SOx, Hg and CCT

SO2

Combines with water vapor to form dilute acid acid rain

Sulfur sources coal volcanoes biological decomposition

Clean Air Act (1970) reduced SO2 emissions Initial reductions by coal cleaning

First US commercial coal-utility scrubber built in 1967 Union Electric, MO

Clean Air Act (1977) essentially mandated scrubbers 52 scrubbers operating in 1982 190 scrubbers operating in 2008 Mandatory after 2018

Typical SO2 reductions >90%

Source: www.netl.doe.gov/KeyIssues/future_fuel.html

0

500

1000

1500

2000

2500

3000

3500

0

2

4

6

8

10

12

14

16

1819

70

1972

1974

1976

1978

198

0

198

2

198

4

198

6

198

8

199

0

199

2

199

4

199

6

199

8

200

0

200

2

200

4

200

6

200

8

2010

2012

2014

2016

2018

2020

2022

2024

2026

2028

2030

Ge

ne

rati

on

, b

illi

on

KW

hrs

Em

issi

on

s, m

illi

on

to

ns SO2

NOX

Generation

Source:EIA

Coal Generation and Emissions

Overview of 1986-1993 Clean Coal Technology Program Begun in 1986

to develop environmental solutions for the Nation's abundant coal resources.

Program's goal to demonstrate the best, most innovative technology emerging from the world's engineering

laboratories at a scale large enough so that industry could determine whether the new processes had commercial merit.

Originally, the program was a response to concerns over acid rain.

President Reagan commissioned the Clean Coal Technology Program as a cost-sharedeffort between the U.S. Government, State agencies, and the private sector.

Industry-proposed projects were selected through a series of five national competitions aimed at attracting promising technologies that had not yet been proven commercially.

Clean Coal Technologies

Advanced, coal-based technologies to meet strict environmental emission standards

Designed to minimize economic and environmental barriers that limit full utilization of coal

Reduced emissions of : sulfur oxides (SOx), nitrogen oxides (NOx) and particulate matter (PM)

Source: USDoE

CCT Goals

Reduce SOx from 20 million tpy to 12 million tpy by 2005

Reduce NOx from 6.8 million tpy to 3.2 million tpy

If CCT-developed technologies were applied to all coal-fired boilers, SOx would be reduced by an additional 10 million tpy

NOx Reduction Processes

Low NOx Burners

Selective Catalytic Reduction (SCR)

Selective Non-catalytic Reduction (SNCR)

SOx Reduction Processes Wet flue gas desulfurization (FGD)

Dry FGD/spray dryer absorption (SDA)

Fluidized bed combustion

Atmospheric (AFBC)

Pressurized (PFBC)

Circulating (CFBC)

Sorbent Injection (LIMB, LIFAC)

Calcium-bearing SOx sorbents all produce large volumes of solid by-products

PC BoilerPulverized Coal

AFBCAtmospheric Fluidized Bed Combustion

Tri-State Generation and Transmission Assoc

Nucla Station, Nucla, CO

Shawnee Power Plant, Paducah, KY

Total Capacity: 1369 MW10 Units

Unit #10: AFBC140 MWStart-up 1989Idled in 2010

CFBCCircuating Fluidized Bed Combustion

JEA (Formerly Jacksonville Electric Authority),

Northside Unit 2, Jacksonville, FL

Spurlock Station, Maysville, KY

Total Capacity: 1371 MW

Unit #1: 325 net megawatts PCUnit #2: 510 net megawatts PCGilbert Unit #3: 268 net megawatts CFBCGilbert Unit #4: 268 net megawatts CFBC

PFBCPressurized Fluidized Bed Combustion

Ohio Power Co., Tidd Unit 1

Brilliant, OH

Wet FGDFlue Gas Desulfurization

Georgia Power Co., Yates Unit 1

Newnan, GA

Wet Scrubber

Wet Scrubber

Sorbent Injection-LIMB Lime Injection Multi-Stage Burner

Ohio Edison, Edgewater Unit 4,

Lorain, OH

Sorbent Injection-LIFACLimestone Injection into the furnace and Activation of calcium

Richmond Power and Light, Whitewater Valley Station, Unit 2,

Richmond, IN

Dry FGD

Source: www.fossil.energy.gov

Sorbent Reactions Wet FGD CaCO3 + SO2 + ½H2O → CaSO3●½H2O + CO2 (inhibited)

