Impacts of Emission from Power Plants on the Ambient Ozone

Concentration in Southern Taiwan

Yee-Lin Wu and Der Ming Tsai 

Department of Environmental EngineeringNational Cheng Kung University

Tainan, Taiwan

October 28, 2003 

Annual average concentrations of CO、 SO2、 NO、 O3, PM10 and NMHC in

southern Taiwan

Year CO SO2 NO NO2 O3 PM10 NMHC

1994 0.80 11.2 10.2 25.2 22.7 91.9 0.42

1995 0.74 11.5 10.8 25.8 21.7 89.9 0.43 1996 0.72 10.0 9.49 24.4 24.7 85.2 0.40 1997 0.70 9.06 9.20 24.0 25.6 80.3 0.39 1998 0.71 8.08 9.37 23.7 24.1 72.7 0.37 1999 0.69 7.71 8.60 23.7 25.8 76.8 0.34 2000 0.65 6.83 8.20 22.2 25.8 80.7 0.31 2001 0.67 6.95 6.69 22.4 28.9 73.5 0.30

The fractions of days with PSI>100 each year

in southern Taiwan. Fraction

O3 PM10

1994 15.2% 2.89% 12.3%

1995 13.5% 3.13% 10.3%

1996 14.4% 5.49% 8.89%

1997 11.9% 6.91% 4.99%

1998 11.2% 6.67% 4.50%

1999 10.5% 5.75% 4.71%

2000 10.4% 3.63% 6.81%

2001 8.21% 5.44% 2.77%

Pollutant

The monthly mean concentrations of SO2、 NO、

CO、 NO2、 O3 and PM10 in southern Taiwan.

0.02.04.06.08.0

10.012.014.016.018.020.0

19

94

01

19

94

07

19

95

01

19

95

07

19

96

01

19

96

07

19

97

01

19

97

07

19

98

01

19

98

07

19

99

01

19

99

07

20

00

01

20

00

07

20

01

01

20

01

07

20

02

01

20

02

07

SO

2,

NO

( p

pb

)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

CO

( p

pb

)

SO2

NO

CO

0.05.0

10.015.020.025.030.035.040.045.050.0

199401

199407

199501

199507

199601

199607

199701

199707

199801

199807

199901

199907

200001

200007

200101

200107

200201

200207

NO

2, O

3 (

ppb )

0

20

40

60

80

100

120

140

160

PM

10 (

mic

rogr

am/m

3)

NO2

O3

PM10

Emission inventory for PM10、 SOx、 NOx、 VOC and CO in southern

Taiwan. The percentage is for the fraction of

Taiwan. (TEDS 4.3) unit: ton

ton/yr PM10 SOx NOx VOC CO

Taiwan 401589 223357 454950 864236 1488429

Kaohsiung City 13656 46104 45142 83651 93164Tainan City 6414 984 3808 19716 36149

Tainan County 24564 12598 23670 91134 82423

Kaohsiung County 26307 36149 44477 57330 89949PingTung County 16062 2376 7314 22144 46895

TaiPower 135 35809 27597 267 354TaiPower/S.Taiwan 0.2% 36% 22% 0.1% 0.1%

Purposes of Study

• To quantitatively evaluate the impact of Taipower’s plants on the ozone concentrations in the southern Taiwan by using modeling analysis;

• Three scenarios in 1999 were used to evaluate the differences in meteorological conditions.

Characteristics of the three high ozone concentration episodes

PeriodNumber of

sitesexceeding 120

Highest O3cocnentration

, ppb

Site with thehighest O3

cocnentration11 to 14, May 10 163 Annan

23 to 27, September 10 171 Sanmin20 to 27, November 10 180 Chaochou

Characteristics of stacks in the three power plants to be studied

Power Plant Typecapacity(MW)

FuelStack Height

(M)Stack

Diameter (M)SOx

(ppm)NOx

(ppm)

