Clean
Coal
Claire Sullivan
Energy Distribution
• Coal - 44.8%
• Natural Gas - 24.1%
• Nuclear - 19.5%
• Hydroelectric Conventional - 6.2%
• Other Energy Sources - 4.5%
• (biomass, geothermal, solar, and wind)
• Petroleum - 0.9%
http://www.eia.doe.gov/cneaf/electricity/epm/epm_sum.html
Mining Techniques
• Surface Mining
• Less than 200 ft
• Machines get rid of overburden
• Expose coal seam
• Underground Mining (deep mining)
• More than 500 ft
• Miners run machines
Carbon Dioxide Concentration
• Increase from 290ppm (1900) to approx.
400ppm
• Due to coal emissions
• Because of increase, average temperature
increased 4-7°F
Clean Coal Technology
• Any technology that improves the
environmental performance of coal-
based electricity plants.
• Any devices that reduce emissions
Carbon Capture and Storage
(CCS)
New Gen Coal - Carbon Capture & Storage
http://vimeo.com/16307994
How CCS Works
• “1. CO2 Capture The process of carbon capture produces a concentrated stream of CO2 that
can be compressed, transported and eventually stored. Depending on the power plant,
carbon capture can take place through:
• Pre-combustion: a process that removes CO2 before it is burned as part of the gasification
process.
• Post-combustion: a process that removes CO2 with a solvent, strips off the CO2 with steam,
and condenses the steam into a concentrated stream.
• Oxyfuel combustion: a process that burns the fuel in pure or enriched oxygen to create a
flue gas composed primarily of CO2 and water.
• 2. CO2 transport Once CO2 has been captured, it needs to be transported to a
storage location. Options for transportation include pipeline, ships, rail and road
transport.Transport of CO2 by pipeline is currently used in the United States
where over 2500 kilometres of CO2 pipelines exist and carry 50 million tonnes of
CO2 per year to enhanced oil recovery projects in Texas and elsewhere.
• 3. CO2 storage The final step in the process is the safe and long-term storage
of CO2. This can take place in either deep geological formations, under the
ocean, depleted oil or gas fields, unmineable coal seams, or enhanced oil and
gas recovery sites.”
www.americaspower.org
QuickTime™ and a
decompressor
are needed to see this picture.
Storage of CO2
• Best destinations for CO2 said to be
“underground formations of sedimentary
rock loaded with pores now filled with
brine (salty water).
(Socolow, 53)
Pros and Cons of CCS
• Pro: • Con:
• Can cut carbon • Not helping to phase
emissions by up to out fossil fuels
90% • Capturing and storing
• Huge amount of carbon uses more
storage space energy and is more
• Cutting carbon expensive
emissions helps stop • Possibility of CO2
temperature increases leaks
• Making coal
environmentally
friendly would be, in
some cases, better
than creating new
renewable energy
sources
Coal Gasification
(including underground coal gasification)
• Coal to gas
• Breaks down coal into basic parts
• “Coal is typically exposed to steam and
carefully controlled amounts of air or oxygen
under high temperatures and pressures.
Under these conditions, molecules in coal
break apart, initiating chemical reactions that
typically produce a mixture of carbon
monoxide, hydrogen and other gaseous
compounds.” http://www.fossil.energy.gov/programs/powersystems/gasification/index.html
Gasification: How It Works
• http://www.youtube.com/watch?v=CD-
0aLh9waU
Pros and Cons
• Pros • Cons
• Near Zero • Complex Multi-
Emissions Stage Process
• High Efficiency • Initial Setup is
• Energy Security expensive
• Syngas need to
be
cleaned/purified