22 ms·

Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel

• T2_t2 10y ago
  > Breakthrough solar cell captures CO2 and sunlight, produces burnable fuel Is it called "A Tree"? Those things are ancient!
• danmaz74 10y ago
  Key facts: > In fact, he said, the new catalyst is 1,000 times faster than noble-metal catalysts — and about 20 times cheaper. > The combination of water and the ionic liquid makes a co-catalyst that preserves the catalyst’s active sites under the harsh reduction reaction conditions, No mention of efficiency compared to photovoltaic cells.
  • dchichkov 10y ago
    There are some efficiency numbers in the abstract of the "Nanostructured transition metal dichalcogenide electrocatalysts for CO2 reduction in ionic liquid." article: Conversion of carbon dioxide (CO2) into fuels is an attractive solution to many energy and environmental challenges. However, the chemical inertness of CO2 renders many electrochemical and photochemical conversion processes inefficient. We report a transition metal dichalcogenide nanoarchitecture for catalytic electrochemical CO2 conversion to carbon monoxide (CO) in an ionic liquid. We found that tungsten diselenide nanoflakes show a current density of 18.95 milliamperes per square centimeter, CO faradaic efficiency of 24%, and CO formation turnover frequency of 0.28 per second at a low overpotential of 54 millivolts. We also applied this catalyst in a light-harvesting artificial leaf platform that concurrently oxidized water in the absence of any external potential. Copyright © 2016, American Association for the Advancement of Science.
  • scotty79 10y ago
    I'm more interested with comparison to plants harvested for biodiesel.
    • Godel_unicode 10y ago
      The key difference in my opinion is that this process would not be competing for land with existing crops. We could do both.
      • callesgg 10y ago
        Yes it would, sun rays only hit the ground once.
        • lorenzhs 10y ago
          There are plenty of areas of this planet where plants don't grow because the climate is too harsh (not enough water and/or extreme temperatures)
          • mattashii 10y ago
            I understand your point, but this system also requires water, and therefore does compete at that point as well. Higher temperatures also have a negative effect at the efficiency of solar panels, but they are indeed a lot more resistant (typically lower temperature=better efficiency for solar panels).
            • Godel_unicode 10y ago
              Cold, water, sunlight, no crops, existing infrastructure for moving fuels. Alaska? There's even high CO2 there from wood stoves (Alaska is 4th per-capita). http://www.eia.gov/environment/emissions/state/analysis/ http://www.eia.gov/environment/emissions/state/analysis/
              • delecti 10y ago
                Alaska is so enormous and sparsely populated that I doubt much that the residents do will have a significant impact on the ambient CO2 levels, compared to a state like Texas or California, which are about 80 and 250 times more population dense for their size. I agree with all the rest of your factors, though high CO2 is likely not a mark in Alaska's favor. My main concerns with Alaska would be suitably large cleared land area to collect sunlight without damaging the environment, and not having panels get covered in snow in the winter.
  • some_guy_there 10y ago
    The efficiency is around 4%, as in Figure 2 from the paper. SFE is solar-to-fuel efficiency. From the paper, " We also calculated the solar-to-fuel conversion efficiency (SFE) for our photochemical process (Fig. 2C), obtaining a value of ~4.6% limited by the maximum efficiency of the PV-a-si-3jn cell (~6.0%) (13, 20). This SFE is higher than that of the water-splitting reaction (~2.5%) previously measured using an identical triple-junction photovoltaic (PV-a-si-3jn) cell (20). " https://d2ufo47lrtsv5s.cloudfront.net/content/sci/353/6298/467/F2.large.jpg https://d2ufo47lrtsv5s.cloudfront.net/content/sci/353/6298/4...
    • spqr0a1 10y ago
      For comparison, most crop plants get 1-2% solar to biomass efficiency on the high end.
• mchannon 10y ago
  In addition to lack of performance numbers, they misstate the amount of sunlight hitting earth by a factor of 10- it's supposed to be 1000 W/m2, not 100.