Hsinta steam 500 x 2 coal 250 6.7 45-210 120-210

steam 550 x 2 coal 250 6.7 150-240 175-250

conbined cycle 440 x 5 NG 60 11 <5 10-20

Nanpu conbined cycle 288.8 x 3 NG 60 6 <5 10-20

Talin steam 300 x 2 coal 130 5 200-250 200-250

steam 375 x 2 oil 130 3.78 90-110 90-110

steam 500 x 2 NG 130 6.1 <5 20-70

The emissions of NOx and SO2 from Hsi

nta plant NOx

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8day

Ton

/da

y

1999/05/09

1999/09/21

1999/11/20

SO2

0

10

20

30

40

50

60

70

80

1 2 3 4 5 6 7 8day

Ton

/da

y

1999/05/09

1999/09/21

1999/11/20

NOx

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

HO

UR

00

HO

UR

02

HO

UR

04

HO

UR

06

HO

UR

08

HO

UR

10

HO

UR

12

HO

UR

14

HO

UR

16

HO

UR

18

HO

UR

20

HO

UR

22

Ton/

hr

1999/05/09

1999/09/21

1999/11/20

SO2

0.0

0.5

1.0

1.5

2.0

2.5

3.0

HO

UR

00

HO

UR

02

HO

UR

04

HO

UR

06

HO

UR

08

HO

UR

10

HO

UR

12

HO

UR

14

HO

UR

16

HO

UR

18

HO

UR

20

HO

UR

22

Ton

/hr

1999/05/09

1999/09/21

1999/11/20

The emissions of NOx and SO2 from Tali

n plant NOx

0

5

10

15

20

25

1 2 3 4 5 6 7 8day

Ton/d

ay

36289.00

36424.00

36484.00

SO2

0

5

10

15

20

25

30

35

40

1 2 3 4 5 6 7 8day

Ton/d

ay

36289.00

36424.00

36484.00

NOx

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

HO

UR

00

HO

UR

02

HO

UR

04

HO

UR

06

HO

UR

08

HO

UR

10

HO

UR

12

HO

UR

14

HO

UR

16

HO

UR

18

HO

UR

20

HO

UR

22

Ton/h

r

1999/5/9

1999/9/21

1999/11/20

SO2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

HO

UR

00

HO

UR

02

HO

UR

04

HO

UR

06

HO

UR

08

HO

UR

10

HO

UR

12

HO

UR

14

HO

UR

16

HO

UR

18

HO

UR

20

HO

UR

22

Ton/h

r

1999/5/9

1999/9/21

1999/11/20

Emission Inventory-TEDS4.3

• Stationary sources– raw data from TEDS 4.3– removal of zero values in TEDS 4.3– using measured data to replace the stack emissi

ons in Giayi county, Tainan county, Kaohsiung city, Kaohsiung county and PingTung county

Emission Inventory-TEDS4.3

• Stationary sources(continue)– The VOCs emissions in Tainan county, Kaohsi

ung city, and Kaohsiung county were replaced by measured data

– The greatest 200 SOx and NOx emission sources in TEDS 4.3 were replaced by data for air pollution fee from Taiwan EPA

– The emission of Taipower’s three power plants were replaced by Taipower’s CEMS data

Emission Inventory-Biogenic sources

• Sources of Land-use– 75 kinds of land-use from Bureau of Forestry

– 7 kinds of land-use from CTCI

Bureau of Forestry CTCI

No. of Land-use 75 7

Totally area(Km2) 16496 30265

Emission Inventory-Biogenic sources

• Treatment of biogenic Land-Use information– To do gridding, Bureau of Forestry’s 75 kinds o

f land-use are used first– CTCI’s data then to be concerned, if Bureau of

Forestry’s data is not reach the max. grid area– Totally area used for this study is 30700 square

km

Input of emission to CCTM for the

simulations in 1999 (ton/yr)

