Co2 scrubber with sodium hydroxide and/or lithium hydroxide

Mar 2018
Atlanta, GA
Ok, so me and a friend want to build our own co2 scrubber. After some reasearch, we narrowed down 2 substances- Sodium hydroxide and lithium hydroxide.
We are wondering if anyone can help us, design and work out the chemistry needed to accomplish our task.
May 2017
I think the only reason lithium comes up in relation to this is because it's lighter ... a prime consideration for Apollo missions ...they used LiOH

So sodium hydroxide is your best bet , easily obtainable and cheap , from hard wear stores in the form of beads about 4mm diam ...of sometimes flakes ...

If I were doing this I would make a vertical transparent colomb , perhaps out of plastic water bottles , fill it up with the hydroxide pellets , and feed air in through the bottom , so it passed up the colomb in between the space between the pellets , coming out the top where it should have a greatly reduced C02 and H2O content ...

Over time the pellets will get wet , the solution dripping down through the colomb , you will have to catch this some how's very nasty and caustic !!

After a while you will have a lot of solution , you have to get the air incontact with this to remove the CO2 to make full use of the hydroxide

2NaOH + CO2 = ............

A much less messy alternative could be carbon , it will be bulkier , a big drum full of C with air in one end and out the other , any charcoal should work, barbecue charcoal ... and when it's full of CO2 you can easily regenerate it driving off the CO2 with fresh air

see here ...
Last edited:
Apr 2018
I am curious to know the purpose of this scrubber: this is only because this was posted in a high school chemistry forum and the materials suggested are highly caustic and should only be handled and used independently by a properly trained scientist or engineer. If you (or anyone reading this thread) are trying to build a re-breather without the proper training or oversight, I implore you reconsider before you hurt yourself. If you are instead interested in scavenging carbon dioxide for some other purpose, please elaborate so that we can offer the safest possible solutions to your chemistry challenge!