CALIFORNIA ENERGY COMMISSION

Compressed Natural Gas Workshop

August 3, 2005

Natural Gas Quality: Power Turbine Performance During Heat Content Surge

William Walters Aspen Environmental Group

Sponsored by the California Energy Commission

CALIFORNIA ENERGY COMMISSION

Summary of Findings

• Uncontrolled NOx emissions increase with increasing natural gas heat content, but that increase is different for each turbine. • Controlled NOx was not found to increase, the emission controls were able to compensate • Additional ammonia was used for the gas turbines with Selective Catalytic Reduction in order to compensate. • Additional data is necessary to determine full impact to the natural gas fired power plants.

CALIFORNIA ENERGY COMMISSION

Natural Gas Excursion Event

• PG&E pipeline coming from Canada experienced heat content excursion for three days.

• Heat content excursion due to outage at a liquids extraction plant in Canada.

• Operating and fuel data from four power plants were obtained around the excursion event.

CALIFORNIA ENERGY COMMISSION

Power Plant Descriptions

• All of the power plants that were monitored are combined cycle power plants.

• Redding is a “muni”, while Sutter, Delta and LMEC are Calpine owned merchant plants.

• Specific Plant Turbine and Emissions Control Descriptions are provided below.

Facility Turbine Type (Number) MW (Turbine/Plant) Emission Control Technologies Redding Alstom GTX100 (1) 43/56 (Unit 5 only) SCONOx Sutter Westinghouse 501FD (2) 175/540 DLN, SCR, and Oxidation Catalyst Delta Westinghouse 501FD (3) 175/861 DLN, SCR LMEC General Electric 207FA (2) 172/555 DLN, SCR, and Oxidation Catalyst

Power Plant Data

Natural Gas Data Performance Data Exhaust Data

Facility Btu

Co

nte

nt

(as

use

d)

Pip

elin

e G

as

Hyd

roca

rbo

nC

om

po

siti

on

Pip

elin

e G

as In

ert

Co

mp

osi

tio

n

Hea

t o

r F

uel

Inp

ut

MW

Ou

tpu

t (G

T o

nly

)

Eff

icie

ncy

Est

.

Am

mo

nia

Flo

w

Pro

cess

Sta

tus

Un

con

tro

lled

NO

x

Co

ntr

olle

d N

Ox

Co

ntr

olle

d C

O

Oxy

gen

Co

nte

nt

Tu

rbin

e/S

tack

Exh

aust

Tem

per

atu

res

SC

R C

atal

yst

Tem

per

atu

re

Redding X - - X - - N/A X X X X X -/- N/A Sutter X - 1 - X X - X X X X X X X/X X LMEC X X 2 X 2 X X X X - - X X X X/- -Delta X X 2 X 2 X X X X - - X X X X/- -1 – Data supplied includes blended gas composition data. 2 – Data supplied from PG&E pipeline adjacent to Delta gas blending facility, but blended gas composition data for Delta was not supplied.

CALIFORNIA ENERGY COMMISSION

Pipeline N

atural Gas H

eat Content

1080

1070

1060

1050

1040

1030

1020

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

8-Jun-05

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

9-Jun-05

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

10-Jun-05

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

11-Jun-05

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

12-Jun-05 0:00:00

13-Jun-05 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

Redding

Delta

Btu/scf (HHV)

CA

LIFO

RN

IA E

NE

RG

Y C

OM

MIS

SIO

N

Turbine F

uel Heat C

ontent Variability

• S

utter Fuel D

ata

Heat Content (Btu/scf)

Btu/scf (HHV)

