Scientists Recycle CO2 with Sunlight to Make Fuel

An anonymous reader brings us this article from Wired about a new method to produce fuel with the help of concentrated sunlight and carbon dioxide. The process "reverses" combustion, breaking down the CO2 into carbon monoxide, which is then used as a building block for hydrocarbons. Quoting: "The Sandia team envisions a day when CR5s are installed in large numbers at coal-fired power plants. Each of them could reclaim 45 pounds of carbon dioxide from the air daily and produce enough carbon monoxide to make 2.5 gallons of fuel. Coupling the CR5 with CO2 reclamation and sequestration technology, which several scientists already are pursuing, could make liquid hydrocarbons a renewable fuel."

More Technical Info

[jcaldwel]

Here is a link for more technical information on how this works http://www.greencarcongress.com/2007/12/sandia-applying.html [greencarcongress.com]

Vaporware

[Anonymous Coward]

This sounds a lot like vaporware, in both senses of the word.

I have come up with a catchy name for the process.

[Kaz Kylheku]

How about: ``photosynthesis''. From the Greek root meaning light, plus synthesis: making up larger hydrocarbons from smaller units.

Whaddya guys think?

Re:

[ATMAvatar]

That's correct - photosynthesis gets is energy input from nutrients the plant gathers. Shame on biologists for using words like photosynthesis (where photo- means light, or under most contexts of photosynthesis, sunlight) to confuse others as to where the real power comes from.

Re:Vaporware

[myc]

You may have missed the part about requiring sunlight. Also, a common misconception about photosynthesis is that plants need "nutrients" to synthesize glucose from CO2. In terms of the biochemical pathways, the only "nutrient" that are required are water and CO2; the free energy required for photosynthesis and de novo glucogenesis is provided by photons from sunlight. ATP and NADPH, energy intermediates that are consumed during the dark reactions of photosynthesis (the Calvin cycle), are generated during the light reactions of photosynthesis.

Re:

[evanbd]

I suppose you neglected to read the whole "solar energy" part of the article? The point of all these things, be they this plan or biofuels, isn't some magic pixie dust source of free energy. It's that the easiest way of getting solar energy into a useful form might be to take a detour through plants or CO or steam or something else.

Fortunately, some people are actually trying to solve these problems rather than bitching on /.

Re:

[evanbd]

The energy content that comes from the solar input is renewable. Certainly the system isn't completely renewable energy, but improvement is a good thing. It would replace some of our oil use with reprocessed CO2 from coal. "It isn't perfect" is a really, really horrible reason to not do something that's far better than the current plan.

underwhelming

[macurmudgeon]

2.5 gallons of fuel produced per plant, per day? It's nice that it might scrub pollutants but it seems the solar energy could be more profitably used to directly produce electricity.

Re:underwhelming

[Anonymous Coward]

2.5 gallons of fuel produced per plant, per day, per installed Counter-Rotating Ring Receiver Reactor Recuperator (CR5).

Re:

[Original Replica]

So the next question would seem to be: Can enough of these be installed on a single plant to reclaim a significant amount of fuel? If there are 100 of these put on a single plant will we still get 2.5 gal per CR5, and is there enough space (88 m2 per unit)for the necessary solar furnace requirements for large numbers of CR5 units? After than I would be curious to know what the CO2 density is needed for these to function efficiently. I'm thinking in terms of just installing them the open air in cities like L

Re:

[HiThere]

1) We won't all be killed by global warming...at least not directly. It might precipitate WWIII.

2) We'll likely be worrying about something new. That's because we have short attention spans, not because we will have found global warming not to be a problem.

3) We won't have run out of fossil fuels...but we may have run out of the relatively clean ones. We *may* have run out of helium.

4) Green energy sources are possible, but that probably won't be sufficient to more than ameliorate the problem. We need t

Re:

[FudRucker]

that was my first thought too, 2.5 gallons of fuel per plant a day amounts to all the coal fired plants in the USA can get together and sell one person a tank of gas for their car...

Re:

[Anonymous Coward]

Uh... I think you need to re-read the quote.

  "CR5s are installed in large numbers at coal-fired power plants. Each of them could reclaim 45 pounds of carbon dioxide from the air daily and produce enough carbon monoxide to make 2.5 gallons of fuel"

Each of the CR5s produce 2.5 gallons... large numbers of CR5 means 2.5 x "large number" per plant per day.

Re:underwhelming

[xaxa]

It would seem easier to pipe the CO2 into a greenhouse and grow some food.

Re:underwhelming

[evanbd]

And steam locomotives would seem easier than high-temperature turbines. "Seems easier" is not what I'd call a good metric for evaluating such a technology.

Re:

[misleb]

It would seem easier to pipe the CO2 into a greenhouse and grow some food.

