Carbon Sequestration

A smart and considerate reader sent me this earlier:

Craig – First off, please let me know if I am sending you too many emails.

I’ve been following news on carbon sequestration, including a recent article about a proof of concept in Iceland where CO2 together with water is injected into volcanic rock and becomes part of the rock.  Which seems better than basically inflating a large balloon deep under the surface and hoping it doesn’t ever leak, but still not that good, because (1) Iceland, which has lots of volcanic rock, doesn’t need to sequester carbon, and (2) it uses a LOT of water.

So I started dreaming about seashells, one of nature’s schemes for carbon sequestration, which I imagined would be something like Ca + O + CO2 -> CaCO3.  I didn’t find any useful information about energy budgets, costs or the facility of the process.

Then I thought, what if CO2 could be incorporated into building materials?  I googled “bricks from co2” and discovered that it’s being done!  But again, I couldn’t find the important information.  I’m hoping you can tell me whether this is a useful (reasonable) concept.  Building a house out of CO2 seems like a win-win deal.

Here are a few links:  sand bricks, CO2 bricks, Carbon capture technology, Ted Talk  CO2.  The Ted talk is full of great visuals about the problem but not too much in terms of their proposed solution. They do imply that their solution requires a cost to be put on carbon.

First, you’re not sending too many emails.  I appreciate your thoughts; you have good ideas.

This is an interesting idea, and I’d like to think that it will be sufficiently inexpensive that it can happen at a scale, though I’m skeptical.  As the developers themselves note, it requires a price on carbon, and I would think it would be a hefty one.

Obviously, if I’m wrong, it represents a wonderful advancement.  Most people who want to do something with captured carbon suggest processes that are carbon neutral, i.e., they capture carbon in one place, but re-release it in another.  WindFuels is an example of this.  Needless to say, it’s better to reduce actively the concentration of CO2.  In fact, most scientists believe that, if we can’t find a way to do this, we’re in deep trouble.

Here’s a presentation on the geologic processes that represent a sink for CO2 in which it forms CaCO3 (calcium carbonate) and is subducted under tectonic plates.   Because it happens too slowly to make a difference to the outcome for humankind, some people suggest accelerating all this by seeding various calcium compounds into the oceans.

Re: that Ted talk, yes, it’s great on stating the problem…and that’s about it.  It’s one of my pet peeves.  On the subject, I wrote:

Btw, there’s a group out here in California that does vigorous fund-raising aimed at getting rid of fossil fuels entirely and replacing the entire energy infrastructure with wind and hydrogen.  They really have no idea what they’re talking about in terms of the practical realities at stake, but that doesn’t stop them; it doesn’t even slow them down.  I’ve seen them in action at large luncheons and other events, and I’m sure they rake in some very large donations from people who know even less than they themselves about this subject.