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Can't we just smelt plastic into igneous rocks?

  1. Aug 19, 2017 #1
    Now cost asides...can't we just smelt plastic into igneous rocks? I'm sure we can achieve the temperature & pressure to do it.

    Plastics Mainly Composed of C H O N Cl S.
    N H Cl are all trappable within rock layers.
    Additives like Si and Fe can be added in various steps of heating to form silica and compounds like Iron Sulfide
    Surely some fancy gas collecting can be done as well to separate things out further in the pot so they don't remix.
    some of the gasses that reform under high temp & pressure such as CO2 can be offset by planting more flora in cityscapes..

    Earth's beginning atmospheric conditions had a composite of Methane, Carbon Dioxide, Hydrogen Sulfide.

    Assuming you can achieve similar conditions..these + rocks would be your very first precipitates out as gas that is manageable by today's standards.
    Leaving plastic mixes with higher N Cl content...by reintroducing different minerals and varying the Temp at pressure as the stage progresses, we should be able to create rock that seals the remaining stuff in the form of things like Salt and Ammonium.

    Jobs for people, companies get a better rep (seriously billions of dollars I have doubts this is not achievable), environment get safer. And Costs of doing this can be offset a little by raising prices of plastic related goods which also helps address consumption issues of such products within their mind as the price starts to reflect unto their purchasing habits.

    Inb4 plastic tax XD
  2. jcsd
  3. Aug 19, 2017 #2


    Staff: Mentor

    The problem is not what to do with plastics, as they can easily be recycled in various ways. The problem is to get a hand on them. Unfortunately we do not recycle them but spread it all over instead, ending up in our oceans. So the difficult part is gathering them. Once we have it, there isn't a problem anymore.
  4. Aug 19, 2017 #3
    Yes plastics are wholly recyclable, the problem is that not enough effort is happening to do that.
    There would an effort to recycle plastic if plastics included unusual elements such as gold, but they don't.
    Mainly they are CNOH compounds and considered as just 'harmless' waste.
  5. Aug 19, 2017 #4
    Well I mean the main problem with recycling is sorting the trash out, as such is the case (from my understanding of the situation anyways) the recycling plants here don't take plastic bags where I live. You've got things like toothpaste, bags, to that filled with grease, and such which makes it hard to separate in a plant and all of that goes to the regular dump here currently.

    Since we are good at burning stuff, my opinion was that we should just take it to the next level. Normally burning batteries and plastics and such will release alot of toxic fumes not so friendly to breathe in, but if you do it at the correct temperature, pressure, and time intervals, with additives as needed you can convert all that stuff back to primary states of the Earth when it was first formed. And then instead of worrying about recycling a battery or a plastic or about separating/sorting them improperly because your average joe is not going to care so much between the cup noodle foam to that of a plastic bag, we just smelt and reset all of the material back to their primary states as raw materials and from there it also saves us having to excavate certain lands for more...So you can see it is not direct recycling as the output of such a procedure would yield the original sedimentary rocks + atmospheric gases, but it can save alot of hassle in the management process.

    Such a plant would probably best be built underground for increased pressure exerted on the outside so the walls of the building can better handle the internal stress that is going to arise from the pressure built within; a costly venture starting out, but may well be worth it in the long term of things for the life on Earth as a whole.
  6. Aug 20, 2017 #5

    jim mcnamara

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    Staff: Mentor

    @SIQI - do you have some sort a citation about this concept? PF does not support personal theory discussions, only the science you can find in professional articles or articles written by professionals for non-professoinal folks.
  7. Aug 20, 2017 #6
    Mineralization of plastics demands isolating them from most accompanying stuff. This demand is strong when we use proposed technique of plastic decomposition into simpler form (if I well understand, even to elements). This is very work, fuel and money-consuming idea. Mineralization in primitive Earth-similar conditions needs either high pressure and temperature reactors capable for processing tens of millions tons per year or billions years of time. Until we have nuclear fusion energetics, it is not a good idea.
    Waste mineralization is possible by far easier way, by collecting them and mixing with some glue- or cement -similar substances. Such mineralized waste can be used in civil engineering instead of "natural" fillers. They should be waterproof, which is of value in hydroconstruction. "Atomization" of plastic is an energy- consuming application. There is another one, energy-producing: burning them to obtain their chemical energy content. In general, it is resource-wasting way, but in situation of waste deluge, the European Commision ordered Member States to burn any waste which is today deposited on landfills. I have published the analysis of material aspects of such a technique: Z. Krawczyk „Burning the waste – necessity or the optimal method?” Chemik 65 (8) 727 (2011).
    Today the Commission wants Member States to apply Circular Economy principles, which should diminish or even eliminate waste appearance. This is a totally different story.
    Most plastic materials may be depolymerized, i.e. recycled to substrates for polymer synthesis. There is strong demand for removing any additional materials including fillers, stabilisers, pigments and many other plastic additives. In my opinion adoption of any from mentioned methods would lead to social, economic and even political revolution. Resignation from action would give at first the environmental and economic catastrophe, and in second depletion of crucial resources in economically acceptable form.
  8. Aug 20, 2017 #7


