Can we remake plastic waste into a rocket fuel??

Discussion in 'Tech Discussion' started by lord95, Jul 29, 2021.

  1. Jeebus

    Jeebus Well-Known Member

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    I hadn't thought about that, but you're right. If plastic eating bacteria spread outside of the industrial sites where they've been found, they could destroy consumer plastic products. At least you can set up traps for termites.
     
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  2. gangbuntu

    gangbuntu Well-Known Member

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    about a decade ago, some chinese invested in indonesia, establishing companies that recycle plastics into pellets to be exported to china.
    they didn't last long because the cost to clean and sort them outweigh the profits. further, the cleaning process introduced a lot of stinky waste into the river.
    profit is definitely a very important factor.

    as what the above shown, downstream recycling is not economical. if we want to change, the culture/mindset of most individuals have to be changed. proper segregation of organic / recyclable should start from every household to the final dump sites.
    i find it is idiotic that some places would have different colored bins for different type of wastes, but when the garbageman arrives, he'd dump them all into the same spot.

    bonus (feel free to ignore the articles, just look at the images):
    - citarum river - https://majalahcsr.id/hanya-1-sunga...kontribusi-pada-pencemaran-laut-oleh-plastik/
    - ciliwung river - https://theconversation.com/riset-ciliwung-termasuk-sungai-terkotor-di-dunia-131927
    indoneisa is the 2nd largest contributor.

    i plead guilty for contributing to the amount of plastic waste as of late due to covid
    - almost always take away for every meal
    - drinking from pet bottles.
    between these and the risk of infecting my comorbid parents - my choice is clear.
     
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  3. Ai chan

    Ai chan Queen of Yuri, Devourer of Traps, Thrusted Witch

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    Until further studies, peer review and patents have been made, Ai-chan would say no. If they ask for money or government grant without patents, Ai-chan would say it's a scam.

    For something to be used as rocket fuel, the following must be taken into account:
    1. The cost of making the fuel
    2. The thrust-to-weight potential of the fuel
    3. The cost to keep the fuel in storage
    4. The cost it would take to deliver a tonne of payload into orbit
    5. The environmental impact of such rocket fuel

    For one, there's a reason why liquid hydrogen+liquid oxygen is the fuel of choice for NASA. The cost of making hydrogen and oxygen is very cheap. All you need is water and electricity. Turning both into liquid is more expensive, but the process itself is simple and foolproof.

    Liquid propellants (such as liquid oxygen+liquid hydrogen) have very high specific impulse and can be throttled and restarted easily.

    While liquid oxygen and liquid hydrogen requires to be kept in cryo and thus raises its cost, it is a straightforward enough that there isn't much that can go wrong.

    As for the cost of delivering a tonne of payload into orbit, Ai-chan doesn't know. Ai-chan isn't a rocket scientist. Ai-chan is sure that there are rocket enthusiasts in this forum who can provide such numbers. Ai-chan wouldn't even try.

    Liquid hydrogen and liquid oxygen, when burned to provide thrust, simply creates water. Yes, that extremely hot rocket fuel outputs thrust, heat and water. Therefore, they are very clean. Can this plastic waste fuel compare to that?
     
  4. lord95

    lord95 Member

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    Yeah, this kind of fuel eventually even beter than kerosene. This kind of pentrol ( remade from plastic) had already been tested and the result of this test has shown that the new type of rocket fuel ( remade of plastic )is 1% - 3% better than kerosene by its energy characteristics.

    It would be a great chance to clean up our environment from plastic waste. We`ve got tons of plastic waste all around the globe. However, only the following types of plastic waste can be converted into the rocket fuel: Polypropylene (PP). Polyester (PE). Polystyrene (PS) and its mixtures and analogs

    Last of all I wanna mention another great invention by this private space company. This is invention is known as the ``hybrid`` rocket. The official name is Skyhy and the term ``hybrid`` has been given to this rocket because of the combination of (HTPB) fuel 90% (H202) liquid oxidiser.
     
