TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The inert gas comprises carbon dioxide rich gas.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The percolators respectively comprise a sealable gas discharge, where the gas discharge is designed such that the switching of gas discharge for gas utilization system, switching of gas discharge into the atmosphere or closure of the gas discharge is possible. The plant comprises at least two gas-tight percolators, which are connected with each other by the gas feed lines, such that the introduction of carbon dioxide rich hydrolysis gas from a percolator into a percolator to be flushed in the exhaust operation, is carried out during time shift operation. A pressure sensor is arranged respectively at the percolators, which are used for measuring the pressure in the percolator.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The operation of the percolator, comprises: (a) loading the percolator with the biogenic substances; (b) carrying out exhaust operation; (c) carrying out gas utilization operation; (d) flushing the percolator with inert gas; (e) flushing the percolator with air; (f) opening the percolator, where the hydrolysis gas is discharged from the percolator as an exhaust in the exhaust operation, and the hydrolysis gas in the gas utilization operation is discharged from the percolator and is fed to an energetic utilization, and the hydrolysis gas present in the percolator during the flushing in step (d) is removed by displacing with the conducting inert gas. The exhaust operation is carried out until the methane concentration of the gas present in the percolator, reaches a predefined threshold value and/or until the pH of the hydrolyzate reaches a predefined threshold value. The gas utilization operation is carried out until the methane concentration of the gas present in the percolator is lower than the threshold value. At least two percolators are operated at different times, such that at least one percolator is present in the exhaust operation, where during the flushing of the percolator, the hydrolysis gas present in the percolator is removed by displacing with exhaust from a percolator operating at different times and in the exhaust operation. An additional percolator operating in a delayed manner and in the exhaust operation is sealed before the flushing of the percolator, so that an overpressure is produced in the percolator, and after reaching a pressure threshold value, subsequently the exhaust from the percolator operating in a delayed manner is conducted into the percolator to be flushed. EXAMPLE - No suitable example given.