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Wednesday, April 25, 2007

Making Gasoline from Carbon Dioxide

A solar-powered reaction turns a greenhouse gas into a valuable raw material.

By Kevin Bullis
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Solar splitter: An amber-colored semiconductor (gallium phosphide), together with metal contacts, is part of a new device that uses solar energy to split carbon dioxide to make carbon monoxide.
Credit: Aaron Sathrum, UCSD

Chemists have shown that it is possible to use solar energy, paired with the right catalyst, to convert carbon dioxide into a raw material for making a wide range of products, including plastics and gasoline.

Researchers at the University of California, San Diego (UCSD), recently demonstrated that light absorbed and converted into electricity by a silicon electrode can help drive a reaction that converts carbon dioxide into carbon monoxide and oxygen. Carbon monoxide is a valuable commodity chemical that is widely used to make plastics and other products, says Clifford Kubiak, professor of chemistry at UCSD. It is also a key ingredient in a process for making synthetic fuels, including syngas (a mixture largely of carbon monoxide and hydrogen), methanol, and gasoline.

The work is part of a growing effort to find practical uses for carbon dioxide, a leading greenhouse gas, says Philip Jessop, professor of chemistry at Queen's University, in Ontario, Canada. Converting carbon dioxide into carbon monoxide is difficult to do, which Jessop says makes the UCSD work impressive and exciting.

At least at first, such a process will not make a significant impact on reducing greenhouse gases in the atmosphere--that would take quite large-scale operations, Kubiak says. But "any chemical process that you can develop that uses CO2 as a feedstock, rather than having it be an end product, is probably worth doing." He adds that "if chemical manufacturers are going to make millions of pounds of plastics anyway, why not make them from greenhouse gases rather than making tons of greenhouse gases in the process?"

The system may also be part of a solution to a continuing problem with solar energy. For solar panels to be useful when the sun isn't shining, the electricity they produce has to be stored. A potentially practical way of doing that is by converting the electrical energy into chemical energy. One popular approach is to use solar cells to produce hydrogen, which could then be used in fuel cells. But hydrogen gas is much more difficult to transport and store than are liquid fuels, such as gasoline, which contain far more energy by volume than hydrogen does. The UCSD system shows that it is possible to use solar energy to make carbon monoxide that then, together with hydrogen, can be converted into gasoline. Currently, carbon monoxide is made from natural gas and coal. But carbon dioxide is a more attractive raw material in part because it's very cheap--indeed, it's something industrial companies will pay to get off their hands, Jessop says. "There are very few chemicals which are cheaper than free, and carbon dioxide is one of them," he says.

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carbon dioxide catalysts nanoparticles solar power

Comments

  • This needs the immediate attention of governments everywhere.
    zippo on 04/25/2007 at 12:13 AM
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    *sputter*-*chokes an last gulp of Fanta*

    Cool... gasoline sans petroleum or coal. Here that whistling noise? It's the sound of plummeting gas prices. :-)

    I think I remember seeing this guy in a PBS doc too. It had something to do with manned Mars missions like the article mentions.
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  • Also possible with other energy sources?
    greeninventions.net on 04/25/2007 at 2:28 AM
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    If I understood this article right gasoline from carbon dioxide can be produced with any energy source, for instance wind energy which has the same “storage problem” as solar energy. I am curious about the feasible efficiency, can it compete with the electric car development since batteries are improving very fast?

    http://www.greeninventions.net
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    • Re: Also possible with other energy sources?
      Hardheadjarhead on 04/25/2007 at 10:55 AM
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      As to whether it can compete...given the development of electric/plug-in/hybrids...I'd say yes.

      It mentioned plastics could be formed from this process.  We still need those.  Further, hybrids need a fuel sources.  The "Volt" concept car's hydrogen fuel cell isn't perfected yet, so the generator will run off of gas or ethanol.

      If this process could be made efficient and cheap, one could hope that the petroleum companies would jump on it and incorporate it. 

      When you think about it, a concrete manufacturing plant would be able to use this to defray their production costs by taking their power bills down.  Any plant that produced CO2 could use it.
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    • Re: Also possible with other energy sources?
      MPERRY on 08/09/2007 at 2:15 PM
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  • What about the platinum...
    mdufourneaudravel on 04/25/2007 at 3:27 AM
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    Hello,

    I think the development of this technology would be limited, as for the fuel-cell, by its need of platinum.

