Renewing CO2 absorbing Soda Lime at home

[bo0ks]

Looks like soda lime for a co2 scrubber can be had for roughly 2.85/lb from ebay, sold as SodaSorb.

I happen to have a second hobby that means I have an electric high-temp kiln floating around, and I was wondering if anyone knew if I could renew/drive the co2 off of existing, used soda lime using the kiln. And if so, what kinds of temps/times would it need to be cooked at.

That way I could calculate my electricity costs and see if its worth doing myself or not. Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

You can drive out CO2 if you run the temp up the about 700 deg C (see graphs in link below), but I am not sure you retain the necessary surface area for rapid CO2 removal from the gas phase.

https://www.mdpi.com/1996-1944/13/21/5052/pdf

 

[admiralmcstabby]

Here's a throwback thread asking essentially the same thing:
https://www.reef2reef.com/threads/regenerating-soda-lime-for-co2-scrubbing.327129/

BTW, if you're new here Randy Holmes-Farley who answered that thread is very well respected in the reef world and has written many articles about the ecosystem...don't take his answers with a grain of salt :-D

 

[bo0ks]

Appreciate the quick response guys. Not being a chemist, I'm reading 'decomposition' as 'breaking' that particular chemistry. So to me, this reads like if I heat it up to ~1300F, it won't really renew it, it'll decompose the constituent parts and make it not really work anymore.

Is that how you read it?

 

[Randy Holmes-Farley Verified Community Expert]

Appreciate the quick response guys. Not being a chemist, I'm reading 'decomposition' as 'breaking' that particular chemistry. So to me, this reads like if I heat it up to ~1300F, it won't really renew it, it'll decompose the constituent parts and make it not really work anymore.

Is that how you read it?

No. at 700 deg C it drives off CO2 and water. Will the heated material work then? Not sure, sinee chemical form is not all that is involved.

If your kiln can go to 700 deg C, and you want to spend the electricity, it may be worth a try.