P.1 

OAR Box 1778 

Prepped by Ollie Stewart 

Document Number: 

39) ll-B-14 

Docket Number: 

A-90-06 

Printed 10/28/2008 9:50:53 AM Sheet 39 of 276 
<^*1>. 

USE 

%«W* 0 < * 

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* • II-B-14 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JIM 24 190 

OFFICE OF ENFORCEMENT 

Mr. Amasjit S. Gill 

General Electric - Gas Turbine Division 

One River Road 

Schenectady, New York 12345 

Dear Mr. Gill: 

This is to respond to your letter of May 19, 1981, 

requesting a determination of the applicability of NSPS and PSD 

to stationary gas turbines converting from middle distillates 

to natural gas. 

The information presented in your letter indicated that 

NOx and SO2 emissions will decrease after the conversion to 

natural gas and hydrocarbons, CO and particulate emissions will 

either remain the same or decrease. As you correctly pointed 

out in your letter, the NSPS would only apply if there is an 

increase in emissions of a pollutant to which the standard 

applies. The NSPS for gas turbines applies only to N0X

 and 

S02 emissions. Since the conversion from middle distillate 

fuel to natural gas for the turbines in question will cause a 

decrease in N0X and SOo emissions, it is not considered a 

modification as defined in 40 CFR 60.14(a). The turbines 

however, could be subject to the NSPS if the conversion falls 

under the definition of reconstruction (See 40 CFR 60.15). 

PSD review would apply to a proposed modification at an 

existing major stationary source if it would cause a 

significant net increase in actual emissions of any regulated 

pollutant. In thetcase of the gas turbine conversions outlined 

in your letter, PSD applicability is determined by evaluating 

any change in emissions rates caused by the conversions. The 

data contained in your letter indicate that the emission rates 

after the conversion will either remain constant or decrease. 

Actual emissions could increase only if there is an increase in 

the production rate or hours of operation, both of which are 

specifically exempt from PSD review. (See 40 CFR 

52.21(b) (2) (iii) (f)). Therefore, since there will not be any 

increase in emission rates or any creditable increases in 

actual emissions, the conversion of the gas turbines will not 

be subject to PSD review. 
P.3 

If you have any questions concerning this determination 

please contact Janet Farella of my staff at 202-755-2564. 

Sincerely yours, 

Edward E. Reich, Director 

Division of Stationary 

Source Enforcement 

cc: Peter Wyckoff 

Mike Trutna 
P.4 

-^ GENERAL f * r.?CT3 l GAS TURBINE 

DIVISION 

GENERAL ELECTRIC COMPANY. ONE RIVER ROAD. SCHENECTADY. NEW YORK 12345 

Telephone 

(518) 385-4131 

OPERATIONAL PLANNING 

May 19, 1981 Copy: Don R. Goodwin, EPA 

Research Triangle Par 

NC 27711 

Mr. Edward Reich, Director 

Division of Stationary Source Enforcement 

Environmental Protection Agency 

401 M Street, S.W. 

Washington, D.C. 20460 

Dear Mr. Reich: 

Stationary Gas Turbines 

Converting from Distillate to Natural Gas 

The Economic Regulatory Administration of the Department of Energy grants 

temporary public interest exemptions, from the prohibitions of the Fuel Use 

Act of 1978, to burn natural gas where such use displaces the use of middle 

distillates, thereby decreasing our reliance on imported oil. 

Existing gas turbines* which 4o not have built-injdual-fue.1 capability, 

musT install new combustion hardware so that they can burn natural gas 

instead of middle distillates. The concern-arises whettrer SiicrTa -conversion 

would be calssified a "modification" or "major modification" and, therefore, 

subject the gas turbine to the New Source Performance Standards (NSPS) or a 

Prevention of Significant Deterioration (PSD) review. 

MODIFIED 

The definition of modification is provided in 40 CFR 60 as: 

60.14 (a) "Except as provided under paragraphs (e) and (f) of this 

section, any physical or operational change to any 

existing facility which results in an increase in the 

emission rate to the atmosphere of any pollutant to 

which a standard applies shall be considered a modification within the meaning of Section III of the Act..." 

