Clean Coal Energy and Environment in China Prof. Kefa Cen€¦ · · 2005-09-0775t/h Slime Fired...

Institute for Thermal Power Engineering 浙江大学热能所

Clean Coal Energy and Environmentin China

Prof. Prof. KefaKefa CenCenZhejiang UniversityZhejiang University, , ChinaChina

2005.8.222005.8.22


Low Per Capita Energy Reserves能源人均储量偏低

2000年人均能源储量Per capita energy reserves in 2000

55.4％90 t煤炭Coal

4.3％1074 m3天然气Natural Gas

11.1％2.6 t石油Petrol

占世界平均值比例

Ratio to world average value

人均可开采储量Per capita minable reserves

种类项ItemCategory


Composition Ratio of Installed Capacity发电装机容量构成比例

1.04.27.51.658.627.1900-9502020

41GW3.98%

36GW3.58%

60GW5.96%

623GW61.9%

246GW 24.45%

1006GW2020

0.93.16.92.060.826.3710-7602015

0.72.35.42.563.6/ （72.7）

25.8550-590（666）

2010

0.52.01.93.566.6/ 25.5430(446)

20050.10.70.34.869.324.83192000

新能源Renewable

%

核电

Nuclear

%

气电

Gas

%

油电

Oil

%

煤电

Coal

%

水电

Hydro

%

总装机Total

GW

Coal power needs 400 X 900 MW Super critical units which consume coal---2 billion ton.燃煤发电净增 400 X 900 MW 超临界机组需消耗20亿吨煤


Gas emission of total world quantity resulted from coal combustion in

China

71 %67 % 87 %

Percentage by coal (%)

13.5 %CO29. 6 %CO10.1 %NOx15.1 %SO2

8~9 %Energy consumption

percent of total world quantitative


Clean Coal Technology

Coal processing

Coal conversion

Advanced power Generation

Flue gas clean technology

Coal w

ashing

Briquette

Coal w

ater slurry

Coal gasification

Coal liquefaction

Supercritical PF technologies

CFB

PFBC

-CC

IGC

C

Flurgas dust

precipitation

FGD

& D

eNO

x

Other

Pollute Contral

technologies


Coal washing and processing

a) Coal WashingThe Combustion , Gasification andPower Generation Technology ofwashing tailing sludge 煤泥燃烧、气化及发电技术

b) Coal water slurry

The State of Art of Clean Coal technology and The Developing Trends

R & D, Application and Development of Clean Coal Technology


Characteristics of coal washing sludgeCharacteristics of coal washing sludge：：1.Particle size<0.5mm,Ash>40%,Moisture>25%1.Particle size<0.5mm,Ash>40%,Moisture>25%2.Non2.Non--Newton fluid, heating value:1000Newton fluid, heating value:1000--3000kcal/kg3000kcal/kg

Coal washing sludge Combustion in CFBCoal washing sludge Combustion in CFB洗煤泥流化床结团燃烧原理洗煤泥流化床结团燃烧原理

Key Techniques and innovations采用大粒度高位给料，以利于燃料形成较大凝聚团

使煤水混合物在流化床内结团燃烧，在较高断面热负荷下实现较高燃烧效率

采用异重流化床技术，以防止凝聚团在流化床内沉积，保证稳定运行。

Large particles feeding at the top of furnace

Conglomerate sludge fired in CFB

Novel technique with different-density bed materials in CFB


Conglomerate sludge fired in CFB煤泥凝聚团--异重流化床燃烧基础

→


0.0

20900

4500

75t/h Slime Fired Boiler Structure in Dongdan Power Plant

东滩75t/h洗煤泥循环流化床锅炉简图

• Now 25 power stations has been built


Replace oil by Coal Water Slurry水煤浆代油燃烧技术

2000年 2010年 2020年 dependence on import（％） 31.0

institute of energyof state planning

commission

45～52 59～62

IEA 61 77IEA 54 72

Dependence on the imported oil of China in 2000-2020


180$/ton; 476$/ton (65$/barrel)

– Year 2005：25.2 billion $； 66.6 billion $.– Year 2010：46.9 billion $； 123 billion $.– Year 2015：81 billion $ ； 214 billion $.– Year 2020：131.5 billion $; 345 billion $.

