In the United Kingdom, we produce 230m tonnes of waste chemicals per year. This number contributes to the ‘8.3bn tonnes of virgin plastic produced worldwide.’ Yet, statistics show that only 9% of plastic waste has been recycled.
With the urgent need to limit plastic waste, science and technology come hand in hand in regarding waste management. George Huber, a chemical engineer at the University of Wisconsin-Madison, tackles the problem of plastic films that are used to keep food fresh. He is pioneering chemical recycling in one such packaging films containing ‘polyethylene and PET, as well as a plastic oxygen barrier made of ethylene vinyl alcohol, or EVOH.’ The recycling process involves using a series of solvents to dissolve the individual plastic components in a product. The trick is choosing the right solvents to dissolve only one kind of plastic at a time, Huber says. Since the film is multilayered, the film must first be stirred into a toluene solvent, to dissolve the polyethylene layer. Then the EVOH-PET film would need to be submerged in a solvent called DMSO to strip off the EVOH. Researchers then remove the remaining PET film and recover the other two plastics from their separate solvents by mixing in ‘antisolvent’ chemicals. By doing so, most of the plastic from the original film would be recovered. Tests have shown this can recover around 95% of each plastic component. Chemical recycling could be humanity’s next step in disassembling multilayer plastic products. There are many benefits to chemical recycling, however, skepticism pervades as the reliability of this method is questioned by others. “It’s really a complete myth when people say that we’re recycling our plastics,” says Jim Puckett, the executive director of the Seattle-based Basel Action Network.