60.2 "'Standard1 means a standard of performance proposed or 

promulgated under this part." 
P.5 

GENERAL © ELECTRIC Page 2 

NEW SOURCE PERFORMANCE STANDARDS (NSPS) 

Hydrocarbons, carbon monoxide and particulates are specifically excluded 

from the NSPS promulgated on Sept. 10, 1979. Justification for the exclusion 

was provided in the Oct 3, 1977 Federal Register on page 53783. 

"HC and CO emissions from stationary gas turbines operating at peak load 

are relatively low because the higher the percentage of peak load at 

which a turbine operates, the more efficient the combustion of the fuel. 

Gas turbines normally operate at 80 to 100 percent of peak load with HC 

emissions averaging less than 50 ppm and CO emissions averaging less than 

500 ppm at 15 percent oxygen. HC and CO emissions from stationary gas 

turbines, therefore, were not selected for control by standards of performance." 

"Particulate emissions from stationary gas turbines depend on the ash 

content of the fuel and are minimal. Consequently, particulate emissions 

from stationary gas turbines were not selected for control by standards 

of performance." 

Since there is no standard for CO, unburned hydrocarbons and particulates 

under NSPS for stationary gas turbines, NSPS would not apply even if there 

was an increase in the emission rate of these three pollutants. As shown 

in the attached four tables, NOx and S02 decrease, and CO, unburned hydrocarbons and particulates remain unchanged or decrease. 

PREVENTION OF SIGNIFICANT DETERIORATION (PSD) 

PSD review would apply if the emissions increase by amounts greater than 

de minimis levels. De minimis levels, shown on page 52709 in the August 7, 

1980 Federal Register, are: 

Carbon Monoxide 

Nitrogen Oxides 

Sulfur Dioxide 

Particulates 

Volatile Organic Compounds 

Tons/Year 

100 

40 

40 

25 

40 

Equiva 

(8760 

lent lbs/hour 

hours/year) 

22.83 

9.13 

9.13 

5.70 

9.13 

For those machines which are not restricted to a specific number of hours of 

operation per year by an enforceable permit condition, allowable emissions 

would be the hourly emission rate multiplied by 8760 hours per year. Then, 

for PSD review purposes, net emissions increases should be evaluated against 

these allowable emissions to see if de minimis levels are exceeded. 
P.6 

GENERAL @ ELECTRIC Page 3 

PSD (cont'd) 

As can be seen from the attached four tables which provide uncontrolled 

emission rates for four GE gas turbines, the hourly emissions rates decrease for NOx and S02 and remain unchanged or decrease for CO, unburned 

hydrocarbons and particulates when the fuel is switched from distillate 

to natural gas. 

Therefore, these four gas turbine models would not require a PSD review 

when the capability to burn natural gas is added and the fuel is switched 

from distillate to natural gas, and "allowable" emissions, as opposed to 

actual emissions, are not exceeded on an annual basis. 

Your official concurrence with our interpretation is requested at your 

earliest convenience. 

Sincerely, 

Jwjyt' 

A.SV Gill, Env 

/eb 

Attach. 
I 

GENERAL @ ELECTRIC 

P.7 

. FUEL -

LOAD -

Output, 

Heat Rate{LHV), 

1 

kW 

Btu/kWh 

Fuel Consump.(LHV)IO6 Btu/hr 

NOx as NO2, 

*SOx as S02/ 

Particulates, 

Hydrocarbons, 

(as CH4), 

CO, 

lbs/hr 

lbs/hr 

lbs/hr 

lbs/hr 

lbs/hr 

NATURAI 

BASE 

74,400 

10,690 

795.3 

450 

0 

< 28 

<12 

< 21 

P G 7 1 

i GAS 

PEAK 

80,500 

10,640 

856.5 

535 

0 

<30 

< 1 2 

< 2 1 

0 1 E 

DISTILLATE 

BASE 

72,900 

10,790 

786.6 

790 

254 

28 

12 

21 

PEAK 

78,800 

1C 750 

847.1 

970 

275 

30 

12 

21 

•Distillat e Fuel with 0.3% Sulfur by Weight, 

Natural Gas Fuel Containing no Sulfur. 

