What is a typical pyrolysis yield split?

There is no single split. Clean polyolefins at 450–550 °C often give 40–75 wt% oil, 5–20% char and 10–30% gas. Woody biomass slow pyrolysis is closer to 30–40% char. Fast pyrolysis of clean wood can reach 50–75% liquid. Tires (steel-free) typically give 40–50% oil, 30–40% recovered carbon black and 10–20% gas.

What temperature maximises pyrolysis oil?

For most plastics and biomass liquids, 450–550 °C with short vapour residence time. Above about 600 °C secondary cracking raises gas at the expense of oil. Char is favoured by lower temperature, slower heating and longer solids time.

What temperature is used for lithium-ion battery pyrolysis?

Two windows: 100–300 °C to drive off electrolyte solvents (vacuum drying avoids HF), and 500–700 °C to decompose PVDF binder. Carbothermal treatment of NMC/NCA black mass around 550–630 °C can raise water-leachable lithium to about 63%. This is a pretreatment, not an oil-yield process.

Can pyrolysis treat asbestos?

Asbestos is a mineral. The relevant process is thermal dehydroxylation and recrystallisation, not organic pyrolysis. Chrysotile structure collapses around 600–800 °C, but fibrous morphology can persist to 800–900 °C. Complete conversion to forsterite/enstatite is typically reported at ≥900–1100 °C with sufficient hold time.

Pyrolysis yield by feedstock, temperature and machine

Q: Does pyrolysis destroy PFAS?

Pyrolysis at ≥400–500 °C typically removes >96–99% of analysed PFAS from the solid (char). That is not the same as mineralisation. Parent compounds and products of incomplete destruction, including TFA and fluorocarbon gases, report to the vapour. Gas must be oxidised at high temperature (often ≥850–950 °C) with hydrogen donors, or captured. Complete mineralisation is rarely achieved below about 950 °C without additives.

This handbook is built for people who specify, permit or QA a unit: battery recyclers, sludge and PFAS destruction, asbestos inerting, tire and plastic oil plants, and anyone who has been sold a single magic percentage. Open the estimator, then the deep pages.

wt% oil · char · gas Windows 2024–2026 literature PFAS: char-clean ≠ mineralised PVC and untreated ACM are special cases

Yield estimator — pick a feedstock

Mid-range bars use the midpoint of the published envelope. Hover the table on yield tables for the full matrix.

Literature envelope

Feedstock

Oil / liquidChar / solidGas

Snapshot: what actually comes out

OilCharGas

Feed	Window	Oil	Char / solid	Gas	Design intent
Clean wood, fast	450–550 °C, <2 s vapour	50–75%	10–20%	10–25%	Bio-oil
Clean wood, slow	400–600 °C, long solids	20–35%	30–40%	25–40%	Biochar
HDPE / PP (clean)	450–550 °C	70–92%	0–10%	5–20%	Naphtha-range oil
PS / EPS	400–500 °C	65–97%	0–12%	3–20%	Styrene-rich oil
PET	400–510 °C	25–40%	15–40%	25–52%	Avoid as fuel feed
PVC	300–500 °C	5–15%	10–25%	50–80% (HCl)	Do not co-feed raw
ELTs, steel-free	450–600 °C	40–50%	30–40% rCB	10–20%	Oil + recovered carbon black
Biosolids @ 500 °C	slow / auger	~40%	~40%	~20%	Volume cut + PFAS off-char
Biosolids @ 700 °C	slow / auger	~33%	~30%	~37%	More gas, cleaner char
LIB black mass	500–700 °C	not the product	black mass remains	HF, VOCs	Binder kill, then hydro
Cement-asbestos	900–1100 °C	none	silicate residue	H₂O, CO₂	Fibre collapse, not oil

Primary collations: MDPI Energies 17:5082 (2024); ACS waste-wood inventory (2024); TSA tyre review (2024); Bamdad biosolids (2022); Energy & Fuels auger ELT (2024). Full citations on sources.

Where the site goes deep

Data

All yield tables

Feedstock × technique × temperature, with the honest width of each envelope.

Hardware

Machines and reactors

Rotary kiln, auger/Spirajoule, fluid bed, moving bed, microwave, plasma — TRL and what they are for.

Process

Ways to pyrolyse

Slow, intermediate, fast, flash, vacuum, catalytic, microwave, plasma, hydro, co-pyrolysis.

Control

Temperature map

From electrolyte drying at 100 °C to asbestos inerting above 1000 °C.

