Pyrolysis Oil
Quick Overview
Alias for pyrolysis — liquid product from thermal decomposition of plastic waste in the absence of oxygen. Used as cracker feedstock for chemical recycling after purification. See [pyrolysis](/glossary/pyrolysis/).
Pyrolysis Oil
Pyrolysis oil (also called py-oil, pyrolysis liquid, or bio-oil when from biomass) is the liquid product obtained from the pyrolysis of plastic waste — thermal decomposition in the absence of oxygen at 400–600°C.
This is an alias entry. For the full process description, technology types, and applications, see Pyrolysis.
Key Characteristics
| Property | Typical Range |
|---|---|
| Appearance | Dark brown to black liquid |
| Density | 0.9–1.1 g/cm³ |
| Water content | 1–5% |
| Calorific value | 35–40 MJ/kg |
| pH | Acidic (3–5) |
Contaminants (Require Purification for Steam Cracking)
| Contaminant | Typical Level | Target for Cracker |
|---|---|---|
| Chlorides | 100–5,000 ppm | <1 ppm |
| Metals (Na, K, Ca, Fe, Zn) | 10–500 ppm | <0.5 ppm |
| Nitrogen | 500–3,000 ppm | <50 ppm |
| Oxygenates | 5–15 wt% | <1 wt% |
| Silicon | 10–200 ppm | <1 ppm |
| Dienes/Olefins | High | Saturated |
Upgrading Pathways
- Hydrotreating (HDT) — H₂ + catalyst → removes Cl, N, S, O, saturates olefins
- Adsorption — Fixed-bed adsorbents for chloride/metal polishing
- Steam cracking — Direct feed (after purification) to ethylene cracker
- Refinery integration — Co-processing in FCC or hydrocracker
Applications
- Chemical recycling feedstock → steam cracker → ethylene/propylene → new plastics
- Fuel blending — marine fuel, heating oil (lower value)
- Chemical intermediates — BTX extraction (BioBTX route)
Related Technologies
- Pyrolysis — Full process description
- Chemical Recycling — Recycling pathway
- Purocel — Evonik’s purification catalysts/adsorbents
- Mass Balance Approach — Allocation method
- Circular Economy — System context
Last updated: July 10, 2026
Alias for: pyrolysis