A small Canadian company is trying to change the way some plastic is recycled with an pilot
plant that will test a new process to reuse the polystyrene that makes coffee cups, food trays and packing material.
Switchable Solutions Inc, a joint venture commercializing the new recycling method, said its industrial-scale pilot should begin operation in about a year.
It will be able to recycle 2,000 tonnes of polystyrene a year in a process the company says is more environmentally friendly than existing methods.
Right now, very little polystyrene is recycled.
“It’s just being thrown out with landfill, which we think is a crime,” said Philip Jessop, the chemistry professor from Queen’s University in Kingston, Ontario, who invented the new technology.
Polystyrene is difficult to recycle because it contains so much air and tends to be contaminated with food waste and chemicals. Jessop said most current recycling methods need to heat solvents to make them work, while his reusable solvent only needs room-temperature exposure to carbon dioxide and air.
“It’s bad because it takes a lot of energy, and because it needs the solvent to be volatile. There’s fire risk, flammability, smog formation risk, inhalation hazards to the workers,” he said.
The company is exploring uses for the solvent in Canada’s oil sands, where Jessop said it could in theory extract oil without creating hard-to-dispose of toxic tailings.
It’s an idea that works in a beaker, but it is not ready for industrial application, he added.
The plant, in Mississauga outside Toronto, will determine if Jessop’s invention is viable for large-scale recycling.
It is a joint venture involving several businesses and non-profit organizations, including GreenCentre Canada, which commercializes green chemistry from universities, and Fielding Chemical Technologies Inc, which will host the plant on one of its existing solvent recycling sites.
Mark Badger, president and chief executive of the new company, said the used polystyrene will likely come from municipal recycling programs. Recovered plastic will be sold on to companies that manufacture such things as food containers and packaging materials.
“There is a huge appetite for recycled materials. The reason why is everyone’s gravitating, as they should, toward sustainable business models,” said Badger.
The specifics of Jessop’s technology are proprietary, but Mohini Mohan Sain, a professor who develops more sustainable plastics at the University of Toronto, said the announcements so far were encouraging.
He said using carbon dioxide in this kind of application is nothing new, but others have only used it in “supercritical” form, a state between a liquid and a gas which requires a lot of energy, compared with Jessop’s process that uses carbon dioxide gas bubbled into water.
“Anything you do with carbon dioxide is good environmentally, because you are consuming something which is a greenhouse gas,” said Sain.
Source : www.reuters.com