Los Alamos Developing Process for CO2 Capture and Stripping from Air for Synthetic Fuels Production

13 February 2008
 Process flow diagram for CO2 capture and recovery based on the Green Freedom electrolytic stripping process. Click to enlarge.

Researchers at Los Alamos National Laboratory have developed a process—called Green Freedom—for large-scale production of carbon-neutral, sulfur-free fuels and organic chemicals from air and water. The primary targets for the Green Freedom fuels are vehicles and aircraft.

Green Freedom consists of two major components: syngas (synthesis gas) production and syngas conversion. The innovation of the new process resides primarily in the method for the production of the syngas; Green Freedom relies on commercially available technology to convert the resulting syngas into product.

The primary components of Green Freedom’s syngas production are:

• Carbon-dioxide capture and recovery. A newly-developed process for capture and recovery of atmospheric carbon dioxide that also produces hydrogen as a byproduct is the core of Green Freedom. The new stripping process requires about 96% less energy than a conventional thermal-stripping process.

• Supplemental hydrogen production.

• Carbon-neutral power source.

While the chemistry of capturing carbon dioxide from the atmosphere can be straightforward (CO2 is readily absorbed into a potassium carbonate solution where it forms bicarbonate ions), the challenge in developing a practical system lies in the large volumes of air that would need to be processed to capture sufficient amounts of CO2 for useful application. Furthermore, according to the Los Alamos team, the conventional processing can only capture 73% of the carbon dioxide from the processed air on a single pass.

By contrast, Green Freedom uses a newly-developed electrolytic stripping process that can capture production quantities of air; capture more than 95% of the carbon dioxide on a single pass; and produces hydrogen as a byproduct that reduces supplemental hydrogen production requirements by 33%.

The new electrolytic stripping process consumes about 410 kJ/mole CO2 of electricity and about 100 kJ /mole CO2 of low-level heat energy. Taking a credit for the supplemental hydrogen production avoidance, the net electrical energy consumption is about 55 kJ/mole CO2 recovered.

The supplemental hydrogen production can be based on any water-splitting technology. For the baseline process design, the team chose water electrolysis. Green Freedom also assumes a carbon-neutral power source to assist production. The Los Alamos studies used nuclear power in its analysis.

 Conceptual diagram of the production of gasoline from air and water. Click to enlarge.

For the baseline conversion process, Los Alamos used methanol synthesis and the ExxonMobil MTG (methanol-to-gasoline) process. (Earlier post.) However, Green Freedom can also use other processes, such as a Fischer-Tropsch process to produce jet and diesel fuels.

Initial system and economic analyses indicate that the prices of Green Freedom commodities would be either comparable to the current market or competitive with those of other carbon-neutral, alternative technologies currently being considered.

—F. Jeffrey Martin, principal investigator

In addition to the new electrochemical separation process, the Green Freedom system can use existing cooling towers, such as those of nuclear power plants, with carbon-capture equipment that eliminates the need for additional structures to process large volumes of air. The primary environmental impact of the production facility is limited to the footprint of the plant. It uses non-hazardous materials for its feed and operation and has a small waste stream volume.

The concept’s viability has been reviewed and verified by both industrial and semi-independent Los Alamos National Laboratory technical reviews. The next phase will demonstrate the new electrochemical process to prove the ability of the system to both capture carbon dioxide and pull it back out of solution. An industrial partnership consortium will be formed to commercialize the Green Freedom concept.

Several other CO2 to fuel projects have been announced recently, including:

• A UOP and USC partnership to develop a process for the production of methanol, DME and other chemicals from carbon dioxide. (Earlier post.)

• A Sandia National Laboratories effort on extending the work on the development of a device for the solar thermochemical production of hydrogen from the splitting of water to recycling CO2 into liquid hydrocarbon fuels—“Sunshine to Petrol” (S2P). (Earlier post.)

• A Georgia Tech concept for the mobile on-board capture of carbon dioxide and the subsequent centralized reprocessing of the carbon dioxide to synthetic fuel. (Earlier post.)

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Comments

Just how much water is used for this? And whose drinking water will we be using to do this?

"Just how much water is used for this?" ... just do the stoichiometry. 2 hydrogen from every water molecule.

wow. Excellent development. and no future science. it can be built and deployed now.

but why not just co-locate this with eisting Coal and other Fossil fuel power plants. Surely if it can pull CO2 form the air, it can pull alot of CO2 from an exhaust stack, and likely much more efficiently. As an interim step, it would allow you to burn coal cleanly for electricity, and produce a functional fuel that works within the eisting infrastructure.
And it would likely be much easier and safer to implement than Carbon capture and sequestration.
i am betting this will be a major source of future liquid fuels.

