A comparative study between RSA, India, EU, China and the US on flue gas emissions from coal fired plants

[1]Coal Research Group, Unit of Energy Systems, School of Chemical and Minerals Engineering, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa[2]Climatology Research Group, Unit for Environmental Science and Management, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom, 2520. South Africa

Delani Njapha[1], Hein Neomagus[1], Raymond Everson[1],

Dawie Branken[1], Roelof Burger[2] and Stuart Piketh[2]

27 & 28 November 2014

Motivation• South Africa – 94% of electricity from coal.• Associated with electricity generation is pollution.• Emission - Eskom's concern.• As a result, within the Eskom Power Plant Engineering Initiative

(EPPEI), a specialization center has been set at NWU.• Specialization center: Emission Control (EC).• A collaboration between:Ø Engineering - engineering solutions to reduce emissionsØ Natural Science – monitoring and impact studies.

• Eskom has prioritized emission reduction in the following order:Ø PMØ SOxØ NOxØ CO2/Hg

Aim and Background

Aim• To investigate available technologies for curbing flue gas emissions

from coal fired power stations.• To conduct a benchmark on emission quantities between South

African coal fired plants with some international plants, India, China, EU and the US.

• To compare emission regulations from various countries.

Background• Coal industry is renowned for the production of flue gases such as

SO2, NOx, CO2, Hg and particulates.• CO2 has been reported as a cause of climate change and SO2 has

been linked to acid rain. Therefore they should be controlled.• The greater part of the world is still dependent on coal as a source

of energy. This is still likely to continue.

World's Energy Demand (http://www.eia.gov/forecasts/ieo/world.cfm)

• Emission related problems are therefore likely to increase unless something is done.

Top ten coal producers (WCA, 2013)

Country ProductionCapacity (Mt)

in 2012PR China 3549

USA 935

India 595

Indonesia 443

Australia 421

Russia 359

South Africa 259

Germany 197

Poland 144Kazakhstan 126

Coal in electricity generation (WCA, 2013)

Country Electricity Generation

Mongolia 98%South Africa 94%

Poland 86%PR China 81%Australia 69%India 68%Israel 59%Indonesia 44%Germany 43%USA 43%UK 29%Japan 27%

Technologies for emission control

De-SOx1. Low Sulfur Fuel2. Fuel Desulfurization3. Flue Gas Desulfurization Systems (FGD)• Regenerable FGD and non-regenerable FGD. • FGD can reduce sulfur oxide emissions by up to 90%.De-NOxCombustion treatment 1. Staged combustion2. Catalytic converters3. Flue Gas Recirculation (FGR)4. Reducing O2 levels5. Low NOx burnersPost Combustion treatment6. Selective Catalytic Reduction (SCR)7. Selective Non Catalytic Reduction (SNCR)

Technologies for emission control

Particulate Matter (PM)1. Electrostatic Precipitators (ESP)2. Fabric Filter Plant (FFP)• Both ESPs and Fabric Filter Plant (FFP) –

removal efficiencies in excess of 99.5%.

CO2 Removal• CO2 can be removed via three methods:1. Separation with solvents/sorbents2. Separation with membranes3. Separation by cryogenic distillationForward Looking• There's a drive to reduce emissions significantly by year 2020.• Evolving legislation will force the coal industry to minimize

emissions.

Courtesy MIP

Emission Regulation, (Guttikunda and Jawahar, 2014)Country PM SO2 NO2 MercurySouth Africa 100 mg/Nm3 until 2015

50 mg/Nm3 by 20203500 mg/Nm3 until 2015500 mg/Nm3 by 2020

1100 mg/Nm3 until 2015750 mg/Nm3 by 2020

None

India 350 mg/Nm3 for <210 MW150 mg/Nm3 for >210 MW

None None None

China 30 mg/Nm3 (proposed all)20 mg/Nm3 for key regions

100 mg/Nm3 for new200 mg/Nm3 for old50 mg/Nm3 for key regions

100 mg/Nm3 0.03 mg/Nm3

Australia 100 mg/Nm3 for 1997 –200550 mg/Nm3 after 2005

None 800 mg/Nm3 for 1997-2005500 mg/Nm3 after 2005

In discussion based on USA standards

European Union

Pre 2003100 mg/Nm3 for <500 MW50 mg/Nm3 for >500 MWPost 200350 mg/Nm3 for <100 MW30 mg/Nm3 for >100 MW

Pre 2003Scaled for <500 MW400 mg/Nm3 for>500 MW Post 2003850 mg/Nm3 for <100 MW200 mg/Nm3 for >100 MW

Pre 2003600 mg/Nm3 for <500 MW500 mg/Nm3 for >500 MW Post 2003400 mg/Nm3 for <100 MW200 mg/Nm3 for >100 MW

