Molten carbonate direct carbon fuel cell systems and methods

A direct carbon fuel cell system comprising:

• a plurality of fuel cells, each fuel cell comprising a porous fuel cell anode and a fuel cell cathode;
• a molten carbonate electrolyte;
• a fuel supply apparatus for flowing a fuel slurry comprising solid carbon particles and a carbon carrier fluid to the fuel cell anodes in parallel, wherein the carbon carrier fluid has a same composition as the molten carbonate electrolyte;
• an oxidant supply apparatus for flowing an oxygen-containing stream to the fuel cell cathodes in parallel;
• and
• an electrolyte circulation apparatus for circulating the molten carbonate electrolyte in contact with each of the plurality of fuel cells,
• wherein, 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,
• wherein each of the fuel cells further comprises an electrolyte flow field chamber interposed between the fuel cell anode and the fuel cell cathode, and a cathode flow field chamber separated from the electrolyte flow field chamber by the fuel cell cathode, wherein the oxidant supply apparatus is configured to flow the oxygen-containing stream into the cathode flow field chambers in parallel, and wherein the fuel supply apparatus is configured to flow the fuel slurry into the electrolyte flow field chambers in parallel, and
• wherein the fuel supply apparatus is further configured to circulate the fuel slurry through the electrolyte flow field chambers whereby, in each of the plurality of fuel cells, after the fuel slurry has been urged through the electrolyte flow field chamber, the fuel slurry is urged into the porous fuel cell anode so that at least some of the solid carbon particles contact the porous fuel cell anode and at least some of the carbon carrier fluid passes through the thickness of the porous fuel cell anode into an electrolyte return chamber, and at least some of the carbon carrier fluid exits the electrolyte flow field chambers via an outlet in the respective electrolyte flow field chamber.