A. Martin, Global Impact Coalition, Geneva, Switzerland; and A. DE LA CAL, Lanxess, Rotterdam, Netherlands
Plastic waste represents one of the most pressing sustainability challenges of our time. With millions of tons discarded each year, the need to view plastic waste as a valuable resource is more urgent than ever. However, the reality is stark: > 80% of plastic waste is still either landfilled or polluting the environment. To move from this linear system to a truly circular economy, we must embrace transformative technologies.
Among these, pyrolysis—a process that converts plastic waste into valuable oils and chemicals—emerges as a critical solution. While its potential to process hard-to-recycle plastics and expand the scope of recycling is clear, scaling up pyrolysis to meet global demand remains a significant challenge. From technical optimization to creating market confidence, addressing these barriers is essential if pyrolysis is to reduce plastic pollution and advance circularity.
A path to circularity. To improve recycling rates, we must focus on strengthening collection and sorting systems, investing in innovative recycling methods such as chemical recycling, and incentivizing manufacturers to incorporate recycled materials into their products. Mechanical recycling provides a clean, homogenous supply of single-polymer plastic waste material, while chemical recycling can help expand the type of polymers and conditions handled.1 Techniques like pyrolysis and gasification break down mixed, contaminated or hard-to-recycle plastics into fundamental chemical components, offering a sustainable solution for materials that would otherwise go to waste.2 Together, these complementary technologies have the potential to revolutionize plastic recycling and create a robust circular economy.
Assessing the environmental footprint of plastic pyrolysis. Plastic pyrolysis stands out as a highly promising technology, thanks to its technical maturity and ability to convert solid waste into valuable liquid and gaseous products under controlled, oxygen-free conditions. These outputs can be further refined into high-value fuels and chemicals, making pyrolysis a key option to advance overall plastic circularity.
However, chemical recycling technologies, including pyrolysis, are still in the early stages of adoption, and comprehensive environmental assessments remain limited due to insufficient lifecycle inventory (LCI) data. Greater collaboration between industry and academia is essential to establish robust LCIs and deepen our understanding of the environmental impacts of these technologies. Research focused on converting waste plastics into naphtha and plastic monomers is particularly critical to scaling circular economy solutions.
Emerging studies are beginning to illuminate the environmental profile of chemical recycling. For instance, lifecycle assessments (LCAs) of polyethylene and polypropylene treatment options reveal significant benefits for closed-loop recycling systems. One study found that recovering ethylene and propylene monomers for plastic remanufacturing delivered the greatest environmental advantages, reducing climate change and fossil fuel depletion impacts by 1,063% and 36,761%, respectively, compared to landfill scenarios.3
Other recycling approaches, such as pyrolysis for producing high-value chemicals and energy recovery, also demonstrated substantial improvements, including reductions in human toxicity, fossil depletion, and both freshwater and marine ecotoxicity. These findings underscore the potential of plastic pyrolysis and chemical recycling in driving sustainable waste management solutions.4
Pyrolysis oil applications and properties. Pyrolysis oil is produced from the thermal decomposition of organic materials, such as biomass or plastic waste, in the absence of oxygen. Its properties depend on system parameters, operating conditions and catalyst attributes. Additionally, combining pyrolysis with other chemical technologies can upgrade the properties of pyrolysis oil, resulting in a versatile product with varied characteristics.5
The properties of pyrolysis oil determine its suitability for various applications:
Fuel: For use as a fuel, pyrolysis oil needs a high heating value, low water content, and low viscosity to ensure efficient combustion and minimal handling issues.
Energy generation: For energy generation, the oil should have a high calorific value and low levels of contaminants to ensure efficient and clean energy production.
Chemical feedstock: When used as a chemical feedstock, the oil should have a consistent chemical composition, low acidity and low levels of impurities to ensure effective conversion into chemicals and materials.
Plastic waste pyrolysis oil has a higher aromatic content, longer carbon chains and various metal contaminants added during production as stabilizers and colorants. Some of the main components of the aromatic share are benzene, toluene, ethylbenzene, xylene and styrene. The presence of long-chain alkanes and alkenes can lead to a heavier, more viscous product. Thus, fine-tuning an efficient and selective pyrolysis process to narrow the product distribution for feasible commercial production remains challenging. Standardizing the chemical composition, acidity and impurity levels of pyrolysis oil intended as chemical feedstock is key to enabling economies of scale and incentivizing investments.