    Best regards.
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  • how do you get the CO2?
    djs on 04/25/2007 at 4:48 AM
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    Combining CO2 with H2 to make syngas (and thus methanol), methane or other products is existing technology. Where do  you get the CO2? Isolating it out of air is not a serious option.
    Storing H2 from solar powered water electrolysis in the form of methanol or indeed gasoline would be best done by combining the hydrogen with biomass (wood, straw, etc)-derived "carbon" (CO, most conveniently)
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    • Re: how do you get the CO2?
      winthrom on 04/25/2007 at 10:23 AM
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      CO2 is the byproduct of coal fired combustion. It is most easily collected at coal fired power-plants from the stack gases.
      The process  of >Making Gasoline from Carbon Dioxide< may also be accomplished by a more direct process using a methanol fuel cell technology in reverse.
      "Interview of Professor George OLAH (Nobel Prize, 1994)"
      http://www.ecolo.org/documents/documents_in_english/methanol_olah-06.htm
      "The second approach involves carbon dioxide. We were co-inventors of the direct methanol fuel cell. This fuel cell uses methanol and produces CO2 and water. It occurred to us that maybe you could reverse the process. And, indeed, you can take carbon dioxide and water, and if you have electric power, you can chemically reduce it into methanol."

      The methanol can then be reacted as follows:
      http://chemelab.ucsd.edu/methanol/memos/final.html
      "The MTG process was discovered by accident by researchers at Mobil corporation. They had been trying to use zeolite ZSM-5 to convert methanol into a fuel additive. The process instead produced dimethyl ether, which with increasing space time next produced olefins (alkenes), and finally paraffins (alkanes) and aromatics. This mixture of paraffins and aromatics is commonly known as gasoline."
      The power to run the methanol fuel cells would come from any source for direct use, e.g., wind, solar, wave, geo-thermal, nuclear, etc. The benefit of this approach is that the existing infrastructure (gasoline, service stations, refineries (blending centers), auto manufacturing, 100 million cars on the road, etc.) all remain viable and CO2 emissions get cut at least 1/3! In due course, the sustained dependance on foreign oil as feedstock for gasoline can be ended.
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      • Re: how do you get the CO2?
        richard schumacher on 04/26/2007 at 9:30 AM
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        But using CO2 from fossil-fuel-fired power plants only delays its addition to the atmosphere, so that process would still add to global warming.  Instead we will ultimately have to collect CO2 from the air.  This could be done biologically or with artificial photosynthesis, but the area required for collecting sufficient Sunlight may make these methods impractical.  A more compact alternative is to mechanically condense CO2 from the air, then dissociate it into CO + O via electrolysis or a reverse fuel cell, and proceed from there.  That of course requires a large energy input from carbon-neutral sources (nuclear, etc.).  It will soon be illegal to use fossil derived carbon so we need to intensively explore ways to manufacture liquid hydrocarbon vehicle fuels.  
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        • Re: how do you get the CO2?
          winthrom on 04/26/2007 at 11:43 AM
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          "But using CO2 from fossil-fuel-fired power plants only delays its addition to the atmosphere, so that process would still add to global warming.  Instead we will ultimately have to collect CO2 from the air."
          >>>>>>>>Right on both counts!
          A: Reducing CO2 from power plants delays the inevitable >>if, and only if<< we burn the products we create without further measures.
              1. Scaled up considerably, we can eventually recycle the carbon: I.e., use the methanol for electric power plants. (I.e., methanol becomes a portable, and sellable, energy storage medium for solar/wave/wind collection systems).
              2. We can choose to use the methanol carbon products to make plastics, etc. Chosen wisely, we can make bio-degradeable plastics for construction, etc. This lessens the use of foreign oil and sequesters the carbon.
          B: Collecting CO2 from the air, via the time honored air liquification process, will provide a source of CO2 raw material. This might also use solar/wave/wind as a power source. This becomes viable when local sources of powerplant CO2 become uneconomical to exploit.

          Both of these solutions are feasable, but the problem is getting such a program to be economically viable from an investor point of view. At first, the best invsetment is to support the coal/oil companies (mostly they are the same), and the infrastructure industries (like car companies and fuel distributors) while pulling down the CO2 emissions. Re-using CO2 as a raw material in large scale production (10 - 15 years) will allow us to then realize that the extraction of CO2 from the atmosphere is a means to generate saleable energy/plastic products to less advanced (politically/economically) countries. In the end, the problem may become "not enough CO2".
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        • Re: how do you get the CO2?
          fran on 07/01/2007 at 7:42 PM
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          Richard, you say:

          "But using CO2 from fossil-fuel-fired power plants only delays its addition to the atmosphere, so that process would still add to global warming."

          Whether this is so or not depends on whether there is a negative impact on the harvest and combustion of new quanta of existing fossil hydrocarbons.

          Clearly, if this process were economically and energetically feasible, but simply added to cheap hydrocarbon inventories, it might simply lead to more profligate hydrocarbon combustion -- with no net gain in GHG-emission reduction. (There might still be some other benefits of course) The same objection could be made of course to biofuel use.

