SOx, Hg and CCT - caer.uky.edu · ... most innovative technology emerging from the world's ... to...
Transcript of SOx, Hg and CCT - caer.uky.edu · ... most innovative technology emerging from the world's ... to...
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
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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