1) pyrolysis 2) gasification 3) destructive distillation the chemical degradation and the irreversible decomposition of any material under the action of heat (at high temperatures, t over 200°C) and under anaerobic conditions GRM: n. (1,2,3) Note: the temperature during pyrolysis of waste is between 500 and 1600°C. Pyrolysis produces a combustible gas, pyrolitic gas. Pyrolysis in the absence of air also produces oil tar and other liquids and a coke-like residue. Pyrolysis with limited air supply produces, beside the pyrolytic gas, ash, and small quantities of tar and oil