中国石油的供需问题Supply and demand of oil in china

Price of imported oil in

2000

Price of imported oil in

2005

Replacement of oil by CWSStandard quality of CWS:● concentration：65~70%；● viscosity：~1000CP；● grain size：d<50μm● ash content：A<7%；● sulfur content：S<0.5%。


水煤浆雾炬燃烧机理Combustion mechanisms of CWS


3.52 MW pilot-

scale test facility

in Zhejiang Univerisity


670t/h (200MW)CWS fired

boiler at Nanhaipower plant,

Guangdong,China


汕头电厂220t/h水煤浆锅炉燃烧效率Combustion efficiency of a 200t/h

CWS fired boiler at Shantou power plant, Guangdong,China

3.652.0522.153.27

carbon in fly ash%

99.5892.031.9280499.7391.882.1560399.7491.112.450299.6091.232.4401

Combustion efficiency

%

Thermal efficiency%

Carbon in bottom ash %

Load %run


Pollution emission from a 220t/h CWS fired boiler at

Maoming power plant

20020.2625.6425.6430.67mg/Nm3Par-ticle

650362.4359.4359.4351.7mg/Nm3NOx

2100541.4585.1585.1634.3mg/Nm3SO2

/180.6177180185t/hload

24th,Jun

23rd,Jun

22nd,Jun

state standard

Ave-rage

timeunitterm

ZJU’s CWS combustion technology have been applied to over 70 boilers.


b) CFBC

d) IGCC

Combined clean coal utilization technologies

Clean Coal Power Generation Technology

The State of Art of Clean Coal technology and The Developing Trends

循环流化床锅炉Circulated fluidized bed Combustor

CFB 降低SOX排放SOx emission reduced by CFB

0 1000 2000 3000 4000 5000 6000

Pulverized Coal

World Bank

US Clean Air Act

European

US Clean Air Act

Typical CFB

mg/MJ

SOURCE: The World Bank Environment Guidelines

W/O Scrubber *

Standard *

Amendment 1995 Limit

Community Standard *

Amendment 2000 Limit

(95% Removal) ** Assumption

4wt% Sulfur ContentHHV=14MJ/kg

0 100 200 300 400 500

EuropeanCommunlty

Standard

Pulverized Coal

World BankStandard

CFB withoutNox Control

CFB with NoxControl

mg/MJ

SOURCE: The World Bank Environment Guidelines

CFB 降低NOX排放NOx emission reduced by CFB


b) CFBCClean Coal Power Generation Technology

International：250MWe CFBC- commercial operation 400Mwe CFBC- design

China：Over 1000 6MWe-125MWe CFBC-OperationImported 300MWe CFBC-demonstration



d) IGCCClean Coal Power Generation Technology

International：250MWe coal fired IGCC power plant put into

operation

China：IGCC system and key technology research300～400MWe IGCC demonstration project



发展多联产技术Multi-product cogeneration technology

气化炉Gasifier

化工产品Chemical products

液体燃料Liquid fuel

供热Heat supply

发电Power generation

合成气(CO+H2)Synthetic gases

固体燃料Solid fuel

→→ →

煤的清洁、综合利用的预期结果Prediction of Coal Clean Utilization

CWS

GasificationGasification((裂解气化裂解气化))

Coal washing（22.5％）

Construction materials

Cement

Extract vanadium

CoalDeSOx40-50％ ash

Semi coke Power

generation

heat & refrigeration

electricitygenerationCoal sludge &

Coal rejectsPower generation

coal gas

Sewage & mud co-fired

Municipal wastes &coal co-fired

Biomass & coal co-fired

煤的清洁、综合利用的预期结果Prediction of Coal Clean Utilization

80kg limestone(石灰石)

1ton coal (煤)

Gasification(气化)

Combustion(燃烧)

Ash utilization(灰处理)

235kg cement(水泥)

1600MW Refrigeration(制冷)

6500MW Heat(供热)

1500kWh Electric(电力)

Residue Char(半焦)

80kg Tar(焦油)

300Nm3 Fuel gas(煤气)

1MW循环流化床燃烧气化多联产试验平台CFB boiler and gasifier based on Gas and Steam

Cogeneration

试验装置系统流程图Experiment diagram

M

M

M

M

放空

(去固定床)