Point Mobile Area bio

PM10 24862 13109 129158PM2_5 15898 7091 69752NH3 82915CO 86087 307269 107120SO2 89911 2166 6912SULF 4732 114 364NO 55370 36716 3871 467NO2 4465 2961 312VOCs Totally 157953 138238 216387 155904ALD2 Acetaldehydes (RCHO, R>H) 1865 4393 2042 12687ETH Ethene (CH2=CH2) 1859 5283 5560FORM Formaldehyde (CH2=O) 11255 1318 977ISOP Isoprene 122 79 274 30694OLE Olefins 11192 3126 8426 5853PAR Paraffins 94745 78882 125693 67325TOL Toluene 10025 12059 39149XYL Xylene 2317 16298 13274TERPB Biogenic terpenes 37324NR 24572 16799 20994 2020

D2

D3

D4

Spatial distributions for the simulated ambient concentrations in layer one. (SO2, NO)

Spatial distributions for the simulated ambient concentrations in layer one. (NO2, O3)

Simulated concentrations of ozone

Time series plot concentrations between simulated a

nd observed results at Fengshan site.

0

10

20

30

40

50

60

70

11/2

0,0

8

16

11/2

1,0

0

8 16

11/2

2,0

0

8 16

11/2

3,0

0

8 16

11/2

4,0

0

8 16

11/2

5,0

0

8 16

11/2

6,0

0

8 16

pp

b

SO2_observed

SO2_Base

SO2_NoTaipowerSO2

0

10

20

30

40

50

60

70

80

90

11/2

0,0

8

16

11/2

1,0

0

8 16

11/2

2,0

0

8 16

11/2

3,0

0

8 16

11/2

4,0

0

8 16

11/2

5,0

0

8 16

11/2

6,0

0

8 16

ppb

NO_observed

NO_Base

NO_NoTaipowerNO

0

20

40

60

80

100

120

140

11/2

0,0

8

16

11/2

1,0

0

8 16

11/2

2,0

0

8 16

11/2

3,0

0

8 16

11/2

4,0

0

8 16

11/2

5,0

0

8 16

11/2

6,0

0

8 16

ppb

NO2_observed

NO2_Base

NO2_NoTaipower

NO2

0

20

40

60

80

100

120

140

11/2

0,0

8

16

11/2

1,0

0

8 16

11/2

2,0

0

8 16

11/2

3,0

0

8 16

11/2

4,0

0

8 16

11/2

5,0

0

8 16

11/2

6,0

0

8 16

ppb

O3_observed

O3_Base

O3_NoTaipowerO3

Comparison of wind speeds between simulate

d and observed at Fengshan site.

0

2

4

6

8

10

12

1 9 17 25 33 41 49 57 65 73 81 89 97 105 113 121 129 137 145 153

Wind MM5

Wind Speed.

The wind speed in Fengshan

1999/05-spatial distribution

1999/09-spatial distribution

1999/11-spatial distribution

Conclusions 1. The simulated results by models-3 are on the same order as the observed data for SO2, NO, NO2, and NMHC.

2. The simulated and observed O3 concentrations are in good agreement if the wind speeds simulated by MM5 are not significantly overestimated.

3. The effects of emission from power plants on the O3 concentrations are highly dependent on the meteorological conditions. That is, it varied from case to case.

4. Episode with the highest ozone concentration doesn’t have the greatest impacts.

Acknowledgements

We would like to thank EPRI and Taipower for supporting this study. Thanks also go to Dr. Wu at National Taiwan University for running the meteorological simulation in this study. In compiling the emission data, help from many consulting companies were also greatly appreciated.

Future Works

O3(ppb)

0 20 40 60 80 100 120 140

Altitude(m)

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1400

Altitude(m)

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O3(ppb)0 20 40 60 80 100 120 140

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13:20-14:20O3(ppb)

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O3(ppb)0 20 40 60 80 100

O3(D)O3(A)

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Altitude(m)

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O3(ppb)0 10 20 30 40 50 60

O3(D)O3(A)

06:30-08:303/27,2003

20:30-23:003/25,2003

EveningAfternoon

Subsidence

Inversion layer

city

EarlyMorning

Wind

Noon

Wind

water

residual layer residual layer