          This however, seems unlikely, especially if some form of lifecycle-based carbon trading or emissions taxes regime came in. I suspect that there are better uses for solar and other low footprint energy sources than this process, and that old-fashioned photosythesis using algae are going to have rather larger pay offs.

          You also claim in passing that nuclear energy is "carbon neutral". This simply isn't so. At the moment, enormous amounts of fossil energy (mostly diesel fuel) are used extracting uranium oxide, dealing with the overburden and pumping water for filtration. Then there's the energy associated with plant construction and the pouring of all that concrete. And of course, nuclear plants and the transport of nuclear materials require massive security all of which requires considerable fossil energy. And as uranium oxide concentrations fall, EROEI will only decline and CO2 footprints rise.

          I'm not aware of any energy production technology that is absolutely carbon-neutral. Some of course are far lower than others in lifecycle terms. In terms of nuclear, use of Thorium as the fertile material would be far lower than what is done now, because there's a lot more Thorium about, and the resultant material isn't as hazardous.

          But really, for low carbon footprint technologies that can be used ubiquitously, it's hard to beat biomass (especially from waste sources) and wind/wave/tidal. 

          Fran



           
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  • What about the hydrogen?
    robert.hargraves on 04/25/2007 at 6:25 AM
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    Using CO to make gasoline or other hydrocarbons like methanol requires hydrogen, which is energy-expensive to obtain. One way to get the energy to separate the hydrogen from H2O is to use a high temperature gas reactor, such as a pebble bed reactor, which can attain temperatures of 850-950 C, using a sulfur-iodine or high temperature electrolysis technology. Plese look at pebblebedreactor.blogspot.com.
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    • Re: What about the hydrogen?
      james2004bwhite on 02/26/2008 at 2:11 PM
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      I have an idea the would be a great way to convert Carbon Dioxid (CO2) gases into usable fuels.  First the CO2 gases from a regular automible is bubled (mixed with) through heavy Salt Water so that a mist of CO2+H2O is created. Then the mixed water and CO2 is the run accrost an ecectro magnet core made of a piece of soft steal wraped with electro magnet copper wire. As the gases CO2 Water mist passes paralel (they must be going in the same direction as the electromagnet in order to be affected) to the electro magnet, electrons from the electro magnet are added when the CO2=H2O mist pases as the electrons in the fule are alined with each other and the Electrons of the magnetic field, therein producing a plazma (electoron combined fuel)of hydgren-Oxeygen mixed CO2 burnable fuel.  If the raactor core is further heated then the electron coleshion is further enhanced as the electron activity is then increased to produce and a better burnable fuel.  The process is simple since the Automiblie has an abundance of CO and CO2 and there is pleanty of Salt Water.   Any amount of this burnable fuel could then be added to the automobile to enhance the fule economy and elliminate all smoge, as then all the extra CO and CO2 Carbons would then be utalized therin increacing (doubleing) the car's milage?   Well Hope this idea works, and of course if it does, don't forget to sent the royalty checks!? Thanks JW
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  • Why not store electricity by compressing air?
    architectrb on 04/25/2007 at 1:48 PM
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  • Interesting science... but
    rhapsodyinglue on 04/25/2007 at 2:46 PM
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    It's interesting as materials science research, but there's no way this will be an economically viable source of liquid fuels.  This process is based on a rather expensive semiconductor technology, which I'm sure is less efficient from a solar energy standpoint than current state of the art PV technology (probably uses limited freq range of sunlight).  In addition then you have to have a source of H2, which we already know is expensive and an inefficient use of energy.  So we end up with... the world's most expensive petrol.

    Better to use the solar to generate electricity either through PV or concentrating solar thermal, and if you want new nuclear in the mix just use it for electricity rather than H2 production.
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    • Re: Interesting science... but
      foggy on 04/25/2007 at 8:06 PM
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      quoting from the article: "At the anode--a catalyst made of platinum--water is converted into oxygen."

      Water cannot be converted to oxygen without also making hydrogen. That's where the hydrogen comes from, if the article is correct.
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  • A much better idea than this..
    TimeTraveller on 04/26/2007 at 10:21 AM
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    ..duh
    Trees, grass, algae. All use sunlight to convert CO2 to carbon compounds, mainly sugar. Plant them, forget them.  I can't believe anyone would seriously invest time and energy in a technological solution when the solution exists already. Imagine, no mining  to get silicon ores, no refineries producing heavy metal residues, not energy consumed to transport and manufacture the solar cells.
    This is just a stupid stupid stupid idea..
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    • Re: A much better idea than this..
      brunascle on 04/26/2007 at 11:14 AM      		 Technology Review TR Staff
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      you're talking about biofuel (e.g. biodiesel). that has it's place, but the advantage of creating gasoline instead is that it can work with the cars still on the road.

