Students at Northeastern University in Boston are working on a process that breaks down recycled plastics to create fuel, providing enough energy to run itself with some left over, too. Because it vaporizes plastic rather than burning it, the process also creates less emissions than conventional combustion. The students and their professor, Yiannis Levendis, envision utility-scale versions of the process, which could be installed at plastic recycling facilities.
The world is awash in plastic waste of all sorts that could be converted to fuel, to say nothing of emerging renewables such as wind and solar energy. In the not too distant future the world can wash its hands of the practice of creating widespread environmental damage for the sake of harvesting virgin petroleum, merely to burn it.
Pyrolysis and Plastics
Pyrolysis is a common industrial (and cooking) process that involves heating an organic substance to a high temperature, causing a chemical reaction that decomposes the solid into gases and liquids. The solid residue left over is rich in carbon. Unlike conventional combustion, pyrolysis does not require oxygen. Pyrolysis is one answer to the problem of recycling mixed plastics, for example from consumer devices that may consist of several different types of plastic. The Northeastern process is designed to recover its own waste heat and recycle it to keep the process going, while also creating steam that can be used to generate electricity.
Many Different Roads to Plastic Recycling
Plastics have only been around for a couple of generations, and in that relatively short time they’ve managed to create a stunning variety of headaches. But an equally stunning variety of solutions is cropping up, too. Aside from pyrolysis, for example, a Welsh company is recycling mixed plastic waste to make modular homes, and a U.S. company is working on recycling waste carpet into plastic pellets that can be used to manufacture everything from plant pots to lab equipment. To grasp the scale of possibilities for recycling carpet alone (much of which is made from olefin, a #5 plastic), the U.S. EPA estimates that four billion pounds of used carpet enters the U.S. waste stream every year. That sure adds up to a lot of plant pots – and a welcome alternative to “drill baby, drill.”
Image: Plastic waste by Josh Kopel on flickr.com.