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Power Science

Purdue Makes Trash To Electricity Generator 250

Posted by kdawson
from the mister-fusion dept.
musicon writes "A group of scientists at Purdue University have created a portable refinery that efficiently converts food, paper, and plastic trash into electricity. The machine, designed for the U.S. military, would allow soldiers in the field to convert waste into power. It could also have widespread civilian applications in the future. Researchers tested the first tactical biorefinery prototype in November and found that it produced approximately 90 percent more energy than it consumed."
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Purdue Makes Trash To Electricity Generator

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  • Yawn... (Score:5, Funny)

    by Anonymous Coward on Wednesday February 07, 2007 @04:05AM (#17917780)
    Wake me when they invent the Flux Capacitor.
    • Re:Yawn... (Score:5, Funny)

      by macadamia_harold (947445) on Wednesday February 07, 2007 @05:21AM (#17918240) Homepage
      Wake me when they invent the Flux Capacitor.

      From the writeup, it sounds like they've created Mr. Fusion. So when the Flux Capacitor is created, at least the inventor won't be chased down at the twin pines mall by middle eastern terrorists in a vw bus.
    • Re:Yawn... (Score:4, Funny)

      by Walt Dismal (534799) on Wednesday February 07, 2007 @08:03AM (#17919154)
      At first, I thought from the heading "convert trash to electricity" that the military had put Britney Spears and Kevin Federline on bicycles with generators, and they were merrily pedalling away. But, nooo, you had to go and spoil it.
      • Re: (Score:3, Funny)

        by tomhudson (43916)

        At first, I thought from the heading "convert trash to electricity" that the military had put Britney Spears and Kevin Federline on bicycles with generators, and they were merrily pedalling away. But, nooo, you had to go and spoil it.

        No, that's their next headline - "Purdue Makes Electricity To Trash Generator"

        This way, they can have a closed-loop system when they send Bush to Mars.

  • "...it produced approximately 90 percent more energy than it consumed."

    Anybody know how that compares to other forms of energy production, say, fossil fuels or nuclear?

    • by Animats (122034) on Wednesday February 07, 2007 @04:23AM (#17917934) Homepage

      This is described as energy returned on energy invested, or EROEI, of 1.9, which is not all that great. Ethanol from corn has a value of about 1.25, and that number is from its proponents. Anything below 1.0 is a lose.

      US oil production has a value of about 3. That number declines over time; it was as high as 100 in the early days of oil production. (Look up "Spindletop") Saudi oil production has a value of about 10. Wind energy has a value of around 5. Solar power values depend on how long the equipment lasts; energy breakeven on solar cells happens some time around 5 years.

      • Solar EROEI (Score:3, Informative)

        by mdsolar (1045926)
        One aspect of large scale solar fabrication is that heat management is easier. One only has to get silicon up to temperature but you don't have to keep it there with more energy in, so the 5 year figure you give is coming down dramatically. EROEI should end up near 40 on a single fabrication cycle, and potentially much higher depending on how recycling of the cells is handled during subsequent fabrication cycles. If the dopant gradiant is preserved through a cell-by-cell reannealing process to repair cos
  • by ed (79221) on Wednesday February 07, 2007 @04:15AM (#17917846) Homepage
    that in order to run the kit and transform the rubbish into a form that actually powers the generaor, they require x energy.

    From the consumption of the next stage they get x + 90% energy, , otherwise it's a load of keech.
  • Mr Fusion (Score:5, Funny)

    by mpfife (655916) on Wednesday February 07, 2007 @04:19AM (#17917886)
    "No no, this thing needs more kick than that. It's nuclear - that's the only way I can generate the 1.21 gigawatts of energy I need."
    • Get the quote right at least?
  • Dual Purpose (Score:5, Insightful)

    by supernova_hq (1014429) on Wednesday February 07, 2007 @04:24AM (#17917936)
    This seems to have two uses, both of which are, by them selves very amazing, together even more amazing:
    1. It reduces garbage 30:1 and turns it into "ash" which seems to be a very easy thing to dispose of (especially at 1/30th of the amount)
    2. It CREATES energy in the process.

    As for the 90% thing, i believe they are saying that the input power would be what-ever power source you give it to turn the trash into electricity, I am pretty sure that the energy already in the trash is not counted in the input.

    Just think, not only could you use your own garbage to power this thing, but just consider the fact that the one thing we have been trying to find a way to get rid of, and inadvertently stockpiling in land fills, can now be reduced by a factor of 30 and turned into electricity, just take a bunch of these to a local landfill and viola, less garbage and more electricity.

    Any municipal government that does not take advantage of this (assuming it gets further developement) should be considered completely incompetent.
    • Re: (Score:3, Insightful)

      Any municipal government that does not take advantage of this (assuming it gets further developement) should be considered completely incompetent.


