TECHNOLOGY FOCUS - ENVIRONMENT - Preferred Method: The method of purifying waste water of hydrothermal carbonization of the biomass comprises an electrode voltage of more than 2 V, and/or a current density of waste water located between two electrodes of more than 55 A/m2. A direct- or alternating current voltage is applied to the electrodes. The precipitate obtained during purifying waste water is supplied to a subsequent process for the recovery of phosphorus. The conductivity of the supernatant after settling or flotation of the precipitate is detected as a measurement variable to obtain a measure for the degree of separation of the ingredients and/or for adjusting the electrical energy per volume of waste water required for the electrolysis. The pollutants accumulated in a contact medium are removed in a subsequent process step, preferably by electrolysis or electrocoagulation.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrodes are made up of iron, aluminum, copper and/or graphite.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Method: The safe treatment of the fuel is ensured and demonstrated by measuring the combustion conditions, preferably temperature, and an alternative fuel is provided until the combustion conditions, preferably combustion temperature are attained in the combustion chamber or the fluidized bed furnace, which allows the safe treatment of the fuel. The waste heat of the exhaust gas stream is provided for heating a reactor (3) for the hydrothermal carbonization of the biomass. The final product from a pressurized reaction volume is supplied with or without a device for adjusting a spraying pressure of a spraying device. Preferred Components: The adjustment of the spraying pressure is carried out by an extender screw pump (1). The spraying device is equipped with a device, with which an effective opening is adjusted, and/or the spraying device comprises at least one nozzle (6), which is switched on and off, respectively.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The additive is mixed in an amount of 1-99%, preferably 10-60% of the biomass. EXAMPLE - No suitable example given.