Method for drying and purifying hydrogen-containing gases that arise during electrolytic water splitting with electric current in the form of an oxygen-rich gas and a hydrogen-rich gas, which contain residues of the other gas, the oxygen-rich gas is discharged into the atmosphere or to a consumer, the hydrogen-rich gas is heated in a heater and subjected to an exothermic reaction in a reactor in which the residual oxygen and the hydrogen are converted into water and a hot, moist process gas is formed, then the water from this process gas is removed under excess pressure by adsorption of the water on an adsorbent in at least two through connecting pipes (31,37;38) and switching valves (33,34,35,36;39,40,41,42) connected adsorbers (9,10) until the adsorbent is loaded with water in the respective adsorber (9,10), after leaving the respective adsorber (9,10) the dried process gas is diverted to the consumer via a filter as high-purity hydrogen clean gas in a clean gas pipe and the untreated process gas is transferred to the unloaded adsorber (9,10) for continuing of the loading and at the same time the loaded adsorbent is regenerated by a partial quantity of the clean gas as regeneration gas which is heated to desorption temperature and the heated gas is fed in a regeneration gas pipe counter to the direction of the flow of the respective adsorber (9,10) that is currently being loaded, wherein a control unit switches the adsorber (9,10) into the adsorption phase and regeneration phase or vice versa depending on the loading of the adsorbent and all electrical users are supplied with electricity from the connected power supply via a power line characterized in that the hydrogen-rich gas to be dried and cleaned is divided into a main quantity fed to the reactor for generating the process gas and a secondary quantity for generating a hydrogen-rich heat carrier gas in a secondary reactor, wherein a branched off partial quantity of oxygen-rich gas is supplied into the secondary quantity before entering the secondary reactor, the resulting heat of reaction is stored in a heat accumulator and the heat carrier gas is heated to at least a temperature above the regeneration temperature in the heat accumulator, than the heated carrier gas is fed to a gas-gas heat exchanger for heating the regeneration gas and returned to the main quantity after the heat exchange, and that a gas-booster with frequency converter, which is connected to the regeneration gas pipe, sucks in the partial quantity of the clean gas as regeneration gas and a flow transmitter with an integrated flow computer adjusts the volume flow of the partial quantity by determining a current rotational speed value of the gas-booster as an actual value or as a fixed value via the control unit, which, if the power supply fails, triggers by a switching device a switchover of all electrical power consumer units such as gas-booster, control unit, switching valves (33 to 36; 39 to 42; 46; 52; 58), control valves (17,27) and if necessary the pump, to an internal/external power source for temporary electrical energy supply via the power line, wherein until the end of the regeneration the gas-booster generates a suction flow circulation of the residual gas that is present when the device switched off on the adsorber (9,10) forming clean and desorption gas (D,F), through an internal flow path that passes through the gas pipes (25, 24, 37, 32, 45, 3b, 22, 23, 3a, 18, 31, 38, 25), the adsorber (9,10), the gas-booster, the gas-gas heat exchanger, the secondary reactor /heat accumulator, the reactor, the heat exchanger, separator und filter, the regeneration gas leaving the adsorber (9,10) switched to the regeneration, is heated via the secondary reactor in the heat accumulator, the heated gas is fed to the gas-gas heat exchanger as heat carrier gas for heating the regeneration gas to desorption temperature, and then the heat carrier gas is fed back into the hydrogen-rich gas before entry to the reactor.