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I saw this recently at an exhibition about plastics. The distilling process suggested to me that you cannot get plastics (naphtha is the precursor) from oil in

I saw this recently at an exhibition about plastics. The distilling process suggested to me that you cannot get plastics (naphtha is the precursor) from oil in a world that does not also use Diesel and gasoline etc as fuels. Because they are all produced at the same time and are by products of each other. Does anyone know if it is potentially possible to increase the yield of naphtha if there is no (or low) need for fossil fuels?

detaro 4y ago
There's lots of ways of shifting the ratios of produced materials and converting them into each other, so it's mostly a question of cost (and cost distribution across products), not of reduced demand making other products entirely unavailable.
tkgally 4y ago
One method for doing that is catalytic cracking: https://en.wikipedia.org/wiki/Fluid_catalytic_cracking https://en.wikipedia.org/wiki/Fluid_catalytic_cracking https://www.britannica.com/technology/petroleum-refining/Visbreaking-thermal-cracking-and-coking https://www.britannica.com/technology/petroleum-refining/Vis...
ljf 4y ago
Hopefully we can move to non-oil based 'plastics' at the same time. In an idea world we could leave these carbon deposits where they are.
- PM_me_your_math 4y ago
  Without fossil fuels, tens of millions of people will starve to death. Fossil fuels are here to stay precisely because no other energy source exists that is as energy dense, portable, safe, and cost-effective. Everything else is just hype and salesmanship.
  - bubbleRefuge 4y ago
    I think nuclear plants charging elecric batteries can go a long long way.
  - ClumsyPilot 4y ago
    With rampant climate change, 2 billion with starve to death from crop failures, from drought induced famine. Europe and US has record low harvests this year. Grain stores are at a lowest point they've been in decades. It will cost trillions to build enough reservours, water canals and greenhouses to feed the remaining population. Yield of wheat is reduced in high temperature even if there is enough water. You will have to eat casava.
    - jhoechtl 4y ago
      > With rampant climate change, 2 billion with starve to death from crop failures, from drought induced famine. Certainly some but not that many. Climate change? Of course! Hiw big is the man made part and how sensitive does it react to change? No answers as of yet.
      - ClumsyPilot 4y ago
        > Certainly some but not that many. What is the basis for this extraordinary assertion? Without adaptation, climate change could depress growth in global agriculture yields up to 30 percent by 2050. That's 2 billion dead. By 2100 it could be more. With some really clever policy it could be less, but there is no evidence of clever policy from anyone. You propose no solutions, only mudding the water.
        jhoechtl 4y ago
        > With rampant climate change, 2 billion with starve to death from crop failures, from drought induced famine. What is the basis for this extraordinary assertion? Sources? Even then your lineage of argumentation is non-conclusive as 30% change doesn't equate 2 billion death.
themitigating 4y ago
Why can't you just make plastic from the oil?
- deleted 4y ago
  [deleted]
- mschuster91 4y ago
  Because there are shorter and longer hydrocarbons in the oil as well. Most of the longer hydrocarbons can be cracked apart, but the shorter (both liquid and gaseous) and extremely long (e.g. tar, bunker fuel, ...) hydrocarbons will still be present and need to be dealt with.
  - gus_massa 4y ago
    I agree. More details. Plastics are made chaining small molecules into long chains. The property of the plastic deepens on the initial small molecule, how many of them you chain and other stuff. Also, if the initial molecule has only two "sticky" points and form a linear chain, or has three or more "sticky" points and then form a net of interlocked chains. Or something in between. Also depending on what is in the initial molecule, the chain may be like a single smooth rope, or have some dangling parts like a Christmas light line. And you can also mix two or more initial molecules, and there are a few methods to make them "sticky", and ... In particular, the size and shape of the initial molecule is very important. You want a very specific one to get the properties of each plastic, not a mix random chemical stuff. Back to oil... Oil has a mix of hydrocarbons of very different sizes and shapes. Some are linear, some have side chains, some have cycles. (This differences are also important if you want to use them as fuel or lubricant.) To make plastic you must add two "sticky" points to the hydrocarbons, changing some part of them, for example adding oxygen or nitrogen. But before that, you must select the correct length and shape of the hydrocarbon. To select the length and shape of the hydrocarbon, the fist step is to boil it, and let the vapor condensate at different temperatures. The short hydrocarbons have a low boiling point and the long hydrocarbons have a high boiling point. Then each part is further proceed and used as a different kind of fuel or for different chemical reactions (to make plastic and other stuff).
xattt 4y ago
Relevant but tangential xkcd: https://what-if.xkcd.com/101/ https://what-if.xkcd.com/101/
joshspankit 4y ago
This makes the push for green-washing plastics make a lot more sense. Otherwise the oil industry would have to deal with plastics as a waste product.
dotancohen 4y ago
I mention this on an answer on SE: https://mechanics.stackexchange.com/a/23916/922 https://mechanics.stackexchange.com/a/23916/922 The gist is that if we decide that we need any fixed amount of any of the oil products, that product becomes expensive and the remaining products become inexpensive byproducts of its production.
kiliantics 4y ago
Yes, we should be demanding alternatives to all petrochemicals. It seems that we take for granted that plastics are just a fact of life now but this is a big reason -- along with other more popular ones like microplastic pollution, ocean wildlife destruction etc. -- that we should move away from them where possible.
Phlarp 4y ago
Absolutely yes, Gasoline is the most demanded product so their production chains are built around re-processing components into as much additional gasoline as possible. Residual products from oil are a convenient feedstock for plastic but it can be made from other sources. Corn is a good example. If we stopped using gas/diesel/jet fuel and stopped refining oil completely the biggest tertiary products the world would miss out on are vaseline and petroleum based fishing lures

detaro 4y ago

There's lots of ways of shifting the ratios of produced materials and converting them into each other, so it's mostly a question of cost (and cost distribution across products), not of reduced demand making other products entirely unavailable.

