Pyrolysis — Definition, Formula, Properties & Uses | AllChemicals | AllChemicals

Also Known As	Thermal pyrolysis, destructive distillation (historical), thermal cracking

What is Pyrolysis?

The chemical decomposition of organic materials at elevated temperatures in the absence of oxygen or other oxidants. Pyrolysis produces smaller molecules from larger ones. Applications include cracking of petroleum to produce fuels and chemicals, and waste treatment.

Properties & Characteristics

Pyrolysis is the thermal decomposition of organic materials at elevated temperatures (typically >300-500°C) in the absence of oxygen. It produces: char (solid carbon-rich residue), oil (liquid condensable organics), and syngas (H₂, CO, CO₂, CH₄). Unlike combustion, pyrolysis is an endothermic process requiring heat input. Pyrolysis chemistry is complex, involving homolytic bond cleavage, radical reactions, and rearrangements.

Uses & Applications

Pyrolysis is used in: production of charcoal, activated carbon, and biochar (from biomass), waste plastic pyrolysis to fuel oil (chemical recycling), production of coke from coal for metallurgy, production of syngas and liquid fuels (pyrolysis-gasification), carbonisation of precursor fibres for carbon fibre manufacture, and in industrial cracking (steam cracking of naphtha to ethylene and propylene).

Safety Information

Pyrolysis gases include toxic and flammable compounds: CO, H₂S, HCN (from N-containing materials), aromatic hydrocarbons (carcinogenic PAHs), and acrolein. Pyrolysis equipment must be sealed and operated under controlled atmosphere with adequate gas scrubbing. Pyrolysis char may contain toxic heavy metals concentrated from the feedstock.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Pyrolysis

Index All "P" terms

Synonyms Thermal pyrolysis, destructive distillation (historical), thermal cracking

Frequently Asked Questions

What is Pyrolysis?

The chemical decomposition of organic materials at elevated temperatures in the absence of oxygen or other oxidants. Pyrolysis produces smaller molecules from larger ones. Applications include cracking of petroleum to produce fuels and chemicals, and waste treatment.

What is Pyrolysis used for?

Is Pyrolysis hazardous?

More "P" Terms

P-type Semiconductor Pairing Pairing Energy Palladium Pd Parachor [P] = M(γ)^(1/4) / (ρ_L - ρ_V) Paramagnetic χ_m > 0; unpaired electrons; μ = √(n(n+2)) BM (n = unpaired electrons) Paramagnetism Partial Ionic Character % ionic = (1 - e^(-Δχ²/4)) × 100% Partial Pressure Partial Pressure p_i = x_i × P_total; P_total = Σp_i Particulate Matter Parts Per Million ppm = mg/L (water) or mg/kg; = (mass solute/mass solution) × 10⁶

View all "P" terms →