Breakthrough In Artificial Photosynthesis Captures CO2 In Acetate

An anonymous reader writes: Researchers from Berkeley Lab and the U.S. Dept. of Energy have created an artificial photosynthetic process that capture carbon dioxide in acetate, "the most common building block today for biosynthesis." The research has been published in the journal Nano Letters (abstract). "Atmospheric carbon dioxide is now at its highest level in at least three million years, primarily as a result of the burning of fossil fuels. Yet fossil fuels, especially coal, will remain a significant source of energy to meet human needs for the foreseeable future. Technologies for sequestering carbon before it escapes into the atmosphere are being pursued but all require the captured carbon to be stored, a requirement that comes with its own environmental challenges. ... By combining biocompatible light-capturing nanowire arrays with select bacterial populations, the new artificial photosynthesis system offers a win/win situation for the environment: solar-powered green chemistry using sequestered carbon dioxide."

Comments

They're called trees.

[jdharm]

"...solar-powered green chemistry using sequestered carbon dioxide." Trees. Quit cutting them down. Plant more. Problem solved.

Re: They're called trees.

[timrod]

I don't know how viable these devices are for mass production or what it takes to keep them running, but you could potentially use them in places (building roofs, taller light fixtures in parking lots) where there isn't enough space or it isn't viable to plant trees.

I do recall, however, someone pointing out to me that industrial hemp is more efficient at removing co2 than even some trees.

Re: They're called trees.

[drinkypoo]

I do recall, however, someone pointing out to me that industrial hemp is more efficient at removing co2 than even some trees.

Hemp is harder on the soil than its proponents would have you believe. Bamboo is even more efficient than hemp, you can harvest it and build stuff out of it every five years or so, sequestering carbon. And you can do it all with hand tools. You do need water, but it can be pretty crappy water.

The proper solution will be varied.

We already have a way to fix CO2 on your roof, it's called a green roof.

Not cutting down the trees is a useful step, because mature growth fixes more CO2 than new growth.

Re:They're called trees.

[Penguinisto]

Trees. Quit cutting them down. Plant more. Problem solved.

Strangely enough, at least in North America, we've planted more trees than we've cut down, and have done so for around what, 100 years now? ( By way of example, here in Oregon, loggers are required by law to plant anywhere from 3-5new trees** for each one they cut down, and they have to survive for at least a year after planting.)

Mind you, this doesn't speak for the third world (where firewood for heat and cooking is an actual thing, farming is a growth industry, not to mention the exotic hardwood cutting), and definitely doesn't speak for Europe and Asia (where the former has few forests left, and the latter is largely ignored and therefore unregulated for the most part).

** the number depends on soil quality, slope, and other factors, but it's at least 3.

Re:They're called trees.

[gtall]

That's not sophisticated enough. The problem is we're taking eons of sequestered carbon and dumping it into the atmosphere all at once. Trees only sequester carbon for about 100 before they're broken down into CO2 and other stuff again. Think of it as time dilated burning. And planting the world over with trees cannot possibly capture all the sequestered CO2 we're dumping.

Re:They're called trees.

[BradleyUffner]

"...solar-powered green chemistry using sequestered carbon dioxide."

Trees. Quit cutting them down. Plant more. Problem solved.

Actually, cutting down trees is a great way to optimize carbon storage, as long as new trees are planted to replace the ones cut down. It clears space for new trees, which grow faster and eat more carbon when they are young. The cut wood keeps the carbon locked up and is a useful building material. As long as the cut wood keeps the carbon in solid form it isn't going to affect the atmosphere.

I've actually seen plans where cut wood is dumped to the bottom of the ocean where it won't decay, then replanted in a constant cycle. That carbon would basically be locked up forever (at least until we start mining it at some point in the far future).

Re: They're called trees.

[Anonymous Coward]

Oh, but it does solve the problem a bit. The old trees die and decompose, most of that organic matter sticks around long enough to be used by the next generation of plant, fungus, and animal. The soil is in turn enriched which supports more life that it previously could which in turn sequesters more carbon. It may be a pyramid scheme, but it is one that has worked for a very long time. Also, if enough organic matter is present it might actually recreate the fossil fuels that caused the problem in the first place completing the cycle (albeit in the distant future).

Re:They're called trees.

[abies]

Europe and Asia (where the former has few forests left [...]

http://en.wikipedia.org/wiki/L...
Canada and the United States 26%
European Union 35%

And from
http://wdi.worldbank.org/table...
Europe it was 36.5% in 200 and 37.9% in 2012.