Why even bother piping in CO2? I hear Monsanto has genetically engineered plants to pull CO2 RIGHT FROM THE ATMOSPHERE. All hail Monsanto, Savior of Mankind and Protector of Intellectual Property (not necessarily in that order). :-P

Anyway, I think the nice thing about these CR5s is that they don't seem to require much external processing. Just put CO2 and Water in and get hydrocarbon fuels out. Not to mention O2. I'm sure the O2 the

OK, Let's Do the Math

[Dr. Spork]

Each of them could reclaim 45 pounds of carbon dioxide from the air daily.

Gee, so, given that coal powerplants in the USA alone produce 1.8 millon metric tons of CO2 per year, we would need 11 million of these devices installed in the US to make American coal power carbon neutral.

Maybe this should help everyone realize just what a bad, bad idea coal power really is, especially when we have much better alternatives.

Re:

[Dr. Spork]

Correction: I messed up the calculation, the actual number is 240,000 units - but stil, a ridiculous quantity.

Re:

[Wonko the Sane]

but stil, a ridiculous quantity.

The article is unclear about how much space these really require. If you can get 1000 of these at each power plant then it seems quite achievable to make all the coal power plants in the US carbon-neutral.

Re:

[misleb]

Correction: I messed up the calculation, the actual number is 240,000 units - but stil, a ridiculous quantity.

Not to mention that even if you did convert all the CO2 from the coal plants... you'd just be burning it again in cars (or something else). The entire process would not be carbon neutral. You're merely reusing the carbon once. In the end, you're releasing the exact same net amount of CO2 into the atmosphere.

Might as well just use the solar energy to create electricity directly and reduce the amoun

Re:

[PReDiToR]

if you did convert all the CO2 from the coal plants... you'd just be burning it again in cars (or something else)

And what would the cars be burning otherwise?

Oil is a fossil fuel too, using coal twice saves on burning gasoline once.

Re:

[russotto]

Maybe this should help everyone realize just what a bad, bad idea coal power really is, especially when we have much better alternatives.

The available (today) alternatives are natural gas (still a fossil fuel, still produces CO2, outrageously expensive per BTU), oil (same thing, plus the Middle East issues), and nuclear (waste, politics). Hydro, wind, geothermal, and solar simply cannot provide enough energy given current technology.

Coal's looking pretty good to me.

Re:underwhelming

[pla]

It's nice that it might scrub pollutants but it seems the solar energy could be more profitably used to directly produce electricity.

Great idea in the equatorial region, but solar really doesn't count as an option in the polar two-thirds of the planet (at least not until we have near-100% efficient PV panels that cost a pittance).

I would also point out that very few companies seem to want to build solar power plants, even in ideal places such as the vast tracts of desert wasteland in the US SouthWest. I presume this results because the long term costs might look great, but the books would take a big hit up front, and most companies (or at least, their current boards) couldn't care less beyond next quarter.

Given those two facts, we can either talk endlessly about why we don't use cool-tech-X, or we can deal with the reality we have now: We use a LOT of cheap and dirty coal power plants. And it costs considerably less to retrofit them with spiffy scrubbers such as TFA mentions than it does to rebuild new clean plants.

Also, who says only power plants can use this? Why couln't I (and everyone else who might care enough to give something like this a try) buy one (probably a scaled-down version to make it affordable) and toss it in my backyard? Five or ten tons a year, times a few hundred thousand people who want a free gallon or two of gasoline per day, could really make a difference.

No one renewable energy source will solve all our problems. Between them all, however, perhaps we can at least keep the planet habitable for a few more generations of humans.

Re:

[maxwells_deamon]

I would guess that you need to run these using the high C02 output of the power plant.

It does not say in the article, but normal air has a much lower C02 %

   

Re:

[timeOday]

solar really doesn't count as an option in the polar two-thirds of the planet

In the same way that food is a silly idea outside of the corn belt, and oil is a silly idea outside the middle east.

Re:

[pla]

In the same way that food is a silly idea outside of the corn belt, and oil is a silly idea outside the middle east.

Corn and oil don't suffer massive transmission lossses over distances of mere hundreds of miles.

Re:underwhelming

[Jimithing DMB]

Interesting? Mods.. please. I really hope the poster was joking.

[...] the solar energy could be more profitably used to directly produce electricity

As if we have a limited supply of solar energy. Yes, we better not do this because we might drain the sun.

The sad thing is that I think there are far too many people on this forum who are completely uninterested in technologies like this. Yeah, sure, we'd love to be able to grab all the energy we need from the sun and we'd love to be able to store during dark periods or transmit it with relatively low loss from lit areas to unlit areas. And it'd be great if we could harvest energy from the winds (hey, I'm a sailboat racer.. I do it all the time) or from the natural water flows.

However, until we can get all of these technologies working, something we may never see in our lifetimes, wouldn't it be nice if we could reduce the amount of pollution we produce and start harvesting at least some amount of energy from the sun? It's basically free energy. Every little thing we can do to use it will greatly improve our ability to continue the lifestyles we enjoy while reducing our environmental footprint.

