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Energy Resource - TED Ankara Koleji Kütüphane ve Bilgi Merkezi

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Energy Resource - TED Ankara Koleji Kütüphane ve Bilgi Merkezi Powered By Docstoc
					                        Deniz Cinalioğlu 10-U
   Coal
   Crude Oil
   Naturel Bitumen
   Natural Gas
   Oil Shale
   Peat
   Nuclear
   Hydropower
   Peat
   Biomass
   Solar Energy
   Geothermal
    Energy
   Wind Energy
   Tidal Energy
   Wave Energy
   Ocean Thermal
   Marine Current
    Energy
   Hydrogen
   Coal gasification
                                                              Deniz Cinalioğlu 10-U




Renewable is the term used for forms of energy that can be regenerated, or
renewed, in a relatively short amount of time. The regeneration process may be
continuous and immediate, as in the case of direct solar radiation, or it may
take some hours, months or years. This is the case of wind energy (generated
by the uneven heating of air masses), hydro energy (related to the sun-
powered cycle of water evaporation and rain), biomass energy (stored in plants
through photosynthesis), and the energy contained in marine currents. The
energy contained in fossil fuels – coal, oil and natural gas – likewise comes also
from the sun's energy, but it was stored in plants millions of years ago, and once
used, it cannot be regenerated on a human time scale. They are examples of
non renewable energy sources. The earth's remaining fossil fuel reserves can
probably provide us with energy for another 100 to 500 years, but this is an
insignificant amount of time in terms of the whole past history of human
civilisation and of its future.
                                                                  Deniz Cinalioğlu 10-U




   Coal (non renewable): It is a fossil fuel, and was formed from the remains of
    plants that were buried and subjected to high presure and heat. It is largely or
    almost entirely composed of carbon with varying amounts of mineral matter.
    After the plants die and buried, the chemical changes gradually lower the
    oxygen and hydrogen content of the cellulose molecules, CH₂O. Coal matures
    through four stages; lignite, subituminous, bituminous and anthracite. Each
    stage has a higher Carbon-to- Oxygen and Carbon-to-Hydrogen ratio. The
    energy available from the combustion of a given mass of coal increases as the
    Carbon content increases.

   Crude Oil (non renewable): A thick, flammable, yellow-to-black mixture of
    gaseous, liquid, and solid hydrocarbons that occurs naturally beneath the earth's
    surface, can be separated into items including natural gas, gasoline, naphtha,
    kerosene, fuel and lubricating oils, paraffin wax, and asphalt. It is used as raw
    material for a wide variety of products.
Deniz Cinalioğlu 10-U
                                                                  Deniz Cinalioğlu 10-U
                                                                                   10-U




   Naturel Bitumen (non renewable): Natural bitumen and extra-heavy oil are
    closely related types of petroleum, but differ from the petroleum. They have
    small amounts of the paraffins, and relative enriched heavy molecules, leading
    to increased density and viscosity. Of these molecules, the asphaltenes are very
    large and has such non-hydrocarbons as nitrogen, sulphur, oxygen, and metals,
    in particular nickel and vanadium.
    The result of the this composition creates problems more than the problems of
    conventional petroleum with respect to exploitation, transportation, storage, and
    refining. This is the reason for the increased cost of extraction and processing
    and the physical limitations on production capacity.
                                                                     Deniz Cinalioğlu 10-U




   Natural Gas (non renewable): Natural gas liquids (NGL’s) are hydrocarbons
    that exist in the reservoir as constituents of natural gas. These are recovered as
    liquids in separators, field facilities or gas-processing plants. Natural gas liquids
    include (but are not limited to) ethane, propane, butanes, pentanes, natural
    gasoline and condensate; they may include small quantities of non-
    hydrocarbons.

   Oil shale (non renewable): It does not contain oil nor is it commonly shale. The
    organic material is mainly kerogen, and the "shale" is usually a relatively hard
    rock, called marl. Properly processed, kerogen can be converted into a
    substance somewhat similar to petroleum. However, to be changed into an oil-
    like substance, it must be heated to a high temperature. By this process the
    organic material is converted into a liquid. This liquid must be further processed
    to produce an oil which is said to be better than the lowest grade of oil produced
    from conventional oil deposits, but of lower quality than the upper grades of
    conventional oil.

   Peat (non renewable): Peat is soil material consisting of partially decomposed
    organic matter; found in swamps and bogs in various parts of the temperate
    zone. It is formed by the slow decay of successive layers of aquatic and
    semiaquatic plants, e.g., sedges, reeds, rushes, and mosses. Peatland is
    defined as follows: for land to be identified as peatland, the depth of the peat
    layer, excluding the thickness of the plant layer, must be at least 20 cm on
    drained, and 30 cm on undrained land.
                  Deniz Cinalioğlu 10-U




     Nuclear
      Energy
    (renewable)
                                                              Deniz Cinalioğlu 10-U




   Hydropower (renewable): Obtained by storing the water in reservoirs
    (dams) and utilizing the potential energy or channelizing the water flow for
    energy generation.
                                                                  Deniz Cinalioğlu 10-U
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   Biomass(renewable): Residues, forestry, industrial, woody, agricultural, aquatic
    crops, animal and plant wastes are currently the main sources of bio-energy . A
    variety of fuels can be made from biomass resources, including the liquid fuels
    ethanol, methanol, biodiesel, Fischer-Tropsch diesel, and gaseous fuels such as
    hydrogen and methane. It is an important form of stored energy.

