Scientists develop CO2 sequestration technique that produces 'supergreen' hydrogen fuel

May 28, 2013 by Anne M Stark
The Great Barrier Reef in Australia already has been affected by ocean warming and acidification.

(Phys.org) —Lawrence Livermore scientists have discovered and demonstrated a new technique to remove and store atmospheric carbon dioxide while generating carbon-negative hydrogen and producing alkalinity, which can be used to offset ocean acidification.

The team demonstrated, at a laboratory scale, a system that uses the acidity normally produced in electrolysis to accelerate silicate mineral dissolution while producing and other gases. The resulting was shown to be significantly elevated in hydroxide concentration that in turn proved strongly absorptive and retentive of atmospheric CO2.

Further, the researchers suggest that the carbonate and bicarbonate produced in the process could be used to mitigate ongoing ocean acidification, similar to how an Alka Seltzer neutralizes excess acid in the stomach.

"We not only found a way to remove and store from the atmosphere while producing valuable H2, we also suggest that we can help save with this new technique," said Greg Rau, an LLNL visiting scientist, senior scientist at UC Santa Cruz and lead author of a paper appearing this week (May 27) in the Proceedings of the National Academy of Sciences.

When carbon dioxide is released into the atmosphere, a significant fraction is passively taken up by the ocean forming carbonic acid that makes the ocean more acidic. This acidification has been shown to be harmful to many species of marine life, especially corals and shellfish. By the middle of this century, the globe will likely warm by at least 2 degrees Celsius and the oceans will experience a more than 60 percent increase in acidity relative to pre-industrial levels. The alkaline solution generated by the new process could be added to the ocean to help neutralize this acid and help offset its effects on marine biota. However, further research is needed, the authors said.

"When powered by and consuming globally abundant minerals and saline solutions, such systems at scale might provide a relatively efficient, high-capacity means to consume and store excess atmospheric CO2 as environmentally beneficial seawater bicarbonate or carbonate," Rau said. "But the process also would produce a carbon-negative 'super green' fuel or chemical feedstock in the form of hydrogen."

Most previously described chemical methods of capture and storage are costly, using thermal/mechanical procedures to concentrate molecular CO2 from the air while recycling reagents, a process that is cumbersome, inefficient and expensive.

"Our process avoids most of these issues by not requiring CO2 to be concentrated from air and stored in a molecular form, pointing the way to more cost-effective, environmentally beneficial, and safer air CO2 management with added benefits of renewable hydrogen fuel production and ocean alkalinity addition," Rau said.

The team concluded that further research is needed to determine optimum designs and operating procedures, cost-effectiveness, and the net environmental impact/benefit of electrochemically mediated air CO2 capture and H2 production using base minerals.

Explore further: ASU grant aims to transform global energy landscape

More information: Direct electrolytic dissolution of silicate minerals for air CO2 mitigation and carbon-negative H2 production, PNAS, 2013.

"CO2 Mitigation via Capture and Chemical Conversion in Seawater," Environmental Science & Technology.

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User comments : 16

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wealthychef
1.9 / 5 (7) May 28, 2013
Wow, if this is cost-effective, feasible and scales, doesn't it completely solve the problem of climate change? What am I missing?
antialias_physorg
4.2 / 5 (6) May 28, 2013
It's probably not very energy efficient (Grabbing CO2 is a doozy if you look at the tightness of the bonds) - but then again: from what they write it seems to do everything but clean the coffee pot.
So definitely worth looking into and seeing how efficient one could make it.
fredrik_asplund
2 / 5 (6) May 28, 2013
Well, fingers crossed I guess.

Linked on Sprawler: sprawler.tumblr.com
gwrede
2.2 / 5 (9) May 28, 2013
Suppose it works as advertised and scales up to a globally useful scale. Then we have the problem of distributing the produce.

Further, the researchers suggest that the carbonate and bicarbonate produced in the process could be used to mitigate ongoing ocean acidification, similar to how an Alka Seltzer neutralizes excess acid in the stomach.
How do you distribute this into oceans without major complications?