In discussion0.03 mg/Nm3

German standard only

USA 37 mg/Nm3 for old6 mg/Nm3 for new6.4 gm/GJ

245 mg/Nm3 for old50 mg/Nm3 for new640 gm/MWh

61 mg/Nm3 for old42 mg/Nm3 for new720 gm/MWh for old450 gm/MWh for new

0.08 gm/MWh for lignite0.01 gm/MWh for IGCC

*Emission regulation on CO2 could not be found

Trend of average NOx emissions from thermal power plants, (IEA, 2010)

Trend of average SOx emissions from thermal power plants, (IEA, 2010)

Emission status in EU

• Approx. 33% of EU's electricity is generated from coal, (Baris, 2011).

• There are mandatory emission standards for SOx, NOx, PM and Hg. • Most plants are equipped with FGD. • FGD is useful in reducing PMs (2.5 µm) by 30 – 40%, by eliminating

the formation of secondary sulfates and nitrates.

Estimated specific emissions from EU power plants, (von Blottnitz, 2006)

Country NOx (mg/kWh)

SO2mg/kWh

PM10Mg/kWh

CO2g/kWh

% of total generation

Austria 490 260 56 900 4Belgium 2530 3162 341 920 14Denmark 1440 640 - 900 27Finland 1400 1080 61 770 30France 3140 2930 290 900 5Germany 560 840 34 945 24Hungary 2600 18500 1180 1100 38Ireland 3430 4980 92 920 28Italy 860 1890 93 800 9Netherlands 1310 560 23 910 15Portugal 2260 4160 180 900 26Spain 3610 14800 400 1060 38United Kingdom 2440 7460 110 950 34

South Africa (rank) 4020 (1) 8970 (3) 390 (3) 960 94

Emission status in India

• 66% of 210 GW of Indian electricity is derived from coal (Guttikunda and Jawahar, 2014).

• There are 111 coal fired plants.• There are no legally mandated emission standards for SO2. • Only 8 plants are mandated to have FGD, (Prayas, 2011).• Only stack heights are mandated.• Health impact due to emissions from coal fired-plants between

2010-11 was estimated as follows:

Emissions in IndiaTotal annual emissions from coal based power in India in 2010 – 11, (Guttikunda and Jawahar, 2014)

State PM2.5 tons PM10 tons SO2 tons NOx tons CO2 million tonsAndhra Pradesh 51 500 107 500 199 500 187 500 62.8Bihar 15 500 31 000 43 000 39 500 13.5Chhattisgarh 39 000 84 000 187 000 172 500 58.9

Delhi 7 500 14 500 20 500 20 000 6.4Gujarat 53000 111 000 214 000 220 000 74.0Haryana 23 500 50 000 100 500 93 500 31.7Jharkhand 15 500 31 500 50 500 48 500 15.9Kamataka 17 500 36 000 61 500 58 500 19.4Madhya Pradesh

49 500 100 000 139 500 130 500 43.9

Maharashtra 80 500 167 000 300 500 278 500 94.6Orissa 40 000 85 000 171 000 159 500 53.9Punjab 16 500 34 000 56 000 53 000 17.5Rajasthan 14 500 30 000 55 500 52 000 17.5Tamilnadu 36 500 74 000 108 500 104 500 34.2Uttar Pradesh 83 500 168 500 235 500 225 000 74.1West Bengal 40 000 835 000 152 000 143 000 47.8Total 580 000 1 200 000 2 100 000 2 000 000 665.4

Emission status in the US

• Approx. 39% of US's electricity is generated from coal, (IEA, 2013).• There are over 600 coal fired plants in the US.• There are mandatory emission standards for SOx, NOx, PM and Hg. • The US operates the most polluted plants in SO2. • A 1990 study showed that 150 ESPs were built in the USA between

1935 and 1990. • In 2008, there were 351 plants with SO2 scrubbers and 146 without.

Most polluted US plants in terms of SO2 during 2006 (EIP, 2007)

Plant Name Year Built Capacity (MW) Total SO2emissions.(tons)

SO2 rate (mg/kWh)

R. Gallagher 1958-61 600 50 819 18 316

Muskingum River 1953-68 1 529 1 22 984 14 869

Warrick 1960-70 755 92 919 14 828

Hatfield’s Ferry Power station

1969-71 1 728 1 35 082 13 113

Portland 1958-62 427 30 685 12 837

Wabash River 1953-56, 68, 95

1165 58 793 12 546

Shawville 1954-60 626 47 287 12 229

Cayuga 1970-72 1062 86 174 12 102

Morgantown 1970-71 1252 98 073 11 830

Keystone 1967-68 1872 1 64 354 11 716

Status of South African Power Plants• South Africa (SA) has 13 power stations excluding Medupi and

Kusile.• Produces approximately 94% of electricity from coal.• Has emission regulation that mandates SOx, NOx and PM.• SA emission standard does not account Hg.• SA coal fired plants are equipped with:

a. Fabric Filter Plant (FFP), b. Flue Gas Conditioning (FGC) and c. Electrostatic Precipitators (ESP).