Neil brings up a very good point. Building the Green Freedom plants next to smokestacks would make for a far more efficient production of fuel. There would be a bigger fanfare welcome by the public , if it were made known that a beneficial way to filter all those belching smokestacks were to be responsible for continued cheap power from coal. The recent public outcry against the TXU coal plants proposed across Texas would be a distant memory if the local goverments that turned against new coal plants , could be led to serve as a cheerleader for the integration of truely clean energy. This technology offers a viable fuel of the future. The system in place is too big to re-work , and too much is at stake to continue in our lathargic do nothing way , so this is the time to act , and now we have another solution. Go , man , go!

Neil brings up a very good point. Building the Green Freedom plants next to smokestacks would make for a far more efficient production of fuel. There would be a bigger fanfare welcome by the public , if it were made known that a beneficial way to filter all those belching smokestacks were to be responsible for continued cheap power from coal. The recent public outcry against the TXU coal plants proposed across Texas would be a distant memory if the local goverments that turned against new coal plants , could be led to serve as a cheerleader for the integration of truely clean energy. This technology offers a viable fuel of the future. The system in place is too big to re-work , and too much is at stake to continue in our lathargic do nothing way , so this is the time to act , and now we have another solution. Go , man , go!

I ask experts to clarify what is happening here.

As nearly as I can determine the important part is the improvement - apparently quite an improvement - in the CO2 capture stage.

Also the H2 coming out of the capture stage reduces energy demands downstream.

The other three blocks: methanol synthesis, electrolysis, and methanol to gasoline are more or less available commercial technology.

No experts here but this is my estimation.

"Initial system and economic analyses indicate that the prices of Green Freedom commodities would be **either comparable to the current market or competitive with those of other carbon-neutral, alternative technologies currently being considered*."
—F. Jeffrey Martin, principal investigator

Even so this "Green freedom" **costs** about the same as other "carbon neutral technologies" Costs may refer to carbon emissions or $costs. As such the public release is too simplistic although It may claim to have a feel for the technology. But some of the other C neutral technologies are renewable, sustainable, low tech or appropriate, Indeed the ones we are interested on this site are truly carbon negative. Solar - 1000% returns, wind, algae. Sorry if yours isn't included here.. What does this all mean? pulling a rabbit from thin air? Not wanting to give too much away here, The Nuclear industry is not known for plain speaking. I suspect the substantial electrical inputs and claims of viable stripping from atmosphere are important aspects. Surely the public interest angle being promoted shouldn't be dependant on Nuclear power generation to be viable? Much of the rest relies on proven technology MTG etc. The bottom line is efficiency , not bigger power stations. It is wrong to say that Nuclear power has no carbon footprint. Of course if one were considering all mining, construction, refining and disposal runs on solar voltaic or some such? I have heard that the carbon footprint of nuclear as much as 40% coal equivalent owing to refining, mining and construction costs. Disposal and containment of waste are somewhat harder to calculate for emissions, but the$ costs are substantial. In a petro or carbon based economy it is valid to equate costs with emissions for estimates.

Better accounting would show nuclear as replacing the addition of fossil carbon to the extent this can be claimed.
This technology will be of interest to big Nuclear power providers as there is a guaranteed market for as much as they can produce but the more produced, the shorter the life expectancy.
To imply that it (or any other) power source is seen as "Free", on this basis is akin to suggesting that water coming from the sky and landing in my cup has no greater value than the some other water on the next continent .

Dazzle us with science by all means. Kilojoules per Mole may be familiar to some but I doubt many readers here can easily conceptualize this.

Capturing CO2 out of the atmosphere is a great idea, but it would't be my first choice. Current coal plants or future IGCC can provide massive amounts of carbon, which at some point will need to be dealt with. Recycling it back into the existing trasportation system using liquid fuels is a sound concept.

It seems the atmospheric carbon capture part of this could be very useful in a PR context, but providing a valid alterative to CCS for coal generation is far more important and practical.

Los Alamos also should't be so bashful about the use of nuclear energy to power the whole thing, shoulda been mentioned in the headline...

I' m still no expert but using the lower 55kj/mole number, (not including the + 100kj waste heat? and the impressive reclaimed 465kj from hydrogen), Inputs are hopefully 1/3 Kilowatthour per kilogram CO2 removed.
My reading suggests that is what we get for our 1/3 KWH.
Doing something with that kilogram will require the next energy input.

