×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

How will we replace plastics?
9

How will we replace plastics?

How will we replace plastics?

(OP)
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..???

RE: How will we replace plastics?

I like the novel idea of simply mining our landfills, that should give us another 100+ years for a lot of materials including plastic....LOL

Bob

RE: How will we replace plastics?

While I do not recall the source directly, I do remember coming across a few articles about extracting polymer bases out of certain plant varieties.

Regards,

RE: How will we replace plastics?

Some plastics can be plant based.  Henry Ford was playing around with the idea of using hemp-based plastic for auto bodies until the 1937 Marijuana Tax Act put an end to it.

RE: How will we replace plastics?

Soy is a wonderful thing...
http://soyworkscorporation.com/

"I think there is a world market for maybe five computers."
Thomas Watson, chairman of IBM, 1943.
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: How will we replace plastics?

3
If they could only find a way to make useful polymers from baby seals and humpback whales...

RE: How will we replace plastics?

Plastics from plant material.

Cotton soaked in nitric acid --—> cellulose nitrate

nitrocellulose + camphor --> celluloid

Used for billiard ball ~1890 however some problems - exploding billiard balls

---------------------------------------------
Plastics from milk

Casein proteins were one of the first plastics,(1900-1930's)  and they are still in use for this purpose. Thin plastic films of casein can be made by adding glycerol or sorbitol as a plasticizer, a substance that lowers the temperature at which a plastic softens, and makes it more pliable.

Vita sine litteris mors est.

RE: How will we replace plastics?

Plastics are built with hydrocarbon chains, methane, works just as well as crude oil, all you need are the hydrogens and carbons...So we build a really large tanker, with a really long dip tube. We run that bad boy out to one of the moons of Jupiter or Saturn where there is a bunch of hydrocarbons in the atmosphere, drop down the straw and fill up the tank. Then bring it back into earth orbit, where we make plastics in orbital stations.

I work for a chemical company that makes HDPE, LDPE, etc, and my boss keeps telling me to think outside the box, how was that??

RE: How will we replace plastics?


I'm not sure how it works, but our local grocer uses plastic containers that are bio-degradable. I think they're similar to the Soy product posted above, but are made from corn. Now I'm curious... gonna go have another look.

RE: How will we replace plastics?

Plastics are made of chains of carbon and hydrogen atoms.

There is no shortage of either element on the surface of Earth. Oceans made of water (two hydrogen atoms per molecule) cover two-thirds of the Earth's surface. Carbon dioxide (one carbon atom per molecule) constitutes 379 parts per million (and rising) of the air we breathe.

The only problem is taking apart the water and carbon dioxde molecules and assembling the polymers of carbon and hydrogen. This requires energy.

The sun provides about 1.3 kilowatts of power per square meter at the distance at which Earth orbits the Sun. As much as 900 Watts per square meter passes through the atmosphere to the Earth's surface on a clear summer day.

All that humans need to do to make plastics is combine these three bountiful quantities (hydrogen, carbon, and energy). The best method would be to genetically engineer plants (including micro-organisms such as algae) to produce polymers. Photosynthesis has been used to produce sugar (C6 H12 06) for eons. It should not be too difficult to redesign plants to produce chains of carbon and hydrogen. Just leave out the oxygen and make long strings of the carbon atoms.

I look forward to the day when the north coast of New Jersey becomes a sea of green instead of a series of refineries and chemical plants.

RE: How will we replace plastics?

2
All responses are based on the assumption that we will continue to enjoy the same standards of life after we run out of oil. IMHO, this is unfounded optimism.

Our current standard of life is all because of high energy consumption. Geographically speaking, developed contries have higher per capita energy consumption. This is a proven hypothesis.

By the same logic, oil being a major source of energy, standards of living will come down. So I think people will care less about plastic and more about mules.

Ciao.

RE: How will we replace plastics?

2
You're thinking about this the wrong way.  There's more than enough oil and oil-convertible fossil fuels to last us, our kids, and our kids' kids even at our (insane) projected future levels of consumption.  All the "scarecity" of low lift-cost crude oil and natural gas will do is push us to more and more expensive, less energy-efficient sources like tar sands, oil shale, and coal gasification combined with gas-to-liquids technology.  All of these mean more tonnes of CO2 and other combustion by-products per kilowatt of energy expended or per pound of plastic delivered etc.