CaCO3 + SO2 + ½O2 + 2H2O → CaSO4●2H2O + CO2 (forced)

Dry FGD Ca(OH)2 + SO2 → CaSO4/CaSO3 + H2O

FBC CaCO3 → CaO + CO2

CaO + SO2 + ½O2 → CaSO4

Sorbent Injection CaO + SO2 → CaSO4/CaSO3 (LIMB)

CaCO3 + SO2 → CaSO4/CaSO3 + CO2 (LIFAC)

calcite hannebachite

calcite

gypsum

portlanditeanhydrite

lime

lime

anhydritelime

anhydrite

calcite

anhydrite

calcite

Mercury in Flue Gas

During combustion, Hg in coal is volatilized and converted to elemental Hgo vapor in the high temperature regions of boiler.

As the flue gas cools, Hgo is converted to Hg2+ and/or other Hg species

The presence of gas-phase chlorine favors formation of mercuric chloride (HgCl2)

Mercury Control

Wet or Dry Scrubbers

Activated Carbon Injection (ACI)

ACI

Several adsorbents, particularly activated carbons, can remove mercury from flue gas.

However, activated carbons are non-selective adsorbents;

i.e. most of the flue gas components adsorb on carbon, competing with mercury and severely reducing their efficiency.

To improve the adsorption capacity, activated carbons are modified with various chemical promoters

e.g. sulfur, iodine, chlorine, bromine and nitric acid

Integrated Gasification Combined Cycle -IGCC

Source: www.fossil.energy.gov

Water Gas Shift Reaction

First used in early 20th century to produce hydrogen via coal gasificationas part of the Haber Bosch Process (1914 patent)

Discovered by Italian physicist Felice Fontana in 1780

Before the early 20th century, hydrogen was produced by reacting steam under high pressure with iron to produceiron, iron oxide and hydrogen

Demand for a cheaper and more efficient method of hydrogen production was needed

Water gas (CO + H2) was produced by

blowing steam over hot coal bed

C + H2O → CO + H2

To maintain high temp of coal (1000oC),

steam was periodically cut off and air was blown through coal bed to produce CO

2C + O2 → 2CO

∴ Gas exiting reactor contains CO and H2

CO + H2O ↔ CO2 + H2

CO + H2O ↔ H2 + CO2

A gasifier differs from a combustor the amount of air or oxygen available inside the gasifier is

carefully controlled so that only a relatively small portion of the fuel burns completely.

This "partial oxidation" process provides the heat. Rather than burning, most of the carbon-containing

feedstock is chemically broken apart by the gasifier's heat and pressure, setting into motion chemical reactions that produce "syngas."

Syngas is primarily hydrogen and carbon monoxide, can include other gaseous constituents; composition can vary depending upon

conditions in the gasifier type of feedstock.

Minerals components in the fuel which don't gasify like carbon-based constituents leave the gasifier as an inert glass-like slag or in a form useful to marketable solid products.

Slag

Sulfur impurities are converted to hydrogen sulfide and carbonyl sulfide from which sulfur can be easily extracted

typically as elemental sulfur or sulfuric acid.

Nitrogen oxides are not formed in the oxygen-deficient (reducing) environment of the gasifier; instead, ammonia is created by nitrogen-hydrogen reactions.

ammonia can be easily stripped out of the gas stream.

Fate of SOx and NOx in Gasification

In Integrated Gasification Combined-Cycle (IGCC) systems, the syngas is cleaned of its hydrogen sulfide, ammonia and particulate matter and is burned as fuel in a combustion turbine (much like natural gas is burned in a turbine).

The combustion turbine drives an electric generator.

Exhaust heat from the combustion turbine is recovered and used to boil water, creating steam for a steam turbine-generator.

IGCC

The use of these two types of turbines - a combustion turbine and - a steam turbine - in combination,

known as a "combined cycle," is one reason why gasification-based power systems can achieve high power generation efficiencies.

Currently, commercially available gasification-based systems can operate at around 40% efficiencies.

(A conventional coal-based boiler plant, by contrast, employs only a steam turbine-generator and is typically limited to 33-40% efficiencies.)

