Electrolyzer and methods of operation of the electrolyzer

The invention relates to an electrolyzer (1) for producing hydrogen and oxygen comprising a one or more parts constructed housing (2) arranged with at least one therein, and toward the interior of the housing (2) sealed electrolysis cell block (5). The electrolysis cell block (5) comprises a plurality of combined in the form of a stack of electrolysis cells (4) having anode and cathode, means being provided for supplying the anode with the anolyte and to supply the cathode with a catholyte liquor circulations. For outgassing of the inside of the electrolytic cells (4) generated oxygen and hydrogen are the electrolysis cell block (5) coupled oxygen separation chamber (29) and a hydrogen separation chamber (28) is provided. According to the invention the electrolysis system pressure comprising oxygen separation chamber (29) and of the electrolysis system pressure comprising hydrogen separation space (28) within the electrolysis cell block (5) are placed. is for supply and discharge of the media involved in the electrolysis, the electrolysis cell block (5) with the housing (2) of the electrolyzer (1) is provided connecting the coupling element (3), and not from the electrolysis cell block (5) the space occupied in the electrolyzer (1 ) is (as a buffer space 8) provided with a buffer fluid, the operating pressure is above the buffer space (8) which is formed can be acted upon with a buffer fluid, the operating pressure is above the electrolysis system pressure.