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Earth Power Science Technology

New Process Takes Energy From Coal Without Burning It 365

rtoz writes "Ohio State students have come up with a scaled-down version of a power plant combustion system with a unique experimental design--one that chemically converts coal to heat while capturing 99 percent of the carbon dioxide produced in the reaction. Typical coal-fired power plants burn coal to heat water to make steam, which turns the turbines that produce electricity. In chemical looping, the coal isn't burned with fire, but instead chemically combusted in a sealed chamber so that it doesn't pollute the air. This new technology, called coal-direct chemical looping, was pioneered by Liang-Shih Fan, professor of chemical and biomolecular engineering and director of Ohio State's Clean Coal Research Laboratory."
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New Process Takes Energy From Coal Without Burning It

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  • by Irate Engineer ( 2814313 ) on Thursday February 21, 2013 @08:19PM (#42974671)
    Sounds nice, except for the 'combusted in a sealed chamber' bit. How is this going to scale up so they can feed 100 tons/hr through the plant cycle? That is the question.
    • by Spy Handler ( 822350 ) on Thursday February 21, 2013 @08:35PM (#42974793) Homepage Journal

      just build it bigger!

      Or if that can't be done economically, just build millions of little ones!

      Oh that's not economically feasible either because each one requires a lot of labor to build? Hmm.... *thinks*

      Ok let's just forget about the whole thing and go nuclear.

    • by vidnet ( 580068 ) on Thursday February 21, 2013 @08:37PM (#42974805) Homepage

      The part that worried me was more the fact that CO2 was still produced, it was just contained within the chamber (the benefit of their technique seemed to just be less/no air space required in the chamber).

      Sequestering CO2 is not simple, and is currently done mostly by pumping it into used oil fields. It's not certain whether these costs were factored in.

      • by MBCook ( 132727 ) <foobarsoft@foobarsoft.com> on Thursday February 21, 2013 @08:46PM (#42974899) Homepage

        Coal is 84% carbon, 10% oxygen, 4% hydrogen, and 2% nitrogen (or so). Short of nuclear fission or fusion, you're going to get carbon and oxygen out of it no matter what you do.

        The question is how much energy you get out. If this process were twice as efficient (in terms of CO2 per MW) then it would still be a worthwhile improvement wouldn't it?

        • by trout007 ( 975317 ) on Thursday February 21, 2013 @09:07PM (#42975063)

          You are forgetting the other part of the reaction. Air is 78% Nitrogen and 21% Oxygen. In this reaction the Iron removes the Oxygen from the air before it gets into the reactor. So no Nitrogen in the reactor means NOx and no Nitrogen gas to remove from the waste stream.

        • by AJWM ( 19027 ) on Friday February 22, 2013 @02:11AM (#42976761) Homepage

          Coal is 84% carbon, 10% oxygen, 4% hydrogen, and 2% nitrogen (or so). Short of nuclear fission or fusion, you're going to get carbon and oxygen out of it no matter what you do.

          Now there's an idea. You'd actually get more energy running the 0.0...whatever percent thorium that's in coal through a fission reactor than you do by oxidizing the carbon.

      • by icebike ( 68054 ) on Thursday February 21, 2013 @09:11PM (#42975073)

        Sequestering CO2 is not simple, and is currently done mostly by pumping it into used oil fields. It's not certain whether these costs were factored in.

        Sequestering it is a lot simpler if you can simply draw if off the top of the CLOSED chamber rather than trying to scrub it out of the stack.
        You've got half the battle won already.

        What to do with it long term is another problem. But its a problem you would have anyway, so having the CO2 handed to you all
        contained is better than where we are today.

        Besides coal ash, it appears CO2 is the only by-produce that is not recycled back into the feed-stock.

        But, hey, Clean Coal stories have to be knocked down immediately. We can't have it prove even partially successful under any
        circumstance. /rollseyes.

        • Sequestering = storage. That "other problem" you speak of is what gp was referring to. But pedantry aside, tech like this, gasification and other clean coal plans do solve some pieces of the clean energy puzzle and shouldn't be simply cast aside with a flippant "clean coal lol" comment.
        • What to do with it long term is another problem. But its a problem you would have anyway, so having the CO2 handed to you all
          contained is better than where we are today.

