Recycling is just one step on circularity path

From the spring 2022 issue of Plastics Recycling.

By Ron Shinn 

Two research scientists at Dow Inc. made an interesting presentation at a recent blow molding conference about the urgency of achieving a circular economy versus the high amount of energy used to reprocess waste plastics. 

The presentation was made by Narayan Ramesh, Ph.D., and Sukaran S. Arora, Ph.D., at the Annual Blow Molding Conference last fall in Atlanta, sponsored by the Society of Plastics Engineers (SPE) Blow Molding Division.  

The big picture is mitigating climate change. Reducing carbon emissions and achieving circularity help accomplish that goal.  

Global greenhouse gas emissions have increased this century and are outpacing reductions resulting from improvements in the energy-supply sector. That’s driving up the earth’s temperature. 

The global plastics industry contributes about 0.5 percent of overall emissions. Only a small percentage of plastics is recycled, so the Dow scientists said the plastics industry has more of a waste problem than an emissions problem. 

Manufacturers of mechanical recycling equipment are continually pushing the envelope to make their machines smarter, faster and more efficient. Auxiliary equipment technology built in the last few years — particularly sorting and picking equipment — is significantly smarter. 

Recyclers generally try to source plastic waste from as close as possible to their plants, which saves money and reduces greenhouse gas emissions associated with transportation. While it is true that it takes a good deal of energy to clean, sort, melt and repelletize plastic waste so it can be used in another plastic product, mechanical recycling is currently the best option for some plastics. Is it truly circular? Probably not, but there is not yet a better alternative. 

Advanced recycling, where waste plastic is converted to feedstock, is the developing frontier and virgin resin manufacturers are making big investments in new recycling operations. Advanced recycling techniques probably also fail the true circularity test based on the amount of energy they use. But this technology is still very much evolving, and it is not yet clear how efficient these plants will eventually be in terms of greenhouse gas emissions. 

Eastman Chemical Co. has announced a $1 billion investment to build a molecular recycling facility in France that will use Eastman’s methanolysis polyester renewal technology to convert polyester waste back into basic monomers to create virgin-quality resin. The proposed plant will have an annual capacity of 176,000 tons.   

Eastman says molecular recycling is part of its strategy to decarbonize. It has deployed its technology in the U.S. for the past two years and has shown 20 percent to 50 percent lower greenhouse gas emissions than traditional virgin resin production. It said it expects to achieve 80 percent less greenhouse gas emissions in France. 

Plastic recyclers have an interesting story to tell. For example, plastic containers generally have a smaller carbon footprint than glass or metal even when made with 100 percent virgin plastic. Most consumers do not know this, so they silently accept it when someone says plastic is bad for the environment. 

But progress is being made. The goal is to reduce global greenhouse gas emissions and I suggest that the entire plastics supply chain, including recyclers, is actively working toward that goal. And plastic would do far less harm to the environment if people stopped tossing it into rivers.  

Recyclers are one step on the circularity path, but an important one. Recyclers need to tell that story to everyone who will listen. 

Ron Shinn, editor

[email protected]