Purdue Makes Trash To Electricity Generator 250
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."
Thermodynamics (Score:1, Insightful)
I really, really hope that what they mean is (Score:4, Insightful)
From the consumption of the next stage they get x + 90% energy, , otherwise it's a load of keech.
Dual Purpose (Score:5, Insightful)
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.
Dreaming in technicolor (Score:3, Insightful)
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.
90% of what? (Score:1, Insightful)
The question is, how much power is that? And does it merit the machine's use.
Thinking about it, it requires a couple of hours running on diesel to prime itself - so a rough guess, assuming its engine is similar to that of a small car, would be that it takes half a dozen to a dozen gallons of diesel to prime it.
In exchange, you get 190% of that in low grade fuel that its robust enough generator can process. So the equivalent energy output of maybe two dozen gallons of diesel but in a low enough grade form that you wouldn't want to put it near a regular engine.
The unit's described as about the size of a small van. Except it's likely denser so let's guess around five tons and it's cumbersome as all hell.
So, end result, you get the equivalent power output of maybe ten gallons of diesel, in a form you can't use to actually power anything much else, several hours later... in a form that likely consumes far more than that ten gallons or so to get it in to the field it's supposed to be used in.
It's cool as a concept but 190% of not a lot is still not a lot - and when the pain of getting it there and waiting for it outweighs the 90% of not a lot extra you get, it starts making more sense on efficiency grounds to stick with lugging a small generator and a couple of five gallon cans of a far more usable fuel.
In short: Just because you can do something, doesn't mean you should do it.
But I'm guessing the publicity will get them their second round funding, which is, I'm guessing, the real point of this.
Re:90% of what? (Score:4, Insightful)
Re:90% of what? (Score:3, Insightful)
Are you perhaps not aware that military forces need large supplies of electricity, just as much as they need fuel for their tanks? That's an idiotic assumption to make. What makes you think this multi-ton diesel engine is going to only be equivalent of a small generator? I have no doubt it's aiming to replace the equally large generators, that are currently in-use by the US military. A tiny, lightweight generator isn't going to handle that kind of load. 190% is a hell of a lot. Half as many fuel shipments... Half as many people putting their lives on the line to truck in that fuel. Less fuel spent in the trucks (or planes) that actually hauls that fuel in. etc.
That's not even mentioning the perhaps equally large benefit of easy disposal of waste. Not having to ship it out to a dump in a war zone could save many lives, as well as even more fuel.
It sounds great. My only question is why they're using a diesel engine, when the military currently uses turbines, which are generally more fuel efficient, and require less maintenance.
Re:Dual Purpose (Score:3, Insightful)
Most municipal goverments are already considered completely incompetent.
Re:Does it run on batteries? (Score:2, Insightful)
Well, the article states it produced approximately 90 percent more energy than it consumed. Strictly read, this means that 1.9 units are produced per consumed energy unit, since totals are mentioned.
As such, the energy efficiency would be 100*(1-1/2.9)%=65,51%. I don't know the usual efficiency of this kind of generator, but 65% seems to be far too much (since combustion is used in the process).
Re:Incredible (Score:4, Insightful)
I didn't say all of it. But it would be possible if humans actually cared enough to put any effort into sustainable energy. Why do you think it's not possible?
I didn't say all of it. But it would be possible if humans actually cared enough to put any effort into sustainable energy. Why do you think it's not possible?
Why the defeatist attitude? Humans have done many things that were deemed impossible only a short time ago. Like flying, or reaching the moon, or transmitting messages invisibly through the air. Solar and wind power are proven to work, we just lack the will to implement it properly. In many ways, powering everything from sustainable sources is much less "far out" than travelling into space was considered a short time ago. I guess we shouldn't bother trying, because you don't think it's possible?
YA Ridiculous solution to a non-problem (Score:3, Insightful)
not going to happen (Score:2, Insightful)
Re:In this house we obey the laws of thermodynamic (Score:4, Insightful)
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
Re:YA Ridiculous solution to a non-problem (Score:4, Insightful)
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.
Re:Great fuels (Score:3, Insightful)
our need for food seems a little more basic and setting up a competition between the two may be a big mistake.
--
Solar: It's not for dinner. http://mdsolar.blogspot.com/2007/01/slashdot-user
Re:Incredible (Score:2, Insightful)
2 stroke diesel engines are extremely efficient. That's why they're used in extremely large engines. eg, The ones that power ships.
They're also less polluting than their gasoline counterparts.
2 stroke gasoline engines the oil is mixed with the fuel, this means you can use a gasoline 2 stroke in any orientation without oil starvation. (Weedeaters, Chainsaws, etc). They also have a very high power-weight ratio which makes them ideal for these applications.
2 stroke diesel engines have crankcase oil. Lubricating oil isn't mixed with fuel oil. Turbo/Super chargers force old air out.
At the same time 2 stroke diesel engines aren't something that are practical for small scale use. Some of these engines have cylinders that you can stand in. They run at well under 1000 RPM, even for max speed.
Re:Incredible (Score:3, Insightful)
The problem with the kind of waste this thing runs on isn't that we throw out the energy contained within it. It's that we throw out the matter contained in it. The matter still has to (a) come from some place and (b) go to some place. True, if the choice was landfilling anything we throw out and using co-generation, co-generation is a better alternative becuse it reduces the total energy consumption used to create/use/dispose of things a bit.
But you're still extracting the same amount of matter and throwing away the same amount of matter, just in different forms.
Re:Incredible (Score:3, Insightful)
Re:Incredible (Score:3, Insightful)
Hmm... last I checked, we were trying our hardest to make sure 'interesting' states like Iran and North Korea weren't allowed to use nuclear power. So unless and until we feel comfortable giving everybody access to nuclear power (and not just the states we trust), nuclear power won't be a good solution.