          There are plenty of industrial uses for CO2 and carbon.
          Having it handed to you on a platter is great news.

      • by Charliemopps ( 1157495 ) on Thursday February 21, 2013 @09:20PM (#42975129)

        Sequestering CO2 is easy. You just don't have a clue how it works. The CO2 is pumped into abandon oil fields at VERY high pressures. This actually results in a return of the field to oil production, as the CO2 forces out more oil. The hydrostatic pressure at that depth is so great that it forces the CO2 into its liquid form. It's not going to suddenly escape to the surfaces, it's miles down and under unfathomable pressure. If we had an earthquake strong enough to crack that, we'd have far more to worry about. Like the really nasty gasses getting released from natural fissures or the earth splitting asunder.

        • by dbIII ( 701233 )
          I used to think it was bullshit but it turns out it's been used as a technique to recover more oil for many years before anyone thought of using it for carbon dioxide storage.
        • Re: (Score:3, Informative)

          Except that stuff from down there DOES make it's way up. Nature has a funny way of moving things from high pressure areas to low pressure ones.

          Better to put the CO2 into a stable form rather than just 'another place'.
        • by Tuqui ( 96668 ) on Thursday February 21, 2013 @11:26PM (#42975937) Homepage

          It's not going to suddenly escape to the surfaces, it's miles down and under unfathomable pressure. If we had an earthquake strong enough to crack that, we'd have far more to worry about.

          If you think that nothing could happen, read about Lake Nyos disaster [wikipedia.org].

    • RTFA-ing is the Key! (Score:5, Informative)

      by TubeSteak ( 669689 ) on Thursday February 21, 2013 @08:41PM (#42974851) Journal

      The researchers are about to take their technology to the next level: a larger-scale pilot plant is under construction at the U.S. Department of Energy's National Carbon Capture Center in Wilsonville, AL. Set to begin operations in late 2013, that plant will produce 250 thermal kilowatts using syngas.

      From 25 kw to 250kw
      Sounds like they're scaling it up.

    • by icebike ( 68054 ) on Thursday February 21, 2013 @08:50PM (#42974927)

      Sounds nice, except for the 'combusted in a sealed chamber' bit. How is this going to scale up so they can feed 100 tons/hr through the plant cycle? That is the question.

      The key to the technology is the use of tiny metal beads to carry oxygen to the fuel to spur the chemical reaction. For CDCL, the fuel is coal that’s been ground into a powder, and the metal beads are made of iron oxide composites. The coal particles are about 100 micrometers across—about the diameter of a human hair—and the iron beads are larger, about 1.5-2 millimeters across. Chung likened the two different sizes to talcum powder and ice cream sprinkles, though the mix is not nearly so colorful.

      The coal and iron oxide are heated to high temperatures, where the materials react with each other. Carbon from the coal binds with the oxygen from the iron oxide and creates carbon dioxide, which rises into a chamber where it is captured.

      They ran this for 9 days straight. They only stopped because they were tired. Scaling it up probably is not that much of a problem.
      The bigger problem might be obtaining both the fuel and the oxidizers in quantity economically.

      Coal powered that finely would be rather dangerous, because it has so much surface area. Exposure to air, any spark could set it
      off. Handling it would require special care never to let it flow around or accumulate around the crushers. They might have to
      make it in a slurry just for safety, then waste more heat drying it before use.

      TFA shows them handling bottles of it, and even then they are wearing masks.

      • Coal is routinely pulverized in order to get it to flow with preheated air through the burners and to provide a large surface area to volume ratio for efficient heating and combustion. 100 micrometers is 0.1 mm, small but not microscopic. This is a typical grain size produced by the pulverizer mills.

        You really don't want any sort of small powder to get in your lungs. Coal is not particularly dangerous.

        Coal contains small amounts of mercury, but not much more so than most other natural ores. The problem with
      • by multimediavt ( 965608 ) on Thursday February 21, 2013 @10:04PM (#42975395)

        Coal powered that finely would be rather dangerous, because it has so much surface area. Exposure to air, any spark could set it off.

