Re: Concentrating hydrogen peroxide

[Earl Colby Pottinger]

(Bill Bogen) :

> It seems that sources for concentrated hydrogen peroxide are drying
> up, perhaps due to liability concerns. But there also seem to be
> mechanisms available commercially (google on 'concentrating hydrogen
> peroxide') to take cheaper, more readily available low-concentration
> H2O2 and bring it up to 90% concentration.

See:

http://www.meditech.ch/exoticthermoengineering/ete15.html

http://www.peroxidepropulsion.com/

http://www.tecaeromex.com/ingles/destilai.html

http://rocketprop.com/index.html - It is not clear if they sell thier
peroxide concentrator or it's output either.

> Have the various X-prize teams using H2O2 looked into making their
> own? Wouldn't there be fewer regulatory hassles (and so lower costs)
> when transporting 35%-50% H2O2, perhaps making it cost-effective to
> buy a concentrator?

While there are few hassles buying/transporting 35%-50% H2O2, there are no
hassle free way to concentrate peroxide.

Problems include thermal runaway, explosive vapours, chemical impurities and
maintaining a vaccumn if doing low temperature distillation.

Large scale concentrators are very hard to design and a real hassle to run.
One company that tried it no longer exists as it's main plant blew up. ERPS
who does concentrate peroxide for thier rockets has thier processing station
installed in the middle of a desert. My personal work is always on a very
small scale, and if I do final scale up it will be on a floating platform in
the middle of a lake up north.

> Also, has anyone looked into using osmotic filtration to concentrate
> H2O2? Or is the H2O2 molecule too similar in size to H2O?

The only filter I have heard of for peroxide was organic in nature. This
gives you near zero margin in error in handling.

Earl Colby Pottinger

--
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[John Carmack]

(Bill Bogen) wrote in message >...
> It seems that sources for concentrated hydrogen peroxide are drying
> up, perhaps due to liability concerns. But there also seem to be
> mechanisms available commercially (google on 'concentrating hydrogen
> peroxide') to take cheaper, more readily available low-concentration
> H2O2 and bring it up to 90% concentration.
>
> Have the various X-prize teams using H2O2 looked into making their
> own? Wouldn't there be fewer regulatory hassles (and so lower costs)
> when transporting 35%-50% H2O2, perhaps making it cost-effective to
> buy a concentrator?
>

I get asked this question at least once a week.

If you are just interested in doing small scale tests and flights,
then doing your own concentration is probably the path of least
resistance. Several amateurs have spent many years working on
concentrators without exactly spectacular success. Note that you need
both concentration and purification if you want to avoid poisoning
solid catalysts.

For an X-Prize competitor, you are looking at needing at least 10,000
gallons of propellant to cover your development program. That is a
chemical plant, not a little garage concentrator.

I am paying for the startup of a small operator that purchased the
equipment from X-L Space Systems after they left the business. They
are months behind schedule and still having problems, and this is with
a setup that was previously in commercial operation. Chemical plant
oepration is an endeavour at least in the same order of magnitude of
difficulty as "rocket science".

Happily, we don't care all that much any more, because we are getting
very good results with our "mixed monoprop" combination, which is made
with readily available chemicals.

John Carmack
www.armadilloaerospace.com