Abstract: In a pyrolysis plant having a preliminary cooling stage and a final cooling stage, in the event of an operational malfunction of the preliminary cooling stage as indicated by temperature measurement of the pyrolysis gas cooled therein, the pyrolysis gas is withdrawn upstream of the final cooling stage and previously stored, cold pyrolysis gas is drawn from a gas reservoir and fed to the pyrolysis reactor and to the final cooling stage so that these parts of the plant can remain in unaltered operation. As a result of this procedure, a shutdown of the entire plant is avoided in the event of malfunctions of the preliminary cooling stage.

Abstract: A plant for the pyrolysis of waste material containing hydrocarbons has a cooling stage. In this cooling stage, the hot pyrolysis gas coming from the pyrolysis reactor is cooled by direct heat exchange with low-boiling pyrolysis oil which is obtained in a further cooling stage by condensation of pyrolysis gas. For this purpose, a multiplicity of spray nozzles disposed in the form of a ring are provided in the heat exchange channel of the cooling stage, with a spray direction of the nozzles pointing substantially downwards. The end of the hot gas line which connects the cooling stage to the pyrolysis reactor is located above the spray nozzles. At the same time, feed lines for a protective, buffer or blanketing gas end in this region. In addition, an annular channel encloses the heat exchange channel and has orifices in the inner wall surface of the heat exchange channel, so that pyrolysis oil fed through the line cools and wets the wall of the heat exchange channel.