Earth Day 2020: Pyrolysis Player Cracks Case of Hard-to-Recycle Waste Plastics

Among plastic waste recycling technologies, pyrolysis could generate one of the biggest profit-pools in terms of growth (25.4%) into the next decade, second only to mechanical recycling (28.3%), according to a McKinsey report, “How Plastics Waste Recycling Could Transform the Chemical Industry.” McKinsey’s analysis suggests that “re-converting waste plastics into cracker feedstocks that could displace naphtha or natural-gas-liquid demand — most likely using a pyrolysis process to do this — may be economically viable, and is more resilient to lower oil prices, remaining stable down to $50 a barrel.”

Pyrolysis is an invaluable technology for treating mixed polymer streams, which mechanical recycling technologies currently cannot handle, McKinsey noted in its report. “Pyrolysis also is an important back-up process to handle polymers that have exhausted their potential for further mechanical recycling. A number of pyrolysis players are coming forward, offering a range of facilities from large-scale plants with capacities of 30,000 to 100,000 tonnes a year to smaller-scale modular units with capacity up to 3,000 tonnes a year."

Encina Development Group LLC is one of those pyrolysis players. Based in Coral Gables, FL, Encina has been in business for six years and began by using carbon as a primary feedstock.

Pyrolysis is the chemical decomposition of carbon-based materials through the application of heat. Pyrolysis can be done with or without a catalyst. David Schwedel, Encina founder and Executive Director, explained to PlasticsToday that when Encina first started its design process, it wanted to ensure that the end products would be carbon neutral. That can be done by capturing and treating CO₂ at the emissions point for further sale or sequestration or by adding diverted waste material from landfill as a blend to the carbon feedstock. This would include items like biomass, municipal solid waste, or waste plastic. Encina’s process, which uses a catalyst, is flexible in that it can take multiple feedstocks and allow the company to change the type of products it makes.

“When we started to explore manufacturing carbon-neutral products, and pushed through various diverted waste material on the front end, we also processed waste plastic as part of our business model,” said Schwedel. “Not one person on our team at that time had plastics industry expertise, but as we started putting this solid waste into our reactor modeling, we saw a high-yield chemical result that far surpassed the use of traditional carbon feedstocks. That’s when we concluded that there’s a lot of good stuff in waste plastic for us.”

It didn’t take long for the company to pivot the business away from traditional carbon to the use of waste plastics as a primary feedstock for its pyrolysis process to create renewable fuels and renewable chemicals. According to Schwedel, the company can take a variety of waste plastic in almost any condition and, without any major handling, sorting or cleaning, produce high-value base chemicals — benzene, toluene and xylene, or BTX — and renewable fuels via its proprietary technologies. “We did not start our business on the basis of creating a solution for waste plastic, but this is, in fact, where we landed,” Schwedel said.

The aromatics Encina looked to produce — C6 to C9 in the chemical chain — were perfected by the plastics industry. These molecules are relatively easy to “crack,” so the company’s engineers decided to focus 100% on waste plastic. “Why bother with carbon feedstock, when all the high-yield stuff is in plastic?” said Schwedel.

Encina’s chemical yield from carbon was roughly modeled at 6 to 8%, but with plastics, Schwedel said the company’s chemical yield came to 50% or more. As a result, the company has decided to focus exclusively on plastics. “Our initial U.S. facility will cost approximately $260 million, and produce BTX from waste plastics,” said Schwedel. “We will need more back-end storage facilities due to an increase in chemical yield, but the plant is being designed to handle 20 tons per hour of waste plastics as a starting point.

“We’re looking at sites from the Gulf Coast up toward St. Louis, and somewhat east and west of that. We are looking to break ground on a new facility between the end of 2020 and Q1 2021,” he added.

Encina deploys proprietary technologies to economically extract BTX through pyrolysis. The Encina process enables the “cracking” of hydrocarbons to create “pygas,” which contains the aromatics that are extracted, captured, and delivered to customers.

“With BTX you can make everything from clothing to pharmaceuticals,” said Schwedel. “We make a high-purity, renewable BTX. The benzene (chemical) is separated from the ‘pygas’ stream, and the remaining toluene and xylene is blended to make a high-octane gasoline, sold as a quality blend stock to large energy companies.”

Carbon-neutral products have always been Encina’s goal. “Today, there’s a huge problem with plastic waste, but our challenge is to get our hands on as much of this material as we can,” said Schwedel. To help find the feedstock, Encina brought in a global purchasing director who has worked in scrap plastic for more than 25 years. Then Encina began addressing the next challenge: “Once we find the plastic, how do we economically get it to our facility?” he said. “Solving the scrap plastic transport efficiency issue is key; otherwise it incrementally costs more.”

To help solve that challenge, Encina has mapped the location of every materials recovery facility (MRF) in the country along with large commercial plastic end users to help capture their material before it goes to waste collection. “The energy and waste management industries have spent hundreds of millions of dollars on collecting, consolidating and moving products and materials on a local, county, state and international level. We’re the beneficiary of their logistics solutions on where to collect and transport waste plastic to our own facilities.”

Encina is in the process of approaching all the large national producers of these waste streams, including the large corporations and MRFs. “It comes down to demographics and population density,” Schwedel explained. “This is important, because most companies want to focus on #1 and #2, which are expensive to buy and transport. We want #3 through #7, which seems to be the waste that nobody wants. That’s the stuff that goes to landfill. That’s what we want. All the waste you’re not using, give it to us.”

Opportunities for collecting plastic waste — including ocean plastic — exist around the world and Encina’s intention is to build one facility in the United States. In Europe, the company is looking at a site in Belgium, near Antwerp, where there are a lot of customers. “We can build a facility next to them and implement the same strategy there,” said Schwedel. “We’re also targeting the Philippines for a plant within Asia to produce and sell chemicals and gasoline there.

“In Latin America, we're looking between Sao Paulo and Rio. We’re also looking at the African continent, which has a market that is up and coming over the next 25 years and will also have proven markets for our end products. We anticipate there will be enough waste plastic there to support a facility. Within three to four years we’ll have global capacity to take it all,” Schwedel added.

“After six months of work, we feel very comfortable that we can get the 175,000 tons of #3 through #7 a year without a lot of heavy lifting. Once we get our logistics down, we’ll take as much as we can get.”

The facilities Encina has designed are scalable via modular expansion, which allows the company to increase throughput as more feedstock becomes available. “More than 240 million metric tons of plastic waste is produced each year,” Schwedel noted. “While that sounds like a huge number, I am concerned that we can’t easily get our hands on it. Our business plan will have to work in each of our five markets at this point, and can process 170,000 tons at each location. So while we can take 850,000 tons per year, or roughly less than 1% of the world supply, we are designing our facilities to expand to take much more capacity.

The way plastic is managed at both the collection and processing levels needs to change in order to be successful, and that will take time, said Schwedel. “Everyone is aware of the problem, and to the plastic industry’s credit, it’s tackling the issues head on,” he commented. “We need plastic in our society — we can’t live without it. It can be handled responsibly through a reliable waste management program.”

Looking at the plastic waste problem realistically, Schwedel believes that pyrolysis and chemical recycling offer the best solutions because these processes can handle dirty, smashed mixed plastics and even ocean plastics, which eliminates the labor-intensive process of sorting, cleaning, and baling. “With our process you do not have to clean it. We’ll take all the #3 to #7 we can get and take it dirty. Our process can handle it. We did not start our business around solving the plastic waste problem, but today I am grateful that our technology is a perfect fit to help solve the problem of plastic waste.”

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