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Pyrolysis and Thermal Depolymerization

R

redwalker

SOC-12
By now probably everyone has heard of companies which claim to be at or past the break-even point for taking waste plastics and miscellaneous hydrocarbons and transforming them into crude oil.

"Thermal depolymerization" is the term used by an American company that turns turkey guts into crude oil --and apparently gets more energy out of the process than it puts in.

Pyrolysis is the general term for using heat to break down organic substances into basic, usable organics.

Assuming I'm understanding this tech correctly (and that might be a big, unjustifiable assumption) just about no Traveller civilization past TL 8 or 9 would need to import oil for use in making plastic.
 
Even if the basic data on the process is correct, the conclusion is only half correct. The Earth uses billions of barrels of oil per day. The exact amount is unimportant, but the fact that the demand for oil far surpasses the world's turkey production capacity. A high TL world could need more plastics than it can produce the raw organic material to convert into oil.

This would be even more of a problem for a predominantly lifeless world (airless means no native plants or animals to process into oil) or for any low population world that might generate too little waste for commercial production volumes.

You are probably correct for most worlds and there may be other carbon compounds that can be converted into plastics available in exotic atmospheres and dirty snowballs.
 
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I always wonder at claims of getting more energy out than put in. They usually overlook the energy already put into the base structure. In the case of making crude oil out of turkey guts have they factored in the energy input to raise the turkey? Naturally the bulk of the turkey is eaten and this is turning a "waste" product into a useful compound, which is fine for the chemical science types to play with but it doesn't really translate into the real world too well.

Take aluminum as an example. A very valuable commodity that typically thrown gets into the garbage daily. Even with recycling programs in place and incentives/penalties to encourage it only a small percentage gets recycled despite the fact that it is far less energy intensive to remake it than make it in the first place.

But back to the question. Such processes might help offset the need for some raw materials in small applications but they won't be enough to meet industrial needs. Though I don't believe, even with Traveller's low cost of space flight, that transporting raw materials several jumps to a factory makes any sense. The factory will be built at the source of the raw materials and the refined product shipped where the markets are.

Or am I missing the point? Maybe you're thinking plastics from plants? We do that already I think, on a limited scale because no one finds it convenient or economical. I hardly think collecting and sorting waste to thermally depolymerize it into crude oil and then process that into plastic is going to be easier or cheaper.

Not to dash the idea, just pointing out some problems to overcome in implementing it.
 
While it's true we use a very large quantity of oil, most of it is used as fuel. If the only reason we needed oil was plastics, and we had cheap fusion power, it would certainly be possible to get the oil we need for those purposes by processing of biologicals.

As for the break-even comment, I'm sure it's ignoring the energy cost of raising the turkey. The only reason to use thermal depolymerization on turkey guts is because it lets you eliminate residue in a clean way (the traditional way is by using it as animal feed, which has some hygiene issues).
 
Anthony said:
While it's true we use a very large quantity of oil, most of it is used as fuel. If the only reason we needed oil was plastics, and we had cheap fusion power, it would certainly be possible to get the oil we need for those purposes by processing of biologicals.
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Unless plastics became an essential structural component of vehicles or buildings at higher TL's - then it will be needed in steal/aluminum/concrete quantities. If plastics are primarily used to make pill casings, then you don't need much. If the Cloud City (from Star Wars) is made of structural plastic panels then you need a LOT.
 
atpollard said:
Unless plastics became an essential structural component of vehicles or buildings at higher TL's - then it will be needed in steal/aluminum/concrete quantities. If plastics are primarily used to make pill casings, then you don't need much. If the Cloud City (from Star Wars) is made of structural plastic panels then you need a LOT.
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Yes, but if you don't care about the energy cost, you can simply manufacture however much you need.
 
Anthony said:
Yes, but if you don't care about the energy cost, you can simply manufacture however much you need.
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I second that. You can make any plastic you wish from simple carbon compounds, water, plus energy and a few catalyst. It would just cost so much more than starting from petrochemicals.

