As the COP21 climate talks are underway in Paris, and government leaders work to hammer out a deal to limit global warming, French company Carbios has announced a technology that may pave the way to infinite plastic recycling — eliminating plastic waste and its impact on climate change.
Yesterday Carbios announced that it has taken a major step forward in the development of its enzymatic depolimerization process of polyesters making it applicable to PET (polyethylene terephthalate), one of the most commonly used polymers.
Carbios’ recycling process enabled for the first time the depolymerization of 100 percent amorphous PET-based commercial products into its original monomers, TPA (terephthalic acid) and EG (ethylene glycol).
The company says the process allows the monomers to maintain the same quality and physicochemical properties as their petroleum-based counterparts. After separation and purification, the monomers extracted from the enzymatic recycling process could then be used for the synthesis of virgin PET — avoiding any loss in value of the recycled material and producing durable, sustainable plastics.
Carbios CEO Jean-Claude Lumaret says the company is working with “major players” to bring the recycling process to industrial scale. “These new progresses will enable us to pursue our efforts and undertake the development at the pilot scale of our PET recycling process and adapt this technology to the recycling of other plastic polymers,” Lumaret says.
Developing endlessly recyclable, durable plastics is the holy grail of polymers. Innovative chemistry companies and scientists are moving closer to making this dream a reality.
“Every day polymer scientists amaze us with new research and innovations in plastics that contribute to our safety, quality of life and ability to live more sustainably,” says Steve Russell, vice president of plastics for the American Chemistry Council.
Recyclable and Durable
In a recent IBM blog, IBM research scientist Jamie Garcia details how her “chance discovery sparked a quest for plastics that are both strong and recyclable.” She says she hopes her work in ploymers will result in plastics that are endlessly recyclable, longer lasting and more durable.
Her breakthrough makes even previously un-recyclable plastics, recyclable hundreds of times over because of a unique thermoset.
As Garcia explains in the blog: “The crosslinking chemical motif, the part that makes this polymer a strong network, has a special property that allows it to be hydrolyzed (the breakdown of a compound by chemical reaction with water) only at very low pH (pH ~ 0). We used computational chemistry alongside experiments to help guide us to the best synthetic method to make these materials, including cure conditions (this is absolutely critical!) and choice of monomer (also critical!) to access materials with the best properties. Usually you don’t get both properties in one material: this thermoset is both strong and revertible.”
But to produce and recycle these ploymers on an industrial scale, Garcia needs a chemical company and its equipment to scale up the process, plus an industrial-scale plant dedicated to chemical recycling for polymers. She says most plastics are recycled with an inexpensive melt-and-remold approach and the infrastructure isn’t in place for chemical recycling methods.
“That said, I still think that in the long run it would be worth it — we could recover more of our materials, and implementing chemical recycling for polymers would ultimately save on energy, resources, and landfill space,” Garcia says in the blog.
Plastics Recycling Increases
Meanwhile plastics recycling in the US continues to increase. Americans have increased the pounds of plastic bottles recycled every year since 1990, according to joint report by the Association of Plastic Recyclers and the American Chemistry Council.
Waste Management World says the report found plastic bottle recycling in the US grew by 3.3 percent or 97 million pounds (44,000 metric tons) in 2014, with the new total surpassing 3 billion pounds (1.36 million metric tons). Additionally, high-density polyethylene (HDPE, #2) bottle collection grew to nearly 1.1 billion pounds (500,000 metric tons), an increase of more than 62 million pounds (28,100 metric tons) from 2013.
“Plastics recycling has grown significantly in recent years thanks to the collaborative efforts of materials suppliers, researchers, retailers, brand owners, and the recyclers themselves,” Russell told Environmental Leader. “Together, we’ve built a foundation that will allow us to recover and use more of these valuable materials.”
Waste and Emissions Reductions
Carbios estimates demand for PET-based virgin plastics in Europe hit 3.2 million tons in 2013, of which 1.8 million tons (57 percent) are recycled. Applying the company’s biorecycling process to PET would allow for treatment of 100 percent of PET waste, equal to an addition volume of 1.4 million tons in Europe that is landfilled or burned for energy, instead of being recycled, the company says.
Carbios says by creating a circular economy model, its biorecycling processes would prevent the emission of 4.6 million tons of CO2e in Europe alone.
Says Russell: “Plastics’ light weight, strength and durability make possible environmental benefits ranging from waste reduction to energy savings and lower emissions — and those benefits can be enhanced when we recycle plastics.”
