Key takeaways
- Pyrolysis thermally cracks mixed polyolefin waste into a naphtha-like pyrolysis oil that is purified and fed back into a steam cracker, producing monomers that polymerise into resin molecularly identical to fossil-virgin — unlike mechanical recycling, the polymer chain is rebuilt from scratch rather than re-melted.
- Because the output is virgin at the molecular level, ISCC PLUS or REDcert2 mass-balance certified pyrolysis grades are accepted for food-contact and medical applications where mechanical PCR generally is not, making them the practical route to the EU PPWR contact-sensitive recycled-content targets of 10% by 2030 and 25% by 2040 for non-PET plastics.
- Recycled content from pyrolysis is allocated by mass balance, not physical traceability — a given pellet may be 100% fossil molecules carrying a certified recycled attribute, so buyers must scrutinise the chain-of-custody model and ensure the claim is third-party audited and site-specific.
- Pyrolysis carries a real cost and yield penalty — pyoil yields are typically 70–85% of feedstock before downstream cracker losses, the process is energy-intensive, and certified circular polyolefins commonly trade at a premium of several hundred to over a thousand USD per tonne over fossil-virgin (indicative), so it complements rather than replaces mechanical recycling.
Chemical recycling — and in polymers that overwhelmingly means pyrolysis — does something mechanical recycling cannot: it breaks the waste polymer back down into hydrocarbon building blocks and rebuilds the chain from scratch. The output is not re-melted scrap with degraded properties and a residual odour; it is resin molecularly indistinguishable from fossil-virgin, because it *is* virgin at the point of polymerisation. That single fact drives everything a buyer needs to understand about where pyrolysis grades fit, why they cost what they cost, and why a brand owner will pay a premium for them on food-contact packaging.
Pyrolysis heats mixed plastic waste — typically polyolefin films and rigids that defeat mechanical lines — in the near-absence of oxygen to roughly 400–600°C, cracking the long chains into a liquid hydrocarbon mix known as pyrolysis oil, or pyoil. After purification, pyoil is a naphtha-equivalent feedstock that re-enters a steam cracker alongside fossil naphtha, producing ethylene, propylene and other monomers that polymerise into new PE and PP. The recycled molecules are diluted into the petrochemical stream, which is exactly why the recycled content is tracked by mass balance rather than by measuring the pellet. For the upstream picture on cracker feedstocks, see our note on naphtha vs ethane feedstock; for the certification mechanics, ISCC PLUS and mass balance is the companion read.
These are complementary, not competing, routes. Mechanical recycling — wash, shred, re-pelletise — is far cheaper, far less energy-intensive, and the right answer for clean, single-stream bottle and film waste. But it cannot remove migrants, it degrades the polymer with each heat history, and regulators are cautious about it for food contact outside closed-loop PET. Pyrolysis is the answer for the mixed, contaminated, low-value fraction that mechanical lines reject, and for any application where virgin properties and a clean food-contact dossier are non-negotiable. A serious circular strategy uses both; for the full landscape, our recycled polymers buyers' guide sets the two routes side by side.
| Attribute | Mechanical recycling | Pyrolysis (chemical) |
|---|---|---|
| Process | Wash, shred, melt, re-pelletise | Thermal cracking to pyoil, then re-crack to monomer |
| Output quality | Property loss; limited heat histories | Virgin-identical at molecular level |
| Feedstock tolerance | Needs clean, sorted single streams | Handles mixed/contaminated polyolefins, films |
| Food-contact use | Restricted (mainly closed-loop PET) | Suitable, subject to FDA / EU 2022/1616 approval |
| Content tracking | Physical (measurable PCR %) | Mass balance (allocated attribute) |
| Energy / yield | Low energy, high mass yield | High energy; ~70–85% pyoil yield before cracker losses |
| Cost vs fossil-virgin | Usually below virgin | Premium of several hundred to >1,000 USD/MT |
The reason pyrolysis grades clear the food-contact bar is the molecular reset. Any contaminant, additive or migrant in the original waste is destroyed or stripped at the cracking and purification stages; what reaches the polymerisation reactor is monomer to specification. The finished resin is therefore assessed like virgin material — against EU Regulation 10/2011 and the recycled-plastics framework (EU) 2022/1616, or US FDA 21 CFR — and most producers hold an FDA No-Objection Letter or EFSA opinion for the named grade. Buyers should still call the Certificate of Analysis and the food-contact declaration for the exact lot, and not assume the certification travels automatically across grades or sites. For the regulatory backdrop, see FDA food-contact polymers.
Purification is the engineering crux. Crude pyoil carries chlorine, sulphur, nitrogen, oxygenates and metals that will poison cracker catalysts and corrode equipment if left in. PVC in the feed is the classic poison — its chlorine forms HCl — and PET introduces oxygenates that disrupt cracker chemistry, so feedstock sorting and de-chlorination upstream matter as much as the reactor itself. A clean, sorted polyolefin feed is what makes a stable, cracker-grade pyoil.
You are not buying recycled molecules in the pellet — you are buying an audited recycled attribute. Read the chain-of-custody certificate as carefully as the spec sheet.
Because pyoil is co-fed with fossil naphtha into a shared cracker, the recycled carbon cannot be physically isolated in the output. Instead, a chain-of-custody scheme — predominantly ISCC PLUS or REDcert2 — audits the recycled feedstock volume in and allocates a corresponding recycled attribute to a portion of the output. A pellet sold as '100% circular PE via mass balance' may contain mostly fossil molecules; the claim is a certified accounting allocation, not a measurement. This is legitimate and widely accepted — but only when the allocation method is transparent. Ask whether fuel-use is excluded from the credit pool (the 'fuel-exempt' treatment), whether allocation is proportional or free-attribution, and confirm the certificate is current and site-specific.