  • imaginenore 10y ago
    100w is closer to reality for most places. 1000W per meter squared is an ideal case for some near-equatorual desert at noon with very clean air.
    • mchannon 10y ago
      Sorry, no. 100W/m2 is highly unusual for any place on Earth. Take the most overcast midday conditions you can imagine and they'll exceed 100W/m2 by a comfortable margin. That can be in Germany, Canada, Colombia, or Antarctica. If it's sunny, it's very close to 1000, no matter where you are. Partly cloudy can even exceed 1000, since clouds can reflect additional sunlight onto the ground. Then there's of course nighttime, which is 0 W/m2. You will have to work really hard to find conditions of 100 W/m2, which is why they standardize on 1000, itself quite straightforward to find anywhere on Earth. "10% sounds right" is specious.
      • detaro 10y ago
        For Germany the yearly average is 110 W/m² or so. Clear summer days go to >1000, but nights and bad weather days push the average down. Maybe they meant that in the article, maybe they missed a zero. If they meant it, it seems like an odd comparison without data if the cell scales with power. If it doesn't, it can't properly utilize bright days and would miss out on most of that average power.
      • imaginenore 10y ago
        Sorry, yes. You're only counting the peak hour of the day. And yes, there's also nighttime, morning, afternoon, and evening. And guess what, nighttime is not zero. The moon gives off some light too.
• ivan_ah 10y ago
  paper: http://science.sciencemag.org/content/353/6298/467 http://science.sciencemag.org/content/353/6298/467 (paywall), but it's available on sci-hub.cc
  • Mizza 10y ago
    http://science.sciencemag.org.sci-hub.cc/content/353/6298/467 http://science.sciencemag.org.sci-hub.cc/content/353/6298/46...
• deleted 10y ago
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• runeks 10y ago
  This is wonderful! We're surrounded by life forms that turn water, CO2 and sunlight into energy. I figure there must be some way to harness this process. I wonder how much power a large tree takes in from its leaves. If we could interface with its root system, perhaps we could extract newly created starch, and either store it or burn it off. Image a huge concrete power plant with large trees growing out of it.
  • eloff 10y ago
    No, that's not likely to happen. Photosynthesis is pretty inefficient, typical plants have a radiant energy to chemical energy conversion efficiency between 0.1% and 2%. Most commercially available solar panels have more than 10 times this efficiency.[1] [1] http://physics.stackexchange.com/questions/109739/is-plant-photosynthesis-more-efficient-than-solar-panels http://physics.stackexchange.com/questions/109739/is-plant-p...
    • doctorpangloss 10y ago
      Sure, but I bet your solar panels don't manufacture and maintain themselves. To the GP's point, the total cost of ownership of a plant that makes gasoline-level fuel is going to be more about water and land than anything else. But the efficiency of solar panels, considering their subsidies, the rare minerals used in their manufacture, their delivery and their maintenance... I'm confident it's a lot less than e.g. coal, even accounting for pollution costs, because if it really were cheaper all-around we'd be using it everywhere!
      • maxerickson 10y ago
        If you look at trajectory, coal is in decline and solar panels are being installed at a great clip. The decline in coal is mostly due to natural gas, but in the US, generation from solar tripled between 2013 and 2015. https://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=epmt_1_1 https://www.eia.gov/electricity/monthly/epm_table_grapher.cf...
      • skriticos2 10y ago
• sdenton4 10y ago
  Interesting that it's a combination of hydrogen and carbon monoxide that it produces. Wonder what the safety implications are.
  • pizza 10y ago
    Could a catalytic converter be used to create CO2 from CO? edit: I forgot what it took as input for a sec there..
    • lisper 10y ago
      > Could a catalytic converter be used to create CO2 from CO? You don't need a catalytic converter, you can just burn it. But breathing a sigh of relief that we can "safely" dispose of the CO in this way is missing the point rather badly.
