INSIGHT: Chemical recycling must not hinder mechanical recycling progress

Author: Matt Tudball

2021/01/29

LONDON (ICIS)--Increasingly, chemical recycling appears to be the area of most interest in the world of recycling and sustainability.

Chemical recycling was a major topic at October’s EPCA (European Petrochemical Association) virtual event.

It was given its own virtual event through the PET Monomer Recycling Forum by Petcore Europe - the association representing the complete polyethylene terephthalate (PET) value chain across the continent.

Chemical recycling generates headlines in the world’s major business papers and can be seen featured in global brands’ and fast moving consumer goods’ (FMCG) sustainability strategies.

Both ICIS and industry players believe commercial-scale chemical recycling (or ‘advanced’ or ‘molecular’ recycling depending on who you are talking to) is at least five to ten years away, but interest in recycling processes is growing at a rapid rate.

But there is concern in the recycling community that the new technologies are in danger of stripping the mechanical recycling industry of its much-needed and increasingly-scarce feedstock of high-quality post-consumer plastic waste.

Another concern is whether the various processes for chemical recycling can produce cost-effective, competitive product from low-quality waste.

Some chemical recyclers currently in operation rely on high-quality material, such as post-consumer bottles or recycled PET (R-PET) (polyethylene terephthalate (recycled-PET) flake as a feedstock in order to get a better quality of output. Bbut this material is already in high demand from the mechanical recycling sector.

ICIS analysis of the R-PET market of 2019 highlights just how under-supplied the R-PET market is in terms of available material.

The study shows that of the 3.4m PET bottles consumed in the EU, just over 2m were collected, with a collection rate of 64%.

Of those 2m, when you take into account wastage rates through the processing cycle, you are left with just under 1.5m tonnes of recycled PET available for use, in the form of R-PET flakes, which can then be processed into food-grade pellet (FGP) or mixed with virgin PET.

Alongside the demand for FGP that has received European Food Safety Authority (EFSA) positive opinion for its use in food contact applications, there is an increasing demand from converters and preform producers. They are seeking larger volumes of R-PET flake for use in new and existing extrusion technology as flake is more widely available and costs less than FGP.

THE FEEDSTOCK QUESTION
Overall, chemical recycling is seen by many as the only way to reach scale for food-packaging recycling, at least in Europe. It also gets around the challenges of the EFSA approval needed for mechanical recycling because it effectively turns plastic waste back into virgin-like monomers.

In an ideal situation, chemical recycling plants would take in mixed waste plastic that mechanical recycling facilities cannot because of issues such as contamination. However, for some processes, this mixed waste plastic can prove as problematic for the chemical recycling process.

Post-consumer waste bales commonly contain contaminants from materials such as wood, metal and polyvinyl chloride (PVC) that are incompatible with most polyolefin chemical recycling processes. These materials have to be sorted and separated prior to processing, with the high heat and pressures used making effective sorting even more critical.

Some processes also require limitations on moisture levels in the feedstocks. Separating and sorting is a costly and highly technical process. It remains one of the core challenges across all recycling.

Because of the cost and challenge of sorting and separating, most chemical recyclers are not targeting low quality waste but rather the same waste streams that would typically be used in mechanical recycling.

As a result, the chemical recycling process relies on the high-quality flake that is ideally suited for the mechanical recycling industry, and which would allow mechanical recyclers to produce more EFSA-approved FGP suitable for food-contact.

ICIS has previously written about the potential danger that chemical recycling could actually take this much-needed, higher-quality and low contaminant content plastic waste away from the mechanical recycling streams, which in turn reduces the quality of the mechanically recycled material.

CHEMICAL RECYLCING AT WORK
One of the largest glycolysis-based chemical recycling facilities currently in operation, Meltem Kimya in Turkey, has been producing R-PET since 2014. The plant has a nameplate capacity of 50,000 tonnes of R-PET produced using the depolymerisation method via a glycolysis process, with plans to expand this capacity with an additional 100,000 tonnes, due for commission in the second quarter of 2022.

Fuat Sahin, Foreign Trade Director at Meltem Kimya said: “We are able to produce between 20%-50% R-PET content resins in different intrinsic viscosity (IV) from 0.64 to 1.4 for different markets.” These markets include water bottles, carbonated soft drinks (CSD) and hot-fill beverages, as well as textile and sheet applications.

“The new plant… will be able to produce [between] 50% to 100% R-PET content.  Together with our current plant and new plant capacity, we estimate to have [a total] capacity of 150,000 tonnes/year of R-PET production by using between 75,000-125,000 tonnes/year of PET flakes depending on the R-PET content,” Sahin said.

