New process could reduce atmospheric CO2 to pre-industrial levels

[pscot]

The new process, called Solar Thermal Electrochemical Photo (STEP) carbon capture, was recently suggested theoretically by a team of scientists from George Washington University and Howard University, both in Washington, DC. Now, in a paper just published in The Journal of Physical Chemistry Letters, the scientists have experimentally demonstrated the STEP process for the first time.

“The significance of the study is twofold,” Stuart Licht, a chemistry professor at George Washington University, told PhysOrg.com. “Carbon dioxide, a non-reactive and normally difficult-to-remove compound, can be easily captured with solar energy using our new low-energy, lithium carbonate electrolysis STEP process, and with scale-up, sufficient resources exist for STEP to decrease carbon dioxide levels in the atmosphere to pre-industrial levels within 10 years.”

As the scientists explain, the process uses visible sunlight to power an electrolysis cell for splitting carbon dioxide, and also uses solar thermal energy to heat the cell in order to decrease the energy required for this conversion process. The electrolysis cell splits carbon dioxide into either solid carbon (when the reaction occurs at temperatures between 750°C and 850°C) or carbon monoxide (when the reaction occurs at temperatures above 950°C). These kinds of temperatures are much higher than those typically used for carbon-splitting electrolysis reactions (e.g., 25°C), but the advantage of reactions at higher temperatures is that they require less energy to power the reaction than at lower temperatures.

The STEP process is the first and only method that incorporates both visible and thermal energy from the sun for carbon capture. Radiation from the full solar spectrum - including heat - is not usually considered an advantage in solar technologies due to heat’s damage to photovoltaics. Even in the best solar cells, a large part of sunlight is discarded as intrinsically insufficient to drive solar cells as it is sub-bandgap, and so it is lost as waste heat.

http://www.physorg.com/news199005915.html


A hat tip to yuriwho over at Dkos, who found this article and posted a diary.

http://www.dailykos.com/story/2010/8/15/893152/-New-method-uses-Sunlight-to-remove-CO2-from-Atmosphere:-Updated

[niceypoo]

1. This would be epic, if true

That is a lot of carbon to get rid of in ten years.

[NickB79]

2. We haven't even been able to scale solar up to replace existing fossil fuel plants

Yet the researchers think we can build enough photovoltaic and solar thermal fast enough to remove ALL of the carbon emitted by fossil fuels in the past 200 years?

[pscot]

3. Solar thermal is easy

It's the photovoltaics that are hard. As I understand it, in the STEP process, the solar is mainly a carbon neutral heat source that drives a chemical reaction. In conjunction with phot-voltaics, it could presumably function independent of the grid.

[NickB79]

7. Yet solar thermal isn't even on course to supplant coal anytime soon at current rates. NT

[eppur_se_muova]

4. Quick, let's tie up all the lithium in lithium carbonate electrolysis cells!

No problems there.

[pscot]

5. By order of the government

with forced requisition of all existing supplies of lithium, if that's what it takes. Shit, I can't believe I just said that.

[lfairban]

6. Hey! I got an idea.

Why don't we mount one of these converters on every smoke stack from every coal burning power plant. The stack itself will allow the photo panels to be placed high enough that no trees or other ground clutter will interfere with their ability to collect sunlight. Then you just run the wires up to the electrolysis unit on the top of the stack. You run a hose to carry the O2 produced down to the air intake to improve combustion, and you place the Lithium electrodes so that when the carbon buildup becomes thick enough, the chunks of carbon fall down through the smoke stack and end up in the combustion chamber.

There is just one thing I am forgetting.




Now, what could it be.




I can't recall what it is.




I knew I had it here somewhere.




Now, what was it.




Oh! Here it is!






:sarcasm:





Sorry, after hearing the clean coal sequestration concept, my concept of reality has gone all funky.

[joshcryer]

8. Anyone have the paper? Clue on how much energy is required to make a kg of solid carbon?

[pscot]

9. Here's the location of the paper

I haven't tried to access it.


More information: Stuart Licht, Baohui Wang, Susanta Ghosh, Hina Ayub, Dianlu Jiang, and Jason Ganley.” J. Phys. Chem. Lett. 2010. 11 2363-2368. DOI:10.1021/jz100829s

[joshcryer]

10. Yeah, I have the DOI, but I can't access it 'cause I don't have .edu access anymore.

I'll try from the library.