How Science Is Fixing Recycling's Grossest Problem

Polypropylene recycling has a problem: It stinks. Food and other residues are almost impossible to remove entirely from polypropylene, a.k.a the number “5” plastic of grocery-store fame. Those residues - anything from yogurt to garlic, from fish oil to baby food - not only stick to polypropylene, they degrade there and start to smell even worse!
Current polypropylene recycling techniques are more down-cycling than re-cycling. Unless you break down its molecules through a highly energy-intensive refining process, the material can only get a second life as a black trash can or an underground pipe - wherever its smell doesn’t matter.
But a new technique, called dissolution recycling, is changing all that. Dissolution recycling uses a special hydrocarbon polymer solvent under finely controlled conditions of temperature and pressure to eliminate ALL of the contaminants embedded in the plastic.
Ingenious is a new web series from the American Chemical Society about how leading-edge chemistry is taking on the world’s most urgent issues to advance everyone’s quality of life and secure our shared future.
Hosted by Alex Dainis, Ingenious spotlights stories from the front lines of chemistry research and development, where passionate innovators are stepping up to confront problems like pollution, overfishing, sustainability, and personal safety.
Ingenious releases every month.
Ingenious is made with funding and featuring scientists from 3M, Ascend Performance Materials, Baker Hughes, BASF, Dow, DuPont, Procter & Gamble, PPG, Royal DSM, SABIC, Solvay, and W. L. Gore & Associates, none of whom influenced any editorial decisions.
#recycling #polypropylene #plastics

[@amadeusakreveusmusic3356]

4:59 Reminds me of the process recrystallization. Damn it feels good to see how research in chem can (and will) save the world and have an affect on our lives, whether it's from plastic, CO2 emissions, clothing, etc. Great video ACS 😀, and thank u Alex for being a hosting 😄!

[@dungeonmaster2176]

I suppose after the alkane solvents are used they will be burned for fuel. Considering most hydrocarbons are used for fuel in the first place makes the alkane solvent waste not quite a waste if it can burned after used for recycling.

[@reigyst]

I was wondering the same thing... what happens to those solvents afterwards when they have the smelly stuff?

[@MohamedIbrahim-tm1wx]

Can the solvent then recycled and reused in another solvolysis process?

[@SkepticalCaveman]

Luckily HDPE (#2 plastic) is very eaay to recycle even at home. It can be melted in an oven at low temprrature and it doesn't give of toxic fumes.

[@Cineenvenordquist]

Couldn't just call it 2 loops 1 solvent? And at that a physical separation...wait, though there has to be a side of each solvent loop where the contaminants are removed; hoping the inks separate by color/clarity/🧄. Still waiting on tips for moving fast with polyalkane solvents and breaking things safely.

[@ryhol5417]

In reality: no. All of it goes into the ground or burned. Nobody has resources to sort the garbage that closely. A million times cheaper to make new plastic. And that’s what everyone does

[@cesarsoto852]

Great it can be done

[@pstreicher]

I've been looking for this answer for weeks now. But, why don't we see this being done locally, everywhere. I believe the cost outweighs the benefit. But, we need to push the government to supplement companies to do this just as we supplement the farmers to grow our food. When will we begin the push? Who can stand up and lead the charge?