A device for decreasing hydrogen concentration of a fuel cell system is installed in an exhaust system for discharging exhaust gas which includes hydrogen and air and is discharged from fuel cells to the atmosphere through an exhaust line. The device includes a catalyst diluter having catalysts for diluting the hydrogen in an exhaust gas by generating a catalytic reaction and connected to the exhaust line. An air diluter is disposed outside the catalyst diluter and guides external air to a gas exit side of the catalyst diluter.

A fuel cell system includes an anode configured to output an anode exhaust stream comprising hydrogen, carbon dioxide, and water; and a membrane dryer configured to receive the anode exhaust stream, remove water from the anode exhaust stream, and output a membrane dryer outlet stream. The membrane dryer includes a first chamber configured to receive the anode exhaust stream; a second chamber configured to receive a purge gas; and a semi-permeable membrane separating the first chamber and the second chamber. The semi-permeable membrane is configured to allow water to diffuse therethrough, thereby removing water from the anode exhaust stream. The membrane dryer may further be configured to remove hydrogen from the anode exhaust stream.

A power generation system, includes: a fuel cell that includes a negative electrode supplied with hydrogen-containing gas and a positive electrode supplied with oxygen-containing gas, and is configured to generate electric power by chemical reaction between hydrogen and oxygen; a separator that includes a hydrogen-permselective separation membrane and is configured to obtain permeated gas and non-permeated gas from mixed gas; and a circulating passage through which negative electrode-side exhaust gas of the fuel cell is sent to the separator, and through which the permeated gas is supplied to the negative electrode. The separation membrane includes a porous support layer and a separation functional layer provided on the porous support layer. The separation functional layer contains at least one kind of chemical compound selected from the group consisting of polyamide, graphene, MOF (Metal Organic Framework), and COF (Covalent Organic Framework).

An air supply system for a fuel cell includes: a fuel cell stack in which multiple unit cells are stacked and that generates electricity through chemical reactions, an air channel to supply incoming air containing oxygen to the fuel cell stack and to transfer air discharged from the fuel cell stack to the outside of the air supply system, and a gas adsorption unit that is disposed on the air channel, positioned near an outlet of the fuel cell stack, and adsorbs oxygen contained in the air introduced into the air channel.

A spiral-wound type gas separation membrane element includes a central tube and a laminate wound around the central tube. Laminate includes at least one structure where a feed-side flow path member, a gas separation membrane, and a permeate-side flow path member are superimposed in this order. Permeate-side flow path member has a thickness of 400 μm to 1300 μm. Gas separation membrane is a membrane where a hydrophilic resin composition layer, a porous layer, and a permeate-side surface layer are superimposed in this order. Permeate-side surface layer faces Permeate-side flow path member and has a Young's modulus of 20 MPa to 400 MPa.

A boil-off management system for a cryotank includes a boil-off conduit which is fluidically connectable to a cryotank via a boil-off valve. The boil-off management system further includes an air feed conduit and a mixing chamber for mixing a first medium (e.g., hydrogen) flowing in through the boil-off conduit with a second medium (e.g., air and/or oxygen) flowing in through the air feed conduit. A catalytic converter is arranged downstream of the mixing chamber and an outlet downstream of the catalytic converter. At least one enrichment apparatus is provided and configured to temporarily increase the proportion of the first medium flowing in through the boil-off conduit in relation to the second medium flowing in through the air feed conduit at the catalytic converter.

The present invention relates to a fuel cell humidifier comprising: a humidifying module for humidifying dry gas, supplied from outside, by using wet gas discharged from a fuel cell stack; and a first cap coupled to one end of the humidifying module, wherein the humidifying module comprises a mid-case, and at least one cartridge which is disposed in the mid-case and accommodates a plurality of hollow fiber membranes. The fuel cell humidifier further comprises a first packing member airtightly coupled to at least one end of the humidifying module through mechanical assembly so that the first cap may fluidly communicate with only the hollow fiber membranes, wherein the first packing member tightly adheres to the cartridge by using the pressure of at least one among the dry gas and wet gas.

A bipolar plate for a four-fluid fuel cell includes a nonporous sub-plate and a porous sub-plate. The nonporous sub-plate includes a water management side, an opposing reactant side, and an internal coolant passage therebetween. The porous sub-plate includes a reactant side and an opposing water management side. The reactant side includes a first reactant flow field, and the water management side is fluidly connected to the water management side of the nonporous sub-plate. Embodiments of the invention include a method to operate the four-fluid fuel cell in thermal boost mode, and a method to accumulate and retain product water.

In order to prevent injury from hot exhaust gas, water is condensed by a metal net in the exhaust pipe.

The present specification discloses a membrane reactor comprising a reaction region; a permeate region; and a composite membrane disposed at a boundary of the reaction region and the permeate region, wherein the reaction region comprises a bed filled with a catalyst for dehydrogenation reaction, wherein the composite membrane comprises a support layer including a metal with a body-centered-cubic (BCC) crystal structure, and a catalyst layer including a palladium (Pd) or a palladium alloy formed onto the support layer, wherein ammonia (NH.sub.3) is supplied to the reaction region, the ammonia is converted into hydrogen (H.sub.2) by the dehydrogenation reaction in the presence of the catalyst for dehydrogenation reaction, and the hydrogen permeates the composite membrane and is emitted from the membrane reactor through the permeate region.