Download - CMU CEIC Gasification talk 4-22-03
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Coal Gasification Coal Gasification and the Meaning of Lifeand the Meaning of Life
Edward S. RubinDepartment of Engineering and Public Policy
Carnegie Mellon UniversityPittsburgh, Pennsylvania
Carnegie Mellon Electricity Industry Center Seminar
April 22, 2003
Outline of TalkOutline of Talk
• What is coal gasification?• How does it work?• Why the interest?• Where does it stand?• Where is it headed?
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What is Coal?What is Coal?
Carbon (wt%) 61.2Hydrogen 4.20Oxygen 6.02Sulfur 3.25Nitrogen 1.16Chlorine 0.17Ash 11.0Moisture 13.0Mercury (ppm,dry) 0.12HHV (Btu/lb) 10,900
47.93.4010.80.480.620.036.4030.40.10
8,335
Bituminous Subbituminous(Ill.#6) (PRB)
Coal vs. Other Fossil FuelsCoal vs. Other Fossil Fuels
COALCOAL C:H ~ 1:1 C H
PETROLEUMPETROLEUM C:H ~ 1:2 C HH
NATURAL GASNATURAL GAS C:H ~ 1:4 C HHHH
H+ = synthetic oil
H H+ = synthetic NG
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What Is Gasification?What Is Gasification?
• Gasification is a process that converts carbonaceous materials, such as fossil fuels and biomass, into mixtures of hydrogen and carbon monoxide (called synthesis gas, or syngas)
• Other gaseous species also are formed in varying amounts, depending on the fuel composition and process conditions
• The syngas can be burned as a fuel, or processed to produce chemicals and other fuels
• While the focus of this talk is on coal gasification, an important attractions of this technology is that it can process other materials besides coal
Gasification BasicsGasification Basics
• Coal gasification must be carried out at high temperature (and pressure, usually) to first decompose the coal then create new products (via addition of hydrogen)
• The source of heat for these reactions is the partial oxidation (combustion) of the coal (requiring some addition of oxygen)
• The most abundant source of hydrogen is water (H2O), added either as a liquid or vapor (steam)
• The source of oxygen is either air or nearly-pure oxygen (supplied by an air separation unit)
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A Typical Coal GasifierA Typical Coal Gasifier
CoalCoal%C, H, S, O, N, %C, H, S, O, N, ClCl%Ash%Ash
HydrogenHydrogenHH22OO
OxygenOxygenAir or OAir or O22
Syngas (raw)Syngas (raw)% CO% CO% H% H22
% CO% CO22
% H% H22OO% CH% CH44
% COS% COS% H% H22SS% HCl% HCl% NH% NH33
% N% N22% Ash% Ash
SlagSlag
Gasification processes use one or more common reactions:
Reaction with oxygen (partial oxidation)HC + O = H2 + CO + heat
Reaction with steam (reforming)HC + H2O + heat = 3/2H2 + CO
Thermal decompositionHC + heat = H2 + C + organics
Reaction with hydrogen (hydrogasification)HC + H2 = CH4 + heat
Gasification ChemistryGasification Chemistry
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Uses of SyngasUses of Syngas
• Electric power generation• Steam generation• Process heat• Chemicals production• Liquid fuels production• All of the above
After cleanup for removal of impurities, syngas can be used for:
Texaco Gasification ProcessTexaco Gasification Process
Syngas
End-productsFeeds Gas RefiningOxygen
Electricity
SulfurSolids
Gasification
SULFURRECOVERY
Co-products:
H2S
HRSG Steam
Combustion Turbine
SyngasAlternatives:
Syngas
CO2
• Hydrogen• Chemicals• Ammonia• Fuel Cells• Fischer-
Tropsch
• Natural Gas
• Any Oil
• Tar/Asphalt
• Petroleum Coke
• Coal
• Wastes/by-Products
• Biomass
GASSEPARATION
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CO + HCO + H22
Acetic Acid
Ethene & PropeneAcetic Anhydride VAM
n-Butyl AcetateTerephthalic Acidn-Butylenep-Xylene
MethanolMethanolMTBE FormaldehydeIsobutylene
Gasoline & FuelsGasoline & Fuels
Lubricants & Lubricants & WaxWax
Ethanol & IsobutanolEthanol & Isobutanol
SNGSNG
HydrogenHydrogen
MDIMDIAniline
Phosgene
1,4-Butanediol
Acetylene
Ammonium SulphateAmmonium Sulphate
AmmoniaAmmoniaPhosphoric AcidAmmonium Phosphate & Ammonium Phosphate & Diammonium PhosphateDiammonium Phosphate
Sulphuric Acid
UreaUreaAmmonium NitrateAmmonium Nitrate
Nitric AcidNitric Acid
Source: Gunal-Akgol, U.Waterloo
Chemicals and Fuels from SyngasChemicals and Fuels from Syngas
An Old TechnologyAn Old Technology
• Coal gas was first used in London in 1790 for gas lights
• Later used for fuel gas in Europe and North America in the 19th and early 20th century
• Used to produce coal-derived transportation fuels in Germany during WWII
• Many different gasification processes have been proposed, employing different schemes for fuel feed, reactor design, etc.