What we need to do is get a grip on our stupid, wasteful consumption addiction.  The only way we're going to do so is to tax consumption of these fossil materials and reinvest the revenue into programs to wean us of our addiction.  Priority should be given to the most appropriate use of these materials.  Crude oil is too valuable as a feedstock to be burning it wantonly like we currently do.

RE: How will we replace plastics?

Would you like paper or... or.. errr, ummm, paper, ma'am?

RE: How will we replace plastics?

or cotton, or hemp...

RE: How will we replace plastics?

Hemp impregnated bronze bearings......great for your rotating equipment designs.

Best Regards,

Heckler
Sr. Mechanical Engineer
SW2005 SP 2.0 & Pro/E 2001
Dell Precision 370
P4 3.6 GHz, 1GB RAM
XP Pro SP2.0
NIVIDA Quadro FX 1400
      o
  _`\(,_
(_)/ (_)

Do you trust your intuition or go with the flow?

RE: How will we replace plastics?

moltenmetal,

I would agree with you on the additional tax if I could actually believe that government would use the additional funds to persue alternatives.  Unfortunately I do not believe it would happen.  A tax on our consumption "addiction" would only feed the addiction of any government (money).  I wonder just how quickly the program funded by this type of tax would be cut or disappear and the funds used elsewhere.  Or perhaps I am just feeling way too cynical this morning.

Regards,

RE: How will we replace plastics?

We already have alternatives.

I remember in college buying ink pens that were made from glucose polymers that were extracted from corn stalks.  To top it off, they were biodegradible when you desposed of them.  That same company also made chairs, desks, and anything you could think of from the corn stalk glucose polymers.

RE: How will we replace plastics?

PSE:  even if the money were merely "consumed" by government on other things (principally health care and education here in Canada- those are the two single biggest government line items here), a tax on consumption would still do part of the job.  Properly coupled to conservation programmes by means of a segregated fund, we'd be much further ahead because then government wouldn't be eyeing these funds for use in schools and hospitals (to which everything else will always lose- people's emotional hot-buttons are easily pushed).

Without a signal to people's pocketbooks, strong enough for them to notice, we'll continue in our addicted la-la land and CO2 and other combustion emissions are going nowhere but up.  

Just using transportation as an example, considering the up-surge in stupid, wasteful consumption in the form of 8-cylinder cars, 2-tonne SUVs for city commuting, the death of the local railroads and the increased use of trucks etc. here in North America, obviously the price signal isn't strong enough yet for it to enter into people's decision-making process when purchasing vehicles, making shipping decisions etc.  When the pricing signal is strong enough, fuel consumption may finally move into the top 10 of people's considerations when choosing a vehicle.  Until it's the #1 or #2 consideration, the price needs to increase.

RE: How will we replace plastics?

Easy solution - stop the wasteful consumption of cheap plastic give-away toys at McDonald's  etc. <sarcasm>

RE: How will we replace plastics?

Posted with a just a hint of sarcasm.  Rather than imposing a consumption tax on plastics. Let goverement impose a ban on Air Conditioning in the goverment builds, especially the capital, house and senate office builds, the court houses and the Whitehouse in DC, and similiarly in each state.  That way maybe the elected offical will not stay in DC long enough to pass wasteful ($) laws. I have no doubt that the funds from a tax on plastics will not be used for other items. All taxes, including FICA that are collected by the federal goverement go into a general fund. - end of screed.

Many of the weight saving, read as increasing gas milage, in transporation systems were accomplished by switching from metal to a polymer material.

Does it take more energy to produce a ton of steel automotive parts or to produce an equivalent amount to plastics components?

Vita sine litteris mors est.

RE: How will we replace plastics?

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 .......

RE: How will we replace plastics?

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!".

RE: How will we replace plastics?

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?

RE: How will we replace plastics?

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.

RE: How will we replace plastics?

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.

RE: How will we replace plastics?

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!

RE: How will we replace plastics?

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.

RE: How will we replace plastics?

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?

RE: How will we replace plastics?

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.  

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources