Chemist questions Encina's process

Apr. 8—Around the country, and most of Pennsylvania, consumers have a recycle bin. sometimes where all recyclables, except glass, are put into the same bin — whether it is paper, cardboard, metal or plastic. That is called zero-type recycling.

"In order to recycle those zero-type materials," said plastics researcher and chemist Sherri A. Mason, director of sustainability, Penn State Behrend. "They have to be sorted — cardboards, aluminums cans and plastics all have to be separated."

The process of separating all of the components in the recycle bin happens at a Materials Recovery Facility (MRF).

At most MRFs, sorting is a mechanical process, using puffs of air, magnets.

"These operate using the physical characteristics of the waste to separate materials," Mason said. "The plastics that come out of a recycle bin generally are mixed. Consumers often are not separating plastic identification numbers 1s (such as water bottles) from 2s (milk bottles) and 3s (shopping bags, for example) from your 4s.

"Those numbers correspond with what kind of polymer is in the plastic. The Nos. 1 and 2 are the easiest recycled plastic material. Therefore, most communities nowadays are only accepting 1s an 2s."

Other plastics, such as plastic grocery bags, or even the plastic containers that hold salads and fruits at a grocery store are not so easily handled by the mechanical sorting process, she said.

Encina says they are looking to take plastics 3-7.

"So, where is Encina going to get 3-7?" Mason said. "Possibly they think surrounding communities will expand their recycling programs and take in more options. But how are they going to separate all of the different kinds of plastic? The 1s and 2s from the 3s, 4s and so on.

"Most MRF facilities cannot do that. They don't have the optical sorting that would be necessary. and to make that happen would be extremely expensive."

In Erie, International Recycling Group was planning to build a sorting facility and their proposed facility would have all those optical sorters, Mason said, citing an example.

"Their intention was to separate the 1s from 2s from 3s ... and so on. But that facility hasn't been built and the timeline that Encina is putting out does not correspond with the timeline the IRG facility is putting out," Mason said. "Let's say Encina is able to get all of the plastic types. They then plan to take it through a pyrolysis process, which uses really high temperatures in order to cut or to break apart these polymers."

The science of the processTo help explain what a polymer is, Mason said, "think of it as a train. A polymer is a long chain molecule that is composed of these repeating units, like a train comprised of individual cars. So what Encina is trying to do will be to cut those individual cars apart. Those cars are what will be taken off and shipped off to become future plastics."

This is Encina's plan, said Mason, who has researched the project.

"It sounds wonderful, but as a chemist, in the pure form, it is just not very realistic," she said. "It will take a lot of energy to do this.

"It is an exceedingly energy intensive process to cut the different polymers apart, and that is why Encina plans to bring in natural gas to power this. You are putting way more energy into this process than you are ever going to get out."

On top of that, Mason said, "Encina is planning to take all these different types of plastics and break them into a mixture of their polymers. But separating those plastic types is not easy. What you tend to get out of this process is 'dirty' oil."

Recycled plastics

Are the end products of this process actually going to be used to make plastics?

"Probably not," Mason said. "What recycling means is a bottle leads to a bottle and that is actually not what is happening here. What is really happening in this process is that they are taking a bottle and turning it into a gas that is used for energy."

In the October issue of Recyling Today magazine, Encina's director of sustainability, Sheida Sahandy, said there is no incinerating of plastic waste in their process.

"Correct," said Mason. "They are not going to burn the plastic. But much of the power they use will come from site-generated fuel they harness as a by-product of the process."

What Encina is saying is they will produce this oil and a lot of that they will burn off-site in order to power the process (pyrolysis) that they are using, Mason said. But they are, in the end, going to be burning this pyrolysis oil that comes out of the process.

Polyvinyl chloride

As soon as Mason saw the number 3 as starting material, she said, "Oh no. We have a problem here because plastic No. 3 is polyvinyl chloride."

Vinyl chloride was the product being transported during the toxic East Palestine, Ohio, train derailment.

"It is what burned and then what was formed was dioxins, which are the most toxic man-made substance. So Encina will be taking their polymerized vinyl chloride and include it in their process. Anytime you have chlorine, when you burn it, you get dioxin," Mason said. "This is known."

Mason said the equivalent of one drop of the toxin in a swimming pool would have an impact on human health, Mason said. "Just at that small of a level."

Encina says there are not going to be any air emissions from their facility.

"There is no other way for me to say it," Mason said. "It's a lie. If you are burning something there are going to be air emissions."

EPA requirements

Encina says, however, they are going to meet the requirement of the Environmental Protection Agency. But the problem, Mason said, "is a lot of air emissions are not regulated. Reported, yes, but not highly regulated."

What happens to most plastic, at best, is down-cycled, Mason said.

Recycled plastic often is used in park benches, fabrics or bags. After that, it's just trash, Mason said. Plastic at best is used one or two times. Ninety percent winds up in a landfill. The 10 percent that is used is down cycled one or two more times when it goes through mechanical recycling, which Mason said is the best process economically and environmentally.

Encina does not intend to use a mechanical process, Mason said. Encina refers to processes that exist using chemicals. "Those processes exist, but not when it comes to plastics," Mason said. Pyrolysis has been around. Catalytic pyrolysis has been around. But not with regard to plastic."

Encina says they are testing this process out with plastics in Texas at various scales.

The Point Township facility would be the company's first using the process on a commercial scale.