Abstract: A reactor for producing a solid carbon material comprising at least one reaction chamber configured to produce a solid carbon material and water vapor through a reduction reaction between at least one carbon oxide and at least one gaseous reducing material in the presence of at least one catalyst material. Additional reactors, and related methods of producing a solid carbon material, and of forming a reactor for producing a solid carbon material are also described.

Abstract: Methods and a system for removing carbon nanotubes from a water stream are provided herein. The system includes a purification vessel, wherein the purification vessel is configured to form a carbon oxide from the carbon nanotubes within the water stream.

Abstract: A composition comprising a mixture of carbon nanotubes having a bi-modal size distribution are produced by reducing carbon oxides with a reducing agent in the presence of a catalyst. The resulting mixture of nanotubes include a primary population of multiwall carbon nanotubes having characteristic diameters greater than 40 nanometers, and a secondary population of what are apparently single wall nanotubes with characteristic diameters of less than 30 nanometers. The resulting mixture may also contain one or more other allotropes and morphologies of carbon in various proportions.

Abstract: Methods of forming solid carbon products include disposing a plurality of nanotubes in a press, and applying heat to the plurality of carbon nanotubes to form the solid carbon product. Further processing may include sintering the solid carbon product to form a plurality of covalently bonded carbon nanotubes. The solid carbon product includes a plurality of voids between the carbon nanotubes having a median minimum dimension of less than about 100 nm. Some methods include compressing a material comprising carbon nanotubes, heating the compressed material in a non-reactive environment to form covalent bonds between adjacent carbon nanotubes to form a sintered solid carbon product, and cooling the sintered solid carbon product to a temperature at which carbon of the carbon nanotubes do not oxidize prior to removing the resulting solid carbon product for further processing, shipping, or use.

Abstract: A method of reducing a gaseous carbon oxide includes reacting a carbon oxide with a gaseous reducing agent in the presence of a non-ferrous catalyst. The reaction proceeds under conditions adapted to produce solid carbon of various allotropes and morphologies, the selective formation of which can be controlled by means of controlling reaction gas composition and reaction conditions including temperature and pressure. A method for utilizing a non-ferrous catalyst in a reactor includes placing the catalyst in a suitable reactor and flowing reaction gases comprising a carbon oxide with at least one gaseous reducing agent through the reactor where, in the presence of the catalyst, at least a portion of the carbon in the carbon oxide is converted to solid carbon and a tail gas mixture containing water vapor.

Abstract: A method of reducing a gaseous carbon oxide includes reacting a carbon oxide with a gaseous reducing agent in the presence of an intermetallic or carbide catalyst. The reaction proceeds under conditions adapted to produce solid carbon of various allotropes and morphologies, the selective formation of which can be controlled by means of controlling reaction gas composition and reaction conditions including temperature and pressure. A method for utilizing an intermetallic or carbide catalyst in a reactor includes placing the catalyst in a suitable reactor and flowing reaction gases comprising a carbon oxide with at least one gaseous reducing agent through the reactor where, in the presence of the catalyst, at least a portion of the carbon in the carbon oxide is converted to solid carbon and a tail gas mixture containing water vapor.

Abstract: A method for producing hydrogen, includes heating a process feed gas stream, flowing the process feed gas stream into a first reaction zone, flowing the intermediate gas stream into a second reaction zone, removing the solid carbon product from the second reaction zone, removing the tail gas stream from the second reaction zone, and removing hydrogen from the tail gas stream. The process gas stream includes methane and steam. The first reaction zone contains a first catalyst, and at least a portion of the process feed gas stream is converted into an intermediate gas stream in the first reaction zone. The second reaction zone contains a second catalyst, and at least a portion of the intermediate gas stream is converted into a tail gas stream and a solid carbon product in the second reaction zone.

Abstract: Primary voltaic sources include nanofiber Schottky barrier arrays and a radioactive source including at least one radioactive element configured to emit radioactive particles. The arrays have a semiconductor component and a metallic component joined at a metal-semiconductor junction. The radioactive source is positioned proximate to the arrays such that at least a portion of the radioactive particles impinge on the arrays to produce a flow of electrons across the metal-semiconductor junction. Methods of producing voltaic sources include reacting at least one carbon oxide and a reducing agent in the presence of a substrate comprising a catalyst to form a solid carbon product over the substrate. Material is disposed over at least a portion of the solid carbon product to form a nanofiber Schottky barrier array. A radioactive source is disposed adjacent the nanofiber Schottky barrier array.

Abstract: A method of thermal energy recovery from production of at least one solid carbon material comprises reacting at least one carbon oxide material and at least one gaseous reducing material at a temperature of greater than or equal to about 400° C., at a pressure greater than or equal to about 1×105 pascal, and in the presence of at least one catalyst material to produce at least one solid carbon material and a gaseous effluent stream comprising water vapor. Thermal energy is extracted from the gaseous effluent stream comprising water vapor. Other methods of generating recoverable thermal energy are disclosed, as is a solid carbon production system having thermal energy recovery.

Abstract: Methods of forming solid carbon products include disposing a plurality of nanotubes in a press, and applying heat to the plurality of carbon nanotubes to form the solid carbon product. Further processing may include sintering the solid carbon product to form a plurality of covalently bonded carbon nanotubes. The solid carbon product includes a plurality of voids between the carbon nanotubes having a median minimum dimension of less than about 100 nm. Some methods include compressing a material comprising carbon nanotubes, heating the compressed material in a non-reactive environment to form covalent bonds between adjacent carbon nanotubes to form a sintered solid carbon product, and cooling the sintered solid carbon product to a temperature at which carbon of the carbon nanotubes do not oxidize prior to removing the resulting solid carbon product for further processing, shipping, or use.