The results are based on field and combustion laboratory test data from the 

same or similar machines and combustion systems, correlated to provide a 

coherent body of emissions data. The data presented are for operation at 

ISO conditions. 
GENERA L ^ ELECTRIC 

P.8 

P G 7 8 5 1 

FUEL 

LOAD — 

Output, 

Heat Rate (LHV), 

kW 

Btu/kWh 

Fuel Consump.(LHV)IO6 Btu/hr 

NOx as NO2, 

*SOx as SO2, 

Particulates, 

Hydrocarbons, 

(as CH4) 

CO, 

lbs/hr 

lbs/hr 

lbs/hr 

lbs/hr 

lbs/hr 

NATURAL GAS 

BASE 

61,300 

11,000 

674.3 

325 

0 

<24 

<11 

<19 

PEAK 

67,700 

10,920 

739.3 

405 

0 

<26 

<11 

<19 

DISTILLATE 

BASE 

60,000 

11,130 

667.8 

510 

216 

24 

11 

19 

PEAK 

66,300 

11,030 

731.3 

640 

237 

26 

11 

19 

•Distillat e Fuel with 0.3% Sulfur by Weight/ 

Natural Gas Fuel Containing no Sulfur. 

The results are based on field and combustion laboratory test data from the 

same or similar machines and combustion systems, correlated to provide a 

coherent body of emissions data. The data presented are for operation at 

ISO conditions. 
GENERAL ^ ^ ELECTRIC 

P.9 

FUEL 

LOAD — 

Output, 

Heat Rate, (LHV), 

Fuel Consump (LHV) 

NOx as N02, 

*SOx as SO2, 

Particulates, 

Hydrocarbons, 

CO, 

kW 

Btu/kWh 

,106 Btu/hr 

lbs/hr 

lbs/hr 

lbs/hr 

lbs/hr 

lbs/hr 

NATURAL 

BASE 

31,750 

11,280 

358.1 

185 

0 

< 13 

< 6 

< 11 

P G 6 4 

GAS 

PEAK 

34,750 

11,210 

389.5 

220 

0 

< 14 

< 6 

< 11 

4 1 A 

DISTILLATE 

BASE PEAK 

31,100 

11,380 

353.9 

325 

115 

13 

6 

11 

34,000 

11,310 

384.5 

385 

125 

14 

6 

11 

•Distillat e Fuel with 0.3% Sulfur by Weight , 

Natural Gas Fuel Containing no Sulfur. 

The results are based on field and combustion laboratory test data from the 

same or similar machines and combustion systems, correlated to provide a 

coherent body of emissions data. The data presented are for operation at 

ISO conditions. 
•J . . I 

' " • ' • .-••, ' 

GENERA L ^ ELECTRIC 

P.10 

P G 5 3 4 1 P 

FUEL 

LOAD 

NATURAL GAS 

BASE PEAK 

DISTILLATE 

BASE PEAK 

Output, kw 

Heat Rate (LHV), Btu/kWh 

Fuel Consump(LHV),106 Btu/hr 

24,620 26,600 

12,300 12,200 

302.8 324.5 

NOx as NO2, lbs/hr 

*SOx as S02/ lbs/hr 

Particulates, lbs/hr 

Hydrocarbons, lbs/hr 

(as CH4 ), 

CO, lbs/h r 

140 

<. 11 

< 5 

< 10 

155 

< 1 1 

< 5 

< 1 0 

24,110 26,050 

12,450 12,340 

300.2 321.5 

200 

97 

11 

5 

10 

225 

104 

11 

5 

10 

•Distillat e Fuel wit h 0.3% Sulfur by Weight , 

Natura l Gas Fuel Containing no Sulfur. 

The results are based on field and combustion laboratory test data from the 

same or similar machines and combustion systems, correlated to provide a 

coherent body of emissions data. The data presented are for operation at 

ISO conditions.