Not sure how good these statistics are, because it says 'Canada &United States = 26%' and then 'Canada =31%' and 'USA= 30.84%'... In any case, Europe has more forest area atm and amount of forest is growing rather than decreasing.

Or did you mean Europe has few forests left compared to situation from 2000 years ago? I can agree with that, but I don't think that global warming is THAT old - we used to have some mini ice age in meantime I think...

Re: They're called trees.

[DigiShaman]

Not cutting down the trees is a useful step, because mature growth fixes more CO2 than new growth.

You're not thinking long-term. Eventually the trees will die, decompose, and go back into the system as CO2. No, what you want to be doing is cutting down trees after their maximum growth rate has been achieved, then sequester the logs someplace. Clearing old growth makes room for newer faster growing trees that will soak up more CO2 than if you left old growth in its place. The only advantage of that (leaving old growth behind) is a more stable ecosystem as it would render that area less disturbed.

Re:They're called trees.

[dave420]

And practically impossible to re-start, as the majority of coal was created because tree-eating bacteria hadn't yet evolved. Clearly they have now, and so the cycle is not just unbalanced, but completely broken. It might be possible to create coal from peat bogs and the like, but that's nowhere near as easy or widespread as forests, clearly.

Re: They're called trees.

[Dr. Evil]

"...mature growth fixes more CO2 than new growth."

Only if your definition of "mature" is the peak-growth period of the trees and not a forest which has stopped growing.

Mature forests are as carbon neutral as an untapped oil deposit. Carbon release through decay balances with carbon capture from growth.

Using forests as a tool for carbon capture means either growing forests to maturity as carbon storage fields, or clearcutting new-growth forests and building permanent structures with a lot of wood, of course considerin the carbon-cost of processing the lumber and restoring soil nutrients.

Hardwood floors in shopping malls might be a good start.

Re:They're called trees.

[moeinvt]

Yes, you have to prevent them from oxidizing somehow. Dumping them in water or burying them raises a lot of questions though. Would the operation of cutting them down and either digging deep holes to bury them or transporting them to the ocean to be weighted down and dumped be carbon negative? The market need for building materials is presumably being filled with current operations, so I don't think you could store much additional carbon that way. Many logging operations also re-plant.

I wonder if something like hemp wouldn't suck up more carbon than trees and be easier to sequester?

Re: They're called trees.

[drinkypoo]

Only if your definition of "mature" is the peak-growth period of the trees and not a forest which has stopped growing.

You've got to take it on a species-by-species basis. Take, for example, Sequoia Sempervirens. Right up until the trees fall down because they outgrow their root systems, older trees put on more mass and thus fix more CO2 than the same area filled to capacity with younger trees.

Even trees which aren't getting taller are often getting thicker, so the question for a given species is whether younger or older members put on more mass for a given area. Virtually all of the non-water mass of all vegetation is carbon, and nearly all of the carbon of all vegetation (even relatively high soil carbon users like corn) comes from the air.

Re: They're called trees.

[bdeclerc]

The sun is _slowly_ brightening - this is happening on timescales of tens to hundreds of millions of years. The fact that CO2 was significantly higher tens or hundreds of millions of years ago is not super-relevant to today's conditions, but it helped keep temperatures bearable in the distant past, when the sun was fainter. We are adding CO2 at a rate that is essentially instantaneous compared to the effects of this solar evolution, they are even still extremely quick on the much shorter (tens of thousands of years) timescales of the Milankovitch-cycles (which are the orbital cycles which are the underlying cause of our glacial-interglacial variation in the past few million years)

What interests us at this time is what we are doing to our atmosphere over a period of tens to hundreds of years, and what effect that has on timescales of tens, hundreds and thousands of years - even if we humans stop all of our CO2 emissions (except breathing of course), the increased concentration versus "before" will be considerable thousands of years into the future, as will the effects of that increase on climate.

So stating "still at the extreme lower end of historic levels" is technically correct, but practically misleading, as it suggests there's nothing wrong with CO2-levels.

Re:They're called trees.

[Dan East]

So, on that wiki article it says the percent of forested land area, by country is:
Canada: 3,101,340 km2 forested which is 31.06%
USA: 3,030,890 km2 forested which is 30.84%

But then Canada and USA combined is: 4,680,000 km2 or 26.00%

Obviously something is quite wrong with that article.

Re:They're called trees.