燃

烧

炉气化炉

放空

布袋除尘+引风

鼓风机

煤气引射器

给砂

给砂

给煤

给煤

P

点火油枪

煤气储罐

紧急排气

工业水

煤气泵煤气燃烧器

阻火器

冷却器2洗涤塔1 洗涤塔2

分离器

过滤器

大水槽冰水

循环水泵

P

P

M

P

M

M

P

M

冷却器1

P

P

P

M

M

P

过热器

烟气冷却器 1

O2

P

P

P

PM

P P P

PP

P

M

浙大研制扬中75T/H多联产循环流化床锅炉Yangzhong multi-generation CFB boiler

煤综合利用多联产系统Multi-generation coal utilization system

cement

multi-generation stone coal utilization system

以煤油、电为主的多联产模式multi-product cogeneration for coal oil and electricity

Coal gasification

Synthetic gas

Gas turbine

Membrane separation

Fuel cell

Oil processing

Synthetic oil

ChemicalProcessing

Flue gas

electricity power

oil

chemical


Near Zero Emissions Near Zero Emissions Coal UtilizationCoal Utilization

Near zero emissions coal utilization technology with Near zero emissions coal utilization technology with combined gasification and combustioncombined gasification and combustion

CoalBiomass

Steam

Char¡¢ash¡¢ CaCO

CaO¡¢ash

Limestone

CO

Pressure or atmosphereCFBcombustor

PressureCFBGasifier

User

SOFCpower

Dust removal

Steam turbine

HRSG CondensationCO disposal

Ash drain

Water

Gas turbine

DustRemovalH2

2

3

H2

H2

2

H2

H2OO2

Air

Gas turbine

AirAirHeater

Exit

AirAir separation


CFB GasifierCO2 acceptor gasification process (~25bar)

• Main reactions in gasifier：C+H2O=CO+H2-131.6kJ/molCH4+H2O=CO+3H2-206.3kJ/molCO+H2O=CO2+H2+41.5kJ/mol

CaO+CO2=CaCO3+178.1kJ/molH2S+CaO=CaS+H2O

CoalBiomass

Steam


CaO¡¢ash

Limestone

CO


PressureCFBGasifier

Ash drain

H2

2

3

O2


CFB CombustorCFB CombustorChar combustion CaCO3 calcinationHydrogen combustion

Main reactions in CFB combustor：

CaCO3=CaO+CO2-178.1kJ/mol

C+O2=CO2+393.791kJ/mol

H2+1/2O2=H2O+286kj/mol

CoalBiomass

Steam


CaO¡¢ash

Limestone

CO


PressureCFBGasifier

Ash drain

H2

2

3

O2

H2 from SOFC


Efficiency calculationEfficiency calculation for a samplefor a sample• Power generation:400MW• Coal gasification ratio: 0.7• Operation Pressure: 25bar• Temperature in the gasifier（K） 1205• Hydrogen production rate（kmol/s） 1.42• System efficiency（％）66.52

Proximate analysis/w%, ar

Ultimate analysis/w%, ar Heat value/MJ/k

g, arM V A C H O N S Qdw

2.7 25.17

21.62 63.39

3.88 6.51 0.78

1.13

23.143


1880 1900 1920 1940 1960 1990 2000 2020

60

50

40

30

20

10

0 First Station

PulverizedCoal

Rankine Barrier

Supercritical Boiler

Thermal Efficiency(%) HHV

USCIGCC

PFBC

IGMCFCTC

IGHTA

AGMCFC

Legend:PFBC -Pressured fluidized-bed combustionIGCC -Integrated gasification-combined cycleIGHTA-Integrated gasification-humid-air turbineIGMCFC -Integrated gasification-molten carbonate fuel cellAGMCFC -Advanced gasification-molten carbonate fuel cellUSC -Ultra super criticalTC -Topping cycle

Efficiency ImprovementWith TimeWith Time

Years

FutureGEN1FutureGEN2FutureGEN3

HUSC


Control of Pollutant EmissionControl of Pollutant Emission

污染物排放控制污染物排放控制


ElementMercury

OxidizedMercury

Gaseous Mercury

Particulate Mercury

Mercury Emission and Control during Coal Mercury Emission and Control during Coal CombustionCombustion

Mercury transportation during coal combustionMercury transportation during coal combustion


Mercury Control ApproachMercury Control Approach

ElementMercury

OxidizedMercury

Gaseous Mercury

Particulate Mercury

• Captured in wet FGD scrubbers

adsorbed onto porous solids

• Subsequent collection in a PM control device


Mercury Control Technology in ZhejiangUniversity

Absorbents

Spray

Additives

Control system

Hg CEM

Coal

AirSeparator

Hg0(g),Hg2+

(g),Hg(s)

Mercury Transportation

Hg0(g),Hg2+

(g) →Hg(s)

Hg2+(g) Hg(s)


Hg removal research in a full-scale semi-dry reactor system

flowmeter

Hg tube

mixbox

oil burner

diesel oil

fan

N2

exhaust fan

separator

fan

Hg

Hg sampling

Hg sampling

compressor

water

fan


Hg removal in flue gas before fabric filter with different absorbents

C/Hg ×103


Fluorine ( F ) emission and control Fluorine ( F ) emission and control during coal combustionduring coal combustion

• Fluorides are one of the most hazardous in atmosphere.

