Abstract: An apparatus to decompose a hydrocarbon reactant into a gaseous product and a solid product includes a reactor volume, a reservoir of liquid material, a plurality of nozzles connected to the reservoir of liquid material, the plurality of nozzles configured to distribute the liquid material into the reactor volume from the reservoir as a liquid mist, a gas inlet connected to a hydrocarbon gas source to receive hydrocarbon gas reactant, a distributor connected to the inlet to distribute the hydrocarbon gas reactant into the reactor volume, a heat source located adjacent the reactor volume configured to heat the reactor volume, a separator to separate the solid product from the liquid material, a re-circulation path connected between the reactor volume and the reservoir to re-circulate the liquid material from the reactor volume to the reservoir, a gas outlet connected to the reactor volume configured to outlet hydrogen gas from the reactor volume, and at least one filter connected to the gas outlet to remove en

Abstract: A redox flow battery may include: a positive half-cell comprising a catholyte; a negative half-cell comprising an anolyte; and an ion permeable membrane, wherein the ion permeable membrane separates the catholyte and the anolyte, and wherein the catholyte, the anolyte, or both comprise a low-transition temperature material comprising: a redox-active phase; and an ionically conducting organic salt.

Abstract: Systems comprising a carbon fiber reactor for fabricating carbon fiber, the reactor comprising a receptacle for containing a carbon-metal melt, and a plurality of nozzles through which a plurality of menisci are formed by the carbon-metal melt for contact with a carbon seed to fabricate the carbon fiber; and a heater for heating the carbon-metal melt.

Abstract: A method for producing a homogenous molten composition and a fluid product is disclosed. For example, the method includes producing a first molten metal composition in an enclosed volume, contacting a hydrocarbon reactant with the first molten metal composition, decomposing the hydrocarbon reactant into at least one fluid product and carbon, forming a metal alloy from a mixture of the carbon and the first molten metal composition, and separating a homogenous second molten composition from the metal alloy.

Abstract: A method for producing a homogenous molten composition and a fluid product is disclosed. For example, the method includes producing a first molten metal composition in an enclosed volume, contacting a hydrocarbon reactant with the first molten metal composition, decomposing the hydrocarbon reactant into at least one fluid product and carbon, forming a metal alloy from a mixture of the carbon and the first molten metal composition, and separating a homogenous second molten composition from the metal alloy.

Abstract: Systems comprising a carbon fiber reactor for fabricating carbon fiber, the reactor comprising a receptacle for containing a carbon-metal melt, and a plurality of nozzles through which a plurality of menisci are formed by the carbon-metal melt for contact with a carbon seed to fabricate the carbon fiber; and a heater for heating the carbon-metal melt.

Abstract: An apparatus to decompose a hydrocarbon reactant into a gaseous product and a solid product includes a reactor volume, a reservoir of liquid material, a plurality of nozzles connected to the reservoir of liquid material, the plurality of nozzles configured to distribute the liquid material into the reactor volume from the reservoir as a liquid mist, a gas inlet connected to a hydrocarbon gas source to receive hydrocarbon gas reactant, a distributor connected to the inlet to distribute the hydrocarbon gas reactant into the reactor volume, a heat source located adjacent the reactor volume configured to heat the reactor volume, a separator to separate the solid product from the liquid material, a re-circulation path connected between the reactor volume and the reservoir to re-circulate the liquid material from the reactor volume to the reservoir, a gas outlet connected to the reactor volume configured to outlet hydrogen gas from the reactor volume, and at least one filter connected to the gas outlet to remove en

Abstract: Methods comprising: contacting a carbon fiber seed to a carbon-metal melt, drawing the carbon fiber seed to form a carbon fiber. And, systems and apparatuses comprising: a carbon fiber reactor for fabricating carbon fiber, the reactor comprising a receptacle for containing a carbon-metal melt, and a plurality of nozzles through which a plurality of menisci are formed by the carbon-metal melt for contact with a carbon seed to fabricate the carbon fiber.

Abstract: A method to decompose a hydrocarbon reactant into a gaseous product and a solid product includes generating a mist of a liquid material within a reactor volume, heating the reactor volume, introducing a hydrocarbon reactant into the reactor volume to produce a solid product and a gaseous product, separating the solid product from the liquid material, removing the solid product and gaseous product from the reactor volume, and recirculating the liquid material be re-introduced to the reactor volume.

Abstract: A system for hydrocarbon decomposition comprising a reactor volume, a mechanism to distribute the liquid catalyst as a liquid mist, a distributor to distribute a hydrocarbon reactant, a heat source, a separator to separate the solid product from the liquid catalyst, a re-circulation path and mechanism to re-circulate the liquid catalyst, and an outlet for at least one gaseous product. A system to distribute a liquid to an enclosed volume as a mist has a plurality of orifices designed to break the liquid into a mist. A method to decompose a hydrocarbon reactant includes generating a mist of a liquid catalyst, heating the reactor volume, introducing a hydrocarbon reactant into the reactor volume to produce a solid product and a gaseous product, separating the solid product from the liquid catalyst, removing the solid and gaseous products from the reactor volume, and recirculating the liquid catalyst to the reactor volume.