In the future, some IGCC systems may be able to achieve efficiencies approaching 60% with the deployment of advanced high pressure solid oxide fuel cells.

Higher efficiencies mean that less fuel is used to generate the rated power, resulting in better economics

lower costs to ratepayers

reduced emissions.

a 60%-efficient gasification power plant can cut the formation of carbon dioxide by 40% compared to a typical coal combustion plant.

Advantages

Combined Cycle

Gasifiers

Transport Integrated Gasification (TRIG)

Source: Southern Co.

Polk Station, Mulberry, FL

Total Capacity: 360 MWNet Capacity: 260 MW

IGCC Start-up: 1996GE Gasifier

97% sulfur removal >90% NOx reduction Achieved 90% availability

Wabash, West Terre Haute, INPublic Service of Indiana, now part of CINergy Corp.

Total Capacity: 322 MWNet Capacity: 262 MW

IGCC Start-up: 1996

Conoco Philips gasifer

Duke Power: Edwardsport630 MWOn-line June 2013$2.3BGE Gasifier

produces 10x power as the former plant at Edwardsport, with 70 percent fewer emissions of SOx, NOx and particulates

combined. efficiency reduces CO2 emissions per megawatt-hour by half

A highly efficient 618-megawatt IGCC plant

The retirement of the circa 1940s 160-megawatt Edwardsport power plant

A Clauss process sulfur removal system

An activated carbon bed for the absorption of mercury on each of the two gasifier trains

Two heat recovery steam generators, each of which will be equipped with selective catalytic reduction for nitrogen oxide control

A multiple-cell cooling tower

No thermal discharge into the White River

Potential for the capture and geologic storage of CO2

The Edwardsport IGCC project includes:

Kemper, MS

Primary fuel LigniteSecondary fuel Natural gasCapacity 582-megawattGasifier TRIG

Status Under construction, Online 2015Construction began June 3, 2010Construction cost $5.53 billionOwner(s) Mississippi Power

South Mississippi Electric Power Assoc.

Cash Creek, Henderson,KY

770 MWCurrently in permitting phaseProjected On-line in 2012, 2013, ?$1.5B

Kingsport, TNChemical from Wood (1920)

Kingsport, TNChemicals from Coal (1983)

Coatings, Adhesives, Specialty Polymers and Inks•Cellulose esters•Solvents Fibers

•Acetate tow•Acetate yarn•Acetyl chemicals

Polymers Businesses•PET•Cellulose esters Performance Chemicals and

Intermediates•Acetic anhydride•Acetic acid•Specialty Intermediates

Eastman Acetyl Stream

DME: Dimethyl Ether

LPMEOH™ process to produce methanol from coal-derived synthesis gas

CO + 2H2→ CH3OH + 21.7 KCAL/gmolCO2 + 3H2→ CH3OH + H2O + 12.8 KCAL/gmol TYPICAL REACTION CONDITIONS: 1,000 psig 440°–520°F

Challenge: remove heat and control temp

Operating IGCC Projects (15)

Edwardsport (Duke)- USA 2013 630 Coal

Kemper (Miss.P&L)-USA 2015 582 Coal

US Proposed IGCC Plants (23/65)PROJECT NAME STATE TYPE SIZE

Baard Generation 1 & 2 Ohio IGCC/CTL, polygeneration 7 million TPY coal and biomass (30%); 250 MW and 53,000 BPD ultra-clean

diesel, jet fuel, and naptha

Cash Creek Generation Kentucky IGCC (via SNG) 1.7 million TPY coal to SNG and 720 MW electricity

Ely Energy Center, Phase II Nevada IGCC 1000 MW (two units)

Gilberton Coal-to-Clean Fuels

and Power Project

Pennsylvania IGCC/CTL, polygeneration 3,700 bpd diesel; 1,300 bpd naptha; 41 MW

Good Spring (aka Future Power)

IGCC

Pennsylvania IGCC Anthracite coal; 270 MW

Great Bend Project Ohio IGCC 629 MW

HECA: Hydrogen Energy

California Project

California IGCC/H2/polygeneration 25% petcoke / 75% coal mix producing 180 MMSCFD H2, used to generate

300 MW, 2208 tpd of urea, and undefined amount of liquid sulfur.

Hyperion Energy Center aka

"Gorilla Project"

