Processing waste materials for anaerobic digestion of the

Abstract

In a process of treating waste materials for an anaerobic digestion of the biogenic organic constituents of the garbage, particularly of the source separated organic waste, the wet waste, the residual waste and the commercial wastes, an easily dewaterable suspension of the biogenic organic substances is formed in a pretreating stage by a mechanical treatment including a selective dissolution and defibration of the biogenic organic substances. In dependence on the adjusted solids concentration the action of flow-dynamical forces is so controlled that the not biogenic organic substances, are not subjected to an appreciable disintegration before they are removed at the end of the pretreatment. Non-digestable substances are removed. The suspension is converted to biogas by an anaerobic digestion and to a compost-like residue. In the apparatus in accordance with the invention a gentle treatment of adhering solids in the crude waste is ensured in the pretreating stage in that the speed of the impeller 14 in the pulping vessel 13 is controlled in dependence on the solids concentration. This will also result in a distinct saving of energy and in a high efficiency.