What You Need to Know
The process involves rapid thermal decomposition of lignocellulosic biomass under limited oxygen, generating a complex mixture of phenolic compounds (guaiacol, syringol, cresols) and aldehydes that condense in a cooled condenser. The resulting liquid contains 0.1–0.5 % phenols, 0.05–0.2 % aldehydes, trace acids, and 0.5–2 % water, with phenol levels above 5 % producing a bitter, medicinal off‑taste.
The Science
Primary Reaction
Pyrolysis of hardwoods (e.g., oak, hickory) at 400–600 °C under limited oxygen