Throwing your plastic soda bottle or lunch container in the recycling bin feels like an easy win for the environment. The plastic gets reused, creating less waste and a fossil fuel use. But the reality is less appealing. In the U.S., less than ten percent of plastics get recycled every year. In fact, in 2018, the U.S. burned almost twice as much plastic as it recycled, according to the Environmental Protection Agency. It’s a big obstacle to the ideal of a circular economy, where everything we throw away gets turned back into something useful.
The most common way of recycling plastic is by chopping it into an avalanche of tiny flakes and then melting down and reforming them. The resulting plastic can be brittle and weak, and in many cases manufacturers simply prefer using new, or virgin, plastic. That requires them to use oil taken from the ground, even as society is attempting to move away from a reliance on fossil fuels. And many of those products — plastic grocery bags, soda bottles, ballpoint pens and millions more — get used and then thrown away, piling up in landfills or ending up in the ocean.
A process known as chemical recycling could be the solution. Plastics are made of long chains called polymers that can be thousands of molecules long. Chemical recycling involves breaking those chains into individual units, called monomers.The monomers can then be refashioned into polymers, creating plastics that are as supple and strong as before. There are a number of ways to potentially chemically recycle plastics, from using high temperatures and pressures to chemical solvents.