  • ams6110 10y ago
    CO is easy to convert to CO₂, just burn it and feed the CO₂ back into the process.
  • twic 10y ago
    As it says in the article: "the artificial leaf delivers syngas, or synthesis gas, a mixture of hydrogen gas and carbon monoxide. Syngas can be burned directly, or converted into diesel or other hydrocarbon fuels." Hydrogen and carbon dioxide are the feedstocks for the Fischer-Tropsch process, which produces conventional hydrocarbon fuel: https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_process https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces... In other words, H2 and CO are exactly what you want!
    • evgen 10y ago
      Probably also worth noting that syngas is the primary input for the Haber-Bosch method used to generate the ammonia feedstock for most of our synthetic fertilizers. If you just take the CO and pump it underground then you are actually producing fertilizer for agriculture using a carbon negative process.
• gravypod 10y ago
  I'd love to see how this would work in my use case. I enjoy brewing alcohol and if I could capture and tap into that with a system like this I'd probably get a better yield then the average user. It would be cool.
• retox 10y ago
  I don't want to poo-poo this achievement, but is another burnable fuel really what we want at this point?
  • maxerickson 10y ago
    If it captures CO2 and can make something like methane or butanol, hell yes. Hydrocarbons have great energy density and simple ones burn clean. If you take the carbon out of the atmosphere, you are net 0 when you burn it back in.
  • deegles 10y ago
    It could be pumped underground to capture the CO2 permanently.
  • eloff 10y ago
    I'm going to say yes, very much so. Remember the carbon here is coming from the atmosphere, so it's carbon neutral and won't contribute to climate change. If the process can be scaled up to produce a gallon of gasoline for less than the costs of extracting crude from the ground and refining it - then it will quickly kill off new investment into the fossil fuel extraction industry. As opposed to alternate energy technologies, like electric cars which will take a long time to replace internal combustion engine cars. It would use all of the existing infrastructure, so all it has to be is cheaper for market forces to work their magic. That's a very big IF, however, so don't get your hopes up.
  • busterarm 10y ago
    But it's CO2 in, CO2 out... It's more like using sunlight to recycle CO2...
  • ebiester 10y ago
    If we had ways to take more CO2 out of the atmosphere, and this was close to carbon neutral, there's no reason to use something like this.
  • usefulcat 10y ago
    Yes, because burnable fuels are usually far more energy dense than batteries, and also as others have pointed out because this process is carbon neutral. Maybe someday we'll have significantly better batteries, but until then..
• loeg 10y ago
  So it's 20x cheaper than the noble gas version — what's the absolute cost? I assume it's not cheaper than pumping fossil fuels yet, but I'm curious to know how far away it is.
  • willvarfar 10y ago
    Yeah, this sentence in the middle of the article: > The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete. Doesn't actually say that this is at a cost comparable to a gallon of gasoline :) Sly words.
    • loeg 10y ago
      It would be pretty shocking if it was already cost comparable, of course :-).
      • Dylan16807 10y ago
        Sure, but there is a big gap between "we can see a path to getting there with mass production" and "sure would be nice, wink"
    • epistasis 10y ago
      I don't get the "sly" part; talking about implications of the work is important, as well as future goals, and the sentence is extremely clear. You'd have to be an idiot to think that they're claiming to be that cost effective, and generally that type of person would not have made it through the intro paragraphs.
• tener 10y ago
  This development is exciting, but the complexity of the chemicals involved looks scary. I wonder if it will impede the adoption. Anyone with the domain expertise to comment on this?
• sevenless 10y ago
  > Authors: Mohammad Asadi, Kibum Kim, Cong Liu, Aditya Venkata Addepalli, Pedram Abbasi, Poya Yasaei, Patrick Phillips, Amirhossein Behranginia, José M. Cerrato, Richard Haasch, Peter Zapol, Bijandra Kumar, Robert F. Klie, Jeremiah Abiade, Larry A. Curtiss, Amin Salehi-Khojin I wonder how many of the scientists who made this discovery would be banned from entering the United States by Donald Trump and the Republican Party.