- Scheme & scope: ISCC PLUS or REDcert2, naming the producing site, valid on the contract date.
- Allocation model: how recycled credits are assigned — proportional, free attribution, or with fuel-use exclusion.
- Audit trail: third-party verified mass-balance bookkeeping from waste intake through to the certified pellet.
- Regulatory eligibility: a supplier warranty that the certified content counts toward the target you are buying against (e.g. PPWR).
The commercial pull for pyrolysis is regulatory. The EU Packaging and Packaging Waste Regulation sets minimum recycled-content thresholds for plastic packaging — 10% for contact-sensitive plastics other than PET by 2030 (rising to 25% by 2040), 30% for PET beverage bottles by 2030, and 35% for other plastic packaging by 2030. Mechanical PCR cannot realistically serve contact-sensitive formats at scale, so mass-balance chemically recycled content is the practical route to those targets. The precise allocation rules under PPWR implementing acts are still being finalised, which is exactly why a forward contract should require the supplier to warrant eligibility and track the final methodology. Our briefing on EU PPWR recycled-content mandates covers the timeline in detail.
Pyrolysis is not free circularity. Every conversion step — waste to pyoil, purification, re-cracking, re-polymerisation — loses mass, with pyoil yields typically 70–85% of feedstock before downstream cracker losses. It is energy-intensive, capacity remains constrained against projected 2030 demand, and feedstock quality is the binding limit. The result is a structural price premium: certified circular polyolefins commonly trade several hundred to over a thousand USD per tonne above fossil-virgin (indicative, not a market quote). For most buyers the right posture is blended — mechanical PCR where it qualifies, pyrolysis grades reserved for the contact-sensitive and high-spec applications that justify the premium, and every tonne backed by an audited chain-of-custody certificate. If you are scoping certified circular volumes, our polyethylene desk and the contact team can structure mass-balance supply against your compliance horizon.
The practical takeaway: treat a pyrolysis grade as virgin resin carrying a certified recycled attribute — qualify the polymer on its spec sheet and food-contact dossier, and qualify the recycled claim on the chain-of-custody certificate. The two are separate diligence tasks, and a credible supplier will pass both without hesitation.
Frequently asked
Questions on the desk
Is pyrolysis-based recycled resin safe for food contact?
Yes, in principle, because the polymer is rebuilt from cracked monomers and is molecularly identical to fossil-virgin resin, carrying no legacy migration risk from the original waste. The resin must still meet the applicable food-contact framework — EU Regulation 10/2011 and the recycled-plastics rules under (EU) 2022/1616, or US FDA 21 CFR — and most producers obtain an FDA No-Objection Letter or EFSA opinion for the specific grade. This molecular reset is the main reason brand owners favour pyrolysis over mechanical PCR for contact-sensitive packaging.
How is the recycled content in a mass-balance pyrolysis grade verified?
Through a certified chain-of-custody scheme — most commonly ISCC PLUS or REDcert2 — which audits the volume of recycled feedstock entering the cracker and the recycled attribute allocated to the output. The physical pellet may contain mostly fossil molecules; the recycled claim is an accounting allocation, not a measurement of the polymer itself. Always confirm the certificate is current, names the specific site, and states the allocation method (free attribution, proportional, or fuel-exempt).
Does pyrolysis count toward EU PPWR recycled-content targets?
Mass-balance chemically recycled content is expected to count toward PPWR plastic-packaging targets, which is decisive for contact-sensitive formats where mechanical PCR is largely unsuitable. The precise allocation rules and any fuel-use exclusions are being finalised in implementing acts, so buyers writing 2030-horizon contracts should require the supplier to warrant PPWR-eligibility of the certified content and to track the final methodology.
Why is pyrolysis resin more expensive than mechanical recycled?
Pyrolysis is energy-intensive and incurs yield losses — converting waste to pyoil, purifying the oil, cracking it and re-polymerising loses mass at each step, with pyoil yields typically 70–85% of feedstock before downstream cracker losses. The certified circular polyolefin therefore commonly commands a premium of several hundred to over a thousand USD per tonne over fossil-virgin (indicative, not a quote), whereas mechanical PCR is usually cheaper than virgin. The premium buys virgin properties and food-contact eligibility that mechanical material cannot match.
Can pyrolysis handle any plastic waste?
It is best suited to mixed polyolefins (PE/PP) and flexible films that mechanical recycling struggles with. PVC and PET are problematic — chlorine from PVC corrodes equipment and contaminates the oil with HCl, while oxygenates from PET disrupt cracker chemistry — so feedstock sorting to strip chlorine and heteroatoms is essential. Heavy metals, sulphur and halogens must be removed in purification before the pyoil meets cracker-grade naphtha specification.
General market commentary from the OmniaStrata desk, provided for information only. It is not legal, financial, tax, or trading advice, and it is not an offer or a commitment to any terms. Figures such as price ranges, spreads, financing costs, and credit periods are illustrative market context, not OmniaStrata's rates or terms. Actual contract terms — including price, payment instrument, credit, insurance, and Incoterms — are agreed in writing on a per-transaction basis and at OmniaStrata's discretion. Market conditions change; figures reflect the publication date.