If you remember your Harry Potter, you’ll recall that in the Prisoner of Azkaban, Hermione Granger has a “Time-Turner”, which she and Harry use to, well, turn back time – and rescue Sirius Black.
(Photo by Daniel Jericó)
Now comes news, less exciting but maybe more important – of turning back time for plastics. Yes, plastics. And what we may be rescuing this time, is our planet.
The magic here, is taking used plastic – and turning it back into the ingredients it was first made from – then using those ingredients to make new, fresh plastic. (In this case, those ingredients are two petrochemicals, ethylene and propylene.)
Plastics (made from petrochemicals) make modern life possible. That’s not news. The list of everything around you, right now, made with plastics – would take up the rest of this story, and the story after that, and the story after that.
But sometimes the same qualities that make plastic such a good choice for making things – strong, long-lasting, flexible, affordable – make a problem when those plastics end up where they shouldn’t be.
So chemical company BASF has developed a “chemical recycling” process for plastics – using heat to break down old plastic, and turn that plastic into an oil (and at the same time, burn off food bits or other non-plastic material that make some plastics difficult to recycle otherwise).
Then heat is used again to “crack” those molecules of oil to produce the petrochemicals (like propylene and ethylene) which can then be used to make new plastic, exactly the same way plastic is made in the first place (from petroleum or natural gas). Turning back the clock on a piece of used plastic, to the moment it was first made – so that it can be remade into something new.
Making new plastic from old – that’s pretty magical. And since the process requires heat, let’s go out with a spell straight from the halls of Hogwarts: Incendio!