Decarbonisation Technology August 2025 Issue

Olens/ circular plastics

Well sorted waste

Pyrolysis oil

Upgraded pyrolysis oil

SRPU E xtraction Low complexity, low capital, suitable for dilution in steam cracker

Pyrolysis unit

Steam cracker

Olens/ circular plastics

Sorted waste

Pyrolysis oil

Drop-in steam cracker feed

SRPU H ydroprocessing Medium complexity, medium C apex, drop-in steam cracker feed

Pyrolysis unit

Steam cracker

Olens/ circular plastics

Bulk plastic waste

Treated syngas

SRPU G asi f ication Most complex and robust, highest capital

Methanol synthesis

Methanol to olens

Figure 3 The SRPU suite offers modular and scalable upgrading technology solutions

technology to produce dilutable steam cracker feed. The process consists of several steps: • Caustic pretreatment removes inorganic molecules from pyrolysis oil. • Solvent extraction eliminates heteroatom- containing and aromatic compounds that challenge steam crackers. • Water washing removes solvent from pyrolysis oil. • Solvent regeneration ensures efficient reuse of the solvent. Operating at low pressures and low temperatures, SRPU Extraction offers safe and robust performance against feed variability and contaminant levels. It also provides a low-investment, modular entry into the plastic circularity loop at a scale that aligns with the availability of plastic pyrolysis oils today, when dilution of the product makes sense. The technology has achieved technology readiness level (TRL) 9 with the successful startup of the world’s first industrial-scale unit at Shell Chemicals Park Moerdijk, the Netherlands, in 2024 ( see box, Proven at scale: Moerdijk ). SRPU Hydroprocessing SRPU Hydroprocessing is a hydroprocessing- based platform with medium complexity and capital expenditure (Capex). It can produce a drop-in steam cracker feed from pyrolysis oil through four main steps: • Pretreatment addresses diolefins encountered at higher levels in recycled oils. • First-stage upgrading targets silicon, nitrogen, oxygen, and chlorine contaminants.

• Second-stage upgrading (optional) optimises the final boiling-point distribution of upgraded pyrolysis oil for naphtha-enabled steam crackers. • Fractionation separates product cuts to match specific steam cracker capabilities. While the heart of SRPU Hydroprocessing is based on traditional hydroprocessing – a field in which Shell has licensed units many dozens of times and supplied catalyst and reactor internals – processing plastic pyrolysis oil presents unique challenges. The high variability and early-stage nature of the market mean that no two samples are alike today, and feed quality is expected to decline further as supply volumes increase. These conditions call for highly flexible operating and design features. To meet this need, Shell is leveraging its extensive library of commercial plastic oils to expand the technology’s feedstock window. This includes stress-testing the SRPU Hydroprocessing configuration through experiments with real feeds across varied conditions for extensive operating hours, addressing mixed plastic waste, and producing circular, drop-in steam cracker feed at scale. SRPU Gasification SRPU Gasification is a comprehensive, robust, and high-investment technology. It converts liquefied plastic waste to syngas, which can be further converted into methanol and then olefins or other derivatives through three main stages: • Pre-conversion transforms solid plastic waste into molten plastic. • Gasification produces syngas from the molten feedstock.