Pouring it down the Mississippi would kill all life in the Gulf of Mexico, and distributing this from thousands of places would severely disturb vast areas along the ocean currents, before getting diluted enough.

Of course this could be sprayed from airplanes or vast tankers, but that is obviously way too expensive.
lonewolfmtnz
1.4 / 5 (5) May 29, 2013
The 'biggest' word in English is "IF". Between a lab bench reaction and practical application lays untold orders of magnitude of pesky details. For starters.
owenwilliams
4.3 / 5 (3) May 29, 2013
Please post DOI.
Lech
2.8 / 5 (4) May 29, 2013
Agree 1000% with gwrede: even distribution of the carbonate compounds will probably be the show stopper..... Perhaps cloud seeding would be worth a look as large oceanic storms could dilute and then distribute over a wide area..
Howhot
4.2 / 5 (5) May 29, 2013
What a great concept. I hope they can scale it in some practical manner that all people will participate. Make it like a device or a product that disguises the good global impact. Maybe something stupid like toilet bowl freshener that lasts for a month and continually adds just the right combination to provide the long term CO2 sequestration we desperately need. Other posters have expressed concern, but you might be surprised that a little seeding could make a lot of things happen. Just think of it like a fluoridation experiment.
narienergy
5 / 5 (1) May 30, 2013
@wealthychef... i think what is missing is that it is not cost effective, yet.

the big IF here is the large amounts of renewable electricity being talked about. Graned it can be done with ocean based windmills that store excess electricity etc.. but people are just in a huge rush to publish and garner more funds nowadays, than actually developing new working applications.
Sorry i am being cynical with the announcement of the next big thing every 2 weeks.
EyeNStein
1 / 5 (6) May 30, 2013
Which Carbonate/Bicarbonate?
Which rock mineral precursor?
How do they make H2? is it electrolysis?
Too many unknowns to judge the merit of this process;
MCPtz
5 / 5 (1) May 30, 2013
Shout out to UC Santa Cruz.

$35 to read it... Is it made available for free via UCSC or LLNL?
MCPtz
4.5 / 5 (2) May 30, 2013
The author linked to phys.org!
https://groups.go...M-hVeTEY

And what appears to be the full paper is available here:
http://www.resear...seawater
Inspector Spacetime
1 / 5 (3) May 30, 2013
If nothing else, take from it this. We shall get there.

We might be a short-sighted species known for our self-destructive tendencies. But we have been remarkably good at survival in our 2 million years on this planet. We like survival.

There may be many things some might want to condemn humanity for, but we are growing, learning. Slowly. As custodians of this planet, we are making mistakes, but who wouldn't?

I am optimistic. We will figure out how to manage our relationship with our world.
Cliff Claven
1 / 5 (5) May 30, 2013
Is Phys.org a science site? I have to ask because the processes described in this article are well-known, and they collectively describe a huge energy sink, not an energy source. Reading the title and text of the article would lead one to believe that this is a wonder process that produces abundant clean energy and sequesters carbon. What is described here is really nothing more than adding massive amounts of electricity (from some unnamed "renewable" source) to sea water to evolve hydrogen and oxygen gas by electrolysis, and then adding massive amounts of ammonia (Solvay process) or soda ash (trona process) and CO2 to the concentrated saltwater left behind to produce baking soda. If we happened to be so blessed with excess electricity that we had enough surplus to decarbonize the oceans, it would have to be from thousands of nuclear power plants, and then we would no longer be burning the carbon fossil fuels that carbonize the oceans. I'm looking for science here, not hype.
antialias_physorg
4 / 5 (4) May 30, 2013
Reading the title and text of the article would lead one to believe that this is a wonder process that produces abundant clean energy and sequesters carbon.

And if you had read the headline and the article you might have norticed: it says nowhere that this is an energy source. It's a HYDROGEN source.

And as with any hdyrogen source: you need to put some energy into it (and kind of power source will do).
EyeNStein
1 / 5 (7) Jun 02, 2013