Holy Crap: CO2 sucked from the air efficiently

October 1, 2008

If this machine is for real, and extracts carbon dioxide for 100 kilowatt hours of electricity per ton extracted, then this is a huge deal!

The heat of formation of that ton of CO2 is 2300 kilowatt hours.

So, for just four percent the energy of what that CO2 generated when it was made, it can be re-captured and used again for something.  (Okay actually twelve percent, because the CO2 generated heat, not electricity, so there’s a ~1:3 efficiency factor there.)

For instance, electricity can be used to make hydrogen gas out of water.  Fine.  If it can be also be used to isolate CO2 out of the air as well, then the H2 and CO2 can be chemically combined in a factory to make hydrocarbons.

So we’re talking about a process that is 100% electrically-driven that makes natural gas and liquid motor fuel.

As for the economics of it all, I’ll have to get back to you.  It could be that the CO2-extraction machine costs a zillion dollars and is therefore meaningless.  But if not, this could be huge because then there’s a price point for renewable electricity that would allow us to make synthetic natural gas and gasoline/diesel/jet fuel that is cheaper than the stuff from the ground.  Shit!

UPDATE: Eric asutely notices and points out that the electricity usage per ton of CO2 isolated is really ten times that, about 1000 kilowatt-hours.  Hm.  That changes the math but doesn’t torpedo it entirely.  More later.

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2 Responses to “Holy Crap: CO2 sucked from the air efficiently”

  1. ekpaulson Says:

    Too good to be true.

    100 kwh/ton is just to run the tower that sprays NaOH through the air to capture the CO2. To recycle the Na2CO3 back into NaOH + CO2 will take an additional 833 kwh/ton, according to the estimates of the researchers who built the tower. So, you’re looking at closer to 1000 kwh/ton to capture CO2 on an ongoing basis, neglecting any costs to build the machinery that actually captures the carbon.

    On the the upside, this technology does have the potential to be located in Iceland or somewhere where energy is cheap and offset carbon dioxide emissions where energy is *not* cheap (such as Connecticut — about $0.20/kwh for me).

  2. craigrmeyer Says:

    Aha! Thanks! My man!

    So it’s 1000 kw-hr to snag 2300 kw-hr’s “worth” of CO2. Given inefficiencoes then it’s really 1000 kw-hr to snag CO2 that generated ~800 kw-hr’s of electricity or mechanical work.

    So roughly 1:1, really… which is still something one can work with.


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