Abstract: Methods of concurrently forming ammonia and solid carbon products include reacting a carbon oxide, nitrogen, and a reducing agent at preselected reaction conditions in the presence of a catalyst to form a solid carbon product entrained in a tail gas mixture comprising water and ammonia; separating entrained solid carbon product from the tail gas mixture; and recovering water and ammonia from the tail gas mixture. Systems for forming ammonia and solid carbon products from a gaseous source containing carbon oxides include mixing means for mixing the gaseous source with a reducing agent, reactor means for reacting at least a portion of the gaseous source with the reducing agent in the presence of a catalyst to produce the solid carbon products and a tail gas mixture comprising the ammonia, and solid separation means for separating the solid carbon products from the tail gas mixture.

Abstract: An apparatus for producing solid carbon and water by reducing carbon oxides with a reducing agent in the presence of a catalyst includes a reactor configured to receive reaction gas comprising at least one carbon oxide, at least one reducing agent, and water. The apparatus includes at least one mixing means configured to mix the reagents to form a combined feed, a first heat exchanger configured to heat the combined feed, at least one heater configured to further heat the combined feed, and a reaction vessel configured to receive the combined feed. The reaction vessel is configured to contain a catalyst, to maintain predetermined reaction conditions of temperature and pressure, and has an output configured to deliver a tail gas to the first heat exchanger. The system also includes a product separator, a water separation unit, and a product packaging unit.

Abstract: A reactor for producing a solid carbon material comprising at least one reaction chamber configured to produce a solid carbon material and water vapor through a reduction reaction between at least one carbon oxide and at least one gaseous reducing material in the presence of at least one catalyst material. Additional reactors, and related methods of producing a solid carbon material, and of forming a reactor for producing a solid carbon material are also described.

Abstract: A two-stage reaction process includes reacting gaseous carbon dioxide with a reducing agent to form carbon monoxide and water. At least a portion of the water is condensed to form a dry tail gas. The dry tail gas, with the possible addition of a reducing agent, reacts to convert at least a portion of the carbon monoxide to solid carbon and water. Other methods include reacting a feed gas mixture to form a reaction mixture, condensing water from the reaction mixture to form a dried reaction mixture, mixing the dried reaction mixture with a recirculating gas to form a catalytic converter feed gas mixture, flowing the catalytic converter feed gas mixture through a catalytic converter to form solid carbon and a tail gas mixture containing water, and flowing the tail gas mixture through a heat exchanger.

Abstract: Methods of forming solid carbon products include disposing a plurality of nanotubes in a press, and applying heat to the plurality of carbon nanotubes to form the solid carbon product. Further processing may include sintering the solid carbon product to form a plurality of covalently bonded carbon nanotubes. The solid carbon product includes a plurality of voids between the carbon nanotubes having a median minimum dimension of less than about 100 nm. Some methods include compressing a material comprising carbon nanotubes, heating the compressed material in a non-reactive environment to form covalent bonds between adjacent carbon nanotubes to form a sintered solid carbon product, and cooling the sintered solid carbon product to a temperature at which carbon of the carbon nanotubes do not oxidize prior to removing the resulting solid carbon product for further processing, shipping, or use.

Abstract: Methods of concurrently forming ammonia and solid carbon products include reacting a carbon oxide, nitrogen, and a reducing agent at preselected reaction conditions in the presence of a catalyst to form a solid carbon product entrained in a tail gas mixture comprising water and ammonia; separating entrained solid carbon product from the tail gas mixture; and recovering water and ammonia from the tail gas mixture. Systems for forming ammonia and solid carbon products from a gaseous source containing carbon oxides include mixing means for mixing the gaseous source with a reducing agent, reactor means for reacting at least a portion of the gaseous source with the reducing agent in the presence of a catalyst to produce the solid carbon products and a tail gas mixture comprising the ammonia, and solid separation means for separating the solid carbon products from the tail gas mixture.

Abstract: A method for production of various morphologies of solid carbon product by reducing carbon oxides with a reducing agent in the presence of a catalyst. The carbon oxides are typically either carbon monoxide or carbon dioxide. The reducing agent is typically either a hydrocarbon gas or hydrogen. The desired morphology of the solid carbon product may be controlled by the specific catalysts, reaction conditions, and optional additives used in the reduction reaction. The resulting solid carbon products have many commercial applications.

Abstract: An apparatus for producing solid carbon and water by reducing carbon oxides with a reducing agent in the presence of a catalyst includes a reactor configured to receive reaction gas comprising at least one carbon oxide, at least one reducing agent, and water. The apparatus includes at least one mixing means configured to mix the reagents to form a combined feed, a first heat exchanger configured to heat the combined feed, at least one heater configured to further heat the combined feed, and a reaction vessel configured to receive the combined feed. The reaction vessel is configured to contain a catalyst, to maintain predetermined reaction conditions of temperature and pressure, and has an output configured to deliver a tail gas to the first heat exchanger. The system also includes a product separator, a water separation unit, and a product packaging unit.

Abstract: A reactor for producing a solid carbon material comprising at least one reaction chamber configured to produce a solid carbon material and water vapor through a reduction reaction between at least one carbon oxide and at least one gaseous reducing material in the presence of at least one catalyst material. Additional reactors, and related methods of producing a solid carbon material, and of forming a reactor for producing a solid carbon material are also described.

Abstract: Systems and a method for forming carbon nanotubes are described. A method includes forming carbon nanotubes in a reactor, using a Bosch reaction. The carbon nanotubes are separated from a reactor effluent to form a waste gas stream. The feed gas, a dry waste gas stream, or both, are heated with waste heat from the waste gas stream. The waste gas stream is chilled in an ambient temperature heat exchanger to condense water vapor, forming a dry waste gas stream.