We've got at least a few generations and probably many more to work this out and come up with creative ways to both meet our demands for energy and reduce our environmental footprint.

Re:underwhelming

[Diego_27182818]

Not only that, but the size of a dish required to focus the sunlight on the "barrel" is not mentioned.

It is mentioned, from the article

An 88-square meter solar furnace will blast sunlight into the unit, heating the rings to about 2,600 degrees Fahrenheit.

Re:

[Wonko the Sane]

What about concentrating the heat from nuclear reactor coolant (if it isn't hot enough we can collect and concentrate it)

How exactly do you "concentrate heat"?

i dunno

[wwmedia]

aint that like recycling dung from a big white elephant in a room?

Doesn't make sense

[SiliconEntity]

It doesn't make sense to me: first you burn coal, which basically creates energy by oxidizing carbon and creating CO2; then you use solar energy to undo that and turn the CO2 back into CO. Wouldn't it make more sense to make electricity directly from the solar energy and not involve the coal at all? Besides which, if the CO is later used as fuel as they say, then eventually you're going to oxidize that anyway and create the same CO2 you would have in the first place. It seems like a very roundabout way to add solar energy into the mix.

Re:Doesn't make sense

[vakuona]

It enables people to not have to change everything overnight. We have a big investment in carbon based fuel processes, so having away to create hydrocarbons which we then burn, and create CO2, then use solar energy to repeat the process means that hydrocarbons are now just an intermediate step, and that we have a dynamic equilibrium, and can forgo the pain of trying to get rid of all our petrol engines and replace them with fuel cell engines. At least, this won't have to be done overnight, and we actually do stop the increase in greenhouse gases, because we recycle them.

If it works, it is a clever solution.

Re:

[saundo]

The mising link is how to get the CO2 that is now emitted from the cars burning said converted fuel. I suspect that it might not be enough to offset that through simply removing CO2 from the atmosphere in equal amounts, but I digress.

The fact that this kind of secondary use of solar energy is starting to come about is a much more interesting development. Sure, you can generate electricity/heat water/etc from solar, but what else can we do with that energy that is also beneficial? THAT's interesting.

Re:

[misleb]

It enables people to not have to change everything overnight. We have a big investment in carbon based fuel processes, so having away to create hydrocarbons which we then burn, and create CO2, then use solar energy to repeat the process means that hydrocarbons are now just an intermediate step, and that we have a dynamic equilibrium, and can forgo the pain of trying to get rid of all our petrol engines and replace them with fuel cell engines. At least, this won't have to be done overnight, and we actually

Re:

[Martin Foster]

If you are going to burn the coal in order to produce the large quantities of energy required to warm and light homes. Then you can alleviate its impact to the environment and reuse some of that waste to make the system more efficient overall.

Solar power as of yet, is not effective enough to produce the energy of a major coal plant (with the same density of land area used). Coal plants however, pollute en-masse and this addition makes them more efficient and less hazardous to the environment as a whole.

N

Re:

[Khyber]

Solar will eventually be as efficient. Nanosolar is working on a way to literally just PRINT out solar cells. If not as efficient, it's so easily and cheaply made that it would be ubiquitous in a very short time (even Google has dropped some serious cash on this company, so it's well worth looking into.)

Re:

[Timmmm]

The problem with clean vehicles at the moment is energy storage. Batteries are expensive, complicated and not very good. Fuel cells are still developing and not very efficient. Petrol on the other hand is a proven energy storage technology. If you could manufacture petrol (or something similar) just using atmospheric CO2 and solar energy, you would effectively make all cars 'green'.

Of course it will be impossible to get enough energy to do that from solar energy. Oh well!

Re:

[maxume]

Impossible is quite a strong word. Why do you think it is impossible?

Re:Doesn't make sense

[Znork]

"Wouldn't it make more sense to make electricity directly from the solar energy and not involve the coal at all?"

To some extent, yes. The main problem is that electricity produced needs to be (almost) instantly consumed. Chemical storage of the energy avoids that problem. As such, there are various forms of chemical energy storage, ranging from batteries, through hydrogen, through ammonia to hydrocarbons, all with their own problems and advantages.

With batteries, the main trouble is they store too little and they (comparatively) rapidly break down.

Fuel cells can run on hydrogen or ammonia, with varying success. Hydrogen is a PITA to store, but perhaps ammonia is a simpler compromise.

Or hydrocarbons. Which have the advantage of being easy to store and fairly stable.

The thing about the energy crisis is there is no lack of energy (in fact, global warming is in essense an excess of it, and provides excesses of it in the form of weather). There's just a huge problem of extracting, transporting and, above all, storing that energy so you can use it when and where you need it.

Re:Doesn't make sense

[Fear the Clam]

perhaps ammonia is a simpler compromise

And unlike gasoline, you wouldn't have to clean up an ammonia spill. In ammonia-fueled car, fuel spill cleans you!

