Chemical Recycling of PET - Is Now The Time It Will Work?
For those in the industry who have seen this all before
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In The News
I wrote about how Eastman is investing in a methanolysis plant in Kingsport, TN. Eastman is putting up about $250 million to recycle PET back into dimethyl terephthalate and ethylene glycol. I put Friday’s story about green chemistry news on Twitter and I got an interesting response from #chemtwitter.
Don Lion (@therealdolion) brought up that DuPont had tried this in the 90s and I’ve seen a lot of skepticism from chemists on LinkedIn about chemical recycling because they have all heard all of this before. I probably felt a similar feeling when I first started working at Hexion and they told me they were attempting to put lignin into phenolic resins and I thought “why is now any different than the 1940s?” I still worked on trying to figure out some uses for lignin.1 2
Today I am going to attempt to answer the question of can we actually recycle polyester with methanolysis and why would a 20+ year old technology work now instead of in the 1990s? I will also attempt to provide some answers on what we might be able to do as citizens to try and figure out how to make these technologies work to combat the plastic waste problem through our local, state, and federal governments. The problem essentially comes down to the following:
Plastics and polymers enable our modern lives, but there is an inherent cost to this modern life that have recently become more apparent—how do we reconcile those costs while keeping the benefits?
DuPont and Eastman Tried This In The 1990s
Don Lion was right via Twitter. DuPont did announce construction of a methanolysis plant in Tennessee in 1994. The initial announcement was $16 million and in today’s money that would be about $28 million:3
DuPont developed the process in a pilot facility started up in Nashville, Tennessee, in 1992. The company claims the proprietary technology enhances methanolysis to improve efficiencies and to allow the use of less pure feedstock. Feedstock for the new unit will come from both post-industrial and post-consumer sources, but the two streams will be kept separate for market re-entry, a company spokesman said.
The company claims the recovered materials will be equivalent in quality to virgin materials and can be used in both polyester films and resins. DuPont obtained US FDA approval for food-contact packaging use in October 1992.
DuPont then also announced conversion of a dimethyl terephthalate unit to a methanolysis unit in Cape Fear, NC for $12 million in 1995 or about $21 million in 2021 dollars:4
At Cape Fear, N.C., DuPont Films is spending another $12 million to convert a former DMT production unit into a methanolysis plant that will use waste PET to produce 100 million pounds of DMT and 30 million pounds of ethylene glycol a year. It expects the unit to be operating by early next year. A pilot project at Old Hickory first tested the process, called Petretec, between 1993 and 1994. That demonstration “went very well,” Binetti said.
DuPont Films both uses DMT in-house in its $1.3 billion film and sheet extrusion business and sells it to outside customers. The chemical has properties compatible with additive systems used in films, engineering plastics and certain fibers and resins, he said.
“Basically the industry is in a sold-out position for those ingredients,” he said.
The polyester market is climbing at a rate of 7-8 percent a year, because of PET's diversity, recyclability, physical properties, such as clarity for packaging, and growing use in engineered plastics, Binetti said.
Craig Binetti who is quoted in the Plastic News article above was the general manager of DuPont’s PET Resins & Chemicals. So in total if we look at the total spend here in two years it was about $28 million dollars or about 1% of the business units revenue over those two years in the form of capital expenditures.
Are you wondering what the hell is methanolysis and what is DMT (it’s not the Joe Rogan DMT)? Making polyethylene terephthalate is done by a condensation polymerization involving dimethyl terephthalate (DMT) and ethylene glycol. At the end of the polymerization we have polyethylene terephthalate and methanol. Methanolysis reverses that polymerization of PET waste back to dimethyl terephthalate and ethylene glycol so that those monomers can be repolymerized.
The big advantage methanolysis has over mechanical or melt reprocessing of the PET is that in theory PET waste considered not recyclable via mechanical recycling can be chemically recycled. The resulting polymers from methanolysis products would be the same as virgin PET. The big issue here is actually an economic problem.
Notice that Binetti said, “basically the industry is in a sold-out position for those ingredients.” While this might have been true at the time I am sure that new capacity was being planned and installed to meet the current and projected demand for dimethyl terephthalate and ethylene glycol in the 1990s. Methanolysis only makes economical sense when running the process and the raw materials i.e. PET waste and energy is cheaper than dimethyl terephthalate that comes from para-xylene.
