US-based University of Wisconsin Madison professor George Huber has announced plans to recycle plastic using pyrolysis process.
Pyrolysis is a process that involves heating up the biomass in a low-oxygen environment in the presence of a catalyst.
The process can break the plastic down into chemical feedstocks, and then recycle it into fuel or develop new virgin plastic.
Huber said: “We started thinking about whether we could pyrolyse those plastics and what we could make if we did that.
“We literally took our reactor, where we were pyrolysing biomass, and instead of adding wood into the feed, we added plastic and made a liquid oil. And then we analysed the chemistry.”
To study the possibility of recycling plastics through this process, the research team melted down polyethylene, a plastic present in shampoo bottles and grocery bags, at a temperature ranging from 500 to 600 degrees Celsius.
Huber, with the assistance of his graduate student Dongting Zhao, then analysed the liquid and gas products of that pyrolysis.
Huber further added: “We’re trying to provide more molecular-level information about the chemicals that you can make from pyrolysis. That gives us ideas about how we can more efficiently go back to the original plastics.”
The professor believes that pyrolysis can be used in recycling large bales of mixed plastics.
Recently, Huber and several colleagues proposed a new multi-university research project called the Centre for Chemical Upcycling of Plastic Waste.
The centre will be used for studying and refining the plastic recycling process.