NOVELTY - The device and improved method comprise a process container, which is placed in a coolant container and surrounded by a cooling medium. The boiling point of the cooling medium is selected in the range of the desired process temperature. The cooling is carried out as circulation system. The flow direction is guided only into a direction through devices within the cooling circuit, which is cooled with circulation of the process container by a further cooling device. The excess heat of the exothermic process is temporarily stored and used to heating tracks of the sequence process.    USE - Device and improved method for aqueous carbonization/hydrothermal carbonization of biomass to receive carbonization product.    ADVANTAGE - The device and method ensures simple, efficient and safe carbonization of biomass by uniformly distributing heat in the process container, economically utilizing biomass, reducing the consumption of fossil and nuclear fuels and reducing the emission of carbon dioxide.    DETAILED DESCRIPTION - The device and improved method comprise a process container, which is placed in a coolant container and surrounded by a cooling medium. The boiling point of the cooling medium is selected in the range of the desired process temperature. The cooling is carried out as circulation system. The flow direction is guided only into a direction through devices within the cooling circuit, which is cooled with circulation of the process container by a further cooling device. The excess heat of the exothermic process is temporarily stored and used to heating tracks of the sequence process. Hydrocarbons e.g. alcohol or mixture of hydrocarbons or its mixture with water or silane is used as coolant. Material components or mixture are used for the composition of the coolant surrounding the process container. The excess process heat is taken away and used to heating tracks. The process container is tended by a device and is locked over a fastener per bayonet mechanics. The filling insert is mounted on or in the process container that prevents refloating of the biomass during the introduction of the fluid. An unloading insert is introduced in the process container so that the process container content is easily transportable during emptying the process container. A separate cooling device of the process container is additionally cooled in the case of defects. The separate cooling device is introduced in the process container. The device controls over a back-up electricity supply.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of device and method for aqueous carbonization/hydrothermal carbonization of biomass.    Flange (4)    Closing head (5)    Bayonet tap (6)    Grip (7)    Value detector. (15, 19)