• Its toxicity is 10～100 times higher than sulfur dioxide and nitrogen oxide.

• 1ppb～5ppb of fluorine in the atmosphere is probably harmful to some impressionable plants.


Fluorine in Coal Fluorine in Coal Fluorine concentration values for coals analyzed from Fluorine concentration values for coals analyzed from

China (dry basis)China (dry basis)

33794259～1956Gangue

311058193～3313Stone coal

7241151～615Lignite

2830861～1800Anthracite

8117317～696Bituminous coal

Number ofsample

Average value(ppm)

Range(ppm)

Coal rank


Fluorine Emission during Coal Fluorine Emission during Coal CombustionCombustion

★ Fluorine release rapidly with increase of temperature

★ The transfer ratio of fluorine is:

●about 95% for PC boiler

●about 80 ～ 85% for grate-chain boiler

●about 70～80% for FBC500 600 700 800 900

Temperature T(C)

10

30

50

70

90

F Tranfer ratio (%)


Relationship between fluorine emission standard of Relationship between fluorine emission standard of industrial boiler and fluorine concentration in coalindustrial boiler and fluorine concentration in coal

7%31%90%lignite

4%19%42%Bituminous coal

Ratio over standard 超标煤样数量

比例

corresponding fluorine in coal

old boiler

4%14%45%meager coal

15%30%40%anthracite

407～452 ppm

169～187 ppm

101～112 ppm

50 mg/Nm315 mg/Nm39 mg/Nm3

Third classSecond classFirst class

Attention: Fluorine transfer ratio is assumed at 80%


Fluorine Retention Fluorine Retention Compositions of Compositions of sorbentssorbents

1.900.160.070.000.030.060.375.9849.44造纸厂白泥white mud

0.03916.3522.83.4218.530.35钢渣steel residue

0.050.070.280.080.000.193.005.4260.98电石渣carbide slag

0.000.290.20.21.6253.98石灰矿渣limekiln residue

Na2OK2OSO3TiO

2MgOFe2O3Al2O3SiO2CaOsorbent


950 1000 1050 1100 1150 1200Fuel-bed temp. (¡æ)

0

20

40

60

80

100E

ffici

ency

of f

luor

ine

rete

ntio

n (%

)

1# sorbent2# sorbent

Effect of temperature on fluorine retention


Dioxins emission and control during Dioxins emission and control during

MSW and coal coMSW and coal co--fired processfired process


Open burning


大气

空气中传播

沉积

人类食物链

再飞散

焚烧

工业过程

浸蚀排放直接排放

废气灰渣


－所谓二噁英是对多氯二苯并二噁英( polychlorinated dibenzo-p-dioxin, 简称PCDD)和多氯二苯并呋喃

(polychlorinated dibenzofuran,简称PCDF)的俗称。

－PCDDs和PCDFs分别由75 个和135个同族体构成

6

98

7

12

34

O

O

6

987

12

34

O

PCDD PCDF

二噁英(Dioxin)

Dioxins emission data from different zones in the world (g I-TEQ/y)

3.7455.6％

MSW incinerationPercentage%

Taiwan

51.40.4%

791564％

12331

1987

2888Total emissionU.S.A

132～4046.7％～10.9%

141～4425.8％～9.5%

151～5304.1%～8.2%

Power plant boilerPercentage%

294～41910％～15％

538～70615％～22％

1102～143422％～29％


1960～38332434～46593685～6469Total emissionEuropean

60.92.1％


67.25Total emission

Zone

110038％


3.3655.0%


2005年2000年1995年


Pilot Scale Multi-Function MSW Incineration Furnace 10t/d

10吨/天多功能垃圾焚烧中试试验台


Dioxin Lab in ITPE of ZJU浙江大学热能所二恶英专业实验室


高分辨率色谱质谱联用仪（HRGC/HRMS）


800吨／日大规模清洁焚烧垃圾电厂全景

The overall look of the 800 t/d MSW incineration plant


Dioxin Emission from Qiaosi MSW Incineration Plant in Hangzhou

杭州乔司垃圾焚烧厂的二噁英排放测试结果2004－1－12

106％100％负荷Load

1废气控制标准 standardI-TEQ ng/Nm3

0.009, 0.077 0.034烟气（省环境监测中心测试结果 I-TEQ ng/Nm3 ）flue gas

0.0025, 0.00820.0068烟气（比利时SGS实验测试结果 I-TEQ ng/Nm3）flue gas

5.6~11.110.1~12.4烟气含氧量% (oxygen)2003-12-232003-12-24测试日期date

78：2284：16燃料比例（垃圾：煤）

fuel (MSW: coal)

