A few weeks ago, YouTube served up a video of a plastic pyrolysis machine.
It was a small desktop unit with what essentially was a pressure cooker, electric heater, and plumbing set up like a alcohol still.
So upon a lot more research, and recalling someone I knew a few years ago proposing this in the Philippines (hint no one locally would do it)
I checked it out and found out a lot more info.
It turns out that if you take non thermoset plastics (like pvc and vinyl) and heat them up in a closed chamber so they do not burn, they will break down and you can transform it into gasoline or diesel, depending on the temperatures. You also have lighter gasses released like propane, butane that can be recovered and burned cleanly to feed back into the system.
What remains is fuel, and carbon black that has a lot of uses.
Now this begs the question. The Philippines has a large problem disposing of plastic waste. Some of it is just too dirty to be recycled.
The Philippines also imports most of its fuel. The country has one refinery. (for 90 million people).
So this begs the question. Why are oil refineries themselves not reclaiming waste plastic back into the system? It cant be cost. Waste plastic is nearly free.
The method to do this is do quick and dirty one could do it in a jungle refinery with hardware store and junk materials, so the tech is not that complicated.
There are continuous use plants that will feed plastic in one side and carbon black comes out the other with the semi refined fuels coming off the middle. One could refine the process more with a fractional distillation column to boost it even more. But even still a crude system would provide a very high quality feedstock for a oil refinery and a much more value added source of hydrocarbons vs crude per volume.
Hi, There has been some discussion of pyrolysis here before:
Unfortunately, in some countries it has a bit of a public relations problem. See https://davehakkens.nl/community/forums/topic/plastics-related-stories-in-the-media/#post-120002
I suspect one of the reasons the main oil refineries don’t do this is because, on a large scale, the waste plastic is not nearly free. Sorting the right types of plastic for any process (recycling or pyrolysis) is very labour-intensive – and the proportional labour costs probably don’t reduce as the volume of waste increases. On a large scale, crude oil will be way cheaper per tonne than sorted waste plastic.
However, for lots of small-scale pyrolysis operations, it might be quite cost effective. This might especially be so if carried out in places where normal petroleum fuels are unusually expensive, for geographical reasons (eg. small islands, or remote mountain communities).
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