The waste heat is not factored in so add 20-25%
The hydrogen bonus is also used up so no longer available.
I hope my babble is some use.

INTERESTING! YOU MUST SEE: http://www.spymac.com/details/?2343829

Magdal SPAM valenties day ALENA

Assuming the data provided is correct, removing 1 kg of CO2 from the atmosphere in this way would indeed require 0.35 kWh of energy. However, the objective is to convert that carbon back into synthetic fuel, which requires additional hydrogen, because the capture process covers only 33% of the demand. Producing the balance requires (410 - 55)*2 = 710kJ/mole CO2 or 4.5kWh/kg CO2 of additional electricity. Much of the chemical energy stored in the syngas is released as heat in the Fischer-Tropsch synthesis. About 40% of that can be used to drive a steam cycle to supplement the nuclear energy driving the whole process. Even so, depending on well-tuned the F-T process is, you're looking at perhaps 6-7 kWh of electrical input to convert 1kg of CO2 plus 0.41 kg of water into synthetic diesel (or gasoline). Add to that perhaps another kWh for pumping the water and distributing that fuel, for a total electricity input of around 8 kWh.

An average US passenger car will emit approx. 300 gCO2/mile, so figure those 8kWh will yield enough fuel to propel that vehicle for approx. 3.3 miles. Compare that to the 40 mile all-electric range GM claims its Volt E-REV will deliver on 8kWh of electricity stored in its battery pack (depth of discharge 50%) - a factor 12 better!

This sounds to me like yet another example of the nuclear industry desperately trying to revive its flagging fortunes by generating bogus demand for vast quantities of electricity. The environmental and national security issues raised by nuclear power, e.g. the as-yet unsolved problem of long-term storage of radioactive waste and the potential for terrorist attacks, are once again glossed over.

If you want to capture atmospheric CO2, please figure out how to safely grow algal biomass with minimal fossil fuel input - preferably out at sea. Photosynthesis may only capture 2% of the energy contained in sunlight, but it's cheap and can be applied to vast areas to compensate.

If you want to reduce oil imports from hostile or unstable regions, please convert those algae into biofuel (e.g. biomethane). The alternative is to reduce emissions of fossil carbon by covering more of your annual miles directly on renewable electricity (e.g. E-REV/BEV, rail, electric bicycles).

it should be noted that if you capture at a flue and convert that carbon to fuel, you are at most reusing the carbopn once, after which it gets into the atmosphere. of course, you could then use the fule to power the power plant, and keep recycling the carbon, but you need an additional energy source - green or nuclear. nevertheless, even re-using the carbon once or twice will signifincalty reduce the net release of carbon into the atmoshpere.

so if you look at two types of deployments, one taking carbon from the flue, and one from the air, you will evenutally win. but, it still needs alot of additional power.

I agree with Rafael that electrification of the auto is substantially more efficeint. no dount. but transport based CO2 is a small % of the overall GHG problem.

so why not deploy something like this to provide additional CO2 benefit?

and even if you don't use nuclear, this is an interesting way to convert renewable electricity into an easily stored and transported fuel.

Arrgg.... guys, the point is not to try to clean up the CO2 emissions from coal-fired power plants, it's to provide a *net reduction* of atmospheric CO2 while providing hydrocarbon feedstock for chemical industry, and car, truck, ship, and construction equipment fuels which can be used in the existing fleet and distribution infrastructure. This is an enormous advance. It allows us to stop using petroleum altogether! and with no nonsense about tar sands or coal-to-liquids.

Yes, plug-in hybrid cars are probably the wave of the future, but replacing a significant fraction of the existing fleet will take decades. Also please note that there will never be plug-in hybrid commercial aircraft; aircraft will need kerosene for the indefinite future. The new process allows us to economically *make* the kerosene, which means that aircraft will be truly carbon neutral. (I expect the developers will apply for Richard Branson's prize...)

As for the water required: that is a second order problem, and a smaller problem than exists for biofuels (plants need to be, wait for it: watered). The waste heat from the nuclear reactors which power the fuel manufacture can be used to help drive desalination to provide the water feedstock.

Algae as a biofuel means farming the sea. Farms may look superficially pretty, but they are highly structured machines which displace and disrupt whatever ecosystem would otherwise exist in the same space. And their inherent low power density and low conversion efficiency means that they would have to be enormous to supply all of our fuel needs. The production of artificial fuels from carbon-free and intense power sources (for example, nuclear fission) will have a vastly smaller footprint.