3＃焚烧炉

Boiler 21＃焚烧炉

Boiler 1设备


Dioxins emission from Power Plant Boilers in Chinaassumption

In 2020, total consumption of standard coal will reach 3 billion tons.

= 1500 g I-TEQ/y EU regulation

15000 g I-TEQ/y National regulation

Equals

4.6 billion tons MSW incineration annual at 0.1 ng I-TEQ/Nm3 emission regulation

0.1 ng I-TEQ/Nm3 ( 0.5 ng I-TEQ/kg coal ) EU regulation

1 ng I-TEQ/Nm3 ( 5 ng I-TEQ/kg coal ) National regulation

We suppose

300MW Boiler stack gas emission

0.01352 ng I-TEQ/kg coal

＝ 40.56 g I-TEQ/y


Removal of MultiRemoval of Multi--pollutants From pollutants From

Flue Gas by OzoneFlue Gas by Ozone


The Removal Mechanism of Several The Removal Mechanism of Several Pollutants From Flue GasPollutants From Flue Gas

32 SOOSO →+

32 HSOOHSO →+

OHSOHOSO +→+ 322

2323 HOSOOHSO +→+

423 SOHOHHSO →+

4223 SOHOHSO →+

2NONOO →+

223 ONOONO +→+

OHNOHONO +→+ 22

222 NHNONOHNO +→++

2322 NHNONOHNO +→++

3 2

Hg O HgOHg O HgO O

+ →+ → + 3 2

2 2 2

Hg NO HgO NOHg H O HgO H O

+ → ++ → +

Can be high

efficiency removed by wet

scrubber

Lifetime of O3• At the

150℃, the decomposition of O3 is about 28% at 10s.

• The decomposition rate is keeping increased when temperature moved up.0 2 4 6 8 10

0.0

0.2

0.4

0.6

0.8

1.0

[O3]/[O3]0

time s

150℃ 200℃ 250℃

Lifetime of the free radical is usually very

short


Reaction time needed by O3/NO reaction • T=150℃

• At this temperature 0.1s is necessary for the conversion of NO.

• SO, the O3’s lifetime is enough for the reaction.


NO removal by O3• T=100℃；• Resident

time is 0.09s；

• NO,NO2,N2O was measured by Rosemount NGA2000 continue emission monitor systems (CEMS) at 5s/scan.

• More than 80% NO can be oxidized

NO oxidized by O3 at 100℃

0.0 0.2 0.4 0.6 0.8 1.0 1.2

0

20

40

60

80

100

NO

oxi

diza

tion

rate

%

O3/NO stoichiometric ratio

NO oxidized rate


O3 and CO

• It found that CO doesn’t react with O3 below 300℃0

100

200

300

400

500

O3/CO=3.5 300℃

O3/CO=3.5 100℃

CO 浓

度 [ppm]

CO

空白 O3/CO=0.86 100℃


O3 with NO, SO2 reactions

0.0 0.2 0.4 0.6 0.8 1.0 1.20

50

100

150

200

NO SO2c

oncentration [ppm]

O3/NO molar ratio

100℃

• SO2 doesn’t have good performance like NO.

• How to improve the SO2 oxidization should be further studied.


0.862581

1.91

0.38

6289.31001.35Million300

By O3

21375kwTotal energy

6.33W/Nm3Average power consumption

100ppmNO removedKg/hO3 neededkW/kgO3O3 generated power

Kw/m3O2O2 generated power

300MWPower generated

7.13％

1.35Million

By Electro Beam

Nm3Flue gas

Power consumption by O3 at 300MW power plant


Thank youThank you

Clean Coal Energy and Environment in China Prof. Kefa Cen€¦ · · 2005-09-0775t/h Slime Fired...

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Transcript of Clean Coal Energy and Environment in China Prof. Kefa Cen€¦ · · 2005-09-0775t/h Slime Fired...