An internal case study from DuPont outlined the primary reason for the methanolysis conversion at the Cape Fear site:5
During fiber processing, large quantities of PET waste were produced and landfilled as solid waste. The facility is presently installing a PET recycling facility which will reprocess this material. The PET material will be converted to DMT and glycol via methanolysis. The DMT will be sold to other facilities for fiber production while the glycol is reused in the production process. All major emissions of VOC generated during the recycling process will be diverted to a Dowtherm process heater for waste heat production
To me this looks like DuPont was attempting to solve their waste problem. Typically as a raw material waste might have a value of $0/lb. From an accounting perspective utilizing waste as a raw material can be very attractive because DuPont was paying X dollars per year to landfill solid PET waste that was coming off of their fiber processing unit. Instead, they had a technology where $12 million dollars that could be depreciated over 30 years would enable them to stop paying to throw out PET and use that waste PET as a new raw material. As long as running the methanolysis unit was less than the X dollars per year to landfill they would be in business.
DuPont wasn’t the only one to do methanolysis back in the 1990s:6
In the 1980s and 1990s, when it was still a part of Eastman Kodak, Eastman operated a methanolysis plant to break down used polyester like X-ray film and turn it into new film products. “There are people on the project today that actually operated that plant at the time,” Ballard says.
The previous effort, perhaps ahead of its time, was shut down, Ballard says. “The market just wasn’t ready for it.”
When you work with solvents at scale you probably have solvent distillate that you need to figure out how to use. The most obvious answer is you can re-use it in the next batch, but eventually the solvent gets too dirty. Then that solvent might be used to wash out reactors or mix tanks until it has too much dissolved stuff in it. Then you might either waste it or pass it through solvent recovery. The same is true of phenol distillate in BPA, BPF, and Novolac synthesis. You need a huge amount of excess phenol that gets distilled out and ideally you recover it and use it again.
This might be news to some people, but modern chemical manufacturing facilities do not like to throw things away because it hurts their bottom line and reduces their profitability. If a manufacturing site is not profitable it gets shutdown and all the people that work there lose their jobs. Once the dumping of waste into rivers, streams, and lakes became illegal companies figured out how use their waste or discontinued products that became unprofitable. Dumping of waste into waterways was banned globally in the 1970s.7 8
The market not being ready for methanolysis in the 1990s/early 00s was not reported on from what I can find. My guess is the issue was that new raw materials got cheaper for PET and methanolysis was not economically feasible. I’m speculating that it became cheaper to landfill PET than to recycle it even with the facilities available to run the recycling.
Is Recycling A Scam Pushed On Us By Big Oil and Big Chemistry?
If you just start searching the internet for information about recycling plastics you’ll probably get led to some interesting stories, but what most of them might tell you is that the public was mislead with recycling plastics. Laura Sullivan did a story for NPR in partnership with PBS that is worth reading:9
The industry's awareness that recycling wouldn't keep plastic out of landfills and the environment dates to the program's earliest days, we found. "There is serious doubt that [recycling plastic] can ever be made viable on an economic basis," one industry insider wrote in a 1974 speech.
This is surprising because the oil embargo was going on in the 1970s so the starting materials of crude oil was difficult to get at the time. Perhaps it was because of the amount of infrastructure for recycling and sorting of the plastic that needed to be built? It’s hard to know without the full speech.
Sullivan then goes on to talk about the many problems of recycling such as sorting, melting it down, and reprocessing it back into something useful. The costs of recycling plastics are higher than producing virgin plastic materials from oil so economically it makes little sense to recycle.
All of these problems have existed for decades, no matter what new recycling technology or expensive machinery has been developed. In all that time, less than 10 percent of plastic has ever been recycled. But the public has known little about these difficulties.
It could be because that's not what they were told.
Sullivan then gets into ad campaigns about recycling while also highlighting the fact that most executives at the companies making the plastic talked about how the economics of plastic recycling would never work. The trade organizations (lobbyist) essentially put out a lot of messaging through advertising about how plastic recycling was going to solve the plastic problem.
At the same time, the industry launched a number of feel-good projects, telling the public to recycle plastic. It funded sorting machines, recycling centers, nonprofits, even expensive benches outside grocery stores made out of plastic bags.
Few of these projects actually turned much plastic into new things.
