Abstract: The bipolar plate is thinner because it includes in a single plane all of the channels (21) for circulation of the oxidiser, the fuel and the coolant fluid (41). The feed plate, which is preferably made of a composite material, has on each of its faces (1A, 1B) a network of channels for the circulation either of oxidiser or fuel, which are supplied through feed apertures (2, 3) passing through the plate. Refrigeration is achieved by means of feed apertures (4) feeding into one or more refrigeration channels (41) positioned between the parts of the circulation channels (21) for the oxidiser or the fuel. Possible through passages (43) allow these different channels to pass from one face to the other so as to organise the circulation and the removal of these three fluids. It is thus possible to distribute the oxidiser and the fuel to both sides of the plate, while also arranging its refrigeration. Application to fuel cells of average and high power.

Abstract: The invention makes it possible to provide a seal at the level of the contact between each membrane-electrode element (1) with the supply plates (10). Sealing means produced either by means of a densification layer (20) or by means of a microporous material for forming the diffusion layers (3B, 4B), are arranged in the diffusion layers (3B, 4B) of the anode (3) and the cathode (4), respectively, opposite the open surface of the cooling channel (15) of each supply plate (10). Application in PEM fuel cells.

Abstract: The bipolar plate is thinner because it includes in a single plane all of the channels (21) for circulation of the oxidiser, the fuel and the coolant fluid (41). The feed plate, which is preferably made of a composite material, has on each of its faces (1A, 1B) a network of channels for the circulation either of oxidiser or fuel, which are supplied through feed apertures (2, 3) passing through the plate. Refrigeration is achieved by means of feed apertures (4) feeding into one or more refrigeration channels (41) positioned between the parts of the circulation channels (21) for the oxidiser or the fuel. Possible through passages (43) allow these different channels to pass from one face to the other so as to organise the circulation and the removal of these three fluids. It is thus possible to distribute the oxidiser and the fuel to both sides of the plate, while also arranging its refrigeration. Application to fuel cells of average and high power.

Abstract: A process is described for the catalytic cracking of ammonia present in a fluid containing hydrogen sulphide, in which the fluid is introduced into a reactor comprising a suitable catalyst and a catalytic cracking effluent is recovered. The temperature in the reaction zone is 1000.degree. C. to 1400.degree. C. and a reactor for carrying out the process comprises at least one heating chamber (3, 4) and at least one catalysis chamber (11) in which the ammonia is cracked without cracking the hydrogen sulphide. In a further variation, the reactor comprises at least one catalyst in the spaces defined between the heating elements.