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 reaction apparatus for use in solid carbon production includes a reactor shell defining a reactor inlet and a reactor outlet. Concentric cylinders or substantially parallel plates of catalytic material are disposed within the reactor shell and are structured and adapted to expose at least one contact surface to gaseous reactants. Another apparatus includes a removable cartridge comprising a plurality of substantially parallel plates of catalytic material disposed within the reactor shell. A system for use in carbon nanotube production may include any such reactor and a solids recovery means for removing carbon nanotubes from the reactor.
Abstract:
A method of producing forests of fibrous solid carbon includes providing a catalyst material over a substrate, forming the catalyst material into catalyst nanoparticles, and reacting carbon monoxide with hydrogen in the presence of the catalyst nanoparticles to form forests of fibrous solid carbon attached to the catalyst nanoparticles. A composition of matter includes an inert material disposed upon a substrate, a plurality of nanoparticles of catalyst material upon the inert material, and a plurality of carbon nanotubes upon the nanoparticles. Some methods of producing a forest of carbon nanotubes include preparing a catalyst surface by depositing an inert material onto stainless steel, and depositing iron onto the inert material. The catalyst surface is placed into a furnace chamber, and the furnace chamber is heated. A mixture of hydrogen and carbon monoxide is provided into the furnace chamber
Abstract:
A reactor includes a vessel, a gas inlet, a solid outlet, a catalyst support configured to at least partially retain a catalyst material and allow a tail gas to pass therethrough, and a tail gas outlet. The gas inlet is in fluid communication with the solid outlet. A system for producing a solid product includes a reactor, a compressor, a heater, a make-up reactive gas inlet, and a solids discharge means for removing the solid product from the solid outlet of the reactor. Methods of forming solid products include providing a catalyst material in a vessel having a porous catalyst support, delivering a reactive gas to the vessel, reacting the reactive gas to form a solid product and a tail gas in the vessel, passing the tail gas through a portion of the catalyst material to separate the solid product from the tail gas, and removing the solid product.
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 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:
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 steel 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 steel catalyst for reducing carbon oxides includes placing the steel 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 steel 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 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. The mixture of carbon nanotubes has specific apparently uncommon properties, including unusual resistivity and density
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.