A chemical engineering question for space colonization

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Logan Kearsley - 28 Jun 2008 02:40 GMT

Say you're floating in the atmosphere of Venus, and you want to
manufacture more lifting gas for your balloon. You've got a mixture of
mostly CO2 with a little bit of nitrogen to start with (just regular
Venusian atmosphere).
What's the simplest way to produce pure nitrogen (for lifting gas) and
pure carbon monoxide (for additional lifting gas and fuel), plus waste
oxygen?

-l.

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Mark Thorson - 28 Jun 2008 03:08 GMT

> Say you're floating in the atmosphere of Venus, and you want to
> manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 3 lines]
> pure carbon monoxide (for additional lifting gas and fuel), plus waste
> oxygen?

Isn't the Venusian atmosphere full of water vapor?
That would be a better lifting gas than either
of your favorite gases.

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Logan Kearsley - 28 Jun 2008 03:51 GMT

> > Say you're floating in the atmosphere of Venus, and you want to
> > manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 7 lines]
> That would be a better lifting gas than either
> of your favorite gases.

Trace amounts of H2SO4 (enough to make the clouds), practically no
water. You could make water from H2SO4, but the vapor pressure isn't
high enough to use on its own without additional heating, and I still
want CO to use as fuel.

-l.

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Linlin Yan - 28 Jun 2008 04:08 GMT

> Say you're floating in the atmosphere of Venus, and you want to
> manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 5 lines]
>
> -l.

I guess that heating may be another way.

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trigonometry1972@gmail.com | - 05 Jul 2008 09:21 GMT

> Say you're floating in the atmosphere of Venus, and you want to
> manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 5 lines]
>
> -l.

I'll suggest this idea is missing to point to an extent in that
at least the first batch of lifting gas will need to drop in from
orbit with the vehicle. And then the H2SO4 may degrade the
balloon before it would need a refill. It is not like one would setup
human residence in such a hostile gravity well with
such a savage environment down below.

The other issue that comes to mind is the nature of temperature
regimen
in the planets atmosphere. It would be nice even for a probe
to remain int a moderate temperature attitude to reduce engineering
challenges.

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Logan Kearsley - 10 Jul 2008 06:48 GMT

On Jul 5, 4:21 am, "trigonometry1...@gmail.com |"
<trigonometry1...@gmail.com> wrote:

> > Say you're floating in the atmosphere of Venus, and you want to
> > manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 9 lines]
> at least the first batch of lifting gas will need to drop in from
> orbit with the vehicle. And then the H2SO4 may degrade the

Where the initial lifting gas comes from doesn't matter, and acid-
resistant materials are available for the balloons.

> balloon before it would need a refill. It is not like one would setup
> human residence in such a hostile gravity well with
> such a savage environment down below.

Human habitation isn't under consideration. Note, I said the oxygen
was waste. I only care about lifting gas and fuel.

> The other issue that comes to mind is the nature of temperature
> regimen
> in the planets atmosphere. It would be nice even for a probe
> to remain int a moderate temperature attitude to reduce engineering
> challenges.

There's a region of nearly-Earthlike temperature & pressure about
around about 60 kilometers altitude.

-l.

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mrdarrett@gmail.com - 06 Jul 2008 05:45 GMT

> Say you're floating in the atmosphere of Venus, and you want to
> manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 5 lines]
>
> -l.

wild guess... membrane separation possibly followed by electrolysis of
CO2 (in molten carbonate)

Michael

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Logan Kearsley - 10 Jul 2008 06:50 GMT

On Jul 6, 12:45 am, mrdarr...@gmail.com wrote:

> > Say you're floating in the atmosphere of Venus, and you want to
> > manufacture more lifting gas for your balloon. You've got a mixture of
[quoted text clipped - 8 lines]
> wild guess... membrane separation possibly followed by electrolysis of
> CO2 (in molten carbonate)

The best solution I've come up with so far is to use pressure-swing
adsorption for the gas separation & zirconium electrolysis to crack
CO2 into CO and O2. Zirconium electrolysis looks pretty much ideal,
but PSA involves several moving parts (valves) with limited expected
lifespan. Something that can work in steady-state with fewer or no
moving parts would be preferred. Are there suitable membranes that
would pass either N2 or CO2, but not both?

-l.

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Natural Science Forum / Chemistry / General Chemistry / July 2008

A chemical engineering question for space colonization