Coal Gasification – A PRB Overview
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Transcript Coal Gasification – A PRB Overview
Coal Gasification : A PRB
Overview
Mark Davies – Kennecott Energy
Outline
• Background – Our Interest
• History – Development of IGCC
• Current status – Commercial Technology
• Poly generation - Synthetic Fuels
• Issues for PRB
• The Future
• Questions ???
Our Interest - Sustainable Development
“development that meets the needs of the present
generation without undermining the capacity of future
generations to meet their needs.”
Rio Tinto’s commitment to SD: Ensure our
businesses,operations and products contribute to
the global transition to sustainable development
Coal’s Sustainability Challenge
• Economic and social criteria make a compelling case for coal –
the issue is environmental performance
• Climate change concerns present a complex challenge for the
continuing use of fossil fuels and coal in particular
Integrated Gasification Combined Cycle (IGCC)
IGCC is essentially ready for use by the coal industry, which
has largely been spared the expense of its development
Twenty years ago oil refinery practice in North America and Europe
underwent a fundamental change as available crude became heavier
This had two implications:
• A significant increase in hydrogen demand to 'sweeten' the
heavier crude; and
• Increased production of highly contaminated petcoke and heavy
refinery residues
Simultaneously, aerospace technology was being applied to the utility
sector to create natural gas fired turbines; and coal based IGCC
started becoming a viable technology
Implication – Current commercial technologies were developed for
Petcoke
Natural Gas Combined Cycle (NGCC)
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Natural gas
Gas turbine
Heat recovery steam
generator
Steam turbine
High efficiency
Low capital
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Simple vs. PC plants
Cookie-cutter design
Low emissions
Integrated Gasification Combined Cycle (IGCC)
Gasification is essentially partial oxidation under pressure
IGCC + Carbon Capture and Storage
Current Commercial Technology
Shell
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Lock hopper feed
Water cooled
Syngas cooler
PRB capable
at cost
GE (Chevron Texaco)
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Slurry feed
Refectory lined
Quench available
Not PRB capable
ConocoPhillips (E-Gas)
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Slurry feed
Refectory lined
2 Stage
???
Impact of Coal Type
• Any coal or biomass feedstock can be gasified
• The issue is the economics!
• Gasification is most efficient with low moisture, low ash
and high heating value feedstock's
1.40
IGCC Capital Cost (E-Gas)
Relative Heat Rate or Capital Cost
1.35
IGCC Heat Rate (E-Gas)
PC Capital Cost
1.30
PC Heat Rate
1.25
1.20
1.15
Illinois #6
1.10
Pittsburgh #8
1.05
TX Lignite
1.00
5,000
6,000
7,000
WY PRB
8,000
9,000
10,000 11,000 12,000 13,000 14,000 15,000
Coal Heating Value, Btu/lb HHV
Source: EPRI
Issues for PRB
• Capital cost disadvantage may be mitigated by fuel cost
• Petcoke/PRB blends can be attractive
• New technology
• DOE/Southern Transport Reactor
• Alternate slurry technology
• Commercial vendors have little ongoing development
Indicative Cost of Electricity
Coal
PRB Coal
Illinois coal
0
5
10
15
20
25
30
35
40
Cost ($/MWhr)
Capital Cost ($/MWh)
Other Fixed Costs ($/MWh)
Fuel Expense ($/MWh)
Variable O&M ($/MWh)
Polygeneration
Syngas is a prime petrochemical feedstock
Traditionally produced by
reforming natural gas
“Natural gas” from Syngas
• Methane reformer
• CO + 2H2 + Catalyst
=> CH4 + clean up
Liquid chemicals from Syngas
• Clean diesels
• Methanol
Indicative breakeven – current
technology
• Liquid Fuels $30 - $35 bbl
• Synthetic natural gas - $5.50 - $7 /MBTU*
* Source – DOE
IGCC + CCS + Poly generation
Barriers to IGCC Commercial Deployment
• Cost → 10-20% penalty for bituminous coal
• Traditional PC can meet current environmental standards
• IGCC financing costs higher than PC – perceived risk
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profile
No reward for risk taking – new plants largely being built
by regulated utilities
Excess capacity in many regions - NGCC overbuild
IGCC needs more project development than NGCC or PC
• To date no standard IGCC design - this will change with GE
entry
• Lack of familiarity with IGCC in the power industry (it is a
chemical plant)
Future Issues
• Environmental regulation, community pressure, uncertainty
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– particularly carbon
Sustained Federal research effort to resolve cost, reliability
concerns
• Especially on low-rank coals
Critical to establish viability and acceptability of carbon
capture and storage
• e.g. FutureGen
Development of of integrated, optimized designs
• GE/Bechtel
• ConocoPhillips/Fluor
Deployment incentives to overcome commercial penalty
(e.g. incentives, production tax credits, etc)
Costs should come down as new plants are built and
improved designs become standard