Process for the preparation of biogas involving the addition of Carbokalk

摘要

The method comprises adding auxiliary substance comprising insoluble calcium and/or magnesium compounds into a surplus, admitting culture medium, which has substrate and digested sludge, to a fermentation plant such as biogas plant, and separating the sludge in a sedimentation process with or without flocculation aids. The space-time yield is more than 9 or 11 kg/m 3>. The calcium compound is carbolic lime. The sludge serves as inoculation material. The auxiliary substance increases velocity of particles in the sludge and reduces discharge of microorganisms from the fermentation plant. An independent claim is included for a calcium- and/or magnesium-containing solid material.