  • sandworm101 10y ago
    Possibly none. Those names don't suggest foreign birth let alone religion or race. Plenty of native-born Americans have such names.
  • jrapdx3 10y ago
    Don't know of course, though it appears to be a "diverse" group who worked on the project. The salient point is Trump has made it clear he was talking about illegal entrants and delaying entry for individuals coming from areas where terrorism is endemic, until a vetting process is established. There are a great number of professionals from Muslim countries regularly admitted who contribute to American society and culture and that would not change.
    • CoryG89 10y ago
      > and delaying entry for individuals coming from areas where terrorism is endemic, until a vetting process is established. I hate to even further the discussion on this off-topic subject, but the above is simply not true. Here is the official statement (still published in it's original form) directly from Donald Trump's website: > Donald J. Trump is calling for a total and complete shutdown of Muslims entering the United States until our country's representatives can figure out what is going on. This is a far cry from "individuals coming from areas where terrorism is endemic". Regardless of your stance on politics, what that statement suggests is blanket discrimination based on religious belief. https://www.donaldjtrump.com/press-releases/donald-j.-trump-statement-on-preventing-muslim-immigration https://www.donaldjtrump.com/press-releases/donald-j.-trump-...
• Animats 10y ago
  "Nanotechnology" again. It's just surface chemistry, people. It's nice that they can do this in the lab, but as usual, the PR is excessive. "The ability to turn CO2 into fuel at a cost comparable to a gallon of gasoline would render fossil fuels obsolete." At least get to pilot plant stage before issuing statements like that. Especially since UC Berkeley announced a similar breakthrough last year.[1] Wikipedia points out that artificial photosynthesis was first achieved in 1912, and some of the same claims were made back then. There are lots of artificial photosynthesis projects. One of the best was in 2011, the first "artificial leaf"[3]. It ran for 44 hours. The usual questions apply. How efficient is this? Does the catalyst get used up, or crud up with contaminants, and if so, how fast? What limits the life of the system? What are the costs like? (Excessive catalyst cost has been a problem.) Is this better than all the other groups doing similar work? Artificial photosynthesis may be useful someday, but this probably isn't the big breakthrough that makes it a commercial product. That may come, though. [1] http://newscenter.lbl.gov/2015/04/16/major-advance-in-artificial-photosynthesis/ http://newscenter.lbl.gov/2015/04/16/major-advance-in-artifi... [2] https://en.wikipedia.org/wiki/Artificial_photosynthesis https://en.wikipedia.org/wiki/Artificial_photosynthesis [3] https://www.acs.org/content/acs/en/pressroom/newsreleases/2011/march/debut-of-the-first-practical-artificial-leaf.html https://www.acs.org/content/acs/en/pressroom/newsreleases/20...
  • valgaze 10y ago
    Serious question: Is there a sassy phrase in the hardcore research world for over-hyping discoveries? Like how we can identify "vaporware" as a concept since we have a word for it. If not there really should be
    • deleted 10y ago
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  • kevinalexbrown 10y ago
    The press release at least attempted to answer some of your 'usual questions'.
    • 10y ago
• OscarCunningham 10y ago
  From the title I thought the article was going to be a sarcastic description of plants.
  • agumonkey 10y ago
    I can't help but picture life of the next millenium to be "men that understand nature":
  • taneq 10y ago
    Even if it's completely inorganic, plants (or algae cultures, etc) are a necessary comparison for anything like this, but that never seems to come up. It's like announcing the invention of the motor car without comparing it to a horse.
    • adwn 10y ago
      > Even if it's completely inorganic, plants (or algae cultures, etc) are a necessary comparison for anything like this, but that never seems to come up. Probably that's because plants are typically only 2-3% efficient when it comes to their use of sunlight, and then it's still a long way (energetically and logistically) to usable fuel or electricity. Plants are really not a good comparison benchmark here.