Emission control devices associated with SA power plants, (Dabrowski et al., 2008)

Power Plant Coal Consumption (Mty-1) Emission Control Device

Arnot 6.0 FFP

Duvha 8.4 FGC

Hendrina 6.5 FFP

Kendal 15.1 ESP+FGC

Kriel 11.1 ESP+FGC

Lethabo 17.3 ESP+FGC

Majuba 10.0 FFP

Matimba 17.4 ESP

Matla 15.5 ESP+FGC

Tutuka 4.9 ESP

Estimated Hg emissions from SA coal fired power stations during 2004, (Dabrowski et al., 2008)

Power Plant Hg emissions (land), tonnes/y

Hg emissions (atmosphere), tonnes/y

Total (land and atmosphere), tonnes/y

Arnot 0.1-0.8 (0.4) 0.1-0.8 (0.4) 0.2-1.6 (0.7)

Duvha 0.2-1.1 (0.8) 0.2-1.1 (0.8) 0.3-2.3 (1.5)

Hendrina 0.1-0.9 (0.5) 0.1-0.9 (0.5) 0.3-1.8 (1.0)

Kendal 0.3-2.0 (1.1) 0.3-2.0 (1.1) 0.6-4.1 (2.3)

Kriel 0.2-1.5 (0.8) 0.2-1.5 (0.8) 0.4-3.0 (1.7)

Lethabo 0.3-2.3 (1.3) 0.3-2.3 (1.3) 0.7-4.7 (2.6)

Majuba 0.2-1.4 (0.8) 0.2-1.4 (0.8) 0.4-2.7 (1.5)

Matimba 0.1-0.5 (0.3) 0.6-4.2 (2.3) 0.7-4.7 (2.6)

Matla 0.3-2.1 (1.2) 0.3-2.1 (1.2) 0.6-4.2 (2.3)

Tutuka 0.02-0.1 (0.1) 0.2-1.2 (0.7) 0.2-1.3 (0.7)

Total 1.9-12.7 (7.1) 2.6-17.6 (9.8) 4.5-30.3 (16.9)

Atmospheric Hg emissions from coal fired power plants in relation to population during 2004, (Dabrowski et al., 2008)

Country Emissions(tonnes Hg.y-1)

Population density (×106)

Fraction of elec. generated from

coal (R)

Relative per capita emissions

(gHg person-1y-1R-1)Canada 1.3 32 0.27 0.15

China 72.9 1306 0.47 0.13

Mexico 1.6 106 0.78 0.03

Poland 20.6 39 0.96 0.55

Russia 16 143 0.68 0.16

USA 42.6 296 0.7 0.20

South Africa 9.8 44 0.92 0.24

Compliance Status of South African Power Plants, (Patel, 2012)

Status of the Chinese Power Plants

• China has approximately 620 coal fired power stations.• Produces approximately 81% of electricity from coal.• Has emission regulation that mandates SOx, NOx, PM and Hg.• Chinese coal fired plants are mainly equipped with:

a. Electrostatic Precipitators (ESP)b. Fabric Filter Plant (FFP) andc. Flue Gas desulphurization (FGD).

Emission estimate by region in 2005 and 2010 (kt), (Zhao et al., 2008)

Region 2005 2010

SO2 NOx PM10 PM2.5 SO2 NOx PM10 PM2.5

Northern 3347 1377 312 165 2157 2114 305 188

North Eastern 990 752 269 146 854 869 270 153

Eastern (most industrialized)

4880 2269 597 321 3791 3075 598 355

Central & Southern

3374 1464 383 209 2578 2080 385 231

South Western 2272 639 176 99 1575 894 168 106

North Western 1235 463 104 54 846 648 98 57

Total 16097 6965 1842 994 11801 9680 1824 1090

Summary• The role of coal as a feedstock for electricity generation will continue

for the next decades. • Coal industry is the major culprit for CO2, SOx, NOx emissions.• CO2 emissions should be given more attention.• Proven technologies are available for clean coal beneficiation.• Medupi and Kusile are the two new SA plants and conform to SA

standard for SOx, NOx and PM emissions.• South African coal fired power plants are amongst the highest

emitters of SOx and NOx. • SA emission standard is more relaxed when compared to

international standards. • There is a need to conduct feasibility studies that looks at retrofitting

clean coal technologies into existing plants.• The US plants also rates high in SO2 emissions. • Mercury emitted by SA power stations is higher than most countries

in this study.

Thank you