Battery

Li-ion and black mass

PVDF, HF, Li water-leach ~63% after 550–630 °C, Duesenfeld vs kiln pyrolysis.

Forever chemicals

PFAS and TFA

Char removal vs mineralisation. Why TFA appears. Gas oxidation is the real destruction step.

Mineral

Asbestos thermal windows

Dehydroxylation vs fibre disappearance. 600 °C starts it; 900–1100 °C finishes it.

Plant

How to manage it

Inerting, vapour quench, oil upgrading, HF/HCl scrub, char cooling, permits.

Machines in one paragraph each

Rotary kiln — industrial workhorse for mixed, lumpy, contaminated feed (tires, sludge, battery modules, ACM). Slow to intermediate. Solids time tens of minutes. Poor vapour-time control. TRL 8–9.

Auger / electrically heated screw (Spirajoule / Biogreen, PYREG-class) — precise dwell and temperature, containerisable, 200–800 °C. Dominates sludge-to-biochar and modular plants. TRL 8–9.

Fluidised / spouted bed — fast pyrolysis for sized particles. Highest bio-oil envelopes. Sticky plastics and metals are hostile. TRL 7–8 for biomass oil.

Moving bed (Pyrum-type) — gravity solids, electrically heated, long residence. Tire rCB + oil at industrial scale.

Microwave and plasma — volumetric or ultra-high-T. Lab-to-pilot for waste (MAP ~TRL 7 in a few plastic prototypes); thermal plasma more proven for hazardous waste and methane pyrolysis than for commodity bio-oil.

Full reactor comparison →

The four streams people get wrong

Batteries are not an oil plant. Pyrolysis is pretreatment: dry electrolyte, kill PVDF, carbothermally reduce cathodes so lithium becomes water-leachable. HF from LiPF₆ and PVDF must be scrubbed (often lime → CaF₂). Low-temperature vacuum drying exists specifically to avoid making HF. Details: batteries.
PFAS-free char is not destroyed PFAS. Solids can go non-detect above ~400–500 °C while fluorinated fragments, including TFA, leave in gas. Mineralisation needs high-T oxidation plus hydrogen donors, or additives that lock F as CaF₂. Details: PFAS / TFA.
Asbestos does not pyrolyse into oil. You are collapsing a silicate fibre. Hold time at ≥900–1100 °C matters as much as peak T. Details: asbestos.
PVC and PET poison a plastic-oil mass balance. HCl and oxygenates. Sort or dechlorinate; do not average them into a “mixed plastic 70% oil” claim.

FAQ

What is a typical pyrolysis yield?

There isn’t one. State the feed. Sorted PE/PP at 450–550 °C: often 40–75% oil. Tires steel-free: 40–50% oil, 30–40% carbon, 10–20% gas. Slow wood: ~35% char. Fast wood: ~60% liquid. Sludge at 500 °C: roughly 40/40/20.

Slow vs fast vs flash — which %?

Slow (HR ≲ 1 °C/s, long solids): char 30–40%, oil 20–45%. Intermediate: oil 40–50%. Fast (10–1000 °C/s, vapour seconds): oil 50–75% on clean wood. Flash is a lab envelope (oil sometimes >75%) and is not how a 10 t/h plant is run.

Does pyrolysis destroy PFAS and TFA?

It strips PFAS from solids at modest pyrolysis temperatures. Destruction of the carbon–fluorine inventory to inorganic fluoride is a gas-phase (or additive) problem. TFA is a documented product of incomplete PFOA thermal treatment. Hydrothermal alkaline water (150–250 °C) is a separate, more specific TFA route.

Battery industry — what yield should I put in a model?

Model mass as black mass remaining after organics leave, plus captured HF/fluoride and VOC/syngas to the oxidiser. Do not put 50% “pyrolysis oil” in a LIB line. Lithium water-leach after ~600 °C pyrolysis is on the order of 60% without extra reductant; oxalic or acid steps go higher.

Which machine should a small municipality buy?

For sludge and PFAS-in-solids, an electrically heated auger or PYREG-class kiln at ~600 °C with a ≥850–950 °C gas oxidiser is the pattern now being deployed (SUEZ/PYREG Pyrolis S2B, 2026). For mixed bulky waste, a rotary kiln. For plastic oil, only if the feed is actually polyolefin.

This page is a technical briefing, not engineering design, not a permit, and not medical or legal advice. Verify against the primary papers listed on sources before you spend capital.

Pyrolysis Yield

Yield is a three-way split. The machine and the temperature decide which bar wins.