Standards, and we made Mr. 

Ziege aware of this contact. Mr. Calcagni will provide EPA's 

official position to you shortly through the Region V office. 

However, Mr. Calcagni expressed his personal belief that the proposed 

S02 removal equipment need not be operated at all times in order to 

be considered a technological system for continuous S02 removal, if 

there exist valid reasons why the equipment cannot be operated at all 

times. 

TECHNICAL CONCERNS WITH DRY SORBENT INJECTIONS (PSI) USE AT LOW LOADS 

As we discussed with you on August 6, there are valid technical 

reasons why we should be exempt from using the DSI equipment during 

Units 1 and 4 start-up, shutdown, and boiler trip or loss of burner 

flame. The reasons the technology should not be applied during those 

boiler operating conditions are described below. 

Inlection of sodium bicarbonate prior to obtaining 325°F precipitator 
P.3 

*AUGr16-90 THU 14:03 

,G-16-9 e TH U 11:S 2 

FAX NO. OOOOOOOOOOOOOOOOOOOO P, 03 

| Tall 

m 

Mr. Paul 0. Yeung 

August 15, 1990 

Page 2 

precipitator operations and collection efficiency* During the startup of a unit, the precipitator internal metal surface temperatures 

typically lag flue gas temperatures by 20 to 30*F. Operating data 

and precipitator inlet flue gas temperatures collected during a 

recent start-up of Unit 3 are provided on Table 1. During that 

start-up, an average precipitator inlet temperature of 325*F was 

first aohleved at an approximate unit electrical load of 22-26 MWe, 

at corresponding feedwater flows of 203-226 Klb/hr. At this point in 

unit start-up, precipitator surface temperatures are estimated at 

300°F. 

sorbent utilization is a measure of how much sodium bicarbonate 

completes the reaction with sulfur dioxide in the flue gas to form 

sodium sulfate. At 100% utilization, approximately 2.7 pounds of 

sorbent will remove one pound of SO,, our test results and other 

published test results have shown that flue gas temperatures below 

300°F significantly reduce sorbent utilization because thermal 

decomposition of the sodium bicarbonate is too slow and incomplete. 

In the 250 - 290°P range, sorbent utilization decreases to the 6S701 range; and below 250°F, utilization or reaction is reduced to 

less than 30*. 

The result of injecting sodium bicarbonate below 325°F to maintain a 

fixed percentage S02 removal would be to increase the sorbent 

requirement due to poor utilization causing a substantial increase in 

the precipitator inlet mass loading and sodium bicarbonate/sodium 

sulfate ratio in the fly ash. The sodium bicarbonate/sodium sulfate 

compounds are highly conductive materials which are easily collected 

in a precipitator. However, because they are so conduotive they are 

easily re-entrained into the gas stream causing an increase in outlet 

opacity. The presence of the highly conductive material in the 

precipitator will also cause excessive precipitator sparking as the 

coal flow is increased to raise unit load. Additionally, we expect 

that the presence of the highly conductive material will cause ESP 

current levels to achieve controlled maximum levels at lower than 

desired voltages. This phenomena will cause lower corona around the 

wires, causing overall lower field densities, and hence, lower ESP 

collection efficiencies for fly ash. 

The overall net effect of injecting the sodium bicarbonate into low 

temperature flue gas and ESP surfaces will be to increase opacity 

during unit start-up, and cause long-term precipitator performance 

problems. 

PROPOSED PERMIT CONDITION LANGUAGE 

Based on the above discussion, we have proposed wording of the permit 

conditions as they relate to the S02 emission limitations for Units l 

and 4. The proposed permit language we offer for your consideration 

is: 
P.4 

riUG-16-90 THU 14:06 

C-16-9 8 TH U 

FAX NO. OOOOOOOOOOOOOOOOOOOO 

l l :S 3 

P. 04 

. 134. 

Mr. Paul 0. Yeung 

August 15, 1990 

page 3 

"The permittee shall install, maintain and operate continuous 

sulfur dioxide emission control equipment (dry sorbent 

. injection) on Units 1 and 4. 