      biofuel is probably the better idea in the long run, but IMO bio-gasoline is an excellent way to transition the current system to that system.
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      • Re: A much better idea than this..
        TimeTraveller on 04/26/2007 at 1:01 PM
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        >>your talking about biofuel
        in part yes, but my main point is if you want to suck CO2 ot of the atmosphere, the "technology" exists, is so simple a 5 year old can do it (eg plant a tree) and the only environmental impact is positive. All you get with this lame solar cel idea is precursors which require even more energy to convert to gas, since CO is still a few energy leaps away from CH4  eg you still have to add energy to break the C-O bond and get CH4 or other alkane fuels from CO. Any energy that the subsequent fuel has, has got to be put into it first and where is that going to come from?
        Bioproduced sugars and cellulose can be fermented by organisms to give ethanol. The only energy that needs to be added is distillation, and even that can be sucked from the ambient environment ( read solar again! ) by lowering the pressure in the distillation vessel. Ethanol can be a raw material for a huge number of fuels and materials. Other possible raw materials are the oils and waxes produced by many organisms. These products are what produced petroleum in the first place.  At the end of the day wood, coal, petroleum, solar, hydro  are just stored solar energy.
        Solar cells are probably the worst possible method of using the energy of the sun.
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        • Re: A much better idea than this..
          rhapsodyinglue on 04/26/2007 at 3:59 PM
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          Concentrating solar should certainly have it's place, especially here in the Southwest US.  Solar water heaters as well.  Both of these are proven technology that compare very well with other sources of energy when one considers the external costs.
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      • Re: A much better idea than this..
        trevmonster on 04/28/2007 at 4:15 AM
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        The best bio fuel in my mind is bio deisel (Vegetable/seed based oils) which requires very little processing from the raw material. The standard deisel engine can use it. All trucks and heavy machiner already are deisel so there is a good starting point. The life of a vehicle is only 10 years so that is a resonable rate for the conversion of all vehicles to be deisels. Lets start now. Its a no brainer.
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    • In the End, It's All solar
      nick47g on 04/27/2007 at 10:15 AM
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      Well Said, Time Traveler!!  Increasing, not destroying, greenspace, coupled with conservation, are the bigest part of the answer.

      Beyond that, all Alt-Energy except for nuclear is solar based, whether wind, biomass, photovoltaic etc.  So the real question is WHAT GIVES US THE BEST BANG PER ACRE???

      In the mean time, what remediation can be used ECONOMICALLY for any given polution or greenhouse source?

      Every little bit helps.
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    • Re: A much better idea than this..
      reallynolie on 07/03/2007 at 11:28 PM
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      Plants alone will not be enough.  Since man has first started the industrial revolution more CO2 has been made than consumed by plants.  Considering this is since the rain forests and plants on the earth were at their greatest numbers plants don't have a chance now.
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  • energy
    drhall on 05/06/2007 at 3:15 PM
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    1. energy conversion expense ... ridiculous
    2. components ... expensive
    3. solar on its own provides all the answers!
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  • Mining carbon dioxide from the air.
    Hardheadjarhead on 05/10/2007 at 3:03 PM
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    Well, we now can mine carbon dioxide from the air:

    http://www.livescience.com/technology/070501_carbon_capture.html

    Sounds like an ALMOST zero sum game.  We could essentially make gasoline at a nuke power plant.
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  • IGCC power plants
    bbrown on 05/31/2007 at 10:08 PM
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    Since IGCC power plants use coal or another fuel to produce CO and hydrogen in the gasifier process to power the plant and produce CO2 as a result of combustion, why can't the waste CO2 be broken down into the CO the plant uses in the first place and used as the feedstock in a closed loop?  You would lose one of the power cycles when the fuel is gasified, but you would use the waste as fuel in the second power block.  The CO feedstock from the waste CO2 would be clean and wouldn't require pollution clean up.  Solar could be an ancillary part of the IGCC plant feeding both electricity into the grid and CO into the plant.
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  • Oxygen formed at the anode
    meenakshi on 06/03/2007 at 4:06 PM
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        When photons are converted into electrons do they not convert the H+ ions of the water molecules to hydrogen.I can assume that the CO2 undergoes reduction with Hydrogen to form carbon monoxide.
         From the article I conclude that electrons react with platinum catalyst at the anode to form oxygen molecules and at the other electrode carbondioxide reacts with electron to get reduced to carbon monoxide.Can the reaction process be explained in detail,since I am unable to comprehend the process.
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  • Can they directly remove the CO from emissions?
    reallynolie on 07/03/2007 at 11:34 PM
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    Catalytic converters were added to gas engines to convert CO to CO2.  This was done to remove smog (carbon monoxide).  If this had not been done North America would be covered in 500' of smog by now.  If there was a way to directly remove the CO from emissions this would save a lot of energy required for the conversion from CO2 back to CO.
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