Opinion article by Dr. Athan Fox, founder of our Member, Ever Resource, and Visiting Researcher at the Department of Materials Science and Metallurgy, University of Cambridge.
Plastics have become synonymous with environmental degradation. In recent years, we have become all too familiar with images of ocean plastic pollution and overflowing landfills. But do these images represent the material’s lasting impact?
The conversation surrounding plastics should not be entirely negative. Plastics are integral to modern society; they enable innovation, safety, and efficiency across various industries. Plastics were at the forefront of our global effort to control COVID-19, and are used to extend the life of many perishable goods. Modern life – including food production, transport, and power to our homes – relies heavily on plastics for efficiency and safety, making them integral to the infrastructure and daily operations of society.
But there are challenges when it comes to plastics – especially their management at end of life. In this opinion piece, I will discuss the important role which plastics play, explore the environmental challenges posed by end-of-life plastics, and highlight promising innovations that may offer sustainable solutions to this pressing global issue.
Plastics have revolutionised industries such as healthcare, transportation, food preservation, and construction. For instance, in the medical field, plastics are used in sterile packaging, disposable syringes, and life-saving medical devices. Plastic-based components such as heart valves, catheters, and IV tubes provide not only convenience but also reduce contamination risks.
In transportation, the use of lightweight plastics has reduced vehicle weight, leading to lower fuel consumption and reduced carbon emissions. Consider also the food industry, where plastics play a vital role in extending the shelf life of products, thus reducing food waste. Relacing plastic packaging with materials such as glass or aluminium would not necessarily lead to better environmental outcomes; in fact, it could increase energy consumption and greenhouse gas emissions. A 2011 study conducted by Denkstatt found that replacing plastic packaging in Europe would increase the weight of the packaging by 3.6 times, increase energy consumption by 2.2 times, and increase greenhouse gas emissions by 2.7 times.
While some argue for the removal of plastics, it is clear that doing so without considering the full impacts of alternatives could have unintended environmental consequences. The focus, therefore, should not be on eliminating plastics as such, but on finding innovative solutions to manage their lifecycle – including reduced consumption through, for example, refill and reuse.
Despite the many benefits of plastics, their end-of-life management remains a significant global challenge. According to a 2021 report by the Organisation for Economic Co-operation and Development (OECD), global plastic waste generation has doubled over the past two decades, reaching approximately 353 million tonnes in 2019 (ref: OECD Global Plastics Outlook, 2021). A shocking 79% of plastic waste ends up in landfills or the natural environment, with approximately 9% being recycled across the globe with many countries in the global south having little to no waste management infrastructure in place.
The environmental damage caused by plastic pollution costs the world economy between $6 and $19 billion annually due to its effects on tourism, fisheries, and clean-up efforts.
Yet, this problem also presents significant economic opportunities. Currently, the value of unrecycled plastic waste is estimated at $100 billion globally. Developing more efficient ways to recycle plastics could unlock significant economic opportunities while mitigating environmental harm.
There are examples of successful recycling systems globally. For instance, in Germany, the dual system of waste collection and recycling has led to one of the highest recycling rates in the world. Countries like the Netherlands and Japan have also implemented successful waste management systems, with Japan recycling up to 84% of its PET bottles. These success stories offer valuable insights, but they often focus on a narrow range of recyclable plastics.
In recent years, bio-based plastics have gained attention as potential alternatives to traditional plastics. Materials like polylactic acid (PLA) and polyhydroxyalkanoates (PHA) are derived from renewable resources and are often biodegradable. For example, Coca-Cola has invested in the development of its PlantBottle, made from 30% plant-based PET. However, while promising, bio-plastics currently represent less than 1% of global plastic production and face challenges such as cost, limited scalability, and a lack of appropriate industrial composting infrastructure.
Additionally, not all plastics can or should be replaced. Certain high-performance plastics used in critical applications, such as medical devices or aerospace components and power, cannot easily be substituted without sacrificing functionality or increasing environmental impact. Therefore, while bio-plastics are part of the solution, they do not currently provide a comprehensive answer to the challenge of end-of-life plastics. We still need to address the billions of tonnes of plastic already in existence.
One promising approach for managing non-recyclable plastics is pyrolysis – a process that involves breaking down plastic waste into smaller molecules by heating it in the absence of oxygen. Pyrolysis has a number of advantages over incineration, as it converts waste plastics into usable products like synthetic crude oil, fuels, and monomer for certain plastics.
However, pyrolysis projects have faced challenges. For instance, in 2022, the UK-based pyrolysis company Recycling Technologies went into administration due to the lack of a supportive legislative framework that recognised chemical recycling as recycling resulting in their investors stepping away – an issue that remains today that has choked off investment in UK chemical recycling infrastructure. Other projects have failed due to high energy costs, complex permitting processes, and issues with feedstock contamination. In the Netherlands, the company Pyrolyx has also shown promise with its tyre recycling technology that uses pyrolysis to extract oil – but the company also entered bankruptcy. Pyrolysis remains an interesting but challenging solution for end-of-life, non-recyclable plastics. However, there are some encouraging signs within the UK market, with Mura Technology recently commissioning a chemical recycling facility in Teesside.
While pyrolysis is a significant step forward, catalytic degradation of plastics could carve another interesting path. Catalytic processes use specific catalysts to break down plastic waste into useful chemical products at lower temperatures and with higher efficiency than pyrolysis. This reduces energy consumption and improves the quality of the end products, making catalytic degradation a highly attractive solution for plastic waste management.
Exciting developments come from the work of Edman Tsang’s group at Oxford University. Tsang’s team is researching the use of novel catalysts to recycle plastic waste into useful chemical feedstocks. One promising approach involves a catalyst that can convert waste plastics into propane and other hydrocarbons under mild conditions. This research could have profound implications for scaling up plastic waste recycling in the coming years.
Other examples include projects such as IBM's VolCat process, which uses a catalytic approach to depolymerise PET plastic waste, converting it into new PET without the loss of material quality.
One notable example of catalytic degradation process that has achieved at-scale processing is City Oil Field, based in South Korea. The company uses a proprietary ceramic catalyst to break down mixed, unsorted plastics at relatively low temperatures of between 200 and 295 degrees Celsius. This process yields high-quality naphtha and kerosene-like oils without the need for any pre-treatment or sorting of the plastics.
While plastics are an integral part of modern life, the issue of end-of-life plastics is one of the most significant environmental challenges we face today. Innovative recycling solutions like catalytic degradation offer promising ways to manage plastic waste more effectively, reducing environmental impact and capturing economic value. However, the road to sustainability will require collaboration between industry, researchers and policymakers to scale these technologies and ensure their long-term success.