NPR tracked down almost a dozen projects the industry publicized starting in 1989. All of them shuttered or failed by the mid-1990s. Mobil's Massachusetts recycling facility lasted three years, for example. Amoco's project to recycle plastic in New York schools lasted two. Dow and Huntsman's highly publicized plan to recycle plastic in national parks made it to seven out of 419 parks before the companies cut funding.
None of them was able to get past the economics: Making new plastic out of oil is cheaper and easier than making it out of plastic trash.
What would eventually happen was that the US would export our plastic waste to developing countries like China where the labor costs on sorting and recycling might have made some sense. Or disposing of this waste was not our problem anymore here in the US. Sullivan actually starts her story with at a local municipal waste facility where they are landfilling plastic waste that was once shipped to China. They are landfilling because they cannot recycle it.
E. A. Crunden has a more recent story in The Atlantic that also poses the question How Useful is Recycling, Really?10:
One of the few things Americans largely agree on is recycling. This simple act is popular with Democrats, Republicans, free-market diehards, and environmental advocates alike, data consistently show. And among recycling enthusiasts, one group is particularly keen—people already concerned about climate change.
So it seems like everyone can agree on recycling. We generally think it to be a good thing thanks to all the messaging that Sullivan told us about starting in the 1970s. So despite everyone agreeing that its good then why did we peak at 9% recycling?
Crunden brings to light another issue that I have written about too:
Americans might want to recycle, but a constant influx of new and hard-to-manage materials in the waste stream poses ongoing problems for facilities with aging infrastructure. This can be compounded by a lack of education and standardization: Recycling programs differ wildly, and people are often so enthusiastic about recycling, they toss items into a bin without verifying that they can, in fact, be recycled.
The enthusiasm about recycling actually can create more problems later on when it comes to separation. Imagine you have 1 ton of solid municipal mixed waste at the town’s waste processing site. You pay to have it sorted into paper, plastic, aluminum, and glass. The glass, paper and aluminum go off on their own. You probably can sort the PET bottles and send them to the state, but then you need to sort the plastic again. You need to figure out what is HDPE, LDPE, PP, PVC, and PS. There might be some PLA in there too that is actually compostable, but because there are no composting waste streams and its plastic so it can be recycled too right? There are also probably some multilayer plastics that were there to keep foods fresh like chip bags which cannot be recycled because of the different. This nightmare of a separations problem is why my town spent a few months to pay someone to walk through the neighborhoods and tell people what was recyclable and what wasn’t via tags on their recycling bins.
Crunden goes on to explain through sources that this is really a symptom of the public wishing they can recycle their way out of their consumption habits. Every Amazon package or new widget we buy has some sort of packaging. We feel bad about landfilling this packaging so we try to recycle it. The truth is that some of it is recycled, but then some of it just ends up in a landfill, but as consumers did our part by putting it into a blue bin on the curb. Our intent was good, but it’s not our fault that it ended up in a landfill right?
The problem isn’t even that simple. The fact is that a large majority of households in the US don’t even have access to curbside recycling or if they do recycle they have to take it to the municipal waste facility themselves and have it pre-sorted.
TRP found that only about half of Americans have access to curbside pickup, and that many who do have access don’t fully participate.
That has led to the inverse of wish-cycling—items are being thrown away that could be recycled. Curbside recycling currently recovers only about 32 percent of what is available in single-family homes, according to TRP. If the remainder were recycled each year, based on calculations through the EPA’s Waste Reduction Model, which determines emissions savings stemming from waste-management practices, TRP has found that "would also reduce U.S. greenhouse-gas emissions by 96 million metric tons of carbon-dioxide equivalent," Harrison said.
Crunden goes on to cover many of the points that Sullivan made for NPR. The oil and chemical industry has for the most part talked a big game when it comes to recycling and has not delivered for the past 20+ years. Crunden and Sullivan are doing their journalistic duty here in trying to point that we have been here before. Why should we believe Eastman or whoever when it comes to investing in Methanolysis?
I think we should believe these companies are attempting to do what their shareholders want and from what I can tell right now shareholders want their companies to focus on figuring out how to deal with these problems of plastic waste and of oil being less abundant in the future. If we look at Eastman’s announcement of $250 million dollars going into this methanolysis plant it is about 5x more money than DuPont spent in the 1990s when taking inflation into account. To me this indicates that Eastman is betting big on this technology being a path forward to the company’s future. I’ll report back if the plant gets finished.
