Decarbonisation Technology August 2025 Issue

Legacy linear path

Renery

Cracker

Polymer

Packaging and use

Disposal

Circular system

Collection

Upgrading

Shell participation Shell partnerships

Sorting a nd separation

Pyrolysis

Figure 2 A circular plastic system depends on effective collection, sorting, and upgrading, among other steps

the global plastics policy landscape remains fragmented. Consequently, all 193 UN Member States have agreed to work towards a legally binding global treaty on plastic waste. While negotiations stalled in late 2024, talks are set to continue later in 2025. With ambitious national plastic recycling targets already set and a potential global treaty on the horizon, what options are available for producers to help accelerate plastic recycling? Beyond mechanical to advanced recycling Plastic recycling falls into two buckets (see Figure 1 ). The first is mechanical recycling, which, while the most established method, offers limited flexibility in terms of the types of plastic waste it can accept, requires extensive sorting, and introduces quality degradation over time. In the second bucket are advanced (or chemical) recycling methods, which include dissolution, depolymerisation, hydrothermal liquefaction, pyrolysis, and gasification – each breaking down plastic waste into increasingly more fundamental building blocks. Though more costly than mechanical recycling, advanced recycling can produce molecules that are indistinguishable from those produced from raw virgin materials and enables almost unlimited recycling cycles without loss of quality. While advanced recycling offers important advantages, it complements rather than replaces mechanical recycling. Both will be needed to build the recycling value chain and close the plastic circularity loop.

The shift to a circular model also depends on effective collection, sorting and – crucially – upgrading, which bridges the gap between oils derived from recycled plastic and existing chemical infrastructure (see Figure 2 ). Upgrading technologies have remained the missing link in advanced recycling line-ups – until now. Shell’s upgrading technology The Shell Recovered Plastics Upgrader (SRPU) addresses the upgrading challenge through a suite of technologies designed to upgrade pyrolysis oils and liquefied plastics derived from plastic waste, thereby making them usable as feedstock for steam crackers and other refinery conversion units (see Figure 3 ). The suite includes modular, scalable solutions that enable operators to start small and phase in investments as regulations tighten, pyrolysis oil becomes more readily available, or demand grows. Moreover, SRPU can be integrated into an existing plant without the need to overhaul the steam cracker or refinery kit. It comprises three distinct technology pathways: SRPU Extraction, SRPU Hydroprocessing, and SRPU Gasification. Each is designed for different feedstocks and customer needs and can be deployed independently or as part of a phased road map. SRPU Extraction SRPU Extraction is a low-complexity, low-capital offering designed for well-sorted waste that is first converted to pyrolysis oil, which is then upgraded using an extraction-based