The invention relates to a process for the thermal decomposition of ammonia. The process comprises passing ammonia through a conduit which contains an ammonia decomposition catalyst in a part thereof. At least a section of the part of the conduit which contains the catalyst is immersed in molten lead as heat transfer medium, which is at a temperature at which the catalyst is capable of catalyzing the decomposition of ammonia into hydrogen and nitrogen. A reactor for carrying out this process is also disclosed.

A fuel cell and a method for regenerating this fuel cell, including a supply of the fuel cell by the main supply conduit by a fluid having a nominal flow rate and a nominal molar fraction of combustion agent, during a regeneration phase of a given group, a switching of the inlet, outlet and recirculation switches of the fluid circuit so as to supply the given group from the recirculation line of the given group and from a fluid discharge line of at least one other group, an application of a regeneration voltage Ve to the cells of the given group, Ve being less than or equal to 0.3V.

Aspects of methods and systems to reduce degradation of a fuel cell (110) during start-up and shut-down cycles are disclosed. An anode exhaust stream (201′) is periodically directed via fluid communication through an oxygen capture media (86). After shut-down of the fuel cell and before or during start-up said media (86) removes oxygen in the anode exhaust stream. Periodically, heating the oxygen capture media (86) is employed to purge the oxygen collected and regenerate the media.

The present invention relates to a sensor device (10) for a fuel cell system (100) for determining a purging parameter (SP) for controlling a purging process of the fuel cell system (100), comprising a first flow channel (20) for arranging in an anode feed section (122) of an anode section (120) of a fuel cell stack (110) and a second flow channel (130) for arranging in a recirculation section (126) of the anode section (120) of the fuel cell stack (110), which are separated from each other, at least in sections, by means of a gas-tight membrane (40), wherein the membrane (40) is designed to be permeable for protons and has an electrode section (42, 44) on both sides, as well as comprising a measuring device (50) for determining a fuel concentration difference between the first flow channel (20) and the second flow channel (30) as a purging parameter (SP) based on an electrical voltage between the two electrode sections (42, 44).

Disclosed is a hydrogen recirculation ejector for fuel cells including a recirculation line configured to recirculate residual hydrogen gas discharged from a fuel cell stack configured to generate electricity using air and hydrogen gas supplied thereto to an inlet of the fuel cell stack and an ejector including a nozzle installed on the recirculation line, the nozzle being configured to supply new hydrogen gas, a venturi tube configured to mix the hydrogen supplied from the nozzle and the recirculated hydrogen with each other, and a diffuser configured to supply the mixed hydrogen gas to the fuel cell stack, wherein the nozzle includes a hydrogen introduction portion, a ring-shaped inner wall, a ring-shaped outer wall, a ring-shaped front end wall, and a ring-shaped rear end wall, and wherein the thickness of the inner wall and/or the outer wall is gradually increased with increasing distance from the hydrogen introduction portion.

The present invention is a method for producing electricity comprising a fuel cell which makes it possible to valorize the heat given off by the cell to generate fuel for said fuel cell by a process of thermal dissociation, applied to the product of the same chemical composition than that produced by the cell, at least part of the heat given off by the cell being supplied to at least one of the endothermic reactions of said dissociation process.

A method of operating a fuel cell system includes the operating a fuel cell unit, the recovery at the outlet of the fuel cell unit of a carbon dioxide-rich anodic gas flow, the cooling of the anodic gas flow and the condensation of the water present in the anodic gas flow in order to form a dry anodic flow, the introduction of the dry anodic flow into a carbon dioxide capture unit in order to form a carbon dioxide gas flow and a carbon dioxide-depleted anodic flow, the recycling of at least portion of the carbon dioxide-depleted anodic flow into the fuel feed flow.

A fuel cell device (10) comprising a reformer (26) is disclosed, which is provided for reforming fuel (B) for electrochemical conversion in a fuel cell unit (12), and a fuel cell unit (12), which is provided to electrochemically convert reformed fuel (RB). It is proposed to arrange a heat exchanger (40) downstream of the reformer (26) and upstream of the fuel cell unit (12) in relation to a supply of reformed fuel (RB) to the fuel cell unit (12).

A fuel cell system includes a fuel cell stack, a fuel inlet conduit configured to provide a fuel to a fuel inlet of the fuel cell stack, an electrochemical pump separator containing an electrolyte, a cathode, and a carbon monoxide tolerant anode, a fuel exhaust conduit that operatively connects a fuel exhaust outlet of the fuel cell stack to an anode inlet of the electrochemical pump separator, and a product conduit which operatively connects a cathode outlet of the electrochemical pump separator to the fuel inlet conduit.

A fuel cell system includes a fuel cell stack, an anode system apparatus, a control unit, an anode outlet temperature sensor, and a purge valve. In a method of starting operation of the fuel cell system at low temperature, a control unit compares a predetermined freezing temperature threshold value with an anode outlet temperature detected by an anode outlet temperature sensor. Then, the control unit performs low temperature control to place the purge valve in the constantly open state in the case where the temperature is not higher than the freezing temperature threshold value, and performs normal control for switching opening/closing of the purge valve in the case where the temperature exceeds the freezing temperature threshold value.