A method for replenishing an electrolyte of a molten carbonate fuel cell stack includes: preparing an electrolyte colloidal solution containing 10% to 20% of the electrolyte and having a viscosity of 200 to 800 Pa.Math.s; replenishing the electrolyte of the cell stack using the electrolyte colloidal solution prepared in step 1 to allow the electrolyte to adhere to an electrode and an internal channel of the cell stack; discharging excess electrolyte colloidal solution in the cell stack; and drying and discharging water or an organic solvent in the cell stack under an inert gas condition to complete replenishment of the electrolyte of the cell stack, and performing a discharge performance test.

The present disclosure generally relates to systems and methods for operating a fuel cell system including a three-port differential pressure switch in a recirculation loop of the fuel cell system comprising a blower and an ejector. A sensor in the three-port differential pressure switch is activated when a pressure ratio of a first pressure difference and second pressure difference exceeds a threshold ratio.

Systems and methods are provided for improving the operation of molten carbonate fuel cells that include cathode current collector structures that have reduced contact area with the cathode in order to create increased cathode open surface area. Molten carbonate fuel cells that have cathode collectors with reduced contact area with the cathode can have an increased tendency to suffer structural difficulties during operation, such as formation of gaps between electrolyte and one or both electrodes. Use of a sintered anode in such a fuel cell can reduce or minimize the impact of such structural difficulties. The sintered anode can provide higher pore volume and/or a more stable pore structure and/or increased structural stability in a fuel cell that includes a cathode collector that has a reduced contact area with the cathode. This can maintain a more stable interface between the cathode and electrolyte and/or between the anode and the electrolyte.

There is described a direct carbon fuel cell system. The system includes fuel cells, each fuel cell having a porous fuel cell anode and a fuel cell cathode. The system further includes a molten carbonate electrolyte and a fuel supply apparatus for flowing a fuel slurry having carbon particles and a carbon carrier fluid to the fuel cell anodes in parallel. The carbon carrier fluid has a same composition as the molten carbonate electrolyte. An oxidant supply apparatus flows an oxygen-containing stream to the fuel cell cathodes in parallel. An electrolyte circulation apparatus circulates the molten carbonate electrolyte in contact with each of the fuel cells. During operation of the direct carbon fuel cell system to generate electric power, carbon is oxidized at the fuel cell anodes to produce carbon dioxide, and at the fuel cell cathodes oxygen and carbon dioxide react to produce carbonate ions.

A caulk composition includes: at least one powder component and at least one binder component. The powder component is a ball-milled powder component comprising ceria, zirconia, alumina, or a combination thereof. The powder component is a heat-treated powder component that has been heated to a temperature of at least 1500° C. The powder component is present in a concentration range of 65 wt % to 75 wt % of the caulk composition. The powder component has a particle size distribution of 95% less than 25 μm and 90% greater than 1 μm. The binder component is present in a concentration range of 25 wt % to 35 wt % of the caulk composition.

A steam methane reformer-integrated fuel cell system includes: at least one fuel cell including: an anode, a cathode, and an electrolyte matrix separating the anode and the cathode; an anode gas oxidizer (AGO) configured to receive anode exhaust gas from the at least one fuel cell and a preheated air stream such that the anode exhaust gas reacts with the preheated air stream to produce a high-temperature exhaust stream, and configured to provide the high-temperature exhaust stream to the cathode of the at least one fuel cell; and a steam methane reformer configured to utilize heat from the high-temperature exhaust stream output from the AGO and to react methane with steam to produce a first product stream including hydrogen (H.sub.2), carbon dioxide (CO.sub.2), and carbon monoxide (CO).

A reformer assembly includes a vortex tube receiving heated fuel mixed with steam. A catalyst coats the inner wall of the main tube of the vortex tube and a hydrogen-permeable tube is positioned in the middle of the main tube coaxially with the main tube. With this structure the vortex tube outputs primarily Hydrogen from one end and Carbon-based constituents from the other end. In some embodiments a second vortex tube receives the Carbon output of the first vortex tube to establish a water gas shift reactor, producing Hydrogen from the Carbon output of the first vortex tube.

A carbon dioxide recovery system for collecting carbon dioxide from an exhaust gas generated in a facility including a combustion device includes: a first exhaust gas passage through which the exhaust gas containing carbon dioxide flows; a fuel cell including an anode, a cathode disposed on the first exhaust gas passage so that the exhaust gas from the first exhaust gas passage is supplied to the cathode, and an electrolyte transferring, from the cathode to the anode, a carbonate ion derived from carbon dioxide contained in the exhaust gas from the first exhaust gas passage; and a second exhaust gas passage diverging from the first exhaust gas passage upstream of the cathode so as to bypass the cathode. A part of the exhaust gas is introduced to the second exhaust gas passage.

A steam methane reformer-integrated fuel cell system includes at least one fuel cell having an anode, a cathode, and an electrolyte matrix separating the anode and the cathode. The system further includes a steam methane reformer configured to react methane with steam to produce a first product stream including hydrogen (H.sub.2), carbon dioxide (CO.sub.2), and carbon monoxide (CO).

A fuel cell system for removing carbon dioxide from anode exhaust gas includes: a fuel cell having an anode configured to output an anode exhaust gas comprising hydrogen, carbon monoxide, carbon dioxide, and water; an anode gas oxidizer; and an absorption system configured to receive the anode exhaust gas, the absorption system including: an absorber column configured to absorb the carbon dioxide from the anode exhaust gas in a solvent and to output a resultant gas comprising hydrogen and a hydrocarbon that is at least partially recycled to the anode; and a stripper column configured to regenerate the solvent and to output a carbon dioxide-rich stream. The anode gas oxidizer is configured to receive and oxidize an anode gas oxidizer input stream and at least a portion of the carbon dioxide-rich stream. The anode gas oxidizer input stream comprises a portion of the anode exhaust gas.