Re:

[Dirtside]

So... in Soviet Russia, I guess that means you DO clean ammonia spills?

Re:

[delt0r]

Hydrazine (H2N2) would be both a better fuel and better at cleaning you. Even the vapors will clean you!

Re:

[nguy]

Chemical storage of the energy avoids that problem. As such, there are various forms of chemical energy storage,

Yes, but using CO2 as a battery seems like one of the worst solutions.

If you want to store large amounts of electricity, pumping water, flywheels, and methods like that work quite well.

Re:

[Znork]

pumping water, flywheels, and methods like that work quite well.

Oh, I agree that pumped water storage and such are superior but that's on a grid-level. It doesn't solve the portability or (to some extent) transmission/offline use issues. You're not going to have them in a car or in a cabin in the mountains, or running hospital backup generators. (And on the grid-level I expect the lazy/desperate alternative will resolve that question: nuke plants.)

But while hydrocarbons stink as an energy storage medium, th

Re:

[Gibbs-Duhem]

Instantly consume the solar electricity instead of increasing the amount of oil you need to instantly consume to then convert back into oil with solar. The result is the same, except that you have more fuel afterwards. (Yes, I know I'm talking about an oil plant. Electricity doesn't care what the source is, and for every grid powered by coal, there's probably an oil plant somewhere contributing that could be removed or have its load decreased)

Re:

[ignavus]

Why not use the solar energy to compress air?

Then you use the compressed air to drive compressed air engines - even small cars for urban use (http://en.wikipedia.org/wiki/Air_car).

If compressed air leaks out of its storage, you get ... plain old air in the air. No pollution problems.

Homes could compress air during the day and consume it at night - or during the next day in their cars.

Compressed air is energy stored in a readily available, non-polluting medium. When it is used, it just returns into the atmos

Re:

[Technician]

I am glad you get it. You burn tons of coal and then using sunlight get back a couple gallons of fuel. Using solar heat to simply replace burned coal makes a lot more sense to me. I do understand that a few solar panels is not going to cut the coal consumption by much. Many greenies simply believe that once the process is perfected a small amount of sunlight will replace the tons of energy released in burning coal and reclaim all the CO2. It can be done, we just need to improve efficiency.

Look up over

Re:

[x2A]

It also works with water (instead of CO2) to extract hydrogen.

Re:

[Pogue Mahone]

One of the problems with using "natuaral" energy sources like sunlight is how to get the energy when it is needed and not when nature sees fit to provide it. In short, how do you store the energy? This seems like a reasonable way, assuming the CO can be stored and used to power the same power station. OK, so there are bound to be losses in the system that will have to be made up with fuel from other sources, but the net result should be lower consumption of fossil fuels. and thus lower CO2 emission.

Re:Doesn't make sense

[Eivind]

Some natural energy-sources (all energy-sources are "natural" by the way, why don't you use the standard terminology and refer to them as "renewable" energy-sources?) are very well able to accomodate fluctuations in demand and produce when we need the power, infact better than nuclear. (most of the cost in nuclear is constructing, safety and decommision, fuel is a pittance, which mean if you throttle down a nuclear powerplant you save essentially nothing. Yes you can do it, but the cost of producing at 25% is going to be 95% of the cost of producing at full-throttle)

For example, in Norway we produce much of our power using hydroelectric powerplants that run water coming from large magazines in our high mountains trough turbines attached to generators. Very nice:

• The magazines are re-filled automagically by a process known as "rain" (solar-powered!)
  
• The magazines store enough energy for like half a YEAR of use, so even longish periods of drougth are no problem.
  
• The powerplants can be ramped up or down according to need inside of less than a minute. Significantly faster than most fossil-fuel-burning powerplants.
  
• Efficiency is high, about 90% in a modern powerplant.
  
• Low impact: some lakes have water-levels that vary more than is natural, a few dams, some rivers have less water in them then they would naturally have. That's about it, the powerplant itself is typically in a mountain-cave and neither visible nor hearable.
  

It's an excellent thing for combining with other renewables: When the sun shines, use that. When the wind blows, use that. When tides are strong, use those. When neither produces much, dial up a hydroelectric or two.

Better still:

With modest investment, the things can be used as batteries: If you've at any time got to -much- power from other sources, use excess power to pump water uphill to one of the magazines, where it can be stored safely for months until needed. (yeah, this pump-turbine cycle will waste like 40% of your power, but that's true for most other kinds of batteries too)

Sucks if you live somewhere -flat- with no or little rainfall, I guess.

Re:

[dvice_null]

> For example, in Norway we produce much of our power using hydroelectric powerplants that run water coming from large magazines in our high mountains

1. Get a high mountain
2. Build hydroelectric powerplants
3. Sell electricity
4. Profit

I never realized it was that easy. So now I only need a mountain...