        Uh, yoohoo, over here! [wikipedia.org] They already use coal dust in existing coal burning power plants. I think they have the processing handling issues down for that bit. And, there hasn't been a major coal dust accident since 1962.

        BTW, for those that trashed my 'we need to stop burning stuff' [slashdot.org] comments regarding how we generate energy. THIS is exactly what I meant. Applause for the researchers. If this does scale and proves out, they should get a Nobel for it!

        'Nuf said.

    • This is the kind of science that will save us from Global warming. I know how grand Solar and wind seem grand, but they aren't powering shit yet. Germany is the shining start of renewable energy right now, and they have 20 old school coal fired plants scheduled to be built in the next few decades. We have a LOT of coal. If there's a clean way to use it, we sure as hell better try. It's going to get used one way or another, and 99% efficiency with easy CO2 sequester seems like a pretty smart way to do it.

      • by Irate Engineer ( 2814313 ) on Thursday February 21, 2013 @09:19PM (#42975119)
        <quote>This is the kind of science that will save us from Global warming. I know how grand Solar and wind seem grand, but they aren't powering shit yet.</quote>

        Wind is powering all sorts of "shit" in Europe. Denmark is pushing about 28% penetration of wind into their power market and many of the surrounding countries have penetrations of 10-20%. And they are building a hell of a lot of offshore wind farms.

        Just because the U.S. is slow to get off its ass doesn't mean the rest of the world is.
    • Pipebomb scalability is limited only by your imagination and supplies on hand.

    • by Weaselmancer ( 533834 ) on Thursday February 21, 2013 @10:12PM (#42975481)

      From TFA:

      No other lab has continuously operated a coal-direct chemical looping unit as long as the Ohio State lab did last September. But as doctoral student Elena Chung explained, the experiment could have continued.

      “We voluntarily chose to stop the unit. We actually could have run longer, but honestly, it was a mutual decision by Dr. Fan and the students. It was a long and tiring week where we all shared shifts,” she said.

      Fan agreed that the nine-day experiment was a success. “In the two years we’ve been running the sub-pilot plants, our CDCL and SCL units have achieved a combined 830 operating hours, which clearly demonstrates the reliability and operability of our design,” he said.

      His entire staff of grad students manned the thing and kept feeding it coal for a week and it ran nonstop the whole time, and could have kept going. So this appears to be a solved problem.

  • by Kenja ( 541830 ) on Thursday February 21, 2013 @08:21PM (#42974683)
    combust:
    Verb
    1. Consume by fire.
    2. Be consumed by fire.
    • by icebike ( 68054 ) on Thursday February 21, 2013 @08:41PM (#42974849)

      A better word might have been "oxidized" but the good professor probably was trying not to confuse the journalism major
      who wrote the story with words too big for their tiny world view.

      Lots of CO2 is produced, but it is retained in the chamber and captured, and oxygen and coal are fed in continuously.
      They operated it for 9 days straight.

      • by MBCook ( 132727 )
        This is a university press release. They probably talked to him and and asked him questions until he put it that way, because "if we say chemically oxidized no one will know what we're talking about". I bet he doesn't use that word in the paper.
    • by gutnor ( 872759 )
      If you really want to be pedantic, your definition is chemically wrong (and the summary actually mentions chemical combustion). Combustion is basically, just an oxydation. Depending how strong/rapid the oxydation is, it is called fire or not.
    • by c0lo ( 1497653 )
      Combustion [wikipedia.org]

      Combustion (pron.: /kmbs.tn/) or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species.

  • huge costs (Score:2, Insightful)

    by Anonymous Coward

    "New technologies that use fossil fuels should not raise the cost of electricity more than 35 percent, while still capturing more than 90 percent of the resulting carbon dioxide. Based on the current tests with the research-scale plants, Fan and his team believe that they can meet or exceed that requirement"

    good luck selling that

  • by SketchOfNight ( 1010207 ) on Thursday February 21, 2013 @08:29PM (#42974755)

    How does the lack of pollution from the process compare against that generated from the acquisition of the coal?
      Is it possible/practical to convert an existing coal power plant?
      Is there an appreciable energy/pollution cost to produce the fine powder coal used in the process?
      How much energy is consumed or how much pollution is produced in transporting the coal to the reactor?
      Is the process itself efficient in regards to the energy output when compared against the total energy costs?

