Chemical energy in plastic is about 22 kWh per kg, roughly twice that of gasoline (12.7 kWh per kg). Right? The only problem is that you have to take the toxic gases and re-heat them to break down the toxins.

The US Environmental Protection Agency, after extensive expert and public review, determined that destruction in high- temperature incinerators is the Best Demonstrated Available Technology (BDAT) for most organic hazardous wastes. This is because incineration safely and effectively destroys the hazardous constituents in the waste.

On the other hand, most experts maintain that this solution is extremely not cost-effective and is also environmentally counterproductive because it creates a need for constant waste input.

The cost of regular incineration is 130 USD per ton, producing 573 kWh. HT incineration is done at 1110C.

But if the plastic breakdown is done in advance, and only then the carbon compounds are introduced to oxygen for incineration and energy production, perhaps we would get much more of the energy back, than just trying to burn the plastic as an incineration process.

This can be achieved in one of two ways:

1. The high-temperature breakdown of the plastic should be done in a near-vacuum non-oxygen environment so that we get mostly carbon and hydrogen, which are only later introduced to oxygen to give cleaner combustion.

2. The plastic breaking up process at high temperatures could be done in the presence of oxygen, so that the combined input heat and extra output heat would be immediately used for creating energy, more than was available (and mostly ignored) from the low-temperature incineration process.

I hope I'm clearer this time, and the idea won't be deemed as cash to confetti anymore.

[link 1 Why high temp incineration is good]

[link 2 Why regular incineration of plastic is bad]

[link 3 Why regular incineration of plastic is horrible]
-- pashute, May 30 2022

High Temperature Incineration is good https://etc.org/adv...ature-incineration/
Washington DC based ETC organization [pashute, May 30 2022]

Regular Incineration is horrible https://environment...g-plastic-solution/
Canadian based "myth busting" Environmental Defence organization [pashute, May 30 2022]

The costs of high temperature incineration https://www.e3s-con..._icaeer18_03027.pdf
and with current technology, how they cannot sustain themselves [pashute, May 30 2022]

Nuclear incinirator power plant Hopefully this fixes that idea [pashute, May 30 2022]

Thermal depolymerization https://en.wikipedi...al_depolymerization
[Voice, May 30 2022]

Turn garbage into charcoal
[xaviergisz, May 31 2022]

Pyrolysis https://www.lowimpa...on-plastics-problem
Isn't much better [4and20, May 31 2022]

The thing about waste plastic is... sure we can burn it. It's inefficient or dirty, as you say. If it's clean and sorted there is more potential for reuse - but generally the cleaning and sorting is difficult and expensive; currently it's often more trouble than it's worth.

But if we just bury it somewhere out of the way, like we always used to - it'll safely hold that fossil carbon indefinitely.

It really seems to me like the way these things are being driven is counterproductive from an environmental stand-point.
-- Loris, May 30 2022


God save us from misanthropists in environmentalist's clothing
-- Voice, May 31 2022


Turn the plastics into handbags and call them "Genuine Dinosaur handbags"?
-- 4and20, May 31 2022


Quoting and summarizing from WP Thermal depolymerization (thank you [voice]!)

...most... proceeds in a disordered manner... giving a mixture of volatile compounds. The result is broadly akin to pyrolysis, although at higher temperatures gasification takes place.

Plastic-to-fuel technologies have historically struggled to be economically viable due to the costs of collecting and sorting the plastic and the relatively low value of the fuel produced.

Thanks [voice] for the link. So I was wrong in my assumption and hope. But why do you call me a misanthropist or were you referring to someone else?
-- pashute, Jun 08 2022


Well now that you've invited me to, how can I resist, you human hating human hater. But I was just speaking in general.
-- Voice, Jun 08 2022


//misanthropists in environmentalist's clothing//

It's at epidemic levels. The people to solve the problems are engineers with the right incentives. The people often in charge of solving the problems view humans AS the problem and act in a sort of self-flagellation by proxy.
-- bs0u0155, Jun 08 2022



random, halfbakery