Re:

[Anonymous Coward]

Norway may have an abundance of craggy valleys and the like, but the reservoir required in most places to generate hydroelectric power is a considerable cost. For example, the Hoover Dam, a large, but not monstrous project, covered 640 km. That is a significant cost, especially in populated regions where people have to be moved. Furthermore, river bottom land is usually the most agriculturally productive, so the cost of hydro power is fairly high, not to mention the environmental costs of damming a river

Re:

[ross.w]

# The magazines store enough energy for like half a YEAR of use, so even longish periods of drougth are no problem.

So six months without filling the lake is a drought is it?

Warragamba Dam near Sydney stores enough water for five years and hasn't been full since 1987.

<Crocodile Dundee>

Now that's a drought!

</Crocodile Dundee>

Renewable not!

[bradbury]

So long as any of the carbon in the cycle is coming from sources currently in the ground or oceans (e.g. coal, oil, natural gas, or methane clathrates). I.e. we are harvesting energy by oxidizing previously reduced carbon -- it is NOT RENEWABLE or SUSTAINABLE!

The only cycles which potentially work over the long term are: (a) solar; (b) fusion reactors; (c) breeder reactors; (d) thorium fuel cycle reactors. That is probably in decreasing order of length of time we could sustain our civilization off of those sources (your opinions may differ).

The coal power plant output conversion of CO2 to liquid fuels simply shifts the problem from an CO2 source one can easily sequester (coal plant smokestacks) to one which is much less easy to sequester (automobile exhausts). You have a fundamental problem here which is when are we going to incorporate the cost of "full sustainability" into our energy costs? That means any carbon you put into the atmosphere you pay to take back out of the atmosphere. Ideally you do more than that to reduce atomospheric CO2 levels back to pre-industrial levels [1], i.e. you are taking more CO2 out of the atmosphere than you are putting into it. We are currently very far from being able to do that.

So long as we continue to live off of the reduced carbon sources (stored solar energy harvested by plants hundreds of millions of years ago) and don't fully pay for them we have a real problem.

Robert

1. Or humanity makes a decision to allow the glaciers and icecaps to melt, the sea levels rise a bit, some islands and low lying areas get flooded, weather patterns to change a bit *and* spends the money necessary to mitigate the negative effects of these processes.

Re:

[x2A]

The artical does say that at the moment they need pure CO2 intake, but as it's developed further, they look to be able to use the atmosphere as a source for the CO2.

Re:

[bradbury]

I'm not saying it is impossible to use CO2 from the atmosphere as an input. Plants do it. But they have a *lot* of surface area to harvest CO2 which is only present at hundreds of ppm levels. We have the same problem with harvesting CO2 from the atmosphere that we have with harvesting solar power from the sun -- one has to produce relatively complex molecular structures, which are hopefully lightweight, at high surface area to mass (cost) ratios.

If we solve those problems for solar cells, we may be on th

Short term, long term, one size doesn't fit all

[Per Abrahamsen]

At the short term, it seems to make coal based energy production more efficient. That is significant, no matter what your long time goals are, coal is going to be a very important source of energy for the next many years.

At the long term, they hope to develop the technology further so it can extract the CO2 needed directly from the atmosphere, and then it will be a renewable if successful.

A problem with the energy and climate discussion is the idea that we should have one solution to all our needs. Short

Re:

[Trailer Trash]

Or humanity makes a decision to allow the glaciers and icecaps to melt, the sea levels rise a bit, some islands and low lying areas get flooded, weather patterns to change a bit

This is a process that's been going on for Billions of years. It's staggering, the arrogance to think that "humanity" is able to "make a decision" on that scale.

Re:

[mortonda]

So long as any of the carbon in the cycle is coming from sources currently in the ground or oceans (e.g. coal, oil, natural gas, or methane clathrates). I.e. we are harvesting energy by oxidizing previously reduced carbon -- it is NOT RENEWABLE or SUSTAINABLE!

Quite right. As I said elsewhere [slashdot.org], it seems a lot of people get caught in some sort of logical error wrt "carbon neutrality".

I understand that we may need to use chemical storage to move energy around and make it useful, but ultimately, we need to reduce our emmissions to less that what the planet can scrub. It makes no difference where it comes from - just that it is less.

This idea seems to defer it a little, but really makes no long term difference, unless the created material is converted into plastic o

Get used to seeing this

[houstonbofh]

There are lots of ways to put energy in a liquid that can move a car. The problem has been that they are not cheap. But since oil is no longer cheap, and associated from people who want to do us harm, the disincentive for alternative fuels is rapidly fading. Get ready to see gas from corn, grass, algae, recycled food, recycled plastics, and now CO2.

Re:

[cyberon22]

I wouldn't agree that Bush and Cheney want to do us harm. More just self-interest coupled with indifference to complex problems.

Re:

[plopez]

There actually a wing i among fundamentalist Republicans who feel that not only are we headed for the apocalypse but it is their job to hurry it along.

