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Joseluki t1_jbtnduf wrote

Baking soda, that degrades into CO2...


WiartonWilly t1_jbu2lif wrote

If acidified.

Question is, where are they getting the sodium (Na)? If they expect to take it from abundant salt (NaCl), then they are left with an excess of acid. That acid either needs to be stored perpetually, or it will eventually liberate the CO2 (as you say)

If there is some natural source of NaOH (a strong base) somewhere, then the CO2 can be sequestered. However, I have never heard of a caustic mine. If they plan to take it from something neutral like salt, then they have an acid storage problem.

The alternatives are potassium (K), calcium (Ca) and magnesium (Mg), but similarly, they are naturally found as salts, in combination with acids that we would rather not release.


mydoglikesbroccoli t1_jbv8m54 wrote

Unfortunately, without knowing any of the details of the process, we can know that this route will not fix the CO2 issue. There literally isn't enough base available on earth to turn the excess CO2 into bicarbonate. We'd turn the oceans as acidic as lemon juice first.

I wish there was a video out there putting into perspective just how much CO2 is under discussion, and what practical limitations that imposes on what routes may and may not work when trying to fix the issue.


WiartonWilly t1_jbvcc1v wrote

The sooner people accept that carbon sequestration will require enough energy to reduce CO2 back to hydrocarbons, the sooner we will accept that the elimination fossil fuels is inevitable.


mydoglikesbroccoli t1_jbvumpl wrote

Which according to thermo, is about as much as we got out of burning them, assuming 100% efficiency. I think there's a little bit of wiggle room if you can find a low energy compound to turn it into, but it's still going to be a lot. And it can't be a neutralized acid like formate or bicarbonate. Maybe add H2 and do some electrochem to make oxalic acid? It's a powder, which would be a bonus for disposal.


AJackOffAllTrade t1_jbvkvvl wrote

Well we mine limestone by the shit ton. Lime water gives you CaOH. What would it take to adjust? I'm not a chemist so I have no idea. It also just happens that my underground limestone mine also has a layer about 100' above the limestone layer filled with salt water. It rains from the ceiling.


WiartonWilly t1_jbvlins wrote

Lime (CaO+H2O—>Ca(OH)2) is derived from limestone (CaCO3). So, you need to release CO2 to make lime, which can then capture CO2 again. No net gain of CO2 fixation.