What About Non-Oil Alternatives?
Some of my readers have also asked me to look into Origin Materials, which is rumored to be considering going public via a special purpose acquisition vehicle or SPAC.11 Origin Materials is also seeking to make polyethylene terephthalate amongst other chemicals and plastics from biomass, specifically cellulosic biomass. Their route would utilize making chloromethyl furfural, which can apparently be rearranged to para-xylene.12 Oxidation of the para-xylene leads to terephthalic acid and esterification with methanol gives dimethyl terephthalate or DMT. Origin Materials’ technology would alleviate our dependence on making para-xylene from oil if it was ever economically competitive.
Origin Materials’ patent describes a method for reacting biomass such as cellulose or glucose with an acid and a salt to form the desired product of chloromethyl furfural. A particular embodiment may be reacting glucose with hydrochloric acid and calcium chloride to yield their target molecule.13 Seems pretty easy in the patent, but I believe it sounds like a difficult process to refine and scale. I know the inventor of the Biofine process, which was dilute acid hydrolysis of cellulose to make levulinic acid. Their demonstration plant in Italy that was never finished I believe got acquired by GF Biochemicals, which I also believe to date has not yet launched a viable product. GF Biochemicals’ last media press release was on partnering to build the largest integrated cellulosic biorefinery in the world in 2017.14 I cannot verify if it actually got built.
If you are an investor into Origin Materials you might say, “but this is a plant based route,” or “there are partnerships lined up and ready to go.” I would say that all of the consumer packaged goods companies have partnerships with all of the start-ups promising a plant based or truly recycled plastics. The hard truth here is that this start-up will not be successful until they can demonstrate economic feasibility of their technology when oil prices are below $75/barrel.
Other companies like Avantium have millions of dollars being given to them to build their first FDCA plant in the Netherlands to eventually scale up polyethylene furanoate, a competitive plastic to polyethylene terephthalate. I’ve written about Avantium at length previously and the challenges that they are also facing. Origin Materials will not only be competing with traditional PET, but also recycled PET from Eastman and maybe even PEF from Avantium. Origin Materials also claims to be able to make FDCA, so perhaps they will compete with Avantium on PEF too.
Even if Origin Materials raises money through a SPAC they still need to wait 2-3 years for a large scale plant to be finished. The permits can take a long time to get approved and if they start with a big plant initially they might be in commercial production by 2025. At that point they have about 9 years left on their patent. Maybe if oil is above $100/barrel at that point, but I doubt that it will be. Further, Origin Materials does nothing for the end of life problem for PET. Even if the material is biobased you still have the same problems of what to do with the plastic.
So What Can We Do?
In the beginning I wrote about how we need to figure out how to reconcile the costs of our modern lives. We know our current path is unsustainable. We also cannot seem to get off of our current path no matter how many companies are started or how many industrial operations appear to get built. This is where governments should play a role I think.
I’m not a public policy person, but here is what I have thought up:
Plastic recycling could become economically feasible by raising the costs to dispose of it via a landfill. We know with some degree of certainty that there is going to be X volume of PET produced in the US in a year and that volume will be consumed. Maybe 20% of the PET gets recycled, but 80% gets landfilled. Tax payers pay to have that municipal waste landfilled because it is cheaper than having it recycled. Raising the price on landfilling PET would raise costs for local governments, but those costs could be offset by levying a waste tax on the actual producers and consumers of PET based products. The tax could be adjusted based on how much was landfilled the prior year.
I would be happy to talk to anyone to develop this idea more.
The best place to start might be a local government or municipality. I’ll write to my town and county if you write to yours.
So Is Eastman Legit?
I think Eastman is actually intending to recycle PET with their methanolysis plant and that this isn’t a publicity stunt. I also never thought that DuPont intended their own recycling facilities to be publicity stunts either. Eastman’s process will also have to compete with enzymatic routes such as those proposed by Carbios and Novozymes. My former thesis adviser Richard Gross also has an enzymatic process for PET depolymerization based on a cutinase. My guess is that Eastman will be very cost competitive with virgin PET and with their intention to make a 15% margin on the recycling operation it actually sounds realistic.
Talk to you Friday,
The views here are my own and do not represent those of my employer nor should they be considered investment advice.
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