Most of these ideas you see about plant based plastics are certainly doable, the big hurdle is are they cost effective. By high tech levels (you can decie what's high) combined with samples of life from 100's if not 1000's of worlds, scince would have developed a bacterium, etc. that with x garbage in produces the plastic you desire. Let the little bugger take care of all the complex synthesis.
 
atpollard said:
The exact amount is unimportant, but the fact that the demand for oil far surpasses the world's turkey production capacity.
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Hooo, boy. You couldn't be more wrong. Our world has more than enough turkeys to turn into oil. Matter of fact, if we turned enough of them into oil, we wouldn't need as much because it would significantly reduce the number of drivers on the road.... :alpha:
 
Ptah said:
I second that. You can make any plastic you wish from simple carbon compounds, water, plus energy and a few catalyst. It would just cost so much more than starting from petrochemicals.

Most of these ideas you see about plant based plastics are certainly doable, the big hurdle is are they cost effective. By high tech levels (you can decie what's high) combined with samples of life from 100's if not 1000's of worlds, scince would have developed a bacterium, etc. that with x garbage in produces the plastic you desire. Let the little bugger take care of all the complex synthesis.
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I like to think that carbon-fiber reinforced plastics are a fascinating and stimulating topic for sci-fi, but I'm just about the only person on planet Earth who holds that view.

I like the counterpoint about microbial chemical engineering. Microbial engineering is already impressive and will only become more so.

(Edit: Unless humanity wipes itself out by abusing technology...)
 
The really exciting thing with biologically created plastic stuff is, that it is likely to be decomposable by biology too.
Ho, ho, think of an average TL world, which suddenly is attacked by a bacteria, which is able to decompose a large amount of materials used in everyday life.

It reminds me of a German film production "Zucker - eine wirklich süsse Katastrophe" ("Sugar - a true sweet catastrophy") about a geneered bacteria, which turn paper/cellulose into sugar :) Funny.
 
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Fritz_Brown said:
Hooo, boy. You couldn't be more wrong. Our world has more than enough turkeys to turn into oil. Matter of fact, if we turned enough of them into oil, we wouldn't need as much because it would significantly reduce the number of drivers on the road.... :alpha:
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Soylent Black?
 
TheEngineer:

"Mutant 59, the plastic eaters" by Gerry Davis and Kit Pedler, 1971

www.fantasticfiction.co.uk/d/gerry-davis/mutant-59.htm

A BIOLOGICAL TIME BOMB?

"In the shaft leading to the [ventilation] grille a mindless, groping mass of malodorous corruption was thrusting its way silently towards the surface. Buoyed up by bubbling foam it steadily rose. Single units in an obscene abrogation of normal order divided and made two. Two became four and four, eight. Endlessly supplied with food, each unit absorbed nutrient and in a soft, ancient certainty fulfilled its only purpose - to multiply, to extend and to multiply...

"In the Coburg Street control room of the London Underground system, there was a full emergency... In a dozen tunnels, trains ground down to a halt. Hordes of terrified commuters made their way anxiously along dark, musty tunnels to the lights and safety of the next station. There were minor explosions, fires, and the failure of a million wires and cables. As the dissolution of plastic proceeded and accelerated in rate, the elegant order of the system gradually turned into complete chaos.

"On the surface, in the freezing December air, the smell of the rotting plastic began to hang permanently in the air. A cloying, wet, rotting smell similar to the smell of long-dead flesh. It filled streets and homes, basements and factories. Traffic lights failed, causing irresolvable jams.... The breakdown of plastic spread into Broadcasting House.... A gas main with polypropylene seals on its pressure regulators erupted into flame.... Plastic cold-water pipes softened, ballooned, and burst, flooding into shops, homes, and restaurants.

"Slowly and inexorably, the rate of dissolution increased; failures occurred in increasing succession until, within forty-eight hours, the centre of London had become a freezing chaos without light, heat, or communication."
 
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