tkgally 4y ago

One method for doing that is catalytic cracking: https://en.wikipedia.org/wiki/Fluid_catalytic_cracking https://en.wikipedia.org/wiki/Fluid_catalytic_cracking https://www.britannica.com/technology/petroleum-refining/Visbreaking-thermal-cracking-and-coking https://www.britannica.com/technology/petroleum-refining/Vis...

ljf 4y ago

Hopefully we can move to non-oil based 'plastics' at the same time. In an idea world we could leave these carbon deposits where they are.

PM_me_your_math 4y ago
Without fossil fuels, tens of millions of people will starve to death. Fossil fuels are here to stay precisely because no other energy source exists that is as energy dense, portable, safe, and cost-effective. Everything else is just hype and salesmanship.
- bubbleRefuge 4y ago
  I think nuclear plants charging elecric batteries can go a long long way.
- ClumsyPilot 4y ago
  With rampant climate change, 2 billion with starve to death from crop failures, from drought induced famine. Europe and US has record low harvests this year. Grain stores are at a lowest point they've been in decades. It will cost trillions to build enough reservours, water canals and greenhouses to feed the remaining population. Yield of wheat is reduced in high temperature even if there is enough water. You will have to eat casava.
  - jhoechtl 4y ago
    > With rampant climate change, 2 billion with starve to death from crop failures, from drought induced famine. Certainly some but not that many. Climate change? Of course! Hiw big is the man made part and how sensitive does it react to change? No answers as of yet.
    - ClumsyPilot 4y ago
      > Certainly some but not that many. What is the basis for this extraordinary assertion? Without adaptation, climate change could depress growth in global agriculture yields up to 30 percent by 2050. That's 2 billion dead. By 2100 it could be more. With some really clever policy it could be less, but there is no evidence of clever policy from anyone. You propose no solutions, only mudding the water.
      - jhoechtl 4y ago
        > With rampant climate change, 2 billion with starve to death from crop failures, from drought induced famine. What is the basis for this extraordinary assertion? Sources? Even then your lineage of argumentation is non-conclusive as 30% change doesn't equate 2 billion death.

themitigating 4y ago

Why can't you just make plastic from the oil?

deleted 4y ago
[deleted]
mschuster91 4y ago
Because there are shorter and longer hydrocarbons in the oil as well. Most of the longer hydrocarbons can be cracked apart, but the shorter (both liquid and gaseous) and extremely long (e.g. tar, bunker fuel, ...) hydrocarbons will still be present and need to be dealt with.
- gus_massa 4y ago
  I agree. More details. Plastics are made chaining small molecules into long chains. The property of the plastic deepens on the initial small molecule, how many of them you chain and other stuff. Also, if the initial molecule has only two "sticky" points and form a linear chain, or has three or more "sticky" points and then form a net of interlocked chains. Or something in between. Also depending on what is in the initial molecule, the chain may be like a single smooth rope, or have some dangling parts like a Christmas light line. And you can also mix two or more initial molecules, and there are a few methods to make them "sticky", and ... In particular, the size and shape of the initial molecule is very important. You want a very specific one to get the properties of each plastic, not a mix random chemical stuff. Back to oil... Oil has a mix of hydrocarbons of very different sizes and shapes. Some are linear, some have side chains, some have cycles. (This differences are also important if you want to use them as fuel or lubricant.) To make plastic you must add two "sticky" points to the hydrocarbons, changing some part of them, for example adding oxygen or nitrogen. But before that, you must select the correct length and shape of the hydrocarbon. To select the length and shape of the hydrocarbon, the fist step is to boil it, and let the vapor condensate at different temperatures. The short hydrocarbons have a low boiling point and the long hydrocarbons have a high boiling point. Then each part is further proceed and used as a different kind of fuel or for different chemical reactions (to make plastic and other stuff).

xattt 4y ago

Relevant but tangential xkcd: https://what-if.xkcd.com/101/ https://what-if.xkcd.com/101/

joshspankit 4y ago

This makes the push for green-washing plastics make a lot more sense. Otherwise the oil industry would have to deal with plastics as a waste product.

dotancohen 4y ago

I mention this on an answer on SE: https://mechanics.stackexchange.com/a/23916/922 https://mechanics.stackexchange.com/a/23916/922 The gist is that if we decide that we need any fixed amount of any of the oil products, that product becomes expensive and the remaining products become inexpensive byproducts of its production.

kiliantics 4y ago

Yes, we should be demanding alternatives to all petrochemicals. It seems that we take for granted that plastics are just a fact of life now but this is a big reason -- along with other more popular ones like microplastic pollution, ocean wildlife destruction etc. -- that we should move away from them where possible.

Phlarp 4y ago

Absolutely yes, Gasoline is the most demanded product so their production chains are built around re-processing components into as much additional gasoline as possible. Residual products from oil are a convenient feedstock for plastic but it can be made from other sources. Corn is a good example. If we stopped using gas/diesel/jet fuel and stopped refining oil completely the biggest tertiary products the world would miss out on are vaseline and petroleum based fishing lures