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The promised land of chemical recycling is clouded by shortcuts like mass balance and book & claim

Chemical Industry

The promised land of chemical recycling is clouded by shortcuts like mass balance and book & claim

Published on 17 May 2021

Chemical recycling is a golden opportunity to meet the future demand of recycled materials. It also provides ample opportunity for making a lot of money. This combination makes it tempting for companies to take shortcuts in order to satisfy the market, often resulting in values like sustainability and transparency being thrown out the window.

Imagine being able to take all kinds of mixed plastics, put it in a recycling machine, and transform it into a new, market-ready product that says “made from 100% recycled plastic”. The market for recycled plastic is absolutely huge – and it would be your oyster. The competition would be in awe and your stock price in the clouds!

Many companies, especially plastic producers, are in the early stages of releasing their chemical recycling technologies in order to recycle plastic – any kind of plastic – which would make the coveted “100% recycled” tag theirs for the taking.

Sounds like magic, doesn’t it? But it’s all true. Sure, the “recycled plastic” is actually mostly new plastic, sold with the claim of being recycled. But who cares about the technicalities, right? In order to understand this alleged wizardry, you need to understand what happens to used plastic.

Where mechanical recycling gets lost

Plastics come in many shapes and forms – PET, PP, HDPE, PVC, just to name a few – and they’re not all created equal. This is especially apparent when the plastic becomes waste.

Today, it is usually possible to mechanically recycle plastics of the same type if it is isolated from other types of plastics. Therefore, a mix of plastics has to be sorted into homogenous groups, before it can be further processed.

The output of the recycling process comes in several different grades, meaning that only a small part of it has a quality that is comparable to virgin plastics. In addition, the knowledge of the chemical content of the recycled product is insufficient.

The quality issues of recycled plastics, combined with the lack of content transparency, means that there are usually no economic incentives for recycling mixed plastic waste. Not when the competition is cheap virgin plastics production – with full control of chemical content.

Couple that with the world’s ferocious plastic dependency, relying on a never-ending stream of freshly made containers, pipes, profiles, packaging materials and the thousands of other products that are made out of plastic – and you have a growing problem.

In addition, many brands have made public commitments to use more recycled content. This has led to a high demand for recycled plastics fulfilling the companies’ requirements, which the supply side has not yet been able to deliver.

Is chemical recycling the right way to go?

This is where chemical recycling of plastics enters the arena. Different kinds of thermal decomposition, where heat is used to break down the plastic material into different mixtures of small molecules, such as pyrolysis oil or syngas, have been the most popular new technologies.

Especially pyrolysis, which will be used as an illustrative example in this text, has been extensively proposed as the leading technology to solve the plastic waste issue.

The common denominator of these technologies is that they have the alleged potential to recycle practically any plastic – in any form – into new, virgin-grade plastic.

We say “alleged” because there are so many question marks around virtually all chemical recycling technologies. This, however, has not discouraged the advocates of chemical recycling, who are selling the idea as the best innovation since…well – plastic.

And many seem to swallow the bait willingly. Even utterly fictitious technologies have attracted huge attention, resulting in stories such as the recent Loop Industries scandal, where two brothers – without any chemical education – claimed that they could turn old plastic into new one, and partnered up with the likes of Coca-Cola and Danone before it all turned out to be a scam.

You can’t blame anyone for trying to solve the plastic conundrum, though; something obviously needs to be done. We cannot keep churning out new plastic forever and ever.

Mass balance and book & claim lead astray

In the light of this urgency, short-cuts will be taken. Enter mass balance and book & claim, the shiny knights of plastic producers with stakes in thermal chemical recycling.

The mass balance model removes the connection between the input (the material being recycled) and the output (the “new” product), making it possible to sell a product with a claimed percentage of recycled content, when in fact it may not contain a single atom of recycled material.

The mere theoretical possibility that the company could produce the “new” product with recycled content is enough.