[drinkypoo]

Strangely enough, at least in North America, we've planted more trees than we've cut down

What we care about is not forested area, although it's relevant to weather patterns, but forest mass. Older trees put on mass faster than young trees, and most of a plant's non-water mass is carbon from the air. Strangely enough, this simple fact seems to go mostly ignored in discussions about global climate and carbon, and I have to bring it up in literally every discussion on this subject here on Slashdot. I can use the karma, but I'd prefer that more of you land-rape apologists would wake up and smell the burning.

Re:They're called trees.

[CaptainLard]

Interesting, but the important question is how much possible forest land is forested? About 1/3 of the US is desert and the top 1/3 of Canada is tundra. I don't think the EU has nearly as much as either. But I won't deny the good news that forests in those two continents are somewhere in the neighborhood of sustainable these days....

Re:They're called trees.

[drinkypoo]

Trees only sequester carbon for about 100 before they're broken down into CO2 and other stuff again.

It's not even that simple. The percentage of carbon which is released instead of being fixed into the soil is related to the rate at which decomposition occurs. However, even tropical rain forests are net carbon sinks. As well, when you harvest timber and build things out of it, you keep the carbon fairly well-sequestered, at least until the wood gets successfully attacked by a fungus or set on fire, etc etc. But mature trees fix more carbon than young trees, further complicating the issue. The truth is that planting the world over with trees is no substitute for not having cut them down in the first place, and no amount of wishing will make it so. That's not an argument against replanting, just an argument against any further cutting of old growth. It should simply not be permitted, unless those trees absolutely will fail regardless — and soon.

Re:They're called trees.

[drinkypoo]

Actually, cutting down trees is a great way to optimize carbon storage, as long as new trees are planted to replace the ones cut down. It clears space for new trees, which grow faster and eat more carbon when they are young.

What? I say, what did you say, son? A quick google search would have proven you wrong, but you didn't even do that. Or, you know, having paid attention to any of these discussions here on slashdot in ages, since I bring this point up every time we have one. I haven't been bothering with links and citations until now, but nobody has asked so I didn't feel it was important since I'm not the only person who knows how to use google, am I? I don't want to fall into the trap of thinking I'm smarter than everyone, but I have this sneaking suspicion that I've been giving the average slashdotter way too much credit — and it wasn't that much, in my estimation.

Re:They're called trees.

[zmooc]

Actually, cutting them down and storing the wood (call it a house or paper) while letting a new tree grow in its place would be much more effective at taking CO2 out of the loop than not cutting them down.

Re: They're called trees.

[sillybilly]

Yeah, but what you are forgetting is topsoil depth is pretty lacking around the world, and when trees die, decay and go back into the global carbon cycle, a portion of them is converted into usable fertile black humus rich topsoil, which is undigestable to even the top digesting lifeforms. Topsoil by far is the ultimate form of carbon sequestration, and also the source of underground coal after millions of years if it undergoes tectonic heat and molten lava silicate phase separation.

On another note, the diagram these scientists give requires two photon captures, one for generating a proton and oxygen, and a 2nd that generates acetate from proton and CO2. This may be the most efficient, hard to tell, but I expected one stage for photon capture that generates temporary chemical energy, and another stage that converts that chemical energy consuming CO2 into acetate, without requiring a 2nd photon capture. Ocean floor volcanic eruption environments have bacterial lifeforms and a whole ecosystem fueled by not the Sun, like the rest of life on planet, but the internal heat of the Earth. These creatures live in absence of sunlight completely and they are based on a sulfur based high energy low energy state chemical cycle. As a crude adaptation one might just have a concentrating solar power collector and a sample of the biosphere from such an environment with water recirculated near the "volcanic eruption hot zone" in a solar concentrator, and cooled to the other zones where these lifeforms live, and there you go, you have a solar based CO2 captturing station, but quantum efficiency would probably be low. However that sulfur cycle could be used as a starting point to create something where the solar capturing stage can be separated from the bacterial farming stage, such as bacteria living in huge underground ponds aerated with CO2 (possibly captured via ethanolaminej or something untouched by the lifeforms in a massive downdraft solar tower) and the light collection sections could take up all the real estate, moreover they could be super high temperature if needed, where reaction rates are faster possibly giving better quantum efficiencies too.

That's my 2 cents.

Re: They're called trees.

[DamnOregonian]

Current levels are not even "average" in the context of history.

What kind of timescale are we talking about? Hundred years? Thousand? Ten thousand? Millions? Hundreds of millions? Billions? You could be very wrong, or very right with that assertion. I'm going to assume you're right, and we'll talk hundreds of millions.