    Methods for Getting Energy from Biomass:

    Wood burning

    Gassification
    This process, usually using would produce a flammable gas mixture of
    hydrogen, carbon monoxide, methane and other non flammable by products.
    This is done by partially burning and partially cooking the biomass (using the
    heat from the limited burning) in the presence of charcoal (a natural by-product
    of burning biomass). The gas can be used instead of petrol and reduces the
    power output of the car by 40%. It is also possible that in the future this fuel
    could be a major source of energy for power stations.
                                                             Deniz Cinalioğlu 10-U




Anaerobic Digestion/Gasification
If a specially formulated mixture of bacteria is added to biomass and water in a
sealed container (so that no oxygen can enter it) the contents soon ferment. The
product of this fermentation is mainly methane (a flamable gas which is the
same as the gas you burn at home) which is an excellent fuel. This process
removes biomass from dirty water and may be used in a water treatment plant.
Fermentation
If the biomass used is (or can be converted into) mostly sugar, then yeast can
be added. The fermentation that follows produces alcohol which is a very high
energy fuel that makes it very practicle for use in cars. This has been tried
succesfully in Brazil.
                                                                  Deniz Cinalioğlu 10-U




   Solar Energy (renewable): With the exception of nuclear, geothermal and tidal
    energy, all forms of energy used on earth originate from the sun’s energy.
    Although sunshine can be collected by solar arrays and used to heat a home or
    supply its hot-water needs, the unconcentrated rays are not strong enough for
    efficient power generation.
    The amount of solar radiation available at the Earth's surface is about 1kW
    thermal energy per square metre.
    The idea of using large numbers of reflective panels called heliostats or multi-
    faced mirrors to concentrate solar radiation has an ancient history dating as far
    back as 212BC when Archimedes in ancient Syracuse is said to have used
    polished shields to focus light onto the sails of the Roman ships to burn them.
    Theoretically, by using mirrors and lenses, the temperature of the sun's surface
    can be reached.
    While photovoltaic cells produce electricity directly, solar thermal technologies
    produce hot air, water and steam for industry. They can also provide energy to
    photolytically process fuels and chemicals and destroy dangerous materials.
                                                                 Deniz Cinalioğlu 10-U
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   In new housing areas, use of solar systems can cut the demand for fossil fuel by
    as much as 70%.
                                                                   Deniz Cinalioğlu 10-U




   Geothermal Energy (renewable): Geothermal energy is the natural heat of
    the earth stored deep below the earth's surface. When the earth was formed
    5 billion years ago from a cloud of hot gas, it was very hot indeed. Ever since
    then the earth has been cooling down, loosing it's heat to the cold reaches of
    space. However a lot of this heat still remains and can be used as a source of
    energy for the ever increasing demands of civilisation. The energy is found near
    areas where volcanic activity has taken place, either recently or many years
    ago. It can be in the form of steam, hot liquid, or hot dry rock. There are many
    ways of getting the energy to the surface in a usefuk form. Wells drilled deep
    into the ground bring steam and hot water to the surface
    There is enough energy for us to consume as much energy as we do now for
    the next 35 billion years. The only problem is getting to all this energy and
    converting it efficiently. It is estimated that at present we can only reach enough
    energy to supply the world's energy needs for one year. This is because of the
    limits of current geothermal technology and the disperse nature of the energy we
    can reach. Geothermal energy is currently cheaper than nuclear power and
    comparable to some conventional energy generation methods, geothermal
    power is ecenomic enough to warrant it's continued use and developement.
                                                                 Deniz Cinalioğlu 10-U




   Wind Energy (renewable): The power contained in the wind represents a vast
    source of energy. There are approximately 20,000 wind turbines connected to
    the electricity network in operation worldwide. Only a very small amount of wind
    energy can be used because of technological and also social limitations. The
    wind turbine vanes use the flowing movement of the air to rotate an electrical
    generator similar to that in a hydropower station. The actual power being
    generated is directly linked to the windspeed such that if the windspeed dropped
    by 10 percent, there will be a 30 percent decrease in available energy. The
    numerous factors that influence the windspeed include local geographical
    effects such as ground roughness and the height of the airflow.
Deniz Cinalioğlu 10-U
                                                                  Deniz Cinalioğlu 10-U




