Hacker News new | ask | show | jobs
by swiley 2196 days ago
I know older spacecraft didn’t have a regenerative material, this is the first I’ve heard about the space station.

You’d have to reduce the CO2 pretty far (I’m betting reducing to CO like in TFA isn’t what you’re looking for.) I think a lot of people underestimate how much energy this takes.

1 comments

Re ISS, I've been clicking around on this a bit more, and

> While cabin air processing, one carbon dioxide removal bed is in the process of regeneration. Regeneration is accomplished using pressure/thermal swing methodology. First, the two-stage pump removes the free air from the adsorbent bed and returns it to the cabin, reducing oxygen ullage. Then Kapton heaters integrated within the adsorbent bed raise the zeolite temperature, and space vacuum creates a low, partial pressure driving the carbon dioxide gas overboard. Daylight and continuous day power cycle is overlapped with the operating cycle. In the daylight power cycle, the carbon dioxide adsorbent bed heaters are only allowed to be powered on during the day portion of the cycle

> [...]

> The CDRA continuously removes 6 person-equivalents of CO, when operating with both C02 removal beds (dual beds) functioning.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/200502...

Converting CO2 into CO would be rather counterproductive (absent a reliable and efficient mechanism to remove CO), I suspect an efficient setup will involve "mechanical" filtration not chemical reactions.

Ah, and this paper contains an incredible amount of details, and zeolite 13x and 5a is really cheap on Alibaba, I'm going to have to try this

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/199700...

Just be careful during the regeneration. CO2 is toxic at high concentrations.