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    Gold Member
    2016 Award

    So you are disagreeing with @fresh_42's post #2 ? Based on what I've read and seen on TV (and I'm a news junkie) I'd say he is exactly right and you are missing the point.
  9. Aug 20, 2017 #8


    Staff: Mentor

    We recycle plastic here. Whether it was a wrap of something or bottles or anything else. It doesn't even have to be cleaned beforehand. There are various applications for it. And none of it is burning it. The plastic waste in the wild is the problem.
  10. Aug 20, 2017 #9
    Generally fresh_42 is right, but in details first thesis of his statement is impractical. There are many methods of doing something useful from plastics, but most of them requires heavy work-financial-energetic input. All of them demand isolation of given plastic in a chemically homogenous form, which at present is economically impossible. This is the fresh_42 point. More than 20 years ago in Germany they introduced a "triple" system of plastic offering into the market. It involves paying for producer for waste utilisation, included in price. The huge success of this system never exceeds 50% of plastics introduced into market. Until we change technology making impossible to mix our plastics with another materials, we cannot even start fight with growing plastic waste mountains, and plastic fields on oceans surface. Recycling plastics also demand changes in technology, as they are not ued as chemically homogenous polymers, but contains various additives. For plastic goods recycling, refer to circular economy ideas.
  11. Aug 20, 2017 #10
    I am happy you success in recycling. What part of market you cover?
  12. Aug 20, 2017 #11


    Staff: Mentor

    I don't understand the question. Our recycle system is private (they sort it by types of plastic) and all wraps have to be taken back, gathered by the usual garbage collection company. It's priced in the product costs, but as it is (by law) for all kind of plastics which are sold, the costs per unit are negligibly small. Apart from that there is meanwhile a market for those resources. In China they even make clothes from PET bottles.
  13. Aug 20, 2017 #12
    My question is about covering hundreds of millions of tonnes plastic garbage per year. Some fifty years ago I also recycled plastic bottles because there was no raw PET on Polish market (it was used for manufacturing clothes, not bottles). But there is nothing to do with millions of tonnes of plastic wastes. In Poland we collect plastic waste in the separate bags as "plastic" or "dry waste" (frequently with glass or metals). For any sort of recycling these goods one must separate raw waste, collecting given kind of goods. Even when such o good is present in large quantities, many other plastics remains in waste. Another situation is with raw material recycling. One can collect various goods made from the same polymer. Leftover may be smaller. Recognition of any popular polymer may be easily done by checking its IR spectra, but I didn't hear on practical application of such a technique for waste. Resuming: even when we do very good things with plastic wastes, most of them remains in environment, and desperate governments try to burn them without segregation, recycling, etc.
    Present regulations, organizations and techniques do not solve the problem of plastic waste, so one must change them in a revolutionary way. Tercium non datur.
  14. Aug 21, 2017 #13
    Thanks for all your replies zbik, my vocabulary is not very much, but I knew there had to be some others working towards such techniques used in the article, just wanted to see where people were at, I've saved the pdf for future reference. There are much more adjustment can be made if only markets ever come together, but they so rarely do, until then...
  15. Aug 21, 2017 #14
    SIQI, whatever you are doing with plastics, remember chemical complexicity of most market products. Any time you think on "mixed" plastics you have to decide: joining given pieces together or not? In my opinion probability of making erroneous decision is propotional to square of both material volume and "species" number.
    It is relatively simple to proceed with homogeneous waste: return them to the producer, they should knew what to do.
    Best regards,
  16. Sep 3, 2017 #15
    The cost is important. The "cost" partially means energy. Right now engineers are working on extracting carbon compounds from rock.

    Which is recycling.

    Logistics is the largest cost in solving many problems. Trash collection is a massive project by itself. If you embed trash into rock then you have to dispose of the rock. How would anyone benefit by converting 1 tons of unwanted material into 10 tons of unwanted material?

    How is this an improvement over current sanitary land fills. When you excavate the space of your deep underground garbage plant what would you do with the excavated material? Would you haul it to the "regular dump"?

    When you do an excavation the machines that drill, shovel, and haul material wear down and eventually stop working. Would you recycle the machines parts, put them in the regular dump, or drop them into the underground pit with the plastic?
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