Abstract: A method for producing a homogenous molten composition and a fluid product is disclosed. For example, the method includes producing a first molten metal composition in an enclosed volume, contacting a hydrocarbon reactant with the first molten metal composition, decomposing the hydrocarbon reactant into at least one fluid product and carbon, forming a metal alloy from a mixture of the carbon and the first molten metal composition, and separating a homogenous second molten composition from the metal alloy.

Abstract: A redox flow battery may include: a positive half-cell comprising a catholyte; a negative half-cell comprising an anolyte; and an ion permeable membrane, wherein the ion permeable membrane separates the catholyte and the anolyte, and wherein the catholyte, the anolyte, or both comprise a low-transition temperature material comprising: a redox-active phase; and an ionically conducting organic salt.

Abstract: An electrochemical stack includes a solid electrolyte membrane as one of the components of a membrane electrode assembly. The membrane may have been formed during stack assembly via an in situ reaction.

Abstract: Methods comprising: contacting a carbon fiber seed to a carbon-metal melt, drawing the carbon fiber seed to form a carbon fiber. And, systems and apparatuses comprising: a carbon fiber reactor for fabricating carbon fiber, the reactor comprising a receptacle for containing a carbon-metal melt, and a plurality of nozzles through which a plurality of menisci are formed by the carbon-metal melt for contact with a carbon seed to fabricate the carbon fiber.

Abstract: An electrochemical device suited to modifying a carbon dioxide concentration in an interior space includes a cathode chamber with an inlet which receives a feed gas containing carbon dioxide. A reduction catalyst layer in the cathode chamber reduces carbon dioxide in the gas to form an ionic carrier species. An anode chamber with an outlet outputs a gas comprising carbon dioxide. A solid electrolyte membrane spaces the anode chamber from the cathode chamber and transports the ionic carrier species between the cathode chamber and the anode chamber. The membrane includes an ionic liquid. An oxidation catalyst layer in the anode chamber oxidizes the ionic carrier species to form carbon dioxide. A voltage source provides a voltage difference across the membrane.

Abstract: A system comprises a first electrode, an electrolyte membrane, and a second electrode. The first electrode is configured to reduce oxygen in a gas to an oxygen carrier ion at an intermediate temperature. The electrolyte membrane is configured to transport the oxygen carrier ion, and the second electrode is configured to oxidize the oxygen carrier ion to an oxygen molecule. Oxidation of the oxygen molecule consumes less than four electrons.

Abstract: Methods comprising: evaporating a catalyst source to produce a catalyst gas; condensing the catalyst gas to produce a catalyst vapor comprising catalyst droplets suspended in a gas phase; and contacting the catalyst vapor with a hydrocarbon gas to catalyze a decomposition reaction of the hydrocarbon gas into hydrogen gas and carbon. And, systems comprising: a catalyst source evaporator that provides a first stream to a reactor; a hydrocarbon source that provides a second stream to the reactor; a cooling column coupled to the reactor via a third stream comprising hydrogen, catalyst liquid, solid carbon, optionally catalyst gas, and optionally unreacted hydrocarbon gas such that the cooling column receives the third stream from the reactor; and wherein the cooling column has effluent streams that include (a) a fourth stream that comprises hydrogen and optionally catalyst gas and (b) a fifth stream that comprises catalyst liquid.

Abstract: Methods comprising: evaporating a catalyst source to produce a catalyst gas; condensing the catalyst gas to produce a catalyst vapor comprising catalyst droplets suspended in a gas phase; and contacting the catalyst vapor with a hydrocarbon gas to catalyze a decomposition reaction of the hydrocarbon gas into hydrogen gas and carbon. And, systems comprising: a catalyst source evaporator that provides a first stream to a reactor; a hydrocarbon source that provides a second stream to the reactor; a cooling column coupled to the reactor via a third stream comprising hydrogen, catalyst liquid, solid carbon, optionally catalyst gas, and optionally unreacted hydrocarbon gas such that the cooling column receives the third stream from the reactor; and wherein the cooling column has effluent streams that include (a) a fourth stream that comprises hydrogen and optionally catalyst gas and (b) a fifth stream that comprises catalyst liquid.

Abstract: A method for producing a homogenous molten composition and a fluid product is disclosed. For example, the method includes producing a first molten metal composition in an enclosed volume, contacting a hydrocarbon reactant with the first molten metal composition, decomposing the hydrocarbon reactant into at least one fluid product and carbon, forming a metal alloy from a mixture of the carbon and the first molten metal composition, and separating a homogenous second molten composition from the metal alloy.

Abstract: A method for transporting nitride (N3?) ions in an electrochemical cell includes providing nitrogen to a first side of a solid electrolyte membrane to form nitride ions and transporting the nitride ions across the solid electrolyte membrane. The solid electrolyte membrane includes a metal nitride. The method may be used for ionically-mediated separation and/or compression of nitrogen or to form ammonia.