Compliance with the S02 emission limitations and percent 

reduction requirements under Section I apply at all times 

except during periods of unit start-up and shutdown, and during 

a boiler trip or loss of flame. 

During a unit start-up, the sulfur dioxide emission control 

equipment shall be operated whenever the average precipitator 

inlet gas temperature is greater than 325°F and the unit is online (main generator breaker closed). The reguired percent 

removal (22% Unit ij 13% Unit 4) shall be obtained prior to the 

unit obtaining 30 MWe net output. 

During unit shutdown, the sulfur dioxide emission control 

equipment shall be operated until just prior to the removal of 

coal fire from the boiler. 

During a boiler trip or loss of flame, the sulfur dioxide 

emission control equipment will be taken out-of-service 

immediately until the furnace purge cycle is completed, unit is 

back on-line, and boiler conditions have stabilized." 

We would appreciate your consideration of the information provided as 

you prepare the final draft of the air permit. The other concerns we 

discussed which we hope you will address in the final permit are 

further allowances for trace metal variability in the coal and a 

slightly higher NOx emission limitation for each boiler following 

renovation. 

We would also appreciate a copy of the final draft permit when it is 

circulated for internal department review. We are anticipating that 

you will be able to issue our air quality permit for this project 

when the public comment period on the DNR's environmental assessment 

closes, which is expected to be about August 31, 1990. 

Sincerely, 

RogiaJ D . Dodds 

Air quality Engineer 

Environmental Department 

rrnm 

cos Wolf Klassen - DNR/SED 
P.5 

AUG-16-90 THU 14:09 FAX NO. OOOOOOOOOOOOOOOOOOOO P. 05 

,G- 1 ©-• T H U 1 1 s 5 4 P . S-9 

bcc: J. W. Boston 

Frank Boucher 

N. B. Childress 

W. A. Ebel 

E. R, Fine 

R. R. Grigg 

H R Platz 

M. P. Steinberg/R. F. Pierce/B* A. Petermann 

P. D. Schumacher 

W. T. Woelfle 

ED File 2.11 
P.6 

AUG-16-90 THU 14:0 9 

„G-ltS--9 e THU 11:5 4 

FAX NO. OOOOOOOOOOOOOOOOOOOO P. 06 

p . e e 

TABLE I 

Port Washington Unit 3 

Start-u p Operating Data 

Tima , 

CO.01:15 

00:11:15 

00:21:15 

00:31:15 

00:41:15 

00:51:15 

01:01:15 

01:11:18 

01:21:19 

01:31:20 

01:41:20 

01:51:00 

02:01:20 

02:11:21 

02:21:25 

02:31:40 

02:42:04 

02:52:32 

03:02:68 

03:13:15 

03)23:47 

03:34:19 

03:45:04 

03:55:31 

04:05: AS 

04i15:03 

04)26:11 

04:36:28 

Unit Lot* 

MU« 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

0.0 

.052 

2.71 

6.00 

6.63 

6.73 

7.05 

6.99 

11.5 

12.3 

13.5 

14.1 

20.1 

21.2 

21.9 

25.8 

26.9 

29.3 

feedwater Plow 

Klb/hr 

58.4 

54.0 

81.2 

66.4 

62.8 

69.6 

66.8 

122 

65.2 

••, 99. 6 

72.0 

74.4 

74.4 

99,2 

75.6 

127 

119 

114 

144 

143 

160 

174 

187 

212 

203 

206 

260 

263 

Air Heater outlet eat Temp. ( f) 

No. 31 Wli M 

261 

264 

268 

271 

273 

275 

277 

278 

277 

277 

280 

283 

283 

290 

292 

291 

292 

292 

294 

296 

299 

304 

307 

310 

314 

318 

322 

329 

277 

281 

284 

288 

289 

291 

294 

296 

297 

297 

298 

301 

304 

308 

309 

308 

307 

308 

309 

311 

314 

319 

323 

328 

332 

336 

340 

347 

ftyeraae 

269 

273 

276 

277 

281 

283 

285 

287 

287 

287 

289 

292 

295 

299 

300 

300 

300 

300 

302 

304 

307 

312 

313 

319 

323 

327 

331 

338