As a bonus, the model can also include a book & claim certification scheme, where “recycling” in one facility generates a certification of a certain amount of recycled material that can be sold to another facility. This transaction lends the facility the right to produce a product completely devoid of recycled content and label it as 100 percent recycled.

Apart from false advertising, some might wonder what the big deal is. As long as something, somewhere is being recycled – who cares about the technical setup behind all of it? Well, the mass balance model doesn’t contain many constraints on how the output material must be handled. So, it’s possible to produce any kind of low-grade product from this material, including selling the material to another company – which is not a part of the certification scheme – opening up for other possibilities, like incineration.

Advocates of mass balance claim that you can use the pyrolysis oil or syngas from the decomposition to make new plastic. Yes – that’s true, at least to some extent. But if you do the math, you quickly realize that this argument doesn’t hold up very well.

Behind the curtain: Fossil raw materials and burnt plastic

Let’s simplify a bit in this example:

You put old plastic containing 100 carbon atoms in your recycling machine. Out of these 100 atoms, about 15-20 are used as fuel in the process.

Of the remaining 80, you’re able to turn about 50 into pyrolysis oil – which is the product from the decomposition.

According to the mass balance scheme, the 50 atoms that are left in the pyrolysis oil are supposed to compensate 50 carbon atoms in brand new, virgin plastic, allowing it to be called recycled.

However, the pyrolysis oil is a mixture of molecules, not all of which can be converted into plastic raw material – monomers – meaning that the 50 carbon atoms will be further reduced before we reach the final plastic product.

In addition, you can’t make new plastic material based solely on pyrolysis oil. Further processing is required, and this process can only handle single-digit percentages of the pyrolysis oil (our 50 carbon atoms). The remaining, and by far largest part – at least 90%, which in our example is equivalent to 500 new carbon atoms – must still be virgin material. This means that the production of recycled plastic still relies heavily on fossil raw materials.

And again: There’s nothing in the method that calls for accounting of what happens to the pyrolysis oil. Some of it could be used to make new plastic – who knows? But honestly, using it as fuel to create more fuel of the same kind is a much easier and cost-efficient solution, although definitely not sustainable, nor circular. That’s just plain ol’ burning of plastics, which is nothing new.

Don’t be fooled by smoke screens and mass balance schemes

We should remember that there is a lot at stake here. The potential to offer recycled content will be highly valued in the future, and the demand will increase significantly in the coming years.

We have already seen the inclusion of different mass balance schemes in certification standards, for example REDcert and ISCC, and there are products on the market with these standards, claiming to contain recycled content.

To illustrate the absurdity of this approach, let’s make a simple comparison with mechanical recycling, which is the only recycling technology running at large scale today. Applying the same method, a company can collect plastic waste, sort it, and turn it into plastic flakes.

However, in another facility, the same company can produce products out of virgin plastic – made from virgin, fossil oil – and brand them as “100% recycled”. Meanwhile, the material from the proper recycling process (the flakes) can be downcycled and used to make any products, without considerations regarding quality or further recycling possibilities. The company also has the option to sell the flakes, without having to care about what the buyer will use them for – even if they end up as fuel.

That is – most would agree – just bizarre.

Let’s get chemical recycling to where it belongs

Building a viable system for recycling of plastics is one of the most important areas in the coming years, and absolutely necessary in order to realize a circular economy.

Therefore, we support the emergence and growth of chemical recycling, completely aware that it is a technology that can play a part in solving the problem with legacy chemicals, which is a question that is very important to us.

But we cannot get behind a model that doesn’t solve any circular or recycling issue whatsoever. That would be detrimental to our efforts of supporting a sustainable market.

So, recycling systems, including chemical recycling – and especially thermal decomposition technologies – need to be developed and regulated to ensure a future-proof system, where the long-term efficiency and overall sustainability are more important than short-sighted solutions born out of financial opportunities.

Innovation must be continuously supported, in order to back the inventions of smaller actors, with specific, more sustainable schemes for plastic recycling. With a little heart, some brains and a whole lot of courage, chemical recycling just might turn from magic and thinly veiled deceit into a much needed part of the solution.