Catalysis 2026 Issue

reliance on virgin carbon, larger, high-quality PPO volumes are required to meet the feedstock needs of these large- scale facilities. Therefore, scaling up chemical recycling via pyrolysis necessitates an upgrading step to remove con- taminants and refine the oil’s properties, ensuring it meets the feedstock specifications of existing petrochemical assets. PureStep technology provides advanced hydroprocess- ing solutions tailored to bridge the gap between raw PPO and steam cracker requirements while avoiding any further yield loss and carrying more than 99% of the carbon to the next step. This process upgrades mixed plastic-derived PPO to on-specification naphtha and heavier steam cracker feedstocks. The unique contaminants in plastic-derived oils, often present in different molecular structures and concen- trations compared to fossil feedstocks, require customised hydroprocessing steps and catalyst formulations. Extensive experience has been accumulated in analysing and processing non-fossil feedstocks, including renewa- ble bio-based materials and plastic-derived oils. PureStep technology, developed through more than 60 pilot tests on various PPOs, combines analytical expertise, hydro - processing know-how, and targeted solutions for specific contaminants such as silicon. By adapting to different liquefaction technologies and oil qualities, the technology offers the flexibility and robustness needed for chemical recycling. As of 2025, the technology had entered commer- cial operation at two plants, demonstrating its potential to transform mixed plastic waste into high-value feedstocks (see Figure 1 ). Value chain collaboration Until now, pretreatment and contaminant removal in WPOs have primarily focused on meeting steam cracker feedstock requirements for specific contaminants. However, it is also important to assess how hydroprocessed WPOs perform in the steam cracker itself and to refine specification require - ments accordingly. Furthermore, while hydroprocessing serves as a key pretreatment step to enable the integration of WPOs into existing production facilities, combining hydroprocess - ing with other pretreatment methods may offer economic advantages, depending on ongoing advancements in non-hydroprocessing technologies. As this value chain is still emerging, continued collaboration and shared learnings from new operating assets are expected to drive further improvements in process efficiency and cost-effectiveness. Scaling and advancements Scaling chemical recycling of WPO to produce olefins will reveal preferred technologies and approaches. The chal- lenge lies in engineering solutions tailored to the recycling needs of diverse plastics, with an emphasis on energy effi - ciency. In the short term, mechanical recycling and chemical recycling via pyrolysis upgrading should be viewed as com- plementary strategies, as they each have their place in the plastic waste hierarchy. Advancements in recycling WPO through FCCs and steam crackers present opportunities for industry

differentiation, particularly in regions with supportive reg- ulatory frameworks. The European plastics industry, for example, may benefit from monetising recycled materials as virgin polymer markets face increasing regulatory and economic pressures. In addition to biofuels, hydrogen, and other decarbon- isation initiatives, the manufacture of circular polymers is pivotal for addressing the nearly 300 million tonnes of plastic waste generated annually worldwide. Large-scale pyrolysis facilities are essential for enabling start-ups and established players to process significant volumes of plas - Large-scale pyrolysis facilities are essential for enabling start-ups and established players to process significant volumes of plastic waste tic waste. Regulatory drivers are shifting towards 2030 and beyond, with commercial recycling facilities expected to play a central role in the circular economy. Whether refinery and steam cracker operators will com - mit to processing large volumes of pyrolysis oils remains to be seen, but ongoing technological and market devel- opments suggest a promising future for chemical recycling.

HydroFlex™ and PureStep™ are trademarks of Topsoe.

References 1 OECD (2022). Global Plastics Outlook: Economic Drivers, Environmental Impacts and Policy Options. Organisation for Economic Co-operation and Development. 2 Plastics Europe (2023). Plastics – the Facts 2023. Plastics Europe. Further reading 1 James Kenney, ID Tech Ex, Chemical recycling technology: Bringing value to plastic waste, Electronic World , 20 May, 2024. 2 Cafiero, L, De Angelis, D, Tuccinardi, L, and Tuffi, R. (2025). Current state of chemical recycling of plastic waste: A focus on the Italian experience. Sustainability . 17. 1293. 10.3390/su17031293. Trine Dabros is Project Leader at Topsoe R&D, Clean Fuels & Circular Plastic, with extensive experience in research and development, spe - cialising in hydroprocessing and sustainable technologies. She leads research and development activities for circular plastic products, driv- ing innovation in the transition towards more circular materials and processes. Dabros holds an MSc and PhD in chemical engineering from The Technical University of Denmark. Email: TRAR@topsoe.com Milica Folić is Product Line Director for Clean Fuels & Chemicals at Topsoe, operating across business development, innovation, and strat- egy. This ties in well with her personal interests in clean technologies and sustainable solutions, aiming at leaving fossil carbon in the ground and using biomass, waste, and emissions as resources. She holds an MSc in chemical engineering from the University of Belgrade and a PhD in process systems engineering from Imperial College London. Email: MFOL@topsoe.com

Catalysis 2026