Separating oxygen from air

  1. is it possible to separate oxygen from air?

    in other words, getting pure oxygen from air
     
    Last edited: Apr 23, 2008
  2. jcsd
  3. damn, that sounds like its going to take a long time. i was seeing if it was possible to get a car to suck in pure oxygen instead of air, but it would have to make a lot of oxygen in a short period of time

    thanks
     
  4. If it were easy, do you think they wouldn't already have thought about it? :smile:
     
  5. fractional distillation or burn hydrogen, collect the water, preform electrolysys and seperate the gases, reuse the H2 and use the O2
     
  6. Q_Goest

    Q_Goest 2,985
    Science Advisor
    Homework Helper
    Gold Member

    Hi QB,
    Just a disclaimer first: saying "pure" is relative. There are always contaminants in your product, regardless of the method used. Even distillation is only going to give 99.99xx percent purity.

    There are plenty of other ways of obtaining enriched oxygen. PSA and other methods using membranes or adsorption are common. Here's a decent overview:
    http://www.uigi.com/noncryo.html

    As for putting oxygen into an engine however, there's no reason to do that. First, an oxygen rich stream in an ICE is going to overheat the engine. Second, it's extremely dangerous - even steel burns readily in a pure oxygen environment at any significant pressure. And third, it don't believe it improve efficiency. I'm not absolutely sure about the efficiency part, but I know there have been discussions in the ME forum about this. Might want to do a search in the engineering forums, there was a discussion not too long ago.
     
  7. It is possible to separate oxygen from air using zeolite materials in machines known as oxygen concentrators. These devices are used by people needing to breathe higher concentrations of oxygen because of various medical conditions. These machines can provide ~5 liters/minute of 95%+ oxygen.
    To learn more about this please read about "oxygen concentrators" and "zeolites" on the wikipedia website.
     
  8. russ_watters

    Staff: Mentor

    It won't. The fuel/air mixture is precisely controlled to provide exactly the amount of oxygen necessary for efficient combustion.
     

  9. Yes, try breathing :wink:
     
  10. Don't understand what you mean; if you can introduce more oxygen in the combustion chamber, you can also introduce more combustible, so you have more power.
    For "spark ignition" engines (example gasoline engines) there would be the problem to control pre-ignition and detonation, but for "compression ignition" engines (example Diesel engines) there wouldn't be such problem and power would increase dramatically, and pollution would decrease dramatically.
     
  11. russ_watters

    Staff: Mentor

    If that's the goal, a turbocharger does a great job of doing exactly that.
    Yes.
    Why? You've changed nothing about the chemistry of the combustion.

    Depending on how you think about it, a turbocharger may increase or decrease fuel consumption. A turbocharger does increase the thermodynamic efficiency of an engine, but the net effect of adding a turbocharger to an existing engine is and increase in power and an increase in fuel consumption. But if, for example, you are looking for a car with 250hp and your choices are a 3.6L V6 and a 2.0L turbocharged 4cyl (both generating 250hp), the turbo 4cyl will use less fuel.
     
    Last edited: May 1, 2008
  12. Have you ever heard of using compressed N2O injected in the combustion chamber to increase power? O2 it's not used just because the bottle/cylinder contains less of it so it finishes soon.
    You don't change the chemistry but you change the physics. You have much less HC with an higher percent of oxygen, because the combustion is more efficient (O2 is less diluted by N2); furthermore, if N2 percent is very low, you would have much less NOx.
     
  13. if you get the right mixture of fuel and oxygen the combustion is more efficent like with cutting tourches in short is what he is looking for the fuel to oxygen ratio is the key
     
  14. chemisttree

    chemisttree 3,721
    Science Advisor
    Homework Helper
    Gold Member

    This thread is over a year old.
     
  15. wouldn't introducing high oxygen concentration to an ICE increase NOX; therefore increasing pollution? Or having to get a bigger EGR valve
     
Know someone interested in this topic? Share a link to this question via email, Google+, Twitter, or Facebook

Have something to add?