How will we replace plastics? 9

[epoisses]

I find it funny how many people wonder what we should do if we run out of oil (economically speaking), while there's a whole range of solutions readily available (GTL, nuclear, fuel cell, hydro, solar, wind...). A much more tricky question IMHO is, how are we ever going the replace LDPE, HDPE, PP, PS, PU..???

 

[BJC]

Fossil fuels are really fossil. The accepted theory now is that petroleum is formed from water, limestone and iron under pressure and heat. No fossils involved, except the ones that made the limestone ( if they did).
So if you can make diamonds you can make petroleum. You need a pressure vessel and .......

 

[moltenmetal]

I've heard this theory about petroleum formation before, but are you sure it's the "accepted" theory? Doesn't much matter, it's still a resource produced on the geological timescale from a finite resource of organic origin (ultimately stored solar energy), and consumed on the human timescale. We'll still rapidly run out of the low lift-cost stuff and that will force us further and further into fuels which generate more CO2 per joule of useable energy.

Your comment reminds me of a departmental brainstorming session we had back in university about what to do with CO2 to reduce global warming. Just about every suggestion for sequestering it was thrown out for what it was- energetically idiotic when your whole intent was to produce energy by burning the fuel in the first place. The "chair" of this session got frustrated and said, "This isn't what brainstorming is about- stop critiquing the ideas, put aside your concerns about the thermodynamics and energy balance, and bring the ideas out!". A particularly sharp colleague of mine then replied, "Well, if thermodynamics are out the window, let's make diamonds and oxygen!".

 

[ivymike]

No fossils involved, except the ones that made the limestone ( if they did).

Are there other plausible theories that you've heard for the source of the limestone? The same magical fairies who created the earth, perhaps?

 

[BJC]

I don't know of, or was I trying to say ther were other plausabel theories of limestone formation. I wasn't sure it all came from seashells or diatoms.
I just read the instantaneous formation of the worlds limestone is a creationist argument, I'm not in that one.

 

[SacreBleu]

My favorite web site for yellow journalism, Rense.com, has plenty of articles about the theory of non-organic oil creation. Also plenty about certain dangers of plastics. Very interesting site, if you have an open mind. About 10% of the articles seem to be credible (one of my hobbies is to make this determination), and you certainly won't read about them in the mainstream news media. Certainly a more interesting read than the Star tabloid, in which an alien was photographed snatching a drug-runner's airplane in mid-air.

 

[moltenmetal]

BJC: I considered your post to be tongue in cheek, but if it wasn't, I'll be happy to explain why attempting to use a salt of CO2 (i.e. limestone) to make petroleum to use as a fuel is energetically infeasible.

I'm no geochemist so I'll leave the origins of petroleum to people who actually study these things. Regardless of the source of the carbon and hydrogen in the first place, the formation of petroleum is demonstrably a process which takes a geologically significant period of time and involves the pressures and temperatures experienced at significant depth in the earth's crust. Waiting around for the earth to make us more petroleum is not an option!

 

[BJC]

Moltenmetal
The first I heard on the non fossil orgin of petroleum was on PBS radio. The show was on a Russian scientist who developed or at least did a lot of work on the theory. He also had a good track record of finding oil. He is now in the US ( Houston of course ) and has a successful consulting business. There are a lot of people around trying to twist science to demonstrate that the world really was created in 4,004 BCE but I don't think he was one of them.
When I was reading on limestone, I found that some people claim that the limestone mass in the Carribean area was created instanteniously by a chemical process about 4 or 5 thousand years ago.
As for creating oil, I know it can made from coal, been there, seen it done. It may not be exactly the same but I'll bet you can make trash bags and cars out of it.

 

[moltenmetal]

BJC:

Sure, you can make synthetic hydrocarbons by the Fischer-Tropsch reaction from syngas produced from coal. Or syngas from natural gas, wood, corn stover, coconut husks or just about any other source of carbon EXCEPT carbon dioxide or carbonate rocks. The latter are mere sources of carbon, NOT FUELS! F-T technology has existed for the past eighty years or so. Chemists and chemical engineers are really good at reconfiguring atoms into the molecules we want, IF you have enough energy to ADD to drive the required processes and separate the products. What's your point?

Going the syngas/Fischer-Tropsch route, regardless of the source of carbon, is (with a very few exceptions) energetically enormously wasteful relative to taking those same hydrocarbons directly out of crude oil or natural gas/gas liquids by simple distillation and/or relatively simpler chemical transformations to make chemical feedstocks. "Energetically wasteful" here also means "generating far more moles of CO2 per kg of plastic produced".

If the intent is to use the synthetic products eventually as fuels, going the syngas/F-T route is energetically idiotic relative to simply burning the natural gas, coal, corn stover etc. itself as a fuel for, say, stationary applications like heating and electrical generation, reserving the existing crude resources to generate transporation fuels and chemical feedstocks.

The only exception where F-T makes sense is perhaps as a use for "stranded gas"- natural gas discovered and produced too far away from major markets to use it within economical reach of a pipeline, such that wasting half of it to make liquid products for burning later makes economic sense. It also makes energetic sense relative to simply flaring this gas.

Long before we need to make massive use of F-T technology to make our liquid fuel needs from coal, we'll be making heavier and heavier investments in recovering heavy oils from tarsands and oil shale resources. Converting these to liquid fuels and chemical feedstocks is far less energetically wasteful than going the coal/syngas/F-T route, and we have HUGE reserves of these resources.

The only question is: can the planet survive us burning all these fossil resources to fuel the expansion of the western world's idiotic, energy-addicted lifestyle to the developing world?

 

[BJC]

I was thinking of the Lurgi process, but in the end the question is how much will we be willing to spend to keep from handling the garbage and the trash.
I can remember putting all the garbage in a 5 gallon can, and the trash in 55 gallon drums. There were more flys and probably more disease.