Abstract: The invention relates to a method and a device for the sedimentation of sediment particles in a method for extracting diesel oil from a liquid substance mixture moving in a circuit and comprising oil, hydrocarbon-containing residues and catalyst particles, by means of catalytic, pressureless depolymerisation (CPD). Sediment particles are removed from the substance mixture by guiding said mixture via a spiral-shaped guide arrangement. Hydrocarbon-containing residues are admitted into a lattice arrangement downstream of the spiral-shaped guide arrangement, wherein the substance mixture flows around or flows through said lattice arrangement.