  5. Jeebus

    Jeebus Well-Known Member

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    Does that mean 1-3% more joules per mole? Energy characteristics isn't a specific term. There's little in the way of useful information listed on their website. Without more information, it's impossible to say whether it's actually doing the environment any good.

    What is the cost to produce, and how much energy is used to produce it? Unless it's at least as cheap as kerosene, then not many people will switch to using ecosene. If the energy required to refine it is greater than that to refine kerosene, then you're not doing the environment any favors by using ecosene, assuming the combustion of ecosene and kerosene release a similar amount of greenhouse gases.

    Without a consumer for the product, it's not going to spur the demand that would be required to put a dent in plastic waste.

    Any idea that broaches plastics recycling is great. I hope they continue their efforts on this front. That said, converting carbon that's already sequestered in plastics into rocket fuel and releasing that carbon into the atmosphere isn't the ideal way of recycling plastics. Unless it can be done more cheaply and efficiently than refining kerosene, it might be better to keep the plastics as plastics or just burn them as is without the extra energy required to convert the plastics to rocket fuel.
     
    Last edited: Aug 10, 2021
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  6. xiazixin

    xiazixin Well-Known Member

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    Isn't the latest space station powered by ion thrusters which use electricity instead of chemical fuel?
    Currently the space station in Chinese space use ion thrusters which reduce the operational amount of rocket fuels by 90%.
    All you need is electric and liquidated nutral gas and little chemicals fuel for alternative truster.
    Over the next few decades, ion thruster should be the next mainstream space engines and replacing the existing trusters.
     
    Last edited: Aug 10, 2021
  7. Jeebus

    Jeebus Well-Known Member

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    For the foreseeable future, chemical rocketry will be a requirement to get payloads out of the atmosphere. Ion engines can't generate enough instantaneous thrust to achieve escape velocity, nor do most ion engines work in the presence of an atmosphere. Once in the vacuum of space, ion thrusters are a great option for propulsion due to their incredible efficiency. In fact, some satellites already use ion thrusters for orbital maneuvering.

    As far as I'm aware, no one is researching ion engines for getting to orbit. Even the most experimental, cutting-edge electrically powered thrusters are only capable of generating around 50 newtons of force. That amount wouldn't be enough to get the engine off the ground, let alone put a payload into orbit. There's also the issue that most ion thrusters meant to work in space simply don't function at all in the presence of an atmosphere.
     
    Last edited: Aug 10, 2021
  8. xiazixin

    xiazixin Well-Known Member

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    Guess no one is researching how to build a giant tower with electromagnetic catapult to space so called space escalators. Guess we are still so primitive.
     
  9. NoLongerTheSame

    NoLongerTheSame Well-Known Member

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    well... I just watched a recent scishow episode about plastics in youtube and... things aren't that simple nor easy... For example, the process of turning plastics into fuel alone might even produce more crap into the environment or...whew~. I'm feeling lethargic just thinking about whats and hows. Researchers really are unsung heroes.
     
  10. Jeebus

    Jeebus Well-Known Member

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    Wouldn't that just be a giant rail gun? To have a railgun launch people into orbit on a spacecraft, the rail would need to be over 100 miles long so as not to kill the passengers with excessive acceleration. It's feasible, but I doubt we'll see anyone build a 100+ mile railgun in the near future.
     
  11. lord95

    lord95 Member

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    Last of all I wanna mention another great invention by this private space company. This is invention is known as the ``hybrid`` rocket. The offecial name is Skyhy and the term ``hybrid`` has been given to this rocket because of the combination of (HTPB) fuel 90% (H202) liquid oxidiser.
    However, I am not sure if this kind of rocket fuel can be used in long space journeys. But still, it would be good enough to this kind of rocket fuel in some small space launches that are aimed at some microgravity missions and experiments.
     
  12. xiazixin

    xiazixin Well-Known Member

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    Then it would be out for Chinese markets, as far I'm aware that Chinese universities always get decommissioned rockets donated by the army and they basically just modify it to launch research satalites.
    They are really cheap for universities, as they get it free.