Energy

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Chapter 4

• Energy

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Resources

• Mineral and energy resources fall into two
  categories
• Renewable - resources that can be replaced or
  replenished over a fairly short time span.
• This would include
• animals for food
• trees, water,
• wind, the sun
• Nonrenewable - resources that take millions of
  years to form and accumulate
• This would include
• Coal, Oil
• Minerals like copper, iron, gold

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• The Earths population has increased and is still
  growing. The demand for resources has increased
  faster than the population. Can you reason why?

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• Fossil fuel - any hydrocarbon that may be used as
  a source of energy
• Includes coal, oil, natural gas
• Coal - forms when heat and pressure (sound
  familiar?) Transforms plant material over
  millions of years
• There are 4 stages.
• Peat - plant characteristics are still visible
• Lignite - brown coal (sedimentary rock)
• Bituminous - black soft coal (also sedimentary)
• Anthracite - hard, shiny (metamorphic)

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• Power plants use coal to generate electricity.

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• Petroleum and Natural Gas - are the remains of
  plants and animals that were buried in ocean
  floor sediments in ancient seas.

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Tar Sands - clay and sand combined with tar It
is too thick to pump so it has to be mined like
coal.
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So what is Tar Sand?

• The oil or tar in these deposits is not really
  oil but something called bitumen. The bitumen is
  what was left in these deposits after the oil
  that was initially deposited there was
  biodegraded over millions of years. Basically
  them dan bugs ate all the good light oil and
  left all the heavy tarry sh behind. This is
  different than oil shale which has never been
  turned into oil yet. Oil shale requires a very
  large amount of energy to turn the raw kerogen
  into a liquid form of hydrocarbon whereas the
  bitumen in tar sands has already gone through
  this process

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• To turn this bitumen into usable energy and
  transportation fuel it has to be heavily refined
  and upgraded, but that is doable. However, as you
  might imagine, this bitumen is not a very valued
  product by most oil refiners. Consequently, it
  sells at a heayv discount (20/bbl ?) to light,
  sweet crude.Right now approximately 1 million
  barrels of bitumen per day are produced from tar
  sands in Alberta. By 2010 that quantity is
  expected to double. It may double again by 2020.

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• In any case, if there is so much of this stuff,
  why cant it stave off peak oil? Good question.
  The answer is multi-fold. First, all of the
  forecasts for future relating to future worldwide
  oil supply already forecast a substantial and
  growing wedge of production from Canadian tar
  sands. Some of these forecasts assume as much as
  5 million barrels per day (total Heavy Oil) by
  2020. But that is not enough to offset the
  decline in other areas.

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• In addition, tar sands require a lot of other
  energy resources to extract and upgrade them.
  Natural gas has been the fuel of choice for most
  of these energy needs as well as to use in
  hydrogenating the bitumen in the upgrading
  process. The forecasted need for natural gas
  collides head on with a forecast of limited
  future supply for this vital resource. There may
  be a way around this conundrum, but right now it
  is considered an impediment to future growth of
  tar sands development.

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• Oil Shale - rock that contains kerogen. Oil is
  extracted by heating oil shale.

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Oil Shale
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• Pound per pound, oil shale contains just
  one-tenth the energy of crude oil, one-sixth that
  of coal, and one-fourth that of recycled phone
  books. Shale outcrops are common in Colorado, but
  in prehistoric times the Utes did not use oil
  shale for heat. Why bother when you could gather
  pine or juniper instead?
• In poor countries, millions of people heat their
  homes with dried manure. Dung cakes have four
  times more energy than does oil shale.

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• Mineral Reserves - deposits from which minerals
  can be extracted profitably.
• Ore - useful metallic mineral that can be used at
  a profit.
• There is lots of gold in the ocean, it just cant
  be extracted profitably
• Some of the most important mineral deposits form
  through igneous processes and from hydrothermal
  solutions.

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• Lead, silver, zinc, gold, mercury and other
  minerals are dissolved in magma. As the magma
  cools, like metals collect near the top of the
  magma chamber. These solutions flow through rock
  fractures and produce deposits.

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Placer Deposits

• Placer deposits - eroded minerals settle quickly
  from moving water. Less dense material, like clay
  sediments, stay suspended longer. Old
  prospectors looked for places where water slowed
  down as it ran downstream.

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• Nonmetallic minerals - fluorite, limestone,
  crushed stone. Limestone is used as a building
  material, Crushed stone has many uses. Fluorite
  is used in steelmaking.

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• Lots of examples of nonmetallic minerals on p 101.

