Abstract: The present invention relates to a process and an installation for the continuous flow of gasification of heterogeneous mixtures of organic substances and compounds such as biomass waste, forestry, municipal solid and liquid waste, sludge from sewage treatment plants and other similar waste. Presentation Of The Invention: The process according to the invention has the following steps: a) the organic raw material in heterogeneous mixture is introduced into the pyrolysis reactor (2) where it is gradually heated, by forced convection and thermal radiation, to a temperature of 900 . . . 1000° C., being kept in contact with metal surfaces that transport thermal energy through conduction from the exothermic area of the gasification reactor. The metal surfaces are placed in fixed positions, different so that the contact surface changes after 5 . . . 20 cm traversed by the flow of organic raw material, each group of metal slats forming 2 . . .