Closed Loop Life Support Systems

My hunch is on something in a vat rather than plants. You would
collect your CO2 by adsorbing it onto a surface, or bubbling the air
through a solution of a hemoglobin-like substance that binds CO2, or
push it through a selectively permeable membrane, or whatever. Then
you would collect your CO2 and run it through what amounts to a
backwards fuel cell, or the equivalent in multiple steps, to make O2
and carbon. Then you react your carbon with hydrogen and water to
make some small organic molecule that you can feed to microbes.

The range of options for the first part includes what they do now.
It's just that the amount of CO2 is so small it's more efficient to
vent it into space and replace than to design, build, and lift the
apparatus for the second and third phases.

It's not a full CLSS, because it doesn't deal with trace compounds.
But it's the core of one.

--- In spacesettlers@yahoogroups.com, "king_rodent"
wrote:
>
> (appologies for lurking for so long)
>
> I would like to broach a subject for discussion. Considering
that a
> completely Closed Loop Life Support System (CLLSS hearafter) would
be
> a difficult, if not impossible, system to impliment for small (ISS
> level, 3-5 personel but under 20) station, creating an on-station
> partial CLLSS system that can recycle atmosphere and/or food
should
> be utilized. Reducing resupply can make on-station operations less
> expensive as long as the infrastructure necessary is less,
amoritized
> over time, than the expense of resupply launches. The question I
> would like to propose for discussion is what emphasis should a
> Partial CLLSS system concentrate on, food or atmosphere?
>
> What is more massive for resupply, food or air? Don't forget
that
> you have to include packaging weight(wrapping for food, lithium
oxide
> canisters or compression tanks for air). Which would be more
> beneficial to reduce or eliminate from resupply launches?
>
> Something that may not have been considered in past discussions
is
> the ammount of plants necessary for CO2/O2 conversion would be
> different than for food production. It is even possible that more
> plants would be necessary for food production than O2 conversion
and