CALCIUM CARBONATE ACCRETION

[ROBERT LARSON]

I am curious about the chemistry of calcium carbonate accretion using electricity. Obviously, there is calcium in seawater and also dissolved oxygen and carbon dioxide, so, world wide, there are plenty of raw materials for corals as well as shellfish. But what would happen if the carbon dioxide in the water got below a certain point being consumed in the calcium combination? Would CO2 dissolve into the global oceans from the atmosphere to maintain a balance? Is there enough calcium in the water to sustain accretion to the point of depleting CO2 from the atmosphere?
Could we help the greenhouse gas problem a little by creating farms of electrically accreted islands with the aid of some cheap solar panels and a bunch of, say, chicken wire?

 

[Lasse]

Welcome to R2R


At this moment - it is to much CO2 in the air (compared with 100 years ago) making more CO2 pressed into the ocean - resulting in an acidification of the oceans. However, you - if I understand your ide in the right way - will create limestone (CaCO3) direct from seawater with help of electricity - is this possible at all? If it possible - yes it will store much of the C as limestone (CaCO3) but you need very, very large operations - first you should compensate for effect of the last 100 years of extra CO2 in the air (around 100 ppm) and after that for the continues extra flux of CO2


Sincerely Lasse

 

[Gareth elliott]

Given our current forms of electrical production. I am not sure if we would not be adding more co2 than we would be sinking. If used co2 independent forms of electrical production(tidal generation comes to mind) would this be more environmentally damaging than the the goals for such a project.

 

[Lasse]

But use of solar cells and only working during daytime - would it work?

Sincerely Lasse

 

[Gareth elliott]

Maybe, theres a lot of math in regards to answering that question that not volunteering to do at this time [emoji23]
But surface area required, avg number sunny days, the efficiency of solar panels and replacement rate in that environment.

What could be more financially feasible would be replacing our reliance on sinked carbon for atmospheric carbon. By increasing our production of bio diesel utilizing algae reactors. Would not necessarily lower co2 but would decrease the net added. Would also allow the private sector to be involved by having something to sell.

Btw interesting thread so far @ROBERT LARSON

 

[ROBERT LARSON]

Thanks for your thoughts. I was just thinking about the possible financial gain of the type operation I was putting out there. Accretion could be done in a sheet from. Possible gain---boat hulls, architecture of all kinds, automatic ferro-cement work, turn it on come back 6 mo later? Let's talk more. I am not a scientist

 

[ROBERT LARSON]

But use of solar cells and only working during daytime - would it work?

Sincerely Lasse

Problems of course, just like terrestrial collectors. You may find this interesting
https://gizmodo.com/coral-arks-rebuild-marine-ecosystems-with-electricity-a-5836650
Also there is actually a company already established---Biorock

Thanks for your interest. I am flattered that you would respond

 

[Lasse]

I´m sorry - I was very wrong and too fast in my thinking - this will not work in order to lower the CO2 levels in the air. This because the C coming down from the air as CO2 will not create any new CO3. The CO3 contain of the ocean comes solely from dissolved minerals. Every reefer knows that – you can´t rely on the CO2 in order to substitute the CO3 taking up by the calcification. You need to put in bicarbonate or carbonate in order to have the carbonate alkalinity at the same level.


I do not know if the electricity will change this but I also know one product that will be the result of electricity and saltwater – forming of chlorine gas.


IMO – it will not work as a new sink for atmospheric CO2 but the result they have shown in restoring coral reefs seems promising. But I still worry about what´s getting out from the anode – it should be chlorine gas




Sincerely Lasse

 

[ROBERT LARSON]

Since I talked to you last, I have investigated the Biorock website and saw in the FAQ section the answer to my question

http://www.biorock.org/faq-page#n40

Is limestone (or Biorock) an atmospheric CO2 sink.
No! It is a source.
This is a complex issue which seems seductively but misleadingly simple, and which so many people have gone astray on.

It seems intuitively obvious that since limestone deposition is removing dissolved inorganic carbon from the ocean, that this should be compensated by one molecule of atmospheric CO2 dissolving in the ocean, but in fact the opposite happens.

The reason is that there is much more dissolved inorganic carbon in the ocean, in the form of bicarbonate ion, than there is CO2 in the atmosphere, and the ocean is a pH buffered system due to dissolution of limestone sediments and also acid base reactions involving weathering of oceanic basalts to clay minerals. So the predominant reaction is:

Ca++ + 2HCO3- = CaCO3 + H2O + CO2

Guess I'm not the first person to imagine this as a way to save the planet

 

[KeysCoral]

Since I talked to you last, I have investigated the Biorock website and saw in the FAQ section the answer to my question

http://www.biorock.org/faq-page#n40

Is limestone (or Biorock) an atmospheric CO2 sink.
No! It is a source.
This is a complex issue which seems seductively but misleadingly simple, and which so many people have gone astray on.

It seems intuitively obvious that since limestone deposition is removing dissolved inorganic carbon from the ocean, that this should be compensated by one molecule of atmospheric CO2 dissolving in the ocean, but in fact the opposite happens.

The reason is that there is much more dissolved inorganic carbon in the ocean, in the form of bicarbonate ion, than there is CO2 in the atmosphere, and the ocean is a pH buffered system due to dissolution of limestone sediments and also acid base reactions involving weathering of oceanic basalts to clay minerals. So the predominant reaction is:

Ca++ + 2HCO3- = CaCO3 + H2O + CO2

Guess I'm not the first person to imagine this as a way to save the planet

Hi!
I stumbled upon your thread because I recently did my masters on mineral accretion structures in Thailand, they were originally modeled after BioRock but have since improved and moved into different entities (CoralAid is now the leading).
I was wondering if you ever went further with your exploration into this? I am currently looking to setting up mineral accretion at tank level because I would like to see how it may impact land-based coral nurseries. I am definitely running into some roadblocks on the materials and chemistry sides of things, like you said it is sold as deceptively simple when it is in fact not!

 

[Randy Holmes-Farley]

Hi!
I stumbled upon your thread because I recently did my masters on mineral accretion structures in Thailand, they were originally modeled after BioRock but have since improved and moved into different entities (CoralAid is now the leading).
I was wondering if you ever went further with your exploration into this? I am currently looking to setting up mineral accretion at tank level because I would like to see how it may impact land-based coral nurseries. I am definitely running into some roadblocks on the materials and chemistry sides of things, like you said it is sold as deceptively simple when it is in fact not!

He has not been on in years, but I am happy to help address any chemistry issues you want to explore.