Can I just do that and stop paying for gas for my car and boiler and generators for like electricity and stuff ?
In: Chemistry
Gasoline is a hydrocarbon derived from petroleum- a long chain of carbons and hydrogens linked by energetic chemical bonds. Breaking those bonds, such as by burning them, releases energy that we can use to do work like drive a car.
Plastic, for the most part is also a hydrocarbon derived from petroleum. It has different chemical properties, and lacks those high energy bonds that make it a good fuel. Instead, plastics are structured from repeating subunits called polymers, which form stable, inert bonds that are ideal for plastics.
So chemically, it’s pretty simple to turn plastic back into a crude mass of hydrocarbons that could be in turn refined into gasoline or another kind of fuel.
The problem is energy. Remember, energy can’t be created or destroyed. So in order to make an energetic substance like hydrocarbon fuel, you need to put a whole lot of energy into the starting material- in this case by heating the plastics to their melting point under high pressure. It’s not yet economical to do that on a wide scale yet. But possibly it’s not too far off.
To add to what people before me have said – plastics aren’t just one thing. There are different types of plastics we use daily and some release very nasty byproducts when burning, most notably PVC, which contains large amounts of chlorine.
If something sounds too good to be true, it’s probably too good to be true. If there was a cheap and efficient way to turn waste plastic into gasoline just by burning it, somebody would have figured it out by now. I don’t doubt it’s possible, but it’s certainly not as easy and revolutionary as clickbaity videos will have you believe.
[That is real, here’s an article from chemical engineering news on one such plant that is that is being opened soon](https://cen.acs.org/environment/recycling/New-plastic-pyrolysis-capacity-planned/98/i27) and [here’s one in Japan that is already open](https://kleanindustries.com/waste-challenges-innovations/plastic-pyrolysis-recycling/spr-japan/) Note that neither actually produces gasoline, they produce a mix of hydrocarbons. The articles mention “pyrolysis”, which is to break down with heat and oxygen, but they would use carefully controlled temperature, pressure, and oxygen level, plus a catalyst. The catalyst may well be platinum. There are toxic byproducts, it is not a DIY job.
[You can DIY wood pyrolysis to run an internal combustion engine](https://www.youtube.com/watch?v=Cm46KAPLZpQ), but you’re generally producing a fuel gas, rather than a liquid. It is possible to make liquid fuel from wood, but it tends to come out like something between tar and diesel, not gasoline.
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