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
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).