Excuse me but there is no free lunch here ...

Burn coal, then capture the CO2 and turn it into fuel and burn the fuel ... sounds good but the net energy is negative.

Still, putting an algae greenhouse *(sunlight, the energy has to come from somewhere) on the roof & lawns of each power plant for CO2 capture might be better than full pollution.

I find it very unlikely that this process will be more efficient that algae and plants evolved over a billion years. The inherent energy costs, the marginal energy costs, etc. all look prohibitive for ground transportation fuel. Burning 1 gallon of gasoline creates, what 18 pounds of CO2?

They seem to be working on a way to create jet fuel...which won't be replaced by batteries or fuel cells any time soon.

Maybe there will be a future date where we have so much renewable energy that this process would be preferrable to importing oil or making microbes that create light sweet crude grade bio oil...but I doubt it.

RS has the correct analysis in my opinion. 8 kwh is a huge amount of electricity for what you end up with. They added the air carbon capture as a way of saying that we can reverse the damage done. Interesting science, but misleading marketing.

What interests me the most is the big picture question: How viable is this as a long-term carbon neutral method of producing hydrocarbons.

I would therefore shelve the issue of whether the thing is powered by nuclear or solar or whatever.

Also, it then makes sense to assume the thing needs to rely on CO2 from the atmosphere.

So here is the big picture question:

Is this approach a viable long-term means of producing hydrocarbons for those essential uses that there is every reason to believe hydrocarbons will always be needed. e.g. plastics, jet fuel.

Aside from all the issues of whether the processes will actually work, it seems to me that the key issue is the EROEI.

Now here we are not looking for a EROEI > 1. Indeed, that is an impossibility.

What we are looking for is whether a reasonable fraction of the electrical energy input into this system comes out the other end in the form of hydrocarbon energy.

I would think what we are looking for is a fraction of perhaps 0.3 or at least 0.2.

If the fraction is too small then we would need a massive build-out of electrical generating facilities in order to produce a small amount of hydrocarbons.

Since they claim the economics seem to work, I would hope that implies that fraction isn't too awfully low.

Presumably if one takes the energy per mole CO2 and factors in an estimate for the energy needed to produce hydrogen also then one could come up with that fraction.

I'm not sure how to translate moles of CO2 into energy equivalent so I don't know how to do the calculation.

But it seems to me that is the central issue.

@ Lance,

I see the issue differently. This method has to compete with every other bio-fuel and synthetic fuel approach. Biofuels also take CO2 from the air, but without requiring so much electricity. There are many competing approaches for the best algal/enzymatic/syngas/other approach to extracting and organizing those hydrocarbons. It would be astonishing if this electricity-centric approach won out in terms of efficiency, net CO2 reduction, and cost effectiveness.

It will take a long time for us to build enough carbon-free power, like nuclear or wind, to replace our coal plants. Using power in this way will always be a much cheaper, more efficient, more effective way of using this power to reduce CO2 than synthesizing fuel.

Further, using electricity directly in Extended Range EV's like the Chevy Volt is about 20 times more efficient: there's a 75% loss in synthesizing the fuel, and a 80% loss in the Internal Combustion Engine. So, we'd get 20x the bang for the buck with EV's.

Finally, we'll have domestic oil for a long time, in slowly diminishing quantities, for residual uses like long-distance ground travel, air and the DOD.

This makes no sense.

Having read the report the final cost of delivered gasoline would be $4.60. Each proposed plant would require a$10 billion investment. Each plant would only supply 18,000 bbl/d so we would need about 700 of these gasoline factories.

Tom, any clue how they calculate $4.60/gallon?? I can't imagine it includes taxes... " Each proposed plant would require a$10 billion investment. Each plant would only supply 18,000 bbl/d"

Wow. Assuming 30 year life, and 7% interest, that's $2.92 per gallon for just the capital cost. Electricity, even at$.05/KWH, would have to be at least $5 per gallon (34 KWH/gallon divided by 33% efficiency x$.05/KWH).

That $4.60 figure is impossible. Add in operations & maintenance, and you're approaching$10/gallon.

Ah. I've figured it out. This makes sense for the DOD in the field, where delivering fuel can cost \$70/gallon. They have surplus nuclear power available from naval vessels. Now it all makes sense, though I don't know how they'll build the air-capture facilities in the field.

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