Embracing a Green Future with Ultra-low Emission ... · PDF fileEmbracing a Green Future with...

Embracing a Green Future with Ultra-low Emission Technologies of

Coal-fired Power Plants in China

Cao Yuchun

Dept. of Thermal Power Engineering

Changzhou University

SAMK, Mar 9, 2016

Dr. Cao Yuchun, Changzhou University

Outline

Introduction

Energy consumption in China

Emission from coal-power plants

Multi-pollutants simultaneous removal strategy

Technical routines for pollutants deep removal

Integrated system design for flue gas cleaning

Application of the retrofitted projects

Challenges and Prospects

Summary

2016-04-01 1


Growth of the total energy consumption in China

2016-04-01 2

From National Bureau of Statistics of China, http://http://data.stats.gov.cn/

14.7 15.6

17.0

19.7

23.0

26.1

28.6

31.1 32.1

33.6

36.1

38.7 40.2

41.7 42.6 43.0

5.5

8.3

14.0 14.4

11.9

8.8 8.0

2.9

4.6

6.8 6.8

3.8 3.5

2.1

0.9

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

0

5

10

15

20

25

30

35

40

45

50

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015

（％

）

Bil

lio

n t

ec

Year

Energy consumption

Growth rate（%）


Energy consumption structure in China

2016-04-01 3

0%

20%

40%

60%

80%

100%

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

72

.4

72

.4

72

.5

71

.5

71

.6

69

.2

70

.2

68

.5

67

.4

66

.0

17

.8

17

.5

17

.0

16

.7

16

.4

17

.4

16

.8

17

.0

17

.1

17

.1

7.4

7.4

7.5

8.4

8.5

9.4

8.4

9.7

10

.2

11

.2

Renewable

Natural gas

Oil

Coal



Comparison of Energy consumption structure

2016-04-01 4

From BP Statistical Review of World Energy 2015, http://www.bp.com/statisticalreview

Energy consumption structure in different countries (2014)

0

10

20

30

40

50

60

70

80

90

100

USA France Germangy Japan China

36.4 32.4 35.9 43.2

17.5

30.2

13.6

20.5

22.2

5.6

19.7

3.8

24.9

27.7

66.0

8.3

41.5

7.1

0.0 1.0

2.6 6 1.5

4.3 8.1 2.8 2.7

10.2 2.5 1.8

Renewable

Hydro

Nuclear

Coal

Natural gas

Oil


Energy Structure of Power plants in China

2016-04-01 5


0%

20%

40%

60%

80%

100%

2010 2011 2012 2013 2014

15

.99

14

.03

17

.37

15

19

.2

80

.29

82

.54

78

.63

80

.25

75

.2

Coal-fired

Wind

Hydro

Nuclear


Emission from coal-fired power plants

2016-04-01 6

SOx

NOx

PM

Heavy metals

Others


Challenges brought by the fossil fuel combustion

2016-04-01 7

NO2

NO

HNO3

OH

RO2, HO2

, VOCs

SO2

H2SO4

H2O2 O3

hv

NH4+

NO3- SO42-

NH3

Chemical reaction

SNA

Em

ission

SOA

…

Primary

PM

N2O5

Dr. Cao Yuchun, Changzhou University 2016-04-01 8

Challenges brought by the fossil fuel combustion

Cheng Z, et al. Environment international, 2016, 89: 212-221.


Latest emission limits for coal-fired boiler in China

2016-04-01 9

From GB 13223-2011, Emission standard of air pollutants for thermal power plants, http://kjs.mep.gov.cn/

Unit: mg/m3

Item Conditions Current limits （mg/Nm3)

New emission limits Monitoring position Non key areas Key areas

SO2

Existing 450/1200 200

400（1） 50

Inside or outside of the stack

New built 450 100

200（1） 50

NOx （NO2）

Existing 650-1500 100 200（2）

100

New built 450-1100 100

PM Existing 50-100 30 20

New built 50 30 20

Hg and Others All 无 0.03


Local emission standard for coal-fired power plants

2016-04-01 10

Province PM SO2 NOx Date

Issued

Completion

Time

Zhejiang 5 35 50 Dec 2014 2017

Anhui 10 35 50 Mar 2015 2020

Henan 10 35 50 Dec 2014 2020

Jiangsu 10 35 50 Nov 2014 2018

Hebei 10 35 50 Mar 2015 2015

Shanxi 10 35 50 Mar 2015 2017

Fujian 10 35 50 - 2020

Shandong 10 35 50 Dec 2014 2020

Hainan 10 35 50 Apr 2015 2020

Guangxi 10 35 50 May 2015 2020

Tianjin 10 35 50 May 2015 2020

Guangdong 10 35 50 May 2015 2020

Unit: mg/m3


Deep removal flow diagram of pollutants

2016-04-01 11

Dr. Cao Yuchun, Changzhou University 12

Pollutants SCR FGC Low Temp.