E.g. http://findarticles.com/p/articles/mi_m1141/is_43_38/ai_93084876 [findarticles.com]

also

http://rightweb.irc-online.org/analysis/2003/0312apocalypse.php [irc-online.org]

And since they kowtow to these groups for their own political ends Bush/Cheney in fact *are* evil.

Re:

[Atzanteol]

This is as retarded as the conservatives who say that the liberals want the US to lose in Iraq...

Please think though what you say sometimes 'kay?

Re:

[bigstrat2003]

Exactly. Most likely, they don't give a damn about us one way or the other. Saying they actively wish to harm us is just kind of... dumb. Why should they care what the hell happens to us (so long as they're getting what they want)?

Not carbon neutral

[Joce640k]

All it adds up to is getting a bit more energy out of the coal.

In the middle of the process there's a small C02 -> CO ->CO2 stage.

Probably better to use all those mirrors to heat some water and drive a turbine.

Re:

[compumike]

Probably better to use all those mirrors to heat some water and drive a turbine.

This may not be the case. Solar traditionally does fairly poorly in thermal systems because of how spread out the energy is. Focusing the energy to yield a higher temperature is possible only with huge arrays of precision mirrors. And without the high temperatures, the thermal to mechanical efficiency must suck at least as much as the Carnot efficiency [wikipedia.org].

In contrast, the light-driven chemical reaction is NOT limited by Carnot, but of course has its own efficiency associated with it. It depends very much

Re:

[xaxa]

The caption for the picture in the article reads "Sandia researcher Rich Diver checks out the solar furnace which will be the initial source of concentrated solar heat for converting carbon dioxide to fuel. Eventually parabolic dishes will provide the thermal energy." so it seems he is concentrating the solar energy anyway.

A New Kind of Cracker

[TheHawke]

Instead of attempting to make hydrocarbon based fuels the article toots about, crack CO down even further using an Old School catalytic cracker containing platinum, breaking CO into the base components of ultra-pure carbon (graphite) and high levels of oxygen.
Now I'd release the oxygen since atomic oxygen is the most corrosive element on the table, recover the graphite and sell it off.'
This would give the high polluting coke refineries something to grieve about since this would put a ding in their profits.

Re:

[c6gunner]

Now I'd release the oxygen since atomic oxygen is the most corrosive element on the table, recover the graphite and sell it off.'

Pure oxygen is very important to the aircraft servicing industry. Instead of wasting half of your output, compress/liquefy it, and sell it.

Govt science at work

[cinnamon colbert]

NASA wanted a pen that would work in zero G; spent millions on RnD
The russians used a pencil

much more productive to focus on using less energy in the 1st place, in terms of energy saved/research dollar

these tech fixes are really obscuring the problem: our basic life style is not good. the govt should stop building highways, put money and tax incentives to get homes and jobs at mass transit accessible sites; just getting one or two million people out of suburbs into nyc lifesytles would do more for the envir

Urban myth

[MyNymWasTaken]

http://www.snopes.com/business/genius/spacepen.asp [snopes.com]
Claim: NASA spent millions of dollars developing an "astronaut pen" which would work in outer space while the Soviets solved the same problem by simply using pencils.
Status: False.

Re:

[evanbd]

Not to mention that pencils are actually pretty bad in space -- too much graphite dust and broken pencil leads, neither of which is good for electronics.

Re:

[ScrewMaster]

NASA wanted a pen that would work in zero G; spent millions on RnD

The russians used a pencil

I'll let someone else correct your misapprehension on this issue.

just getting one or two million people out of suburbs into nyc lifesytles would do more for the enviroment then a million years of Rnd

What about those people who just don't want to live in a city? I don't: I grew up in a small town and would be abjectly miserable living in a city. Offer all the tax incentives you want and I would still never

Re:

[Brian Stretch]

What about those people who just don't want to live in a city?

Then their fuel bills go up, like they've been doing. Which is fine if you have the money. Just don't expect me to sympathize too much.

What bugs me is all the preachy "green" types who whine about any attempt to build housing with more than a few stories. David Owen covered the topic very well here:

NYC is the Greenest City in America [walkablestreets.com]

Wrong.

[Qbertino]

NASA wanted a pen that would work in zero G; spent millions on RnD

Coming up with a pressurized ball-point mine and optimizing it to make it feasable and 'certified for flight' costed only about 100.000$. Paying the team, building the prototypes, testing them NASA-style, building the tools and rigging a new assembly line for something like that costs that much. Fairly cheap considering they ditched the ball-point pens biggest downside: Unable to write overhead, under water or - as the case may be - in zero g

Summary a bit too rosy ...

[ScrewMaster]

Scientists Recycle CO2 with Sunlight to Make Fuel

They're leaving the production of actual liquid fuel to other people ... all this thing does right now is produce carbon monoxide.

