The most versatile version of chemical recycling is “feedstock recycling“. Also known as thermal conversion, feedstock recycling is any process that breaks polymers down into simpler molecules using heat.
The process is fairly simple – take a plastic drinks bottle. You put it out with your recycling for collection. It is taken, along with all the other waste, to a sorting facility. There, the rubbish is sorted, either mechanically or by hand, into different kinds of materials and different kinds of plastics.
Your bottle is washed, shredded and packed into a bale ready for transportation to the recycling centre – so far, the same as the conventional process. Then comes the chemical recycling: the plastic that formerly made up your bottle could be taken to a pyrolysis centre where it is melted down. Next it is fed into the pyrolysis reactor where it is heated to extreme temperatures. This process turns the plastic into a gas which is then cooled to condense into an oil-like liquid, and finally distilled into fractions that can be put to different purposes.