ESP WFGD

WESP

(Option)

PM ο ▲ √ ● √

SO2 ο ο ο √ ο

SO3 ▲ ▲ √ √ √

NOx √ ο ο ● ●

Hg ▲ ▲ ● ● ●

Notes:

√-Directly, ●-Directly simultaneous, ▲-Indirectly simultaneous, ο-No effects


2016-04-01 12



2016-04-01 13

Single device model Simultaneous removal model

FGD SOx SOx

NOx

PM

Hg

…

…

…

SCR NOx

ESP PM

… …

Equipment

Equipment

Remove the primary pollutant directly or others indirectly Create suitable work conditions for other equipment as

possible



2016-04-01 14

SCR

ESP AH

FGD

S

T

A

C

K FGC

Boiler

FGR WESP

Hg

Hg2+

Low NOx

Combustion Technology

High efficiency catalyst for SCR

( Hg→Hg2+)

Reduce the flue gas temperature (about 90 ℃) ; SO3 adsorption by fly ash; Improve particle size after the ESP exit.

Reduce the specific resistance and improve the breakdown voltage.

Further removal of the small PM (Option).

Tray design optimization; using novel nozzle; Improved the

demister performance; Improve nozzle arrangement and

absorption for NO2 removal.


Technical routines for deep removal of pollutants

2016-03-05 15

Technical routine 1

S

T

A

C

K

Boiler

AH FGD FGC

WESP FGR

ESP

SCR

Option

Key equipment

Technical routine 2

Low Temperature ESP

S

T

A

C

K

Boiler

AH FGD FGC

WESP FGR

ESP SCR

Option

Key equipment

Rotating electrode ESP


Low Temperature ESP

Flue gas temp. vs Electrical

resistivity of fly ash

Flue gas temp. vs PM

collecting efficiency

Nakayama Y, et al. Hiroshima Research & Development Center, 2011: 1-11.


Low temperature ESP application at Jianxin

2016-03-06 17

Air preheater

ESP Heat recovery

1000MW power plant at Jiaxin


Wet ESP for flue gas cleaning

2016-04-01 18

Corona

Flue gas

2

Minus Ions

Dust

3

吸引力

4

Dust Capture

5

Ash collection

Hammer

6

Ash storage

Hopper

Chamber

7

Spray Nozzle

6

Hopper

Chamber

Pit

1 Chamber

Orifice plate

Flue gas

7



2016-04-01 19



On-site Wet ESP installing

2016-04-01 20

烟箱

灰斗


Diagram of rotating electrode ESP

Rotating drive

Insulator chamber

Fixed electric field

Rotating electric field Rotating anode plate

Anode cleaning device

Cathode rapping

Discharge electrode


Two FGD design models for deep SO2 removal

2016-04-01 22

Wet scrubber inside FGD

Wet scrubber outside FGD


High efficiency FGD design for deep SO2 removal

2016-04-01 23

PH

Wet scrubber

Single tower Double zone


Novel design for NOx control

2016-04-01 24

Vertical reactor Horizontal reactor

4NO + 4NH3 + O2 → 4N2 + 6H2O

NO + NO2 + 2NH3 → 2N2 + 3 H2O

To air heater N2& H2O

NH3

NOx Catalysts

NOx control reactor


Technologies adopted by different power plants

2016-03-05 25

Location PM Emission

Zhejiang Jiahua, 2×1000MW Low temperature ESP+Wet FGD+Wet ESP <5

Zhejiang Luheng,

2×1000MW

Rotating electrode ESP+Wet FGD

+Wet ESP <5

Zhejiang Zhoushan,

1×350MW

Rotating electrode ESP+Wet FGD

+Wet ESP <5

Guangdong Hengyun,

2×700MW Low temperature ESP+Wet FGD+Wet ESP <5

Guangdong Zhuhai,

2×300MW

Electrostatic-fabric integrated

precipitator(EFIP)+Wet FGD+Wet ESP <10

Jiangsu Changsu, 4×330MW Electrostatic-fabric integrated

precipitator(EFIP)+Wet FGD+Wet ESP <10

Huaneng Beijing, 1×200MW Rotating electrode ESP+Wet FGD <10

Shanghai Waigaoqiao,

2×1000MW ESP+Wet FGD <10

Jiangxi Jiujiang, 2×300MW ESP+Wet FGD+Wet ESP <10

Unit: mg/m3



2016-03-06 26

Application at a 1000MW coal-fired power plant

54.8

Stack

AH ESP

引风机

FGD Boiler

NOx/mg/Nm3

WESP

SCR

Heat recovery

150 20 < 50 < 100

1600 24 20 < 35 < 50

SO2mg/Nm3

Dust/mg/Nm3 18430 10 4.5 4.5 < 5 < 20

Temperature/℃ 362 118 85 52.8 52.8/80 > 50

30

AH

7.5

Gas-fired

power plant


Scientific evaluation the current retrofitted projects. System performance

Costs

Problems existed in the present retrofitted projects. Low temperature corrosion on ESP collection electrodes

Equipment performance stability

Technical adaptability for different kind of coal-fired power plant Unit Capacity

Coal parameters

Boiler type

… …

Accuracy of CEMS (Continuous Emission Monitoring System)

Technical supports for the future integrated design optimization toward the different power plants.

2016-04-01 27

Challenges and prospects


Summary

According the latest emission limits, multi-pollutants simultaneous removal strategy will be expected carried out for a widely utilization for the whole coal-fired power plants in China.

Through the design optimization of the integrated flue gas cleaning system, multi-pollutants can be deeply simultaneous removed. The technical routine choice depends on the coal-fired power plant itself.

Based on the practice of the present retrofitted projects, the coal-fired power plants are ongoing further technologies update in China.

2016-04-01 28


Embracing a green future of coal-fired power

2016-04-01 29

Thanks for your attention！ Any comments are welcome!

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