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Alternate Energy Sources

• Solar Energy
• Passive solar energy systems - takes advantage of
  available sunlight. South facing windows,
  building walls that trap heat and radiate it
  during dark hours.
• Active solar collectors uses equipment
  specially designed to collect the heat from the
  sun. The heat collected can be used to heat air
  or water.

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This map represents areas where solar energy is
feasible.
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• Experimental solar stations concentrating solar
  energy using mirrors has been used to heat water
  in pressurized panels to 500C.

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• Nuclear Energy
• Currently meets about 7 of the energy demand of
  the US
• The fuel comes from radioactive material (U238
  , this is an isotope of Uranium). When U238 is
  bombarded with neutrons, the atom splits,
  releasing neutrons and heat energy.
• The neutrons released from splitting the atom
  strike other U238 atoms, producing a chain
  reaction.

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• If this reaction continues uncontrolled, it would
  create an atomic explosion.
• In a nuclear reactor, the reaction is controlled
  by moving neutron-absorbing rods in or out of the
  nuclear reactor.
• The huge amount of heat energy released by the
  reaction is used to heat water, producing steam,
  which turns a turbine to produce electricity.

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• Wind energy
• People have used wind energy for centuries.
• Used for grinding grains using windmills
• Sailing ships.
• Today, windmill arrays turn turbines that produce
  electricity.
• Some experts think that in the next 50-60 years
  wind power could meet up to 10 of the energy
  needs of the US.

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Hydroelectric Power

• Water is held in a reservoir behind a dam. Water
  falls using the force of gravity to turn a
  turbine that produces electricity.
• Waterwheels have powered mills and other
  machinery for centuries.

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Geothermal energy

• Geothermal energy is harnessed by tapping natural
  underground reservoirs of steam and hot water.
• Hot water is used for heating and to turn
  turbines to generate electric power

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Tidal power

• This is a means of utilizing the oceans energy.
  
• This energy source has been used for centuries.
  Again, use for powering grist mills and saw
  mills.
• Used during the 17th and 18th centuries to
  produce flour in Boston.
• Not feasible unless there is at least 8 meters
  (24 feet! ) of tide range.
• A narrow enclosed bay must be available. Few
  places on earth meet these requirements.

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Water Air and Land Resources

• Water
• Water covers 71 percent of the planet
• Most of this water is salt water, not fresh
• Ocean currents help regulate and moderate Earths
  climate
• People, plants and animals need fresh water
• People need fresh water for drinking, cooking,
  bathing, and growing food.

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• Freshwater pollution
• Point Source - pollution that comes from a known
  and specific location. From a specific pipe or
  factory.
• Nonpoint source pollution Pollution that doesnt
  have a specific source of origin. Runoff water
  that flows over the land rather than seeps into
  the ground.
• Runoff can carry pesticides from fields and oil
  from roads or parking lots.
• Runoff from mines can carry sulfuric acid into
  rivers or lakes
• Pollutants can carry pathogens, cause birth
  defects, cause certain types of cancers, can kill
  aquatic life.
• It is dangerous to eat fish from some polluted
  water.

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Earths Blanket of Air

• The chemical composition of the atmosphere helps
  maintain life on Earth.
• Ozone (O3) in the atmosphere absorbs harmful
  solar radiation.
• Pollution comes from oil burning power plants,
  motor vehicles, any fossil fuel combustion

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• Burning fossil fuels produces CO2, which is a
  harmful greenhouse gas
• The increase of CO2 has led to some degree of
  global warming.
• CFCs (chemicals once used in air conditioning
  and plastic foam production) has destroyed some
  ozone in the stratosphere.
• Air pollution causes health problems like
  coughing, wheezing, headaches, and long term
  health effects such as asthma, bronchitis,
  emphysema and lung cancer.

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Land Resources

• Soil is necessary to grow the food you eat.
• Forests provide lumber for homes, furniture and
  paper
• Petroleum provides energy and is the raw material
  for plastics.
• Minerals, such as copper, gold, zinc, aluminum,
  and nickel make up coins and other materials we
  use daily.
• Mining tears up Earths surface and destroys
  vegetation. It causes pollution and erosion and
  contaminates surrounding soil and water.

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• Agriculture has allowed many dry areas to be
  farmed but irrigation has depleted the
  groundwater and caused a build-up of salts in
  soil. This can make soil useless for growing
  crops.
• Clear cutting forests can damage land, destroy
  ecosystems and wildlife habitat.

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• The US actually has more forest today than it did
  100 years ago, but this is second growth forest
  and doesnt have the same numbers of species that
  it had when a virgin forest.
• Land serves as a disposal site for waste
  material. This process can be done correctly but
  old land fills leak harmful wastes.

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