      • gregschlom 10y ago
        Given that we are currently using plants such as corn to make biofuel (at an industrial level, not just in the lab), I think it's actually a very valid comparison.
• calebm 10y ago
  I wonder what the effeicency is compared to growing and burning trees (which of course, also capture CO2 and sunlight and turn them into burnable fuel).
• nether 10y ago
  How many times per year do we see this? I'll give a shit when I can buy a panel of these cells off Amazon.
• ckcortright 10y ago
  One way to make a system like this one more efficient/cost effective would be to draw the CO2 from ocean surface water which has a much higher concentration than the atmosphere, depending where you are in the world.
  • semi-extrinsic 10y ago
    Flue gases with a high CO2 content are better than cheap; people will actually pay you to get rid of them. And we have a lot of them (this is kind of the problem in the first place). If you look at something like the exhaust from an oxyfuel turbine, you can get 70/30 N2/CO2 with relatively high purity. For this reason, I'm always skeptical of atmospheric capture projects. It's just got to be more efficient to capture from a mixture with 20% (or more) CO2 than from a mixture with 0.04%.
    • ckcortright 10y ago
      Cool idea to go straight to the source. I wonder if the same type of technology would be applicable. Likely not based on rate of reaction.
      • semi-extrinsic 10y ago
        My guess is that existing CCS technologies (such as amine-based separation) are much more efficient at high CO2 concentrations.
    • danieltillett 10y ago
      Actually if the CO2 absorbent is efficient it is not much harder to capture CO2 from the atmosphere than from flue gas. The key really is the CO2 flux rate which wind provides. The real advantage of atmosphere capture is you can do the capture where the cost is lowest, not where the CO2 is emitted.
      • semi-extrinsic 10y ago
        > The key really is the CO2 flux rate which wind provides. Indeed. This brings us to the issue of volumes. A useful carbon capture plant needs to capture at least 100 000 tons of CO2 per year (then we need "just" ~ 10 000 such plants). This means each of these minimal plants has to process an air volume of 250 billion cubic meters of air per year. At an air speed of 1 m/s (you can't flow too fast or there is no time for reaction), and assuming a wildly optimistic 50% capture from the filtered air, you need a reaction area of over 15 000 square meters. Mind you, that's the area of the membrane which processes air. Add the auxiliary stuff around it, you can add at least another factor of 100 to the area, so each of your 10 000 plants have to be 1.5x the maximum planned size of the Tesla Gigafactory. And we're being optimistic.
• karma_vaccum123 10y ago
  I am Jack's middlebrow dismissal. Why not just type "pffft" and save us the tedium of pouring through your "references"? This is every comment you post.
  • azernik 10y ago
    Because we care about rigor and accuracy in this forum, and would prefer to be aware if and how the article title and content don't reflect reality. If these comments bore you, skip them.
    • karma_vaccum123 10y ago
      There is nothing rigorous about the ongoing fantasy that random HN commenters know things that no one else does.
      • lifeisstillgood 10y ago
        I have regularly found that random HN commenters often turn out to have years of professional experience in the industries they are commenting on. Its one of the fun parts of reading HN.
        • Gargoyle 10y ago
          But it'd be great to have an "ignore user" function for those few who just google their skepticism.
          • azernik 10y ago
            If their recently-googled skepticism is accurate, then I don't care how cursory it is - it saves me the five minutes of looking up the same sources myself.
          • grapehut 10y ago
            You might want to get the "Hacker News Enhancement Suite" extension. It's incredibly useful for cases like this, for instance I have tagged Animats (the creator of this sub thread) as "faux expert" after reading some of his crypto posts (a topic I know something about) that were written as if he was an expert, but completely and dangerously wrong. Not knowing anything about chemistry, I would've been inclined to believe his post if it wasn't for the Hacker News extension suite, and I can read from someone who actually knows the field
• B1FF_PSUVM 10y ago
  One of these days, some cleverclogs is going to present to the press a black box that stores electrical charge (and even gives back almost all of it when asked politely) with an energy density almost as good as liquid fuels. If he can shut up about it containing liquid fuels that are synthesized on the spot, they'll eat it up and hail the finding of the battery holy grail.