    I'm sure there's a lot of other things that don't spring to mind instantly, but I'm certainly not an expert on any of this. Doubts notwithstanding, this is pretty cool.

    • by LoRdTAW ( 99712 )

      I'll bite...
      "How does the lack of pollution from the process compare against that generated from the acquisition of the coal?"
      In many places, coal is mined using giant shovels that are electrically powered. Underground mines also tend to use electric shovels and other machinery, though not all. From the mine pit or shafts, its either directly loaded into train cars or haul trucks to trains cars. So its pretty much the same.

      "Is it possible/practical to convert an existing coal power plant?"
      Imp

  • No emission-less (Score:5, Informative)

    by OzPeter ( 195038 ) on Thursday February 21, 2013 @08:30PM (#42974761)

    Its not emission-less. If you read his presentation from 2008 you'll see that the C02 is the byproduct of the reaction that is is used to transfer heat to the steam boiler. The C02 still gets generated as before, just now it can be more readily sequestered - assuming that you want to spend the money on that part of the equation.

    Coal Direct Chemical Looping Retrofit for Pulverized Coal-fired Power Plants with In-Situ CO2 Capture [doe.gov] (PDF - but why the hell in this day and age do I need t tell you that? Can't you just look at the link?)

    • by Raptoer ( 984438 ) on Thursday February 21, 2013 @08:44PM (#42974877)

      Even if you don't sequester the carbon and just put it out a smoke stack you're still at an advantage over normal coal burning. One of the major problems with coal burning is not the CO2, but the fly ash that contains heavy metals and causes respiratory problems. This process allows for those heavy metals to be contained in the coal ash which is kept within the plant. Depending on the concentration of metals in the ash it may be economical to mine the ash.

      Additionally since the CO2 is pure it can be used industrially without having to distill out the nitrogen that you would if you got it from regular burning.

  • by Gorobei ( 127755 ) on Thursday February 21, 2013 @08:32PM (#42974769)

    So it captured 99% of the CO2 in a vessel. Great! Now what does it do with it? Vent it to the atmosphere for zero gain?

    Or use some magic zero energy cost process to convert it to chalk or something? Guess the article was missing that.

    This is like Sasha Cohen's Hoverboard invention - it's a plank that real scientists can figure out how to levitate. Can I have venture capital?

  • by kasperd ( 592156 ) on Thursday February 21, 2013 @08:35PM (#42974797) Homepage Journal
    Maybe they can capture the carbon dioxide, but what are they going to do with it afterwards? Put it in a container and bury it underground? The carbon dioxide will still be there, and the only way to get rid of that is through another reaction, which most likely needs energy to happen.

    Another important question is the efficiency. Are they able to produce the same amount of electrical energy from each ton of coal as traditional methods? If their efficiency is worse, then I am very unimpressed. If their efficiency is better, then that may be a more interesting story than that of capturing the carbon dioxide.
    • The CO2 can be fed to algae tanks to continue another energy production process. It would be easier than doing the same with traditional coal plant if the CO2 is clean and not mixed with ash etc.

      • The CO2 can be fed to algae tanks to continue another energy production process. It would be easier than doing the same with traditional coal plant if the CO2 is clean and not mixed with ash etc.

        And when you burn the oil you got from the algae that formerly fossil CO2 is now in our atmosphere. So maybe you got more energy per ton of CO2 out of it than we normally would. You're still filling the atmosphere with fossil carbon.

        'Clean coal' is marketing, pure and simple.

