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New ventures try again to recycle polystyrene

Start-ups link with plastic makers on new recycling techniques

by Michael McCoy
May 10, 2018 | A version of this story appeared in Volume 96, Issue 20

A photo of piping at Agilyx's Oregon plant.
Credit: Agilyx
Agilyx started up this depolymerization plant last month.

Big plastics producers are joining with two start-up companies to pursue what is currently an unrealized goal: large-scale recycling of polystyrene.

In one deal, the polymer business of the French oil giant Total will join with Polystyvert, a Montreal-based start-up, to advance a polystyrene recycling method based on dissolution. In another, the plastics maker Ineos Styrolution will work with Agilyx to advance a depolymerization technology.

In both cases, the companies seek to cost-effectively reuse a plastic that is currently recycled at much lower rates than polyethylene terephthalate and polyethylene, two large-volume competitors. Partly as a result, polystyrene foam products are the subject of ban legislation in U.S. cities such as Baltimore, New York City, and San Francisco.

Polystyrene foam is a recycling challenge because it is 95% air and thus expensive to ship to recycling centers. Moreover, post-consumer polystyrene is often contaminated with food. Although firms such as Plastic Recycling Inc. do recycle post-industrial polystyrene, several high-profile, post-consumer recycling efforts have failed in the past.

Polystyvert’s answer, says founder and CEO Solenne Brouard Gaillot, is to take advantage of polystyrene’s solubility in the solvent cymene. The firm reduces transportation costs by dissolving waste polystyrene in cymene-containing concentrators set up at customer locations. It then brings the polystyrene-rich solvent to a central location where it filters out contaminants and recrystallizes the polymer.

Agilyx, meanwhile, uses pyrolysis to turn polystyrene back into styrene monomer. Last month it opened a “chemical recycling” facility in Tigard, Ore., that can convert up to 10 metric tons per day of polystyrene waste into styrene for sale to Ineos and Americas Styrenics, another plastics firm. On April 26, Agilyx announced a follow-on agreement with Ineos to develop a second plant at or near an Ineos facility in North America.

The techniques each have pros and cons, observes Brian Riise, president and technical director of the consulting firm Sustainable Materials Recovery Group. Agilyx’s approach, for example, closes the raw material loop for polystyrene makers but doesn’t address waste collection issues.

Riise says he’s impressed that big polymer makers are backing both approaches. “If they really have an interest in doing this, they may have to prime the pump,” he says. “It’s not going to be profitable overnight.”


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