Producing fertilizer from fermentation residue of a biogas plant comprises obtaining the fermentation residue from the biogas plant and adding mineral acid to adjust the pH value of the total (neutralized) substance to specified value

摘要

Producing fertilizer from fermentation residue of a biogas plant comprises: obtaining the fermentation residue from the biogas plant and adding mineral acid to the residue to adjust the pH value of the total substance, as neutralized fermentation residue, to 5-7.5 (preferably 5.5-7). An independent claim is included for a device, for carrying out the above method, comprising a mixing container (2), a separator (4), a mixing screw (5) and a dryer (6), where: the mixing container comprises a first supplying means (21) for providing the fermentation residue originating from the biogas plant or an intermediate store and a second supplying means for providing the mineral acids and a first outlet means for transferring the neutralized fermentation residue to the separator or an intermediate stock and a second outlet means for venting mixing gases originating from the biogas plant; and the separator separates the neutralized fermentation residue into a solid fraction and a liquid fraction and distributes to a first and second connecting line, which provides the liquid fraction into the mixing screw into which a portion of the dried fermentation residue is supplied from a product conveyor and mixed together with the liquid fraction and supplied to the dryer via a third connecting line and in the dryer, the solid fraction together with the conditioned liquid fraction is dried. ACTIVITY : Fertilizer. MECHANISM OF ACTION : None given.