• 67726e 10y ago
  Add unsweetened shebenchnach. C
• vonnik 10y ago
  Isn't it counterproductive to turn it into fuel to be burned? It seems like that would leave us at best at no net new carbon dioxide, when we really should be sucking CO2 out and sequestering it away. How about we turn it into bricks or something...
  • jp555 10y ago
    like how a tree uses solar energy to turn air (CO2) into wood?
  • lrem 10y ago
    Ever heard of concrete? ;)
  • the_duke 10y ago
    Well, there is nothing out there that can equal the energy density of fossil fuels, which would be essential for powering trucks, buses, airplanes, ships, tanks .... And if we ever get batteries to be competitive, it's a long, long way of.
  • drcode 10y ago
    A car using this stuff wouldn't need to refuel as frequently as one that uses a battery (environmental concerns are an orthogonal issue)
  • neltnerb 10y ago
    It's counterproductive in the sense that you'd be guaranteed to reduce carbon emissions more (globally) if you were to instead just not burn fossil fuels at all. If you took the solar cell part and just used that electricity to displace carbon fueled power plants, you'd end up ahead. That said, for a little while at least, having liquid fuels is inherently given a bonus relative to electricity only. Of course, you can just make those from the original fossil fuel sources as well... Honestly it seems like a bit of a mess since each team solving problems locally rarely has all the expertise needed to see the impact globally. I certainly don't, though I've been studying it for many years. I very much appreciate that things like the CA-GREET models have been trying hard to make it easier to apply wide systems analysis expertise to understand a small part of the overall system without spending years doing the math. But probably it will end up needing to be solved by AlphaGo...
• deleted 10y ago
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• sidcool 10y ago
  This is good finding, but anything substantial will take some time to materialize. But good we are trying to find ways to suck the excess CO2 from the atmosphere.
• fernly 10y ago
  Can anyone comment in a knowledgeable way about the chemicals involved? 1. tungsten diselenide 2. an ionic fluid called ethyl-methyl-imidazolium tetrafluoroborate Just offhand I see selenium in #1, and fluorine and boron going into #2. There's some expense there, and some handling and exposure dangers. If you have a lot of these cells around, are there public health dangers either in handling or in disposing/recycling old ones?
  • selimthegrim 10y ago
    WS2 should be a relatively inert wafer/flake, the desirable property is the so-called van Hove singularity in the electronic density of states that makes it ideal for solar cells.
• ryanmarsh 10y ago
  I can think of another way you can take sunlight and CO2 and produce a burnable fuel...
• Ultimatt 10y ago
  You mean growing trees for wood fuel...
• johnchristopher 10y ago
  More `burnable fuel` doesn't seem to be part of any answers to climatic change though.(haven't read the whole article yet)
• known 10y ago
  Is it scalable to drive a Car?
• Quequau 10y ago
  I think what would make for a larger breakthrough is a process which produced a replacement of cement aggregates from air or sea water at gigantic industrial scales.
• kelvin0 10y ago
  Another interesting concept from Daniel Nocera a few years ago (Sun Catalytix), seemed to be full of promise as this one. http://www.forbes.com/sites/michaelkanellos/2014/08/26/mit-curse-part-ii-lockheed-martin-scoops-up-sun-catalytix/#287da5446da8 http://www.forbes.com/sites/michaelkanellos/2014/08/26/mit-c... It looks like these great promises never quite reach the level where they can get to market and create the impact they claim. Trust me, I really wish it were different, and I root for each and evey one of them to succeed. Maybe military and big corp. snatch the tech before they reach consumers (most likely).