Energy

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Energy

• Part 2 Fossil Fuels

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Coal

• Types
• Lignite soft, lowest heat content
• Bituminous soft, high sulfur content, 50 of US
  reserves
• Anthracite hard, high heat content, low sulfur,
  2 of US reserves

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Coal

• Supplies 25 of world energy
• China and the US consuming the most
• 87 of coal in the US is used to produce
  electricity
• Clean Air Act requires a 90 reduction of
  sulfur-containing gases from coal combustion

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• Coal is dead plants not dead dinosaurs

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Extraction and Purification of Coal

• Extraction methods
• Surface mining
• Underground mining
• Purification
• Removes foreign materials
• Screens for size
• Crushes and washes coal to remove contaminants
• May convert coal to liquid through clean coal
  technologies

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Clean Coal

• Process to reduce the negative impacts on the
  environment from burning coal
• Washing coal to remove minerals and impurities
• Capturing sulfur and carbon dioxide from flue
  gases
• Others
• using natural gas
• Microbial fuel cells charged with biomass or
  sewage

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Steps of Clean Coal Technology

1. Oxygen is introduced to burn coal completely
2. Coal is pulverized to burn more completely
3. Ash is removed using electrostatic precipitators
4. Steam is condensed and returned to the boiler
5. CO2 is removed using live and then sequestered

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Steps of Clean Coal Technology
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Coal Reserves and Global Demand

• Coal is the worlds largest sources of fuel used
  to produce electricity
• US has largest reserve
• China is largest producer
• Reserves expected to last about 300 years

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Coal

• Pros
• Abundant, known reserves (300 years worth)
• Unidentified reserves (1,000 years worth)
• US reserves will last 300 years
• Relatively high net-energy yield
• US government subsidies keep prices low
• Stable, non-explosive not harmful if spilled

• Cons
• Extraction methods disrupt environment and lead
  to pollution
• Underground mining is dangerous and unhealthy
• Up to 20 ends up as fly ash, boiler slag, sludge
• Releases mercury, sulfur, and radioactive
  particles into the air
• 35 of CO2 pollution
• 30 of NOx pollution
• Expensive to process and transport
• Pollution causes global warming
• Pollution controls are expensive

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Energy Crisis

• Shortages of fuel in the world market
• Mainly petroleum
• OPEC (Organization of Petroleum Exporting
  Countries)
• Control world Petroleum supply
• OPEC decrease production to increase cost of oil
  or increase production to decrease the cost of
  oil
• As prices for oil increase tar sands and oil
  shale become profitable sources of oil

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• Sorry, your car is not running on dead dinosaurs
• Petrochemicals (derived from oil) are used for
  manufacture of paint, drugs, plastics, etc.
• Natural Gas often found with oil deposits
• Also with coral beds, shale, gas hydrates, and
  tight sands

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Oil Extraction and Purification

• Extraction
• Drill down to the oil, usually trapped in porous
  sandstone
• Oil under pressure flows out naturally
• Low pressure wells must be pumped
• Purification
• Crude oil is sent to a refinery and cracked
• Cracking separating the components by boiling
  point
• Produces gasoline, heating oil, diesel oil,
  asphalt, etc.

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Natural Gas Extraction and Purification

• Extraction
• Usually present below non porous areas and above
  the oil
• Extraction similar to oil extraction
• Flows from well under own pressure and pumped
  into gas pipelines
• 560 billion m3 produced in the US each year

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Clean Burning vs. Dirty Fuels

• Clean Burning
• Methane
• Not Clean burning
• Coal, wood, crude oil, gas

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Methane Hydrates

• Methane locked in ice
• Located in permafrost regions
• At water depths greater than 1,640 feet (500m)
• Natural gas uses expected to increase
• Natural gas is clean burning
• Natural gas plants are relatively cheap to build
• US Natural gas consumption is expected to
  increase 40
• Due to use in transportation
• Alternative liquid fuel