Re:

[IamTheRealMike]

Right. IIRC you'd need to split water to get hydrogen, and then combine the CO and H2 in the Fischer-Tropsch process [wikipedia.org] to actually get liquid fuels. So it'd take a lot of energy to do, but if you can suck CO2 out of the atmosphere (a hard, hard problem), voila, you have renewable petroleum.

More steps, more energy loss

[Veramocor]

Or you could use solar energy directly (photovoltaics or solar thermal) to generate electricity and not use as much coal decreasing Carbon dioxide emissions that way. Instead they generate electricity using coal, then use solar energy to convert the CO2 back, which is dumb because each processing step has inefficiencies associated with it and adds unneeded complexity to the system.

In the best case it takes as much energy to break the CO2 bonds as you get from generating the CO2, in reality it will take much more.

Same process as wood gasification?

[bear_phillips]

Is this basically the same process used in wood gasification? In a wood gasifier, wood turns to charcoal, to CO2 then to CO. This seems to be the same thing but using the sun as the heat source instead of hot burning charcoal.

solar fuel is the way to go

[Goldsmith]

Photovoltaics are great, and biofuel is nice, but why not just directly generate fuel from sunlight? I haven't heard of the particular technique the Sandia guys are using.

The technique most people are using is based on titanium dioxide catalysis in UV light. Japan is crazy for this stuff. It oxidizes pollution, makes it easier to clean buildings and windows and breaks water into oxygen and hydrogen (it's also in paint and sunscreen). It also can convert (reduce) CO2 into alcohols or methane in the right

Old Technology

[PPH]

Convert CO2 to fuel with sunlight. We've had that for years. They're called plants.

Why not nuclear rather than solar?

[mpthompson]

However, creating a powerful and efficient solar power system to get the cobalt ferrite hot enough remains a major hurdle in implementing the technology on a large scale, said Aldo Steinfeld, head of the Solar Technology Laboratory at the Paul Scherrer Institut in Switzerland, in an e-mail.

Using solar power to generate the heat introduces a lot of practical problems to overcome such as space for the solar reflectors, dependence on time of day and weather and other issues. It seems that a compact nuclear re

Long-Term Solution for Aircraft Fuels

[GospelHead821]

One of the BIG problems I always imagine when I think about the entire economy becoming electric is that of aircraft. I have a hard time conceiving of an airplane that operates on an electric motor. One possible solution is to phase out aircraft in favour of fast, electric trains. This technology, if it works as claimed, could provide another solution. Even if the amount of infrastructure necessary to satisfy all of our energy needs with reclaimed CO2 would be too cumbersome, it might be feasible to use

Turning Up the Heat on Solar

[Doc Ruby]

"It's a heat engine," Stechel said. "But instead of doing mechanical work, it does chemical work."

If it's really a heat engine, then it might be powered better by something other than sunlight. Sunlight does offer an average (across night/season/weather/latitude) of about 400W:m^2 in North America, but this machine will consume quite a lot of energy to produce and maintain, while consuming area that could deliver more energy in direct power from the sunlight than what it stores in "reformed CO2". Which eith

Amazing!

[mqduck]

An anonymous reader brings us this article from Wired about a new method to produce fuel with the help of concentrated sunlight and carbon dioxide.

The scientists inventing this method are calling it "tree".

I saw something like this before!

[Brett Buck]

It's called a tree.

          Brett

This vs biofuels, sustainability & how to do i

[cgraves]

I am working [columbia.edu] on a similar process that synthesizes hydrocarbon fuels from carbon dioxide, water, and non-fossil energy (could be solar) and should eventually have some publications out about this. There are several ways to go about this. But first, let me comment on some of the comments:

Regarding the "They're leaving the production of actual liquid fuel to other people ... all this thing does right now is produce carbon monoxide." comment [slashdot.org], reducing CO2 to CO is the hardest part of the process. Once you have concentrated CO, you can follow the coal-to-liquids processes and water-gas shift (CO + H2O => CO2 + H2) to get hydrogen and run the syngas (CO + H2 mixture) into Fischer-Tropsch [wikipedia.org] reactors. They've been doing this for 50 years in South Africa to produce synthetic diesel.

Regarding the "Renewable not!" comment [slashdot.org] and using power-plant flue gas CO2 as the input to this process, this would indeed not be sustainable. However, if industrial capture of CO2 from the air [columbia.edu] is available, one can fully close the loop and have a sustainable hydrocarbon fuel cycle. Flue gas CO2 could be a good option in the short term, however. For instance, if solar and other nearly-carbon-free energy sources begin to rapidly take over, coal plants will not immediately be shut down. Other CO2-emitting industrial plants such as aluminum smelters, etc, will also have CO2 emissions to deal with, and this form of using it to store non-fossil energy by recycling it once as a liquid fuel would be worthwhile. One comment [slashdot.org] discussed this transition well.

Related, other comments [slashdot.org] say "why not just use the solar energy to produce electricity". These intermittent resources need storage, and liquid fuel storage is not a bad method (and very versatile). Others responded [slashdot.org] about storage.

