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

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Discussion Overview

The discussion revolves around a proposed method for separating hydrogen gas (H2) from oxygen (O2) using a sand-filled container, referred to as the "Sand drum method." The focus is on the feasibility of this concept in achieving a high level of purity for hydrogen gas, particularly in the context of hydrogen production through electrolysis.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant proposes a conical container filled with smooth beach sand to separate hydrogen from oxygen, suggesting that hydrogen would rise to the top while oxygen settles at the bottom.
  • Another participant challenges the effectiveness of the proposed method, arguing that the size of sand grain pores is too large for hydrogen to diffuse effectively and that gravity is insufficient for separation.
  • It is noted by some participants that oxygen contamination is not a significant issue in hydrogen production via electrolysis, as separation occurs at the electrodes, and water vapor is the more common contaminant.
  • A later reply elaborates on the limitations of gas separation in open volumes, suggesting that convection would hinder complete separation, and speculates on the role of sand cavities in affecting gas movement.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of the sand drum method for gas separation, with no consensus reached on its effectiveness or practicality. There is also disagreement regarding the significance of oxygen contamination in hydrogen production.

Contextual Notes

The discussion highlights assumptions about gas behavior in porous media and the effectiveness of gravity in separation processes, which remain unresolved. The varying purity levels of hydrogen produced by different electrolyzers are also mentioned but not fully explored.

LeonStanley
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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 particle 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:
 
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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.
 
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, which can be removed with water absorbing chemicals.
 
willem2 said:
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, which can be removed with water absorbing chemicals.

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.

willem2 said:
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.

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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