South Dakota IGCC/H2, polygeneration 7,400 TPD petcoke to 450 million SCFD H2; 200 MW and 2.4 mmlb/hr

steam. [507 MW total IGCC capacity to be used onsite]

Lima Energy Project Ohio IGCC/SNG/H2,

polygeneration

Three Phases: 1) 2.7 million barrels of oil equivalent (boe), 2) expand to 5.3

million boe (3) expand to 8.0 million boe (47 billion cf/y), 516 MW

Mesaba Excelsior Energy Coal

Gasification Project I

Minnesota IGCC 603 MW

Mesaba Excelsior Energy Coal

Gasification Project II

Minnesota IGCC 603 MW

Nextgen South Dakota IGCC or SCPC 700 MW

PurGen New Jersey IGCC Coal to 500 MW (also co-producing fertilizer, etc. with primary gasification

product hydrogen). Latest source says 750 MW.

Somerset Gasification Retrofit Massachusetts IGCC (Plasma) Coal, biomass to 112 MW (10% of the produced electricity will power the

gasification process)

South Heart Coal Gasification

Project

North Dakota IGCC/H2 Lignite - 14,000 TPD; Product plan has changed: syngas to hydrogen to 175

MW electricity, rather than SNG & 200 MW plant power.

Southern California Edison Utah

IGCC

Utah IGCC 1 million TPY Coal to 500 MW

Sweeny Refinery Gasification

Project

Texas IGCC 5,000 TPD petcoke to 400 MW (one source says 683 MW, may be output

equivalent) elec., also H2 (~65 MMCFD)

Taylorville Energy Center

(Christian County Generation,

LLC/Tenaska/Erora)

Illinois IGCC High-sulfur, sub-bituminous IL coal to SNG (methanation train) which is then

used to generate 602 MW in NG turbine power block

Texas Clean Energy Project

"NowGen"

Texas IGCC/polygen 1.8mm TPY PRB to 400 MW(Gross) 710,000 TPY Ammonia/Urea

Twin River Energy Center Maine IGCC/CTL, polygeneration 700 MW and 9,000 BPD diesel

Wallula Energy Resource Center Washington IGCC 915 MW

World Proposed IGCC Plants (13/16)PROJECT NAME LOCATION SIZE

Captain: The Clean Energy Project United Kingdom, Grangemouth on the

Firth of Forth west of Edinburgh, Scotland

Undetermined

CoolGen IGCC Demonstration Japan, Hiroshima 170 MW

Don Valley CCS Project United Kingdom, Stainforth in South

Yorkshire

650MW (net)

Jamnagar Gasification Project India, Jamnagar 20,000 TPD petcoke

85% Cogen (Power & Steam), 15% Polygen

(Fuel & Hydrogen)

Jazan IGCC plant Saudi Arabia, Jazan Economic City 2400 MW

Jiutai Energy China, Dalu New Area, Zhungeer Banner,

Ordos, Inner Mongolia

600,000 mtpy ethylene and propylene

JV Bharat Heavy Electricals Ltd. (BHEL) and

NTPC

India, Dadri, Uttar Pradesh 100 MW

Kochi Refinery Expansion Project India, Kerala Petcoke feedstock to generate 500MW

Korea Western Power Co (KOWEPO) South Korea Undetermined

Mmambula Energy Project Republic of Botswana 1200 MW

Tees Valley Renewable Energy Facility U.K.Teesside/Billingham, 50MW (one of four planned for the UK,

Total = 200 MW)

Tianjin IGCC Project China, Tianjin 250 MW

Vaskiluodon Voima Oy Vaasa, Finland 140 MW

Gasifiers Around the World

Region Gasification Plants

North America 28

South America 1

Europe 30

Asia/Australia 133

Africa/Middle East 5

Total 197

Source: EIA

Repowering

Replace ageing steam production with new technology

Replace old boiler with new steam-producing facility

Add additional steam producing facility

Combustion turbine

New steam process

Add heat recovery to combustion turbine exhaust

Increase efficiency

Increase electricity output

Reduce emissions

Repowering Examples

Gas turbine addition using heat from exhaust gases in steam cycle

Recover heat from turbine exhaustto preheat feedwater

http://soapp.epri.com/papers/Repowering_Fossil_Plants.pdf

…and the protest continue