So, processes like this are a way to store non-fossil energy as a convenient energy-dense fuel which can be used in our existing petroleum fuel infrastructure and vehicles (as opposed to hydrogen and batteries). Biofuels can do the same, and there are many comments above ("I saw something like this... it's called a tree") mentioning biofuels and how this process replicates it with much more complexity; indeed you could call this whole process including the Fischer-Tropsch fuel synthesis "artificial photosynthesis". However, this process cuts out the middle-man of the plant in biofuels processes, which has much lower sunlight-to-fuel efficiency than industrial solar collectors (PV or thermal) and requires a lot of fertilizers and pesticides to boost growth rate. Such land- and resource-intensive agriculture is not sustainable [sciencemag.org] in its current form and may not ever be on the scale we will need it.

TFA discusses a solar-heat-driven thermochemical process that has potential. A somewhat similar solar-heat thermolytic process splits CO2 directly [www.lare.us] at higher temperatures. There are many other methods of accomplishing this that are at different levels of development and being researched, including electrochemical (pdf link1 [risoe.dk], pdf link2 [confex.com]), photoelectrochemical, photo(bio)chemical...

Grampa's biotech solution

[Harmonious Botch]

My grandfather used to be an employee in a biotechnology venture in the 30's. It was a two stage process. The first was a corn - or sometimes a potato - plant. The second was a still. ( He was a tinsmith. ) The input was CO2 and sunlight, the output was ethanol.

Re:

[arivanov]

Not a lot have changed. Then the economics were perverted by the prohibition, now the economics are perverted by subsidies. In either case the process does not make sense neither for booze (grapes are better) nor for fuel (oil plants are better).

Re:

[arivanov]

Neither.

I am referring to the massive subsidies received by the corn farmers in the USA and the sugar beet farmers in Europe.

Re:

[edwardpickman]

Yeah but this time they are hoping to run a car with the fuel instead of running your grandfather.

Re:This is

[x2A]

Seems to be a couple years old though, this page [sandia.gov] (second story down) which includes the same photo is dated feb 2006, and includes a much better description of how it works, including how they use alternate direction rotation rings for heat conservation within the drum, although it looks like they've more recently been trying it with CO2 instead of H20. This page [greencarcongress.com] contains more info and diagram [typepad.com] of the counter rotating drum. Very interesting stuff though.

Recycling CO2

[Gibbs-Duhem]

I feel like I should point out that this does not remove CO2 from the atmosphere.

Fuel made by this, when burned, releases the CO2 back into the atmosphere. I suppose the only reason they talk about doing it on coal plants is because the concentration of CO2 is higher where it's being used. However, as usual there's no way that the energy input is equal to the energy in the fuel, so what is the point? If you put that solar electricity on the grid, you need to burn that much less *actual* oil, so you have no

Re:

[Dare nMc]

if you put that solar electricity on the grid, you need to burn that much less *actual* oil, so you have no energy loss at all...

considering over 1/2 of the cost of electricity is in the delivery, where as less than 5% of the cost of gasoline is in the delivery. got that from the (pump price - taxes) - the cost of fuel at the refinery (from bloomberg.com)

Means if I run my car on electric I double the cost of electric getting it to my house/work, then I lose 40% when I charge the batteries. So if they can

Re:

[x2A]

"this does not remove CO2 from the atmosphere"

Well technically it does, it's just that burning it puts it back into the atmosphere. Anybody who feels strongly enough could bury it instead.

Re:

[homer_ca]

Oil is already too expensive to use for power plants. Liquid fuels sell at a premium because all our transport runs on internal combustion, and the fuel produced by this process goes into a completely different market from the one for grid electricity. Electricity is probably still more efficient for harnessing solar energy, but as long as we need liquid fuels for transport, we'll need to consider ways like this to reduce oil usage.

Personally, I'll worried more about the production rate of 2.5 gal of fuel p

Re:What could possibly go wrong...

[Cyberax]

You can immediately use CO for synthesis of more complex chemicals. No need to store it.

BTW, chemical plants have a lot more nasty compounds than CO.

Re:

[xaxa]

You can buy CO detectors, I expect anyone dealing with CO has to have them. My local water treatment place had a chlorine alarm and a big tower, if the chlorine alarm sounds everyone has to run to the tower and climb to the top floor.

Re:

[misleb]

Even a small leak at this plant can kill many workers or even people in a nearby town without them even realizing they should run away for safety.

Yeah, because everyone knows that it isn't possible to make a CO detector.

Re:

[ScrewMaster]

A high-technology industrial economy is dangerous. It's the trade-off we make for having all thing good things it brings us. Some people don't understand that.

A friend of mine used to work for the old Baxter-Travenol pharmaceutical operation. In the building he worked in, he said that a few floors up was a facility that was making intermediate compounds (amines, I believe he said, but this was twenty-odd years ago so my memory could be faulty) used in the production of certain drugs. This was a complete