Sustainable clean coal power generation within a European context The view in 2006

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Sustainable clean coal power generation within a
European context The view in 2006

• Fuel 86 2124 - 2133. 2007

A.J. Minchener J.T. McMullan
Darin Bagshaw ENVI 5048 October 3rd, 2007
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Key Questions

• Why is clean coal power generation needed?
• What are the processes involved in clean coal
  power generation?
• Is it economically viable and sustainable?

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Worldwide Energy Demand Projections to 2030
(Business as Usual)
Fig. 1. World primary energy demand .1
Under this scenario, global GHG emissions would
rise by 60!
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Future Scenario for Coal

• Global coal use projected to double by 2030 (4.5
  trillion tonnes oil equivalent)
• OECD countries see coal as key component of their
  energy mix - recognize need for reducing its
  environmental impact
• Environmental standards will tighten for lower
  emission levels of SO2, NOx and micro-pollutants
  (such as mercury)
• Predominant need to reduce CO2 emissions to
  assist Europes climate change commitments

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EU Scenario

• Challenges
• Security of energy supply
• Implementing technologies that greatly reduce GHG
  emissions
• Maintaining competitiveness when introducing CCS
• Pressing requirement to meet Kyoto and post-Kyoto
  obligations
• Future business-as-usual energy projections
  create further complications

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EU Energy Sector Emissions options

• Reducing energy consumption
• Cost-effective solutions now available
• Enhancing carbon sinks (eg. Forests)
• Capacity is limited
• Not necessarily secure for holding carbon
• Alternative fuels
• Viable, but cant meet all CO2 reductions
• OR

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CO2 Capture and Storage (CCS) Opportunities

• Electricity generation from fossil fuels
  largest industrial CO2 emitter in Europe
• Urgent need to build and retrofit power stations
  in the next 25 years - power generation companies
  can work cooperatively to incorporate CCS
  technology
• Buys time until alternative energies can develop
  and become predominant
• European Union CO2 Emissions Trading Scheme
• Clean Development Mechanism (CDM) for projects in
  developing countries
• Market and regulatory standards requiring clean
  technology

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Capturing CO2

• Why capture only CO2?
• Impractical to transport and store entire gas
  stream due to energy costs and other associated
  costs
• 3 main approaches
• Post-combustion capture
• Pre-combustion decarbonisation
• Oxy-fuel combustion

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Capturing CO2
Fig. 4. CO2 capture options.
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Post-Combustion Capture

• Flue gas is compressed and sent through absorbent
  membrane
• CO2 separated from other flue gases
• Remaining flue gases discharged to the atmosphere
• Already done in small scale scenarios
• Requirement for higher efficiency scrubbing and
  SO2/NOX removal processes in large scale scenarios

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Pre-combustion Decarbonisation

• Processes fuel with steam and air or O2
  produces mixture of CO and H2
• Additional H2 and CO2 produced by reacting the CO
  with steam in 2nd (shift) reactor
• CO2 gas stream and H2 separated
• CO2 separated from fuel gas, H2 used as clean
  energy source for many applications
• Higher pressure process - more favourable for CO2
  separation than post-combustion
• Technology already in use (ie. ammonia/fertilizer
  production), but not for power plants

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Oxy-fuel combustion

• Still at testing phase
• Goal of process to establish more concentrated
  stream of CO2
• Uses O2 for combustion to produce water vapour
  and CO2 (in higher concentrations)
• Water vapour removed by cooling compression
• May require further processes to remove all
  pollutants and gases from CO2 before it goes to
  storage

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CCS Transportation Storage
Fig. 2. Three main steps for CCS to avoid CO2
release to the atmosphere 10.
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CO2 Storage

• Need locations with sufficient capacity
• 3 possible locations
• Gas or oil fields (operational or depleted)
• Deep saline aquifers (porous rock formations such
  as sandstone or limestone)
• Unmineable coal beds (least researched option)

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Storage Potential

• Gas/oil fields
• European capacities (14.5 billion tonnes
  offshore, 13.1 billion tonnes onshore)
• North Sea 25-year estimates (200 million to 1.8
  billion tonnes)
• Aquifers
• Capacity in 8 EU countries (80 to 100 billion
  tonnes)
• Unmineable coal beds
• To be determined (still in development)

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Other Potential Benefits

• Gas/oil fields
• Improve recovery of oil and gas by 4 to 20
• Unmineable coal seams
• Enhanced Coal Bed Methane projects can displace
  N2 and CH4 enhances coal production

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CCS Long-Term

• With growing consumption in China and India, coal
  will account for 22 of world energy mix in 2030
  (IEA World Energy Outlook 2004)
• Although much uncertainty and debate, scenarios
  predict 2,000,000 Mt CO2 reduction during the
  century (sufficient storage capacity available)
• Additional electricity costs (0.01-0.05 per kWh)
  and carbon mitigation costs (25-30/t CO2)
• Higher than cost of energy efficiency and non-CO2
  GHG reductions, but significantly lower than most
  renewable options

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CCS The impact

• Assumes a package of many GHG emission reduction
  options
• Also assumes that technology can be made
  available in a timely manner and costs can be
  reduced to attract investment
• To 2100
• 15 to 55 of total emission reductions
• Reduce overall mitigation costs by 30 vs.
  non-CCS portfolio of options

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CCS One Part of Larger Process For
Zero-Emissions Power Plant

• Co-utilisation with biomass and wastes
• Process efficiency improvements
• Development of new technologies (eg. gas and
  steam turbines)
• Hydrogen toward a more diverse transport fuel
  system and power production system

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Issues for R,D D

• CO2 capture
• Cost of CCS process
• Increasing scale of installations for
  demonstration and commercial use
• Operational reliability and commercial viability
• CO2 transport and infrastructure
• Development of transport options for range of
  sources
• Impact of new infrastructure on the environment
• CO2 storage
• Identify criteria for selection of suitable
  storage sites, proper operating conditions and
  methods of injection site closure

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Moving Forward

• European Commission
• Technology Platform for Zero Emissions Fossil
  Fuel Power Plants integrated strategy for
  zero-emission plants by 2020
• Strategic Deployment Document roadmap with
  interim targets for market place deployment
• EU industry
• Large scale demonstration for CO2 scrubbing
  technology (Post-combustion capture)
• Pilot plant for CO2 brown coal power station
  using oxy-fuel combustion process
• Target of 2015 or 2020 for use of these power
  stations

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BOOK REVIEW - Sustainable Fossil Fuels Mark
Jaccard (SFU)
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Sustainable Fossil Fuels Mark Jaccard

• Jaccard for many years, strong proponent of
  renewable energy, energy conservation and nuclear
  energy
• Upon further review, he questions the premise of
  the demise of the fossil fuel era
• flaws in arguments, assumptions and facts
• sufficient fossil fuels for next century and
  beyond
• In the short term, renewables, energy
  conservation and nuclear wont have enough impact
  to be the complete solution
• Balancing the mix with fossil fuels will allow
  for proper development of these other resources
• may further stress the environment, but not to
  the point of collapse

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Questions to Ponder

• Are clean fossil fuels a credible option?
• Reliability of CO2 capture, transport storage
• Timeframes for technology implementation
• Renewables the ultimate green solution?
• Land use issues
• Life-cycle analyses
• Is there a proper balance between fossil fuels
  and renewables?