• Current generation of gasifiers are cleaner and more efficient than earlier designs
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A 1942 view of coal gasification
. . . from John Wayne and friends
Byproduct Coke Plant Byproduct Coke Plant (World(World’’s Biggest, ca. 1970)s Biggest, ca. 1970)
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Why the Current Interest?Why the Current Interest?
• Gasification is already commercially attractive for a variety of refinery and petrochemical processes
• Offers a way to utilize low-value products or wastes as “opportunity fuels” (esp. petroleum coke)
• Can produce multiple products (polygeneration)
Worldwide Gasification CapacityWorldwide Gasification Capacity
Source: SFA Pacific /DOE, 2001
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Gasification by Global RegionGasification by Global Region
Source: SFA Pacific /DOE, 2001
Largest Gasification ProjectsLargest Gasification Projects
Source: SFA Pacific /DOE, 2001
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Gasifier TechnologiesGasifier Technologies
Source: SFA Pacific /DOE, 2001
Primary Gasification FeedstockPrimary Gasification Feedstock
Source: SFA Pacific /DOE, 2001
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Gasification ApplicationsGasification Applications
Source: SFA Pacific /DOE, 2001
Source: Chevron-Texaco
Pet Coke Gasification to H2 and CO2 for Ammonia and Urea
Farmland Industries, Coffeyville, Kansas
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Pet Coke Gasification to H2 and CO2 for Ammonia and Urea
Farmland Industries, Coffeyville, Kansas
Regina
Bismarck
North Dakota
Saskatchewan CanadaUSA
WeyburnWeyburn
COCO22
Regina
Bismarck
North Dakota
Saskatchewan CanadaUSA
WeyburnWeyburn
COCO22
SNG Plant Supplying CO2 for Enhanced Oil Recovery (EOR) and
Sequestration
Dakota Coal Gasification Plant
Sources: USDOE; NRDC
EOR at Weyburn
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Why the Current Interest?Why the Current Interest?
• Gasification is already commercially attractive for a variety of refinery and petrochemical processes
• Offers a way to utilize low-value products or wastes as “opportunity fuels” (esp. petroleum coke)
• Can produce multiple products (polygeneration)• In the U.S., great interest today is in the potential for
IGCC power plants to meet stringent air emission standards — especially future CO2 capture and storage reqmts — at lower cost than combustion-based plants
Fate of ImpuritiesFate of Impurities
Coal Combustion Systems• Sulfur SO2• Nitrogen NO + NO2• Ash (Bottom Ash) + Flyash
Coal Gasification Systems• Sulfur H2S (+COS)• Nitrogen NH3• Ash Slag (+ Fines)
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PC Plant with COPC Plant with CO22 CaptureCapture
IGCC Plant with COIGCC Plant with CO22 CaptureCapture
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A Modern Gas Turbine
Integrated Coal Gasification Combined Cycle (IGCC) Plant
Wabash River, Indiana
Source: Global Energy, 2002
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Polk Power StationIGCC Plant
(Tampa Electric, 250 MW)
EPRI Cost and Performance EstimatesEPRI Cost and Performance Estimates(without CO(without CO22 capture)capture)
Note: Hg removal adds ~2-3$/MWh to PC and 0.3$/MWh to IGCC COE.
Technology SubPC SuperPC UltraPC AFBC IGCC NGCC
MW 500 500 500 500 590 506
Capital ($/kW) 1364 1397 1416 1426 1502 500
HHV Heat Rate 10,070 9550 9402 10,024 8891 7646(kJ/kWh)
Fuel ($/GJ) 0.948 0.948 0.948 0.948 0.948 2.50/3.71/2.50
Capacity Factor (%) 80 80 80 80 80 80/80/40
COE ($/MWh)Capital 24.0 24.6 24.9 25.1 26.5 8.8O+M 6.8 6.7 6.7 8.9 7.2 3.2Fuel 9.5 9.0 8.8 9.7 8.4 19.1Total 40.3 40.3 40.5 43.7 42.1 31.1/40.3/41.9
Source: Holt, 2002
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Cost of Alternative OptionsCost of Alternative Options
0
20
40
60
80
100
120
0 100 200 300 400 500 600 700 800 900 1000
Cos
t of E
lect
ricity
($ /
MW
h)
PC
CO2 Emission Rate (kg / MWh)
IGCC
Coal Plants(combustion,gasification)
Wind, Biomass
Nuclear,Hydro
Natural GasCombined Cycle
Coal and GasPlants with
CO2 Capture
Gasification vs. CombustionGasification vs. Combustion
• A Chemistry Perspective:Combustion = Oxidizing atmosphereGasification = Reduction atmosphere
• A Disciplinary Perspective:Combustion = Mechanical EngineeringGasification = Chemical Engineering
• A Technology Perspective:Combustion = Power Plants Gasification = Chemical Plants, Refineries, etc.
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Where Do We Go from Here?Where Do We Go from Here?