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Fossil fuels

  1. Apr 16, 2008 #1
    Fossil fuels was created by nature. Dose that mean as we speak the processes continues and fossil fuel is continually being made if not why?
     
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  3. Apr 16, 2008 #2

    mathman

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    Fossil fuels result from the decay of dead organic matter, mostly plants. However, the process took millions of years to reach its current state. Although it is still taking place, the process is extremely slow for coal or petroleum. The only useful quick solution to the fossil fuel problem, using such material, is biofuel.
     
  4. Apr 16, 2008 #3
    I always wondered what is the connection between the amount of fossil fuels and the amount of CO2 in the atmosphere. Could we say that for each C atom less in fossil fuels, there is one more in the atmosphere? Does anybody know the answer?
    (I hope my assumption is wrong, otherwise CO2 concentrations would need houndreds of thousands years to recover).
     
  5. Apr 16, 2008 #4
    Yes, essentially the same processes are in place today as there were millions of years ago which led to the formation of the fossil fuels we exploit today. The whole process is quite complicated and takes a long time. Sunlight still shines giving us life on earth, the life still dies and gets buried, over time the buried material gets buried further which matures the dead organic material (the "fossils") into hydrocarbons, the hydrocarbons still flow through little gaps in the rocks until they get trapped in a reservoir.
     
  6. Apr 16, 2008 #5

    russ_watters

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    The chemistry is quite simple. For the best fossil fuel (methane), it looks like this:

    CH4 + 2 O2 -> 2 H2O + CO2 + Energy

    So every molecule of methane burned yields one molecule of carbon dioxide. Propane, for another example, is C3H8 - so every molecule of propane, when burned, yields 3 molecules of carbon dioxide.
     
  7. Apr 17, 2008 #6
    I based my assumption on the conservation of atoms in chemical reactions. In the moment after burning the number of additional CO2 molecules in the atmosphere must be the same as the number of missing C molecules in the fossil fuel.
    But I'm not sure if this change can only be reversed by photosyntesis (more exactly by photosyntesis that is not followed by decay). Maybe there are also chemical reactions that can bind carbon into inorganic molecules. That reactions might run faster in case of higher CO2 concentration, so increased concentrations caused by fossil fuel burning might recover in a shorter time than the fossil fuels need to form again.
     
    Last edited: Apr 17, 2008
  8. Apr 17, 2008 #7
    that process is very complicated and it needs alot of time to give us fossil fuel and we are already using that fossil fuel every millisecond in our life.
    than how can the process of making the fuel and taking it equal!!!!
     
  9. Apr 17, 2008 #8

    mathman

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    It is not equal. The petroleum reserves in the world are being used up. Why do you think the price of gasoline keeps going up??
     
  10. Apr 17, 2008 #9

    Danger

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    The bottom line essentially is that we can't break even. There's enough biomass on the planet to replace the petroleum that we've been using for a couple of hundred years... but only if we stop using it and wait a few million years.
    And anyone who comes up with the brilliant idea of compressing organic matter to make oil must remember that it would take more energy to do that than you could ever recover.
     
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