1,0

80

.00

1,0

70

.00

1,0

60

.00

1,0

50

.00

1,0

40

.00

1,0

30

.00

• LM

EC

Fuel D

ata 1,0

20

.00

1,0

10

.00

1050

1040

1030

1020

1010

1000

990

980

970

9-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

10-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

11-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

12-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

13-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

14-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

12:00 PM

4:00 PM

8:00 PM

12:00 AM

4:00 AM

8:00 AM

12:00 PM

4:00 PM

8:00 PM

12:00 AM

4:00 AM

8:00 AM

12:00 PM

4:00 PM

8:00 PM

6-Ju

n-0

5

7-Ju

n-0

5

8-Ju

n-0

5

9-Ju

n-0

5

10

-Jun

-05

11-Ju

n-0

5

12-Ju

n-0

5

13-Ju

n-

12:00 AM

05

4:00 AM

8:00 AM

12:00 PM

4:00 PM

8:00 PM

12:00 AM

4:00 AM

8:00 AM

12:00 PM

4:00 PM

8:00 PM

12:00 AM

4:00 AM

8:00 AM

12:00 PM

4:00 PM

8:00 PM

12:00 AM

4:00 AM

8:00 AM

12:00 PM

4:00 PM

8:00 PM

12:00 AM

4:00 AM

8:00 AM

12:00 PM

CA

LIFO

RN

IA E

NE

RG

Y C

OM

MIS

SIO

N

https://1,010.00https://1,020.00https://1,030.00https://1,040.00https://1,050.00https://1,060.00https://1,070.00https://1,080.00

Gas T

urbine Load Variability

• R

edding Turbine

Heat Input (MMBtu/hr)

440.0

420.0

400.0

380.0

360.0

340.0

320.0

300.0

9-Jun-05 10-Jun-05

11-Jun-05 12-Jun-05

13-Jun-05

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

0:00:00

4:00:00

8:00:00

12:00:00

16:00:00

20:00:00

2000

1800

1600

1400

1200

1000

800

• S

utter Turbines

600

400

200 0

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

0:00:00 4:00:00

9-Jun-05 10-Jun-05

11-Jun-05 12-Jun-05

13-Jun-05 14-Jun-05

8:00:00 12:00:00 16:00:00 20:00:00

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

0:00:00 4:00:00 8:00:00

12:00:00 16:00:00 20:00:00

180

160

140

120

100

80

60

40

20

0

CT

1 MM

Btu/hr

CT

2 MM

Btu/hr

CT

1 MW

CT

2 MW

CA

LIFO

RN

IA E

NE

RG

Y C

OM

MIS

SIO

N

CALIFORNIA ENERGY COMMISSION

Uncontrolled NOx Emissions vs. Heat Content

Sutter Turbine 2 Redding

1020 1030 1040 1050 1060 Natural Gas Heat Content (Btu/scf)

25

26

27

28

Unc

ontr

olle

d N

Ox

PP

M

970 980 990 1000 1010 1020 1030 1040 1050 Natural Gas Heat Content (Btu/scf)

20

22

24

26

28

30

Unc

ontr

olle

d N

Ox

PP

M

CALIFORNIA ENERGY COMMISSION

Ammonia Consumption

• Sutter Turbine 2 ammonia injection rate vs. natural gas heat content at near similar operating loads

975 980 985 990 995 1000 1005 1010 1015 1020 1025 1030 1035 Natural Gas Heat Content (Btu/scf)

70

75

80

85

90

95

100

105

110

Am

mon

ia In

ject

ion

Rat

e (lb

s/ho

ur)

CALIFORNIA ENERGY COMMISSION

Controlled NOx Emissions vs. Heat Content

Redding Controlled NOx

Sutter Controlled NOx

0.34

0.35

0.36

0.37

0.38

0.39

0.40

0.41

0.42

0.43

0.44

1020 1025 1030 1035 1040 1045 1050 1055 1060

Natural Gas Heat Content (Btu/scf)

Con

trol

led

NO

x P

PM

1.8

1.9

2

2.1

2.2

2.3

2.4

980 990 1000 1010 1020 1030 1040

Natural Gas Heat Content (Btu/scf)

NO

x E

mis

sion

s P

PM

Turbine 1 Turbine 2

CALIFORNIA ENERGY COMMISSION

Conclusions • Results of this study may not apply to all newer

combined cycle gas turbine facilities; particularly different turbine models/makes and those with different combustors.

• Additional data from other combined cycle plants, including any 7F turbine base load plants, should be collected when similar natural gas heat content excursion events occur.

• Additional data from simple cycle plants should be collected.

• Additional data from other older facilities that make up the bulk of the current natural gas fired power plant emissions (i.e. cogeneration units, perhaps even steam boilers).