Meltem’s process takes high-quality post-consumer PET bottles and flakes and turns them back into their monomer components, which are incorporated with virgin purified terephthalic acid (PTA) and monoethylene glycol (MEG), to produce a virgin-like material with a maximum 50% recycled content.

Meltem sources its R-PET from the Turkish market, which was not included in the ICIS 2019 study, but questions would be raised of any chemical recycler that looked to source up to 125,000 tonnes of R-PET flake from within the EU given the growing competition for supply from within the mechanical recycling sector and non-bottle end markets.

One of the biggest attractions often associated with chemical recycling is its ability to take lower quality, hard to recycle waste and produce virgin like material, leaving high quality material for the mechanical recyclers.

“Colourful or lower quality feedstocks also can be used in our R-PET resin plant for chemical recycled R-PET resin production but that will bring quite more operational costs and lower quality in [the] end product.

Sahin added that the company allocates high quality and transparent feedstocks for chemically recycled R-PET resin production, and coloured and lower quality feedstocks to its plasticizer plant for use as raw material replacing purified terephthalate acid (PTA) in recycled dioctyl terephthalate (DOTP) plasticizer production.

THE QUESTION OF COSTS
As well as securing the right feedstock for chemical recycling, there is also the question of how much the processes cost from both the financial and environmental points of view.

Detractors argue chemical recycling’s carbon and energy intensity compared to mechanical recycling, its economic viability, and low-yield, mean that it should not be considered in EU targets, accusing the industry of being engaged in a form of green washing.

An additional argument believes material being returned to fuels or oils and being used to feed petrochemical plants should be classed as recovery and not as recycling under the waste directive – meaning it would not count towards recycling targets such as the EU’s.

Supporters for the process argue chemical recycling has a lower environmental impact than virgin and works in tandem with mechanical recycling to treat waste volumes that would otherwise go to landfill or incineration.

Supporters also argue that although yields are currently low and economics unfavourable this is largely due to the current life cycle stage of the processes. With the benefit of economies of scale and technical breakthroughs chemical recycling can be cost competitive with virgin values, they add.

Without independent data on these aspects it is impossible to know what the true environmental impact and cost of chemical recycling is. But as the technologies scales up, they may be realised as being capable of using low-quality waste in place of R-PET flakes.

Perhaps the biggest question from the PET buyers’ point of view, though, is how much does this glycolysis based, chemically recycled, high quality PET cost?

“According to our calculations, the price of 100% chemical recycled R-PET will be a little bit more expensive [than] FGP,” Shahin said.

Free delivered (FD) northwest Europe (NWE) R-PET FGP prices currently command a margin of close to 55% over FD West Europe virgin PET prices but this was closer to 90% during 2020 when virgin PET prices were lower.


As chemically recycled material like Meltem’s becomes more widely available, there will be increasing calls for clarity on costs, particularly from buyers, but Meltem’s process gives some insight into their individual price make-up, whilst also not divulging specifics.

“We conduct another conditioning process at our PET flake conditioning plant using our own technology in order to minimise impurities and contaminant levels inside the flakes,” Sahin explains.

“[After a conditioning process] we take the flakes to our R-PET resin plant’s processor. There are some additional costs during the processing of PET flakes, such as higher energy consumption because of the depolymerisation process, wastage cost from flakes to resin, frequent filtration change costs, plus additional labour cost and depreciation cost of the plant.”

Potentially, the price of chemically recycled PET may vary from producer to producer, and from process to process, making it harder to assess chemically recycled PET from different output streams.

GOOD INTNETIONS, BUT QUESTIONS REMAIN
Meltem Kimya’s R-PET plant does boast one of the largest chemically recycled R-PET capacities in Europe, but it still poses the question of how the chemical recycling industry can co-exist harmoniously alongside the mechanical recycling industry without the former starving the latter of feedstock material.

Chemical recycling is very popular amongst global brands, with several investing in chemical recycling start-ups around the world, or signing off-take agreements with companies like Meltem in order to secure supply of food-grade material. Meltem already has supply agreements in place with global beverage brands.

But chemical recycling processes will come under a lot of scrutiny from within the petrochemical and recycling industries, as well as from non governmental organisations (NGOs), the press and general public who will want to make sure that the new technologies are not doing more harm than good.

There also needs to be more clarity from bodies such as the EU as to how it sees chemically recycled material fitting into existing targets for recycled content.

Time will tell how both the physical and environmental costs stack up, and whether or not chemical recycling and mechanical recycling can truly exist side by side for the foreseeable future.

Insight by Matt Tudball

Additional reporting by Mark Victory