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Purdue Makes Trash To Electricity Generator
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."
Wake me when they invent the Flux Capacitor.
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.
"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."
Which part of this sentence:
don't you understand?Ignore this signature. By order.
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.
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.
Not on a large scale, I think. This is likely to be a very polluting energy source. Hence it being described as "tactical." Good for emergency use - or for a desperately poor village that doesn't have any electricity to meet basic needs. But not to power your Plasma TV or Playstation.
... and then they built the supercollider.
The local landfill where I live, the Johnston landfill, here in Rhode Island, operates a methane recovery plant. This methane gas then flow through eleven twelve-cylinder turbocharged engines, to power a bank of generators.
This produces 15.3 megawatts of power. 1.3 megawatts is used to power the plant and landfill site. The remaining 14 megawatts is sold back to the grid, and provides power for 21,000 homes.
It's not quite 1.21 gigawatts, but it's still pretty cool.
RTFA they say the generator has to run off diesel oil for several hours to power the bioreactor/reformer. Once the components have had time to break the waste material down into ethanol, methane, and propane that gets funneled back into the generator that the net result is 90% additional output. If it was to take 10 liters of diesel to start the process, after using those 10 liters, and also burning the resultant fuels from the bioreactor/reformer it would be approximatly equal in electric output to having only used a plain old generator with 19 liters of diesel. In addition it reduces the trash input to aproximatly 1/30th of the volume in ash. It is bascially a mobile trash incenerator/generator that can be jumped started with diesel. Electrical plants that burn trash to produce electricty has been around for a long time. This sounds only slightly more efficent/environmentally friendly in that they use a bioreactor to produce ethonal from the biowastes, and use gasification techniques on the other types of trash instead of just plain burning all the trash together with a steam generator.
No matter is 'converted' to energy, it is only a chemical process to rearrange the the energy in the chemical bonds of the existant trash into a more useful form of energy(ie. electricity). Same as burning coal or any other fuel, the energy is released in the form of heat to provide work.
Would not be benificial to the average joe, however for the military I am guesing that it is a much better solution. We do not actually know how much more it weighs over a standard military generator and all the fuel that would be lugged around. In addition it reduces a units "signature" by removing the trash that would otherwise have to be hauled back out or destroyed in some other way. Also once it had been primed with several hours worth of diesel, it would be self supporting untill you either ran out of trash, or moved the unit somewhere and had to reprime it. I can see it reducing the logistics for diesel fuel and trash hauling for a military unit setting up a temporary base of operations.
Easy enough to do. What the article means is that for every joule the energy consumes it generates 1.9 joules. The joules it is consuming are not from the trash itself. It might be converting the trash at an efficiency of only 5% (making that number up, of course). It's just saying that it does, in fact, actually generate a net positive amount of energy while consuming the trash.
Somehow I suspect I haven't made this any clearer.
Consider the "Mr. Fusion" reference. We've created fusion generators that actually produce energy through fusion. However, so far, they've all produced less energy than it has actually required to run them, thus resulting in a net negative. All that 90% figure means is that this is a net positive.
Ben Hocking
Need a professional organizer?
Only globaly/universally. From the point of view of the (non-closed) system of the machine, it is giving out more energy than it is getting in.
Pointing at the mass and saying E=mc^2 is about as useful in this context as pointing to a lump of coal in your living room and saying that it can heat the room for the rest of your life. But it remains a lump of coal until you extract the energy. If you use less energy to ignite and burn the coal than it emits then you're ahead of the game, regardless of E=mc^2 or any other pointless appeals to thermodynamics.
I'm not saying you're wrong; I'm saying that your argument is irrelevant to a discussion of the usefulness of this device.
TWW
"Encyclopedia" is to "Wikipedia" what "Library" is to "Some people at a bus stop"
Not all materials are metals which can be relatively inexpensively melted back down and used with no negative effects in the next recycled generation. Paper recycling, for example, might be a cure worse than the disease.
The harsh chemicals used to remove the many and varied dyes from paper to be recycled are pretty terrible to begin with (And unlike bleaching regular pulp, you don't know what's going to be there, so you can't reformulate all that well), then you end up throwing the recovered pulp right back into the pulper anyway, so while there are likely some gains in energy, it's not necessarily friendly to the environment. Making matters worse, recycled paper seems to have less strength than original pulp.
In the end, you're making more use of toxic chemicals for a product of lower quality. I'm sure there are other similar materials where the friendly concept meets unfriendly process control reality.
It's been a long time.
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.