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SUPPLIES OF COAL
UNITED STATES - 3 TRILLION TONS (50% IN WYOMING, MONTANA, NORTH DAKOTA)
WESTERN COAL - 60% LOW SULFUR (0.7%S) - AT STRIP MINING DEPTH - >1000 MILES FROM DEMAND CENTERS - $5- $15/TON
U.S. COAL RESERVES
RECOVERABLE - 10% U.S.G.S - 50% DOE
“UNRECOVERABLE” - TECHNOLOGICALLY - ECONOMICALLY - (EXTRACTION, RECLAMATION COSTS)
AVAILABLE COAL ENERGY
3 TRILLION TONS X 50% RECOVERABLE X 2000 LB/TON X 10,000 BTU/LB = 3 X 1019 BTU
- 1980 U.S. CONSUMPTION = 80X1015 BTU (TOTAL) - 375 YEAR SUPPLY
AT PRESENT COAL CONSUMPTION RATES (20 X 1015 BTU/YEAR) - 1500 YEAR SUPPLY
COAL RANK
1. ANTHRACITE -14,000 BTU/LB
2. BITUMINOUS -12,000 BTU/LB
3. SUB-BITUMINOUS -9,000 BTU/LB
4. LIGNITE (30% WATER) - 7,000 BTU/LB
TABLE 4Representative Composition of Western Lignite
(As Received)
Proximate Analysis Ultimate analysisFixed carbon 27.2% Carbon 44.9 %Ash 11.7% Hydrogen 3.4%Water 25.4% Oxygen 13.2%Volatiles 34.5% Nitrogen 0.2%Sulfur 1.2% Sulfur 1.2%
Heating value 7500 Btu/lb Ash 11.7%
Water 25.4%
FINANCIAL DILEMMA
SYNTHETIC FUEL COST (2008) - $7.50-15.00/MM BTU
INVESTMENT - 75 X 1012 BTU/YEAR PLANT, 25 YEAR LIFE - $4-6 BILLION
? COST OF OTHER ENERGY SOURCES ?? (O.P.E.C) - NEED A FLOOR ON THE PRICE OF ENERGY OVER A LONG TIME FRAME
EXTRACTION
TRANSPORTATION
PREPARATION
CONVERSION - GASIFICATION- LIQUEFACTION- COMBUSTION
POLLUTION CONTROL - PARTICULATES- SO2
- H2S- NOX
EXTRACTION
1. STRIP MINING 0-200 feet
2. SHAFT MINING 200-5000 feet
3. IN SITU GASIFICATION
(2)USED AS EARLY AS 1819 IN TEXAS (1) USED SINCE 1954 (ROCKDALE)
STRIP MINING - CONTOUR STRIPPING- AREA STRIPPING
ENVIRONMENTAL ASPECTS
1. STRIP MINING OF TEXAS LIGNITE
AREA STRIPPINGOVERBURDEN NOT HIGH SULFURRECLAMATION COST CT= 0.055 CA/T(SUFFICIENT RAINFALL) – NEGLIGIBLE IN MOST CASES
CT, COST PER TON IN CENTS
T, COAL SEAM THICKNESS IN FEET
CA, RECLAMATION COST IN DOLLAR PER ACRE ($200 IN TEXAS)
COAL PIPELINES
COAL (200 MESH)/ WATER SLURRY
LARGE INVESTMENT COST
CURRENT OPERATION – BLACK MESA, ARIZONA(1750 MW) 270 MILES
PLANNED OPERATION – HINDERED BY EMINENT DOMAIN, WATER SUPPLY PROBLEMS
NOT FEASIBLE FOR LIGNITE
FOUR UTILIZATION ISSUES
1. LOCATION
2. MODE OF EXTRACTION
3. SULFUR REMOVAL
4. FINAL PRODUCT
SOLUTIONS TO THE SULFUR PROBLEM IN POWER GENERATION
1. LOW SULFUR COAL
2. MECHANICAL TREATMENT (BENEFICIATION)
3. COAL GASIFICATION/LIQUEFACTION
4. DOLOMITE INJECTION/FLUIDIZED BED
5. FLUE GAS SCRUBBERS
1, 2, 3 PRE-COMBUSTION
FLUE GAS SCRUBBERS
LIMESTONE SCRUBBING AT LOW TEMPERATURE
DESIGNED FOR 90% REMOVAL
COMMERCIALLY PROVEN, COST = $200/KW (vs. $1000/KW for ENTIRE POWER PLANT)
HAS DISPOSABLE BYPRODUCT (e.g., CAS04)
6-8 % LOSS IN THERMAL EFFICIENCY
DOLOMITE INJECTION
REMOVAL OF SO2 SIMULTANEOUS WITH COMBUSTION
CACO3 SERVES AS A SCAVENGER FOR SO2 (PRODUCES CASO4 THROWAWAY PRODUCT)
REQUIRES LOW TEMPERATURE 1600 ºF
HANDLES HIGH ASH COALS
LOWER EMISSIONS OF NOX, TRACE METALS
ATTRACTIVE FOR SMALLER POWER PLANTS (LESS THAN 100 MW)
COAL GASIFICATION/LIQUEFACTION
VERY EXPENSIVE
GASIFICATION ONLY REASONABLE WHEN PLANT IS INTEGRATED
COAL LIQUIDS ATTRACTIVE FOR TRANSPORTATION
COMMERCIAL SCALE OPERATIONS (e.g., S.AFRICA)
H2S/CO2 REMOVAL ARE PROVEN TECHNOLOGIES
H2S + O2 = H2O + SO2
H2S + SO2 = S + H2O
SELECTION OF A GASIFIER
1. TYPE OF BED
2. OPERATING PRESSURE
3. SLAGGING, NON-SLAGGING
LURGI (FIXED BED, HIGH P, NON-SLAGGING)
KOPPERS-TOTZEK (ENTRAINED BED, LOW P, SLAGGING)
WELLMAN-GALUSHA (FIXED, LOW P, NON-SLAGGING)
WINKLER (FLUIDIZED, LOW P, NON-SLAGGING)
Kellog Brown and Root (KBR)
IGCC PROCESS
IGCC Plants in the US
The Tampa Electric IGCC ProjectMulberry, Florida, 1996
Using: GE Energy Gasification Output: 250 MWe
The Wabash River IGCC ProjectWest Terre Haute, Indiana, 1995Using: The ConocoPhillips E-Gas
Gasification process Output: 262 MWe
PREDICTIONS(MADE IN 1990) ?
1. COAL COMBUSTION WILL CONTINUE AS THE DOMINANT MODE OF COAL UTILIZATION DURING THE REST OF THIS CENTURY.
2. SYNTHETIC FUELS WILL BECOME POPULAR AGAIN IN THE FUTURE (HISTORY REPEATS ITSELF) – PERHAPS 10 YEARS FROM NOW, THE U.S.A WILL HAVE ANOTHER ENERGY “CRISIS”.
3. PREDICTIONS FOR 2010?