NOVELTY - Producing hydrogen comprises electrochemically converting water into hydrogen and oxygen and separating the hydrogen form electrolyte aerosols, depleting hydrogen with electrolyte aerosols, and separating the electrolyte aerosols from the hydrogen in a wet electrostatic precipitator (4) in a hydrogen atmosphere.    USE - The method is useful for the production of hydrogen, preferably for a subsequent methanation process (claimed).    ADVANTAGE - The method ensures simple and cost-effective production of hydrogen using application of wet electrostatic precipitators with hydrogen atmosphere, and avoids the formation of explosive mixtures (oxyhydrogen gas) and the contamination of product gas if ambient air diffuses into hydrogen in case of leakages at the high-voltage isolator of the discharge electrode.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an electrostatic precipitator, for use in a process for producing hydrogen, comprising a housing, a discharge electrode, a collecting electrode, an inlet for water, an inlet for depleted hydrogen, an outlet for water and an outlet for purified hydrogen. INORGANIC CHEMISTRY - Preferred Method: The depleted hydrogen is: passed through the precipitator from bottom to top; and passed through the precipitator counter currently to water sprayed into the precipitator. The depleted hydrogen is introduced into the lower third of the precipitator, preferably through a gas distributor. The oxygen is removed from the hydrogen gas stream in a first catalytic step in the presence of a palladium (Pd) catalyst and where in a subsequent second catalytic step methane is produced from the educts carbon dioxide and hydrogen. The pressure of the inert gas buffer is maintained at a level between the inside pressure of the precipitator and the ambient pressure surrounding the precipitator. The area around the insulation of a discharge electrode is heated. The steam is introduced together with carbon dioxide and hydrogen into the first catalytic step. Preferred Components: The electrolyte is an alkaline electrolyte, preferably potassium hydroxide. INSTRUMENTATION AND TESTING - Preferred Components: The discharge electrode is provided within the precipitator, where the discharge electrode is insulated from the precipitator housing by means of an inert gas buffer. The discharge electrode is insulated from a ceiling of the housing by an inert gas buffer. The pressure detector is provided for measuring the pressure of the inert gas buffer- and/or where a hydrogen analysis system is provided for measuring the hydrogen concentration inside the inert gas buffer. The precipitator (4) is vertically oriented. The gas distributor is provided in the lower third of the housing (41) for introducing the depleted hydrogen. The electrostatic precipitator has precipitation modules each comprising a system of a discharge electrode and a collecting electrode.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic flow sheet of the process.    Electrolyzer (1)    Oxygen withdrawn line (2)    Inlet for depleted hydrogen (3)    Wet electrostatic precipitator (4)    Buffer tank. (5)