Optimizing the pyrolysis oil supply chain: Addressing key challenges. The global pyrolysis oil market, valued at $326.64 MM in 2022, is projected to grow to $465.42 MM by 2032, with a compound annual growth rate (CAGR) of 4%. Despite its promising potential, the market faces several hurdles, including high initial capital requirements and limited consumer awareness of its benefits. To unlock the full potential of chemical recycling technologies, collaboration across the supply chain is essential.
While pyrolysis presents a significant opportunity to increase plastic recycling rates and reduce emissions from incineration, the technology's scalability is hindered by challenges such as insufficient investment, unclear regulatory standards and the lack of market-driven offtake agreements. Overcoming these barriers will require concerted efforts across the public and private sectors, focusing on:
Developing clear regulatory frameworks that support chemical recycling technologies.
Establishing industry-wide standards and feedstock specifications to ensure consistency and build trust.
Securing offtake agreements that enhance investor confidence and reduce risks for innovators.
Overcoming barriers to unlock pyrolysis’ circular potential. Pyrolysis offers a transformative pathway to enhance plastic recycling rates and reduce the reliance on incineration, yet its full potential remains untapped. To scale this technology, significant investment, standardized practices and robust market mechanisms are essential. Regulatory clarity and industry-wide collaboration will play a pivotal role in enabling pyrolysis to become a cornerstone of the circular economy.
The stakes are high: without scaling innovations like pyrolysis, the gap between recycling aspirations and environmental realities will continue to widen. Addressing the barriers to adoption is not just a technological imperative but a collective responsibility to reduce waste, conserve resources and build a more sustainable future. By fostering alignment across the value chain, pyrolysis can help redefine plastic waste as a resource, paving the way for a more circular economy. HP
LITERATURE CITED
Catizane, C., Jiang, Y. and J. Sumner, “Improving plastic pyrolysis oil quality via an electrochemical process for polymer recycling: A review,” Royal Society of Chemistry, December 2023, online: https://pubs.rsc.org/en/content/articlehtml/2024/ya/d3ya00389b
Xayachak, T., Haque, N., Lau, D., Parthasarathy R. and B. Pramanik, “Assessing the environmental footprint of plastic pyrolysis and gasification: A life cycle inventory study,” ScienceDirect, May 2023, online: https://www.sciencedirect.com/science/article/pii/S0957582023002653
Reports and Data, “Pyrolysis oil market is segmented by type (wood-based biomass-based, tire-based, plastic-based, and others), by application (fuel, chemicals, and others), and by region forecast to 2032,” July 2024, online: https://www.reportsanddata.com/report-detail/pyrolysis-oil-market?form=MG0AV3
Erkmen, B., Ozdogan, A., Ezdesir, A. and G. Celik, “Can pyrolysis oil be used as a feedstock to close the gap in the circular economy of polyolefins?” Polymers, 2023, online: https://doi.org/10.3390/polym15040859
Maqsood, T., Dai, J., Zhang, Y., Guang, M. and D. Li, “Pyrolysis of plastic species: A review of resources and products,” ScienceDirect, October 2021, online: https://www.sciencedirect.com/science/article/abs/pii/S0165237021002813
AMANDA MARTIN oversees communications for the Global Impact Coalition (GIC), a CEO-led, cross-industry accelerator platform, enabling emissions reductions and circularity in the chemical value chain. In this role, Martin leads media relations, event programming and community engagement. Previously, she led the sustainability communications and engagement consulting practice at Quantis, a BCG company specializing in environmental services. With more than 20 yr of experience, Martin has advised leading global consumer goods and chemical companies on brand strategy, sustainability communications and stakeholder engagement. She has worked across three continents, sharing impactful stories and transforming complex scientific concepts into meaningful, accessible messages. Martin earned a degree in cultural anthropology and urban geography from Macalester College in Saint Paul, Minnesota (U.S.).
ANA DE LA CAL is the author of the Net Zero Chemistry blog and the Superintendent of Operations Improvement at Lanxess. Over the past 15 yr she has built a distinguished, international career, excelling in various roles in the manufacturing and marketing of high-performance materials and specialty chemicals. de la Cal earned an MSs in chemical engineering and economics research. Her vision to become a catalyst for systemic change drives her to utilize her platform to divulgate and inspire others. de la Cal contributes forward-thinking content, best practices research and innovations, making an impact on accelerating the industry's sustainable transformation.
