Stage 01 — BOSS
Density separation
BOSS removes multilayer structures and non-target polymers by density before pyrolysis — isolating a polyolefin-rich fraction from mixed post-consumer waste.
Chemical recycling
Improve Chemical Recycling using BOSS for Feedstock Preparation
BOSS technology separates mixed post-consumer waste plastic into cleaner, more consistent polymer streams, improving feedstock quality for pyrolysis, solvent-based recycling and other advanced recycling processes.
The industry challenge
Chemical recycling starts with feedstock quality.
Chemical recycling technologies are increasingly being deployed to process difficult waste plastic streams — but performance depends heavily on the consistency of the incoming material.
Around 60% of post-consumer flexible packaging is coloured or printed and cannot return to food-contact applications through mechanical recycling. Meeting PPWR recycled-content targets depends on finding a route for this material — and that route is chemical recycling.
Pyrolysis converts plastic into a hydrocarbon feedstock for steam crackers, but it doesn't remove contamination — it redistributes it. The oxygen and nitrogen locked into multilayer barrier films, printing inks, paper labels and adhesives pass straight into the pyrolysis oil, reducing its similarity to fossil-derived naphtha and limiting how much can be blended into existing cracker feed.
Mixed waste plastic often contains contamination such as PET, PVC, PA, EVOH, paper, metals and multilayer structures. These non-target materials reduce yield, disrupt processing, foul catalysts and increase clean-up costs — undermining the commercial case for advanced recycling before the reactor is even reached.
Feedstock preparation is often the weakest part of the chemical recycling value chain. Optical sorting and manual picking cannot reliably deliver the polyolefin purity that pyrolysis and solvent-based processes require to run at design throughput.
The solution
BOSS technology as the front-end solution.
BOSS (Baffled Oscillation Separation System) uses water-based density separation to isolate polyolefin-rich fractions from mixed waste plastic — a proven upstream stage for chemical recycling operators.
What BOSS delivers
- Separates PE and PP from heavier contaminants
- Concentrates target polymers before chemical recycling
- Removes problematic non-target materials
- Improves consistency of input streams
- Reduces downstream processing costs
- Improves yield and product quality
Process flow
- 01Mixed waste plastic
- 02BOSS separation
- 03Polyolefin-rich fraction
- 04Chemical recycling
- 05Circular feedstock
BOSS sits between waste collection and the chemical reactor — turning a variable, contaminated input into a clean polyolefin-rich feedstock.
Why feedstock chemistry matters
Clean polyolefins produce naphtha-like oil. Contamination doesn't.
Feedstock composition determines how much pyrolysis oil a steam cracker will accept — and therefore how much recycled hydrocarbon can displace fossil naphtha.
A clean polyolefin feedstock produces pyrolysis oil that closely resembles conventional naphtha — carbon and hydrogen convert into usable hydrocarbons. Contamination behaves differently: PET, EVOH and polyamide barrier layers introduce oxygen and nitrogen; nitrocellulose printing inks decompose into oxygenated and nitrogen-containing compounds; paper labels and cellulose fibres add further oxygen; adhesive residues do the same.
Current industry practice limits pyrolysis oil from mixed post-consumer flexible waste to around 1–2% of total steam cracker feed. A highly purified polyolefin feedstock can raise that to 30–40%. For an 800,000 tonne per annum steam cracker, that's the difference between 8,000 and 240,000 tonnes of recycled hydrocarbon a year.
0–0%
Pyrolysis oil accepted into steam-cracker feed today, from mixed post-consumer flexible waste.
0–0%
Achievable blend rate with a highly purified polyolefin feedstock.
0 t
Recycled hydrocarbon a year from a single 800,000 t/pa steam cracker on clean feedstock — up from 8,000 t.
Two-stage purification
BOSS separates. HydroDyn cleans.
Two complementary stages engineer a feedstock closer in composition to virgin polyethylene.