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Oil Shale

• Contains kerogen
• Heating oil shale in the absence of air turns
  kerogen into oil
• 3 trillion barrels of recoverable oil from oil
  shale in the world
• 750 billion located in the United States
• Largest reserves Estonia, Australia, Germany,
  Israel, Jordan
• In US Wyoming, Utah, Colorado

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Oil Shale Mining

• In suti heat oil shale in the ground to extract
  oil and gas via pumping
• Potential to affect aquifers
• Surface Mining
• Destroys environment
• Moderate net energy yield due to high inputs
  required to extract oil and repair environment

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Tar Sands

• Contain Bitumen semisolid form of oil
• High in sulfur (5) dirty oil
• Represent about 2/3 of world oil reserves
• Most in Canada and Venezuela
• Keystone Pipeline
• Moderate net-energy yield due to high inputs
• Strip-mining
• In suti recovery

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Hydrofracking

• Removes natural gas that was previously
  urecoverable
• Process
• Chemicals are mixed with large quantities of
  water and sand
• Mixture is injected into wells at extremely high
  pressure to create fractures in rock
• Oil and natural gas to flow out of the well
• Estimates 80 of natural gas wells will be with
  hydraulic fracking

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Hydrofracking

• Pros
• Process of bringing well to completion is short
• Well can be in production 20 40 years
• Makes it possible to access new reserves of oil
  and natural gas
• Stimulates the economy
• Allows independence from foreign sources of oil

• Cons
• Dangerous chemicals used in the process can enter
  the water supply
• Toxic, radioactive, caustic liquids pose storage
  problems
• Currently no regulations for fracking
• Results in contaminated water, air pollution,
  destroyed streams, and negative environmental
  impacts

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Oil World Reserves and Demand

• 45 - 70 of worlds reserves already depleted
• About 50 year supply left
• Competition between emerging economies
• 2/3 of oil in US is used in transportation
• 1/4 of oil used in industry

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Natural Gas World Reserves and Demand

• US has an estimated 75 year supply
• 34 in Middle East
• 40 in Russia and Kazakhstan
• 3 in US

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Oil

• Pros
• Inexpensive (prices increasing)
• Easily transported through pipes, etc.
• High net-energy
• Ample supply short term
• Large US government subsidies in place
• Versatile used in manufacturing many products

• Cons
• Limited reserves are declining
• Produces pollution
• Causes land disturbances through drilling
• Oil spills on land and ocean contaminate the
  environment
• Disrupts wildlife habitat
• Supplies are volitile

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Natural Gas

• Pros
• Pipelines and distribution networks are in place
• Easy to transport
• Relatively inexpensive
• Estimated 125 year reserve
• Less pollution than other fossil fuels
• Extraction leads to less environmental damage

• Cons
• H2S and SO2 released in process
• LNG is expensive and dangerous
• Lower net-energy
• Leakage of CH4 has more impact on global warming
  than CO2
• Disruption to collection areas
• Extraction leads to waste water
• Land subsidence

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Synfuels

• Any fuels produced from coal, natural gas, or
  biomass through chemical conversion
• Creates substances the same as crude oil or
  processed fuel
• Eg SNG synthetic natural gas created through
  coal liquification

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Synfuel Pros and Cons

• Pros
• Easily transported through pipelines
• Produces less air pollution
• Large supply of raw materials are available
• Can produce gas, diesel, or kerosene without
  reforming or cracking

• Cons
• Low net energy
• Plants to build are expensive
• Would increase depletion of coal due to
  inefficiencies
• Product is more expensive than petroleum

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Case Studies

• Arctic National Wildlife Refuge (ANWR)
• ANWR in NW Alaska (19 million acres)
• Drilling debate since 1977
• Controversy economics of oil recovery compared
  to environmental damage

• Keystone Pipeline System
• Transport synthetic crude and diluted bitumen
  from Canadian oil sands to refineries in
  Illinois, distribution hubs in Oklahoma, Texas
  ports
• Continuing debate over costs and benefits to US
  economy and environment