It's amusing you cite the Sun in any fashion because it wasn't all that long ago than any mention of the Sun with regards to climate change was dismissed out of hand.

I had assumed in the first quote, you were defining history as "a really fucking long time", which humorously enough, is the exact timescale where the Sun's variance over time starts to play a real part in the Earth's thermodynamic equilibrium game. Turns out solar evolution is a pretty slow process. Of course, now that you've asserted that short-term variations in solar output are driving climate change, I can see I you've just attempted to change the definition of "history" that you initially assigned to fit a contradicting argument. Seems legit.

What you are doing is making shit up on the fly and talking in circles just avoid the fact that the CO2 concentrations today pale with what the traditionally have been.

At least he isn't changing definitions every other statement to support his assertion. Ignorant, or trolling? Can't tell.

Re:They're called trees.

[DamnOregonian]

Bingo. The primary problem isn't that we're producing too much CO2, it's that we're putting Carbon that has been out of the cycle for a very long time back into it. If we source our carbon from the cycle, we're not adding anything to it. Whether that can be done is anyone's guess, but we need to stop adding carbon back into the cycle, otherwise we will *never* find magical ways to sequester it. That coal comes from a time when the entire damn planet was covered in trees. It can't be that way again. One hole. Trees go in it. Plant more trees. Rinse and repeat until carbon cycle contains desired amount of carbon.

Re:They're called trees.

[dwye]

If you burn the 20,000 pound tree after cutting it, then your complaint is valid. If, in an extreme example, you bury it in the Thames as pilings for the Roman bridge in Londonium (most are still down there) while the 3-5 new trees are growing (and sequestering) you are doing much better than leaving a huge tree to rot and hollow out.

Anyway, the high tech "solution" in the article is must better at sequestration than a mere tree, more than an order of magnitude better. The trick is whether it can scale to the point that it affects the planet, rather than just a submarine or even just a rebreather for one diver.

Re: They're called trees.

[drinkypoo]

it doesn't matter, because the earth has never been habitable to humans when the CO2 levels have been higher. We don't care if the current CO2 levels are average or not, it's completely irrelevant. What we care about is whether they are convenient for us. The earth has gone through numerous ice ages without substantial perturbation of the cycle. Now we've created conditions that may change the cycle upon which we depend for existence, and we've already seen negative effects which are attributable to this carbon release.

Atmospheric CO2 levels certainly have been this high before, but the last time coincides with the last great exinction, so that is in fact a spectacularly shitty argument for denialists to engage in.

From TFA

[Anonymous Coward]

It appears to convert into acetate as opposed to capturing in acetate

"However, this new artificial photosynthetic system synthesizes the combination of carbon dioxide and water into acetate, the most common building block today for biosynthesis."

Re:Amazes me

[itzly]

yet no one ever correlates the increase to deforestation of rain forests.

They do. Deforestation is a well known part of the CO2 problem. But fossil fuels are a bigger part.

Efficiency

[itzly]

With this approach, the Berkeley team achieved a solar energy conversion efficiency of up to 0.38-percent for about 200 hours under simulated sunlight, which is about the same as that of a leaf.

That's lousy. It may be a breakthrough for this particular field, but compared to regular PV panels, it sucks. It would be much smarter to keep the carbon in the ground, and set up more photovoltaics instead.

Re:Amazes me

[Anonymous Coward]

We can very easily attribute what degree of co2 increase is due to fossil fuels because co2 from fossil fuels has a isotopic signature:

http://www.skepticalscience.com/print.php?r=384

In the 70s and 80s ozone was the big concern, and we changed some of the chemicals we use in our products because of it.

Now as we have learned more and as the world has changed there is a new concern.

Re:Skating, not butthole surfing

[Anonymous Coward]

In the future we won't need to worry, Systemd will properly attenuate global C02 levels to ensure optimum balance between human survival and the needs of other species.

"Artificial photosynthesis" is misleading

[MrVictor]

If I am understanding TFA correctly, this would be more aptly titled "solar powered electrolysis apparatus to feed oxygen to acetate-secreting bacteria on a nano-wire substrate". Bad science journalism. This will not save the world.

Re:Amazes me

[dave420]

Just as many are gobsmacked by those who assume they know all there is to know about the issues surrounding global warming, and then use their stilted, malformed knowledge of the subject to condemn those who take a more rational, rigorous approach as being hoaxers or charlatans or whatever other pejorative springs limply to mind...

Ozone was a different problem, which has been largely alleviated by international action.

You really should brush up on your knowledge before proudly telling everyone just how little you know.