      Most municipal goverments are already considered completely incompetent.
    • Re:Dual Purpose (Score:4, Interesting)

      by jimicus (737525) on Wednesday February 07, 2007 @05:59AM (#17918462)
      IIRC emissions is a big problem. You're not quite sure what's going in, so minimising the amount of pollution you chuck out is not easy.
    • by Black-Man (198831)
      My sister in law worked from a large midwestern city's waste management division and was the safety director when the brought on-line a trash burning power plant. There were explosions 2-3 times a week... heavy metals spewed into the air in greater amounts than coal burning plants and eventually the thing was shut down and scrapped. A HUGE waste of money.

      The bottomline is... if you can't completely regulate what is getting burned - it will never work. And the sad part... this plant had a conveyor belt where
  • Sweet (Score:3, Funny)

    by cinnander (964876) on Wednesday February 07, 2007 @04:24AM (#17917942) Homepage
    90% more energy than it consumes, eh. So all we have to do now is hook this thing up to, say, a pastry factory, a good supply of flour, fat, water and such, and there will be free, unlimited pastry and energy for everyone, assuming we feed the pastry scraps and uneaten pies, pasties and tarts back in the other end! :D
    • by Churla (936633)
      Or kittens...

      Kittens go in.. pop tarts come out!

      Too vague?
  • Looks like they're distilling something from garbage and then burning everything in a diesel engine or something. What about the toxic fumes you get when you burn plastic?
  • by Anonymous Coward on Wednesday February 07, 2007 @04:31AM (#17917998)
    If a lot of people have been working on a problem for a long time, you shouldn't expect a huge breakthrough. The reason I say these people are dreaming in technicolor is that they imagine that every restaurant will want one of these to process its food waste. The technology to do that has existed for a long time. The reason everyone isn't doing it is because it isn't economic.

    People have been doing biodigesters since forever. The guys at Purdue haven't said they have found a magical new process. AFAICT, they are using the same process as everyone else. Ergo, they should have the same results as everyone else.

    The other part of their system involves gassifying paper and plastic trash. That's another area where people have been working for a long time. It's the holy grail for municipal trash disposal. In fact, many municipalities are generating electricity from garbage but their plants are glorified incinerators not gas generators. In the early twentieth century many/most cities had gassification plants for coal. Now they are having to clean up the coal tar that was left behind to pollute the environment. The guys at Purdue didn't mention how nasty the waste product from their process might be. The people converting turkey guts to oil said that was one of the main problems they had to solve.

    The guys in the story seem to have combined existing technologies and they haven't mentioned the known issues that the existing technologies suffer from. I don't expect to see one of these behind my local restaurant any time soon.
    • by GerTheDwarf (678874) on Wednesday February 07, 2007 @09:36AM (#17919800) Journal
      Did you even read the article?

      The reason everyone isn't doing it is because it isn't economic.
      The point of the work was to make it economical. There hasn't been any work, until now, on _small_ scale waste management that _directly_ produces electricity. Before, the inventions required the business to perform some technical/dangerous/expensive task, mainly storing the gas, or installing a permanent structure.

      AFAICT, they are using the same process as everyone else. Ergo, they should have the same results as everyone else.
      No, not ergo, because the "results" are not based only on the fuel production process. What they were measuring was the ratio between diesel fuel consumed and electricity produced. They are probably using a highly efficient, highly modified engine, as well as other more advanced parts.

      The guys at Purdue didn't mention how nasty the waste product from their process might be.
      From the article:

      The machine produces a very small amount of its own waste, Warner said, mostly in the form of ash that the Environmental Protection Agency has designated as "benign," or non-hazardous.
      Back to the Anonymous Coward:

      I don't expect to see one of these behind my local restaurant any time soon.
      True, but I don't expect you would even look.
  • it produced approximately 90 percent more energy than it consumed.
    So for 90 units of energy produced, it consumes 190 units of waste?
    So, that means it's got a efficiency of 47.3%.
    • by geekoid (135745)
      for every 1000Kwh of petroleum, you get 1900 Hwh from the device from the potential energy in the trash.

  • So does 90% more out than in mean it's overunity?
    • by ajs318 (655362)
      No. It needs some fuel to warm it up initially. After that, it's able to power itself on the potential energy stored in the garbage. For every kWh. of "starter" fuel you put in, you get out 1.9kWh; of which the extra 900Wh. are coming from the garbage.
  • by srussia (884021)
    I, for one, fear the military applications of this...not like it wasn't possible before, but perhaps this might give some people ideas that would ultimately be used to kill people...

