Posted on 06/15/2004 8:29:27 PM PDT by ckilmer
Ask Umbra: Waste makes haste Grist Magazine - grist magazine
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Dear Umbra,
What is thermal depolymerization?
Ann Freehold, N.J.
Dearest Ann,
A polymer is a large group of linked molecules. We're made of polymers such as protein, eat polymers such as starch, and wear polymers such as leather and nylon. Thermal depolymerization is a heat-driven process that breaks down or transforms polymers into the shorter chains from whence they came: oil. Our planet's automatic transformation of dead dinosaurs and dead cavepeople and other organic matter into petroleum is thermal depolymerization -- the slow conversion of our ancestors into Dodge Caravan fuel.
People who understand science better than you and I are investigating the possibility of artificially speeding up the thermal depolymerization process to take advantage of our waste products and add to the oil supply. One company, Changing World Technologies, is currently refining the process of refining giant food conglomerate ConAgra's turkey offal into refined oil in a Missouri plant. Changing World churns up turkey leftovers, subjects them to high heat, and decants crude oil in far less time than Mother Earth takes to accomplish the same trick. Or at least that's the idea; all this is still under development. Other parties have experimented with swine waste, but in any case, you get the picture; the hope is to transform waste into oil.
To get to what I suspect is the heart of your rather succinct question: Alternative-fuel folks are keeping close tabs on the evolution of this process, which may someday provide one solution to our many waste and fuel problems. Or maybe not. Past attempts to speed up this side of nature have proven too energy intensive to be practical. The folks at CWT and other scientists working with swine waste think they've found a better technique that leverages water, heat, and pressure in an economical and efficient combination. Interested observers, including yourself, are eagerly waiting to see if their successes can be reproduced on a larger scale.
Monomerly, Umbra
(c) 2004, grist magazine
URL: http://www.workingforchange.com/article.cfm?ItemID=17109
They are claiming that they can recover some of the solar energy converted to chemical bonds in plants (an inconvenient fuel source), reconverted to chemical bonds in animals (an even more inconvenient fuel source), and re-reconvert it into liquid fuel that can easily be refined to universally usable and convenient gasoline and diesel fuel, while siphoning off about 10-15% of the energy to keep the process running.
They are further claiming the waste products of this process are sterile, and occupy less volume than the input raw materials.
Additional claims are that the solid waste can be further processed to recover minerals.
None of the technical claims seem to be in doubt, given that pilot production has been started, and is subject to review.
I will grant that it may not be economical to run, given the ability of the alternates to lower their rates, but the process itself does work, and does not violate the laws of physics. Neither energy nor matter are created or destroyed in the process.
Total massive BS. If this were true (which it isn't) then we could heat our houses by burning our garbage. But believe what you want. I suggest that you invest your life savings in this scheme if you are really a true believer.
I see. So burning garbage won't reduce the amount of fuel you need to buy???
This part is probably true however, the next part is the BS part
that can easily be refined to universally usable and convenient gasoline and diesel fuel, while siphoning off about 10-15% of the energy to keep the process running.
I've been reading about these sorts of schemes since the '60s and somehow they never seem to work. For a whole lot of input energy you can get a little useful energy out of grabage. The kicker is that it always takes more input energy than you get out.
Practally speaking no. How are you going to feed a bag of dirty diapers to your air conditioner? There isn't enough energy in waste to justify the expense of extracting it.
Agreed. However, I believe the energy balance is negative: it takes more energy to raise a turkey (or whatever) than you can recover from its crap and offal, which is why I'm calling it "energy recovery."
The alternative is to throw away the stored energy. Worse, the alternative is to PAY to throw away the stored energy...
nah, you ain't fooling me: this is what happens when you melt velveeta in the microwave...
Good Lord NO!
Just trying to keep all the inputs and outputs visible.
"What is thermal depolymerization?"
Sounds painful.
Muttly thinks he had "a large group of linked molecules" once. But when the swelling went down, it fell off.
Have humble suggestion...Muttly eat pigs and chickenses, make important gas for nice people to drive around with.
The plant in Missouri seems to belie your skepticism. I would never bet my life savings on a single company, but I would invest some money in this one if it were publicly traded. My concerns are more in the realms of cost-effectiveness and zoning type issues -- can these plants recover the costs of building and maintaining them? Does the process produce inordinate noise or odor (a detriment to building them in lieu of landfills)? From the technical side, how "known" does the input mix need to be to be efficient?
You would not want the leftovers from turkey processing. Trust Me.
We're talking guts, bones, etc. Every piece of otherwise usable meat is cut from the carcasss for sale to retail or commercial users.
After that, the carcass is ground up to make mechanically deboned turkey (called MDM turkey). Bone chips come out one side, MDM out the other. MDM is used in turkey bologna, wieners, sausages, etc.
They also make MDM chicken, for the same use.
If thermal depolymerization works, it will be the greatest think since internal combustion!
Muttly have internal combustion.
As the operators gain experience they plants could be built to handle more variable streams such as municipal or industrial waste.
There's still a whole lot of engineering that needs to be done. Think of it as automobiles in the 1930's or semiconductors in the 1960's...
I don't think bones would work, though the marrow inside them might be useful.
There is a more common form of thermal depolymerization that most of us use all the time. I'm speaking, of course, about the simple act of cooking a potato.
The starches in raw potatoes are indigestible. When we cook them, the cell walls break down and the starches are made available to us....
Since the system outputs are oil, natural gas, purified water, and refined minerals, I can see this being an excellent replacement for sewage treatment plants, along with other types of monolithic biological waste. Tackling more "mixed" waste will be an interesting challenge -- will they be able to keep efficient with an input with a varibale mixture of different types of itmes? From the process description, I'd bet it would work fine -- the "unknown" mix of minerals refined from the process could probably be separated into layers via centerfuge.
Of course, for non-biological (and non-petrochemical) waste, you'll get less oil and gas and more minerals in the output, because it's really only hydrocarbons than can be re-arranged, as far as I understand.
On an interesting note, the company is in talks with auto manufacturers in Detroit to build a plan to process shredded cars. Again, this should produce much less oil and gas than bio waste, but it should produce pure iron and aluminum (and whatever they're alloyed with) to be used in future products. One thing they need to watch out for -- I beleive the electronic systems may use mercury switches, they'll need to separate out the mercury and keep it well away from plant workers.
Not so, Just proves that there were enough investors roped in to finance the plant. The trial of my scepticism will come if the plant actually makes a net profit.
There were studies done in the '70s by IEEE on internal combustion powered small generators off the methane produced by landfills - same concept. Their conclusion was that it wasn't cost effective.
Agreed. Do I have time for a shower?
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