While chemical recycling opens new possibilities for the circular economy, only a full lifecycle approach will be able to determine the real environmental benefits in terms of saved energy and global warming emissions, a senior EU official has said.
Dealing with toxic substances contained in old plastic products – or “legacy chemicals” – is seen by many as the next frontier in recycling, if not the Holy Grail.
Recycled plastics are currently seen as worthless by most manufacturers who prefer higher-grade virgin materials. Since those also happen to be cheaper and safer, Europe’s recycled plastics often end up in landfills or in incineration plants when they are not shipped abroad.
This is where “chemical recycling” comes in. The technique holds the promise of isolating toxic substances contained in plastics, which are now banned in Europe, making it possible to retrieve feedstocks that can be used to manufacture products which are as good as new.
“All chemicals can be broken down to simpler building blocks and made into the same or different chemicals again, even if they are heavily mixed or contaminated,” said a recent white paper by the Ellen McArthur Foundation.
“The opportunity in such ‘chemical recycling’ technologies – in contrast to mechanical ones – is that they generate virgin-grade feedstock” which can then be used to “make new materials and chemicals of virgin-grade quality,” the paper said.
At least that’s how the theory goes.
“Chemical recycling is a promising technology,” said Kęstutis Sadauskas, director at the European Commission’s environment directorate in charge of the circular economy and green growth.
“However, some challenges remain,” he told sustainability consultant Michael Laermann in a July interview published on his blog. This, he explained, includes “the need for more information on the overall environmental performance of these technologies, in particular regarding energy consumption and the nature and safety of the process output.”
“A life-cycle approach needs to be followed in order to consider all the possible benefits and risks of this new approach, including on climate,” the official cautioned, saying “the results of ongoing pilot projects still need to be expanded in order to have a representative picture of the possibilities of this technology”.
The European Commission is expected to kick off a comprehensive review of its chemicals policy with the launch of a “Chemicals Strategy for Sustainability” in the autumn. The review is one of the main chapters of the European Green Deal presented last year by the EU executive, which aims to reduce global warming emissions to net-zero by 2050.
And chemical recycling could end up playing a key role in the Commission’s new strategy, which Sadauskas said will seek to ensure more coherence between legislation dealing with chemicals, products and waste.
“The first issue is the presence of banned or restricted substances in waste streams, so-called ‘legacy chemicals’,” the EU official said, pointing to a lack of information about the presence of toxic substances in certain products.
Legacy chemicals have been a nagging issue for recyclers, who have so far failed to deal with old plastics that may be “contaminated” with banned substances.
EuRIC, a trade association representing the European recycling industries, agrees that chemical recycling could provide a solution to address plastic waste that currently cannot be recovered through traditional “mechanical” sorting methods.
“However, EuRIC wishes to underline that chemical recycling cannot be considered as the silver bullet solution as such,” it said in a position paper last year, warning that the term covers “a large number of different technologies,” many of which are still at an early stage of industrial development.
Moreover, it said those different processes will face the same issues as mechanical recycling, including competition from virgin materials, which are currently cheaper to produce.
According to EuRIC, the oil price would need to reach at least $65-75 per barrel in order for polymers obtained from chemical recycling to become competitive with virgin materials. Oil prices currently stand around $40 per barrel.
These doubts are echoed by environmental groups, which issued a technical report earlier this year pointing to the large amounts of energy required by some chemical recycling processes, saying those can pose a climate risk.
“We have reservations on the use of chemical recycling which, far from being a mature technology, remains resource- and energy-intensive and which we consider only suited as a last-resort case for plastic which is too degraded, contaminated or too complex to be mechanically recovered,” said Janek Vahk, a campaigner at Zero Waste Europe.
“Given the low oil prices and the type of plastic it addresses, it doesn’t look like it would make economic sense to invest into this kind of infrastructure,” Vahk said.
Still, chemical recycling is seen as a promising way of attaining the EU’s ever-higher recycling goals.
Two years ago, EU legislators agreed a new target to recycle 55% of plastic packaging by 2025. And with tougher targets again being considered under the European Green Deal, new ways to boost recycling rates must be found.
“Chemical recycling shows good potential in helping to achieve a climate neutral circular economy,” said Dr Christian Haessler from German company Covestro, a world-leading supplier of high-tech polymer materials.
According to Covestro, chemical recycling can complement mechanical recycling techniques and is “particularly helpful” to recycle plastic waste which would otherwise be incinerated or landfilled.
“Of course, we must and will take care that it is competitive in economical as well as ecological terms compared to fossil-based and virgin production routes,” Haessler admitted, saying the company is investing in renewable energies and digitalisation in order to reduce the environmental impact.
In fact, the industry doesn’t deny the challenges lying ahead. Earlier this year, the German state of North Rhine-Westphalia brought together researchers, scientists and industry representatives in order to evaluate some 133 pyrolysis processes currently being envisaged for chemical recycling. Of those, only two were depicted on a pilot scale, the remaining 131 still being on laboratory scale.
“It can be concluded from the overview of the technology readiness of pyrolysis that there is still a considerable need for research and development in the application of chemical recycling of mixed plastic waste,” said their discussion paper, published earlier this year.
[Edited by Zoran Radosavljevic]