    Uh, nevermind, I just read TFS.
  • by rohar (253766) * <bob.rohatensky@sasktel.net> on Wednesday February 07, 2007 @07:03AM (#17918796) Homepage Journal
    There were a fairly large number of motor vehicles converted to wood gas [wikipedia.org] during oil shortages in and after WWII.
    FEMA [wikipedia.org] wrote a book in 1989 on how to build your own [webpal.org]. I think they had the foresight to realize that the U.S. military will eventually commandeer the available oil supplies again and we can try and figure out how to get to work burning garbage and the trees out of the backyard.
    /* This is not a Hummer. [wikipedia.org] */
  • This whole article sounded a little fishy to me. First of all, why didn't they even mention the more general applications of this generator -- namely converting municipal waste into electricity. I know several attempts have been made in the past, (e.g. Trash to Natural Gas [cnn.com]). Universities love bragging about the exciting possibilities for any new technology they develop. Seems strange they'd only mention military applications. One possible explanation is that the work was conducted under a military grant, a
    • First off, 99% of things military trickle down to the civilian sector in some front, even if it isn't obvious. I mean, the Wii uses optical gyros that were at one point military technology.

      Second, the very first paragraph says, and I quote, The machine, designed for the U.S. military, would allow soldiers in the field to convert waste into power and could have widespread civilian applications in the future. It goes on to say "I think it could be used outside the military shortly thereafter."

      Does this

  • Nice one team, first things first!
  • by Ancient_Hacker (751168) on Wednesday February 07, 2007 @07:38AM (#17919030)
    Gotchas almost too numerous to mention:
    • Anything marketed as "for the military" usually means, "totally uneconomical".
    • Burning trash makes a lot of smoke and airborne toxins-- Mercury, heavy metals, Dioxin, etc...
    • Diesel fuel could be better used to run a generator directly.
    • The volume of trash is not a problem-- garbage trucks have hydraulic squeezers.
    • The burnt remnants of trash are considered hazardous waste in most localities.
    • Burning trash with refined petroleum is really, really, really loopy.
    • by Anonymous Coward on Wednesday February 07, 2007 @09:37AM (#17919802)
      I agree with some of your assessment, however I think there are some aspects being overlooked.
      First: This was designed for a specific military purpose, and will presumably serve that purpose well. The soldiers need electricity (among other things) and have trash and garbage they want to eliminate. Sounds like a good trade.

      Second: If this innovation (i.e. small form factor bio-reactor) can serve additional purposes, then great. The article is not stating that your local McDonalds will have one of these portable reactors outside converting leftover stale fries and leftover scraps next year. What it is saying is that when and where there is an emergency, FEMA (or anyone) can airlift and truck in hundreds of these to provide local power. Presumable there is plenty of trash and garbage around that can be converted into power. Again, there is likely a need for electricity and plenty of resources to convert.

      Third: EPA decided the ash is benign. It will not be considered hazardous waste.

      Fourth: If this technology can be improved and made cost effective, it will be used at the local level, rather than in regional trash burning plants. There are many things which are ineffective and inefficient at regional/large scale which are more efficient and effective at local levels (Bureaucracy, zoning, and waste management are examples).

      Fifth: There is a definite problem in this country of waste volume and landfills. If this technology can be used to extend the life of a current landfill by 10%, 50%, or even 3,000% (30:1 volume reduction), then this savings must be considered in the total cost and benefit of the reactor. A city can spend millions of dollars purchasing land for a 30 year landfill. This technology can be used to extend the life of current landfills and also enable the city to find multiple smaller sites in the future. Not to mention the reduced costs of transportation in time, labor, and fuel.

      Sixth: Your point that diesel fuel would be more efficient to run the generator is ass backwards. The point is that we have a resource that is costing us time, money, and space to dispose. This technology enables us to use it to generate a positive net of electricity AND reduce the cost of disposal. Using diesel or gasoline to power a generator is definitely NOT more efficient when looking at the larger system.

      My only questions are how much one of these units costs to purchase and maintain, how heavy are they, and what kind of regulations will we need to follow to have one in our towns permanently? I wouldn't mind taking my recycling AND garbage to the local collection place, knowing that one will be reused and the other will be turned into electricity.
    • by geekoid (135745)
      Anything marketed as "for the military" usually means, "totally uneconomical".
      Like aircraft, and new etals,and cutting edge plastics, and csatalites.

      Yeah, Whole list of "totally uneconomical" items.

      "Burning trash makes a lot of smoke and airborne toxins-- Mercury, heavy metals, Dioxin, etc..."
      it CAN do that, it depends on whats burning, and assumes that it isn't captured.

      "Diesel fuel could be better used to run a generator directly."
      Well, when the bi-product of consuming food, using toilet paper creates die
  • by Anonymous Coward
    We will never see this thing in action. ExxonMobil will buy the patent and keep it stored in very safe place!
  • But! (Score:3, Funny)

    by Rob T Firefly (844560) on Wednesday February 07, 2007 @10:24AM (#17920314) Homepage Journal
    Can you.. you know... go in it?

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