摘要:
Carbon-nanotube arrays, yarns, films and composites, and the methods for preparing the same are provided. The substrate used is non-flat and has a radius of curvature of at least about 10 μm. The length of the carbon-nanotube yarns and films is at least about 1 cm. The method for preparing the carbon-nanotube composites includes the step of contacting a carbon-nanotube yarn or film with a polymer.
摘要:
The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 μm in length. The carbon nanotube agglomerates, ranged between 1˜1000 μm, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20˜800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.
摘要:
The present application provides multistage and multilayer reactors useful for the efficient and continuous production of carbon nanotubes and methods of using the apparatus in the preparation of carbon nanotubes. In one aspect, the multistage reactors include an array of interconnected fluidized-bed reactors. The multilayer reactors include a plurality of reaction zones.
摘要:
The present application provides multistage and multilayer reactors useful for the efficient and continuous production of carbon nanotubes and methods of using the apparatus in the preparation of carbon nanotubes. In one aspect, the multistage reactors include an array of interconnected fluidized-bed reactors. The multilayer reactors include a plurality of reaction zones.
摘要:
The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 μm in length. The carbon nanotube agglomerates, ranged between 1˜1000 μm, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20-800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.
摘要:
Powder catalysts that comprise particles of chemical compounds of Au and Cu deposited on acid-washed carbon-based supports are effective catalysts in ethyne hydrochlorination to produce vinyl chloride monomers (VCMs). They give a high selectivity and productivity of VCM and decreased amounts of the byproducts of chloroethane, dichloroethane and others. Thiocyanates are used as complexing agents to extend the catalyst lifetime. The activity of the catalyst is enhanced by doping nitrogen atoms into the support.
摘要:
The present invention provides a fluidized bed reactor and its use for producing olefins from oxygenates, the fluidized bed reactor comprises: a reaction zone located in the lower portion of the fluidized bed reactor and comprising a lower dense phase zone and an upper riser, wherein the dense phase zone and the riser are connected with each other transitionally; a separation zone located in the upper portion of the fluidized bed reactor and comprising a settling chamber, a fast gas-solid separation means, a cyclone and a gas collecting chamber, wherein the riser extends upwardly into the separation zone and is connected at its outlet with the inlet of the fast gas-solid separation means, the fast gas-solid separation means is connected at its outlet with the inlet of the cyclone via a fast gas passage, the cyclone is connected at its outlet with the gas collecting chamber, and the gas collecting chamber is located below the reactor outlet and connected therewith; and a catalyst recycle line for recycling the catalyst from the settling chamber back to the dense phase zone, a catalyst withdrawl line for withdrawing the deactivated catalyst from the settling chamber and/or the dense phase zone to the catalyst regeneration means, and a catalyst return line for returning the regenerated catalyst from the catalyst regeneration means to the dense phase zone.
摘要:
The present invention provides a fluidized bed reactor and its use for producing olefins from oxygenates, the fluidized bed reactor comprises: a reaction zone located in the lower portion of the fluidized bed reactor and comprising a lower dense phase zone and an upper riser, wherein the dense phase zone and the riser are connected with each other transitionally; a separation zone located in the upper portion of the fluidized bed reactor and comprising a settling chamber, a fast gas-solid separation means, a cyclone and a gas collecting chamber, wherein the riser extends upwardly into the separation zone and is connected at its outlet with the inlet of the fast gas-solid separation means, the fast gas-solid separation means is connected at its outlet with the inlet of the cyclone via a fast gas passage, the cyclone is connected at its outlet with the gas collecting chamber, and the gas collecting chamber is located below the reactor outlet and connected therewith; and a catalyst recycle line for recycling the catalyst from the settling chamber back to the dense phase zone, a catalyst withdrawl line for withdrawing the deactivated catalyst from the settling chamber and/or the dense phase zone to the catalyst regeneration means, and a catalyst return line for returning the regenerated catalyst from the catalyst regeneration means to the dense phase zone.
摘要:
A method and apparatus for measuring the gas amounts adsorbed on a powder which directly measures pressure changes in a gas supply chamber with the use of differential pressure sensors between the gas supply chamber and a reference chamber which gas amount is maintained constant. Calculations of the gas amounts adsorbed are based on the pressure changes in a sample cell and the pressure changes in the gas supply chamber or a gas reference chamber. The method and apparatus of this invention measures the adsorption or desorption isotherm or gas uptake at constant pressure curve of a powder with, as compared with presently available measurement techniques, increased accuracy and resolution. The experimental data can be analyzed to obtain information on the surface area, pore size distribution, pore volume, pore structure and diffusion coefficient of the powder.