   Marine current energy (renewable): The global marine current energy
    resource is mostly driven by the tides and to a lesser extent by thermal and
    density effects. The tides cause water to flow inwards twice each day (flood tide)
    and seawards twice each day (ebb tide) with a period of approximately 12 hours
    and 24 minutes (a semi-diurnal tide), or once both inwards and seawards in
    approximately 24 hours and 48 minutes (a diurnal tide). In most locations the
    tides are a combination of the semi-diurnal and diurnal effects, with the tide
    being named after the most dominant type. The strength of the currents vary,
    depending on the proximity of the moon and sun relative to Earth. Generally the
    marine current resource follows a sinusoidal curve with the largest currents
    generated during the mid-tide. The strength of the marine currents generated by
    the tide vary, depending on the position of a site on the earth, the shape of the
    coastline and the bathymetry (shape of the sea bed). Along straight coastlines
    and in the middle of deep oceans, the tidal range and marine currents are
    typically low. Generally, but not always, the strength of the currents is directly
    related to the tidal height of the location. However, in land-locked seas such as
    the Mediterranean, where the tidal range is small, some variable marine currents
    exist.
Deniz Cinalioğlu 10-U
                                                                 Deniz Cinalioğlu 10-U




   Ocean Thermal (renewable): It is common since that if the oceans have
    sunlight shining on them for up to fifteen hours a day, they are going to be
    warmed up by this process. In a way this thermal energy (the energy of heat) is
    solar energy. The oceans make excellent traps for this energy. One of the main
    advantages is that the oceans do not cool very quickly and therefore, energy
    can be extracted from them during the night. This is obviously not the case with
    traditional solar energy technologies. To work effectively, energy conversion
    from fluids (water in this case) needs a supply of hot and cold water. In the
    tropical and subtropical regions of the world there is a big difference in
    temperature between the temperature of the ocean at the surface and at depth.
    Basically, hot water is pumped in to the plant from the surface of the ocean and
    cold water is pumped in from the ocean depths. This source of hot and cold fluid
    drives a heat engine (an engine that runs on energy flow from hot to cold).
    Below is a basic diagram showing what goes on.
Deniz Cinalioğlu 10-U
                                                                  Deniz Cinalioğlu 10-U




   Wave Energy (renewable): Waves supply many sportsmen and women with a
    great deal of entertainment and excitement, but out at sea their awesome power
    can smash ships apart or flip them on their backs. Waves tens of meters high
    with wavelengths of more than one hundred meters are common in the atlantic
    and pacific oceans. This energy will exist as long as there are large expanses of
    water on earth and could supply huge amounts of energy but as yet there are no
    large scale commercial organizations to exploit them.
Deniz Cinalioğlu 10-U
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                                                                    Deniz Cinalioğlu 10-U




   Tidal energy (renewable): Most countries have concentrated on the use of
    capturing structures to create artificial reservoirs that can be used to control the
    natural tidal flow. It was concluded that building a permeable barrage across an
    estuary(arm of the sea which extends to the opening of the river) minimizes the
    cost of civil structures for the quantity of energy that can be produced. Complete
    closure of estuaries would be achieved by placing a series of prefabricated
    sections, or caissons, made from concrete or steel which could be floated and
    then sunk into position. Tidal barrages would consist of gates and turbine
    generators. During the ebb tide water is allowed to flow through the gates. When
    water level becomes high the gates are closed. Storage of water allows a head
    of water (i.e. difference in vertical height of water levels) to be created as the
    flood tide progresses seaward of the barrage. Once a sufficient head has been
    created, water is allowed to flow back through the turbines to generate
    electricity. In this respect a tidal energy barrage is no different to a low-head
    hydro-electric dam.
Deniz Cinalioğlu 10-U
                                                                  Deniz Cinalioğlu 10-U




 Hydrogen: Hydrogen has a potential as a fuel. It has an advantage over fossil
  fuels in that the only product of hydrogen hydrogen combustion is water, fossil
  fuels produce carbon dioxide in addition to water. H₂(g)+1/2o₂(g)=H₂O(l)
  Currently, hydrogen is maintained from the treatment of natural gas with steam
  CH₄(g) + H₂O(g)=3H₂(g) + CO(g) but this is not economical. Therefore new
  ways to maintain hydrogen are being searched. Production of hydrogen from
  water is possible; by electrolysis of water,thermal decomposition of water,
  thermochemical decomposition of water and biological decomposition of water.
  This energy source is not a very common one as it is quite new.
 Coal Gassification: It is the most economical way of converting dirty coal into
  clean burning gaseous fuel. It involves four steps.
  -hydrogasification (high temperature and pressure):
   C(coal)+H₂O(g)=CO(g)+H₂(g)
  -catalytic”” increase of H₂:
   CO(g)+ H₂O(g)=CO₂(g)+H₂(g)
  -removal of CO₂, H₂:
   desulfurisation (removal of impurities, H₂S)
  -catalytic methanation:
    3H₂(g)+CO(g)=CH₄(g)+H₂O(g)
 H₂O(g) is removed and CH₄(g) is called synthetc natural gas. Advantages of coal
  gassification include the prevention of pollution by sulfur dioxide, but the process
  requires %30 of the energy content of coal for conversion!

				
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