Stage 02 — HydroDyn
Hydrodynamic cleaning
HydroDyn, our hydrodynamic cleaning stage, then removes surface contamination — mechanically entrapped cellulose fibres, adhesive residues and printing residue — that conventional washing leaves behind. Together BOSS and HydroDyn engineer a feedstock closer in composition to virgin polyethylene.
Applications
Designed for real-world waste streams.
BOSS handles the mixed, contaminated streams that dominate post-consumer and post-commercial collections — the same streams chemical recyclers are targeting.
Household flexible packaging films
Mixed rigid packaging
Multilayer films
Post-commercial waste plastic
Automotive plastic fractions
Industrial mixed polyolefins
Complementary pathways
Mechanical and chemical recycling can work together.
Right technology for the right polymer stream.
Not all waste plastic streams need chemical recycling. BOSS can create streams suitable for direct mechanical recycling where possible, and direct more complex fractions into chemical recycling where necessary.
This improves overall economics across the value chain, supports the waste hierarchy, and ensures that advanced recycling capacity is used where it delivers the most circular value — not on material that could be mechanically recycled instead.
Where material is suitable for mechanical routes, it flows into our recycled PP and PE products, with melt flow rate tailored by PRE — so the whole stream finds its highest-value circular route.
Commercial proof
Commercially proven at scale.
BOSS is deployed in the UK and internationally, backed by an established licensing model.
UK operations — over ten years
Operating plants in Durham and Glasgow, with a combined capacity of 30,000 tonnes per annum across mixed rigid, flexible and medical waste plastic.
Finland — Syklo licence
50,000 tonnes per annum across mixed rigid and flexible waste plastics under BOSS licence at Hyvinkää — the first international commercial-scale deployment.
Read about the Syklo partnershipLicensing model
An established licensing route for third-party operators, built on a decade of UK operating experience.
Read the technical paper
Engineering Feedstocks for Chemical Recycling.
Our detailed analysis of contamination sources in flexible packaging and their impact on pyrolysis oil quality and steam cracker acceptance.
Download the paperFAQ
Chemical recycling feedstock questions.
Common questions from chemical recyclers, polymer producers and packaging partners assessing BOSS as a front-end feedstock stage.
Chemical recycling processes such as pyrolysis and solvent-based recycling perform in proportion to the consistency of their input. Mixed post-consumer waste plastic carries PET, PVC, PA, EVOH, paper, metals and multilayer structures that reduce yield, foul catalysts and raise clean-up costs. BOSS removes those non-target materials up front so the reactor runs closer to design throughput.
Pyrolysis redistributes contamination rather than removing it — oxygen and nitrogen from barrier films, inks, labels and adhesives pass straight into the oil and reduce its similarity to fossil naphtha. By isolating a clean polyolefin-rich fraction first, BOSS produces an input that yields naphtha-like oil, which steam crackers can accept at far higher blend rates.
They are two complementary stages. BOSS uses water-based density separation to remove multilayer structures and non-target polymers. HydroDyn then removes surface contamination — entrapped cellulose fibres, adhesive residues and printing residue — that conventional washing leaves behind. Together they engineer a feedstock closer in composition to virgin polyethylene.
No — the two work together. BOSS can create streams suitable for direct mechanical recycling where possible and direct only the more complex fractions into chemical recycling. This supports the waste hierarchy and ensures advanced recycling capacity is used where it delivers the most circular value.
Yes. BOSS runs across UK plants in Durham and Glasgow with a combined 30,000 tonnes per annum, and under licence at Syklo in Finland at 50,000 tonnes per annum — the first international commercial-scale deployment. An established licensing model makes the same route available to third-party operators.
Chemical recycling partners
Looking to improve chemical recycling feedstock quality?
Impact Recycling works with chemical recyclers, polymer producers, waste managers and packaging companies to improve feedstock preparation and unlock higher-value circular outcomes.
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