  • So the CO2 san be safely captured and preserved for future generations on this planet.
  • by trout007 ( 975317 ) on Thursday February 21, 2013 @08:51PM (#42974941)

    Reading between the lines the difference is you aren't getting air into the reactor. So you don't have to heat and separate the Nitrogen. It says the iron pebbles are exposed to air in the reactor but I don't think that is entirely accurate. I think they are exposed after they give up their oxygen to the carbon and are still hot but outside of the actual reactor. This would provide an easy way to chemical way to separate the oxygen from the nitrogen. So the only gaseous byproduct is pure CO2 not CO2 mixed with Nitrogen which is harder to process.

    I could be wrong.

  • “Unfortunately, it also produces carbon dioxide, which is difficult to capture and bad for the environment"
    Without carbon dioxide, the carbon cycle wouldn't exist and all plants and animals would die.

  • by Anonymous Coward

    Last I checked, burning is combustion.

    Nor do I understand what the hell is advantageous about it. They admit to oxidiation of the hydrocarbons (ie, burning), heating it to high temperature, and the release of CO2 gas. So exactly what is so great about it?

  • by manu0601 ( 2221348 ) on Thursday February 21, 2013 @10:02PM (#42975381)
    This is nice, we have the opportunity to capture all produced CO2. But what are we going to do with it?
  • by Grayhand ( 2610049 ) on Thursday February 21, 2013 @10:57PM (#42975755)
    For a fuel that requires little or no processing it's extremely energy dense. Ultimately the problem wouldn't be with the process but the budget minded power companies. There's a reason "clean coal" is like bigfoot, largely a myth. Clean coal would cost more money reducing profits. It's the reason the industry doesn't remove mercury and coal dust from the exhaust, reduced profits. They even had a government mandate and the still waited until the deadline and are now saying it's too hard. The process can trap 99% of the CO2, the trick is keeping the power companies from not releasing it into the atmosphere to save money. White Diesel is a great source of fuel and second only to natural gas for being a clean fossil fuel but it involves stripping of the CO2 and you are faced with the same problem. Sequestration isn't as simple as it sounds. Compressing huge amounts of CO2 gas takes energy and the underground storage areas don't tend to be near power plants. When you start burning more coal just to store the CO2 from the last batch the efficiency goes way down. If the existing plants had been positioned and built with all this in mind we wouldn't have all these problems. Now there are no cheap and easy solutions. Personally I prefer using algae or greenhouses to store the CO2. Try this approach, pump the CO2 into large cheap greenhouses that grow Kenaf, it's related to hemp but totally legal and interchangeable with industrial hemp. Use as much as industry needs for fiber and seed oil then turn the rest into biochar, a good one to read up on if you aren't familiar. The char can be mixed with farmland improving the soil and it'll absorb the excess fertilizer reducing run off and reducing the amount needed to grow food. The carbon is stored for thousands of years, if not millions. The power companies get to make extra money off the Kenaf and they greatly reduce the CO2 and mercury released. The Mercury will get trapped in the char and the CO2 will be stored as solid carbon. These days they try to solve everything with technology when mother nature has been doing it for billions of years.
  • by Neil Boekend ( 1854906 ) on Friday February 22, 2013 @02:15AM (#42976779)
    They just burn it with pure oxygen instead of with air. The innovation, and it is an innovation IMHO, is that they used iron to capture and transfer the oxygen. This prevents the forming of NOx, which is a good thing.
    This means they can burn the coal hotter without emitting dangerous amounts of NOx.
    1. They let iron pellets rust. Or they buy rust in the first place.
    2. They put the rust pellets into the chamber with coal dust.
    3. They ignite the mixture (this requires a bit more heat than usual burning. At least 1566 ÂC or 2850.8 F)
    4. The coal dust pulls the oxygen out of the rust and binds it with the carbon into quite pure CO2.
    5. Heat (a lot of it)
    6. Use the heat in a default thermoelectric power plant.
    7. The pellets can rust again, to capture oxygen.
    8. ...
    9. Profit.

    If they would combine it with an iron smelting plant then the energy required in step 4 to pull the oxygen out of the rust would not be wasted. Then the iron pellets are one of the end results. Of course, then you'd have to emit step 7.

    To me this seems familiar. If I am correct this is the way Thermite works, just with aluminium powder instead of coal dust.

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