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New idea -needs feed-back. A gas separator.

  1. Oct 25, 2009 #1
    The safe usage and storage of Hydrogen gas H2 requires a decent level of purity- say above 98%. Those who have researched hydrogen production using electrolysis would be aware of several methods of separating out the small amounts of heavier gases like oxygen that are often present.

    Here is another concept that just may work. Consider the following:-

    The Sand drum method.

    You have a container that is shaped like an old fashioned spinning top - a conical shape on top pointing upwards - and a conical shape on the bottom pointing down- the two halves sealed together. The container is filled with clean beach sand of a smooth partical type. In the Esperence region of Western Australia we have perfect white beach sand whose grains have smooth rounded egdes. It squeaks under your feet when you walk on it.

    Now 90% pure H2 is piped into the lower/mid centre (the core) of this sand filled container at a low flow rate. I suppose that the H2 would slowly disperse upwards to the H2 exit pipe at the apex - and O2 would settle to the O2 exit pipe at the bottom?? It would also double as a flash-back arrester?

    Any objections or feed-back to this idea? Thanks. :smile:
  2. jcsd
  3. Oct 28, 2009 #2
    If anyone know of a more appropriate forum where I can post similar queries? - please let me know. Thanks.

    I did google "inventors forums" once, but come up with disappointing results. Guess I have to search longer and harder.
    Thanks anyway.
  4. Oct 28, 2009 #3
    It's indeed possible to separate H^2 because it diffuses much easier through almost everything. The holes in sand grains are much too big for this to happen.
    You combine this with separation by gravity. Gravity is much too weak for this however. If this
    would work, all the hydrogen would come on top in an ordinary container.

    I don't think oxygen contamination is a problem with H2 production through electrolysis. You can separate them at the electrodes. The most common contamination is water vapour, wich can be removed with water absorbing chemicals.
  5. Nov 1, 2009 #4
    I understand that the purity of the H2 varies with the type and quality of the electrolyzer. Some of the more rudimentry electrolyzers output H2 at around 92% purity.

    In an open volume space (a drum without sand in it) convection would stop the complete separation of the gases. Even with convection there is a partial separation of the gases.

    In a sand filled space, I assume that each little cavity between the sand will act as a decision gate as the gas seeps through it, and in effect, giving the oxygen a sort of half life as it passes through successive cavities.
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