We are living in the age of plastic. Each human is estimated to produce their body weight in plastic waste each year. Most of these plastics are dumped in landfills, where they need many centuries before they degrade naturally. Millions of tons of plastics also end up in the ocean each year. They even found their way to the bottom of Marina Trench – the deepest place on earth. We desperately need a better way to handle our plastic waste..

Chemists have invented a new process that could turn polypropylene, which makes up 25% of all plastic, into hydrocarbon fuel (such as coal or oil) and natural gas. The new method requires supercritical water – water that is extremely pressurized and heated many times above its boiling point. The steaming water breaks down plastics first into smaller plastic chains and further into small hydrocarbons that can be used as fuel. Over 91% of the input plastic was converted into fuel with this process. With longer reaction times, natural gas could also be made.

This new method is more energy efficient than recycling or incineration. It could one day help reduce plastic waste and generate energy at the same time. So far, the chemists only experimented on a small amount of clean plastic at a time. The process will need to be tested at larger scales with real plastic waste before it could see widespread commercial use.

Managing Correspondent: Veerasak (Jeep) Srisuknimit

Original Paper: ACS Sustainable Chemistry and Engineering

Press article: Vice, Antropocene Magazine

Related SITN articles: The plastic in our oceans

Image Credit: Flickr