Process for processing carbon material

Abstract

This invention relates to a process for the preparation of fibrous carbon which comprises contacting a metallic catalyst with a carbon-containing gas at elevated temperature, characterized in that said catalyst is a porous metal comprising a transition metal or an alloy thereof.

1 . A process for the preparation of fibrous carbon which comprises contacting a metallic catalyst with a carbon-containing gas at elevated temperature, characterized in that said catalyst is a porous metal comprising a transition metal or an alloy thereof.  
     
     
         2 . A process as claimed in  claim 1  wherein said catalyst is particulate.  
     
     
         3 . A process as claimed in  claim 1  wherein said catalyst is a Raney metal.  
     
     
         4 . A process as claimed in  claim 1  wherein said catalyst comprises an element selected from Ni, Co and Fe.  
     
     
         5 . A process as claimed in  claim 1  wherein said catalyst is particulate with a mode particle size of 1 to 300 μm.  
     
     
         6 . A process as claimed in  claim 1  wherein said catalyst forms part of the surface of a metal article.  
     
     
         7 . A process for the production of fibrous carbon which comprises contacting a particulate catalyst comprising a transition metal or an alloy thereof with a carbon-containing gas at elevated temperature, characterized in that said gas comprises natural gas.  
     
     
         8 . A process for the production of particulate carbon by contacting a carbon-containing gas with a transition metal catalyst at elevated temperature, which process comprises selecting the temperature and gas pressure at which gas:catalyst contact occurs so as to produce particulate carbon having a desired ration of graphitic to amorphous carbon.  
     
     
         9 . A process for the preparation of carbon nanofibres which comprises contacting a catalyst for carbon nanofibre production with a carbonaceous gas, characterized in that said gas comprises methane and carbon monoxide in a mole ratio of from 1:99 to 99:1.  
     
     
         10 . A process for the preparation of carbon nanofibres which comprises in a first stage contacting a catalyst for carbon nanofibre production with a first carbonaceous gas at a first temperature for a first time period and subsequently containing said catalyst with a second carbonaceous gas at a second temperature for a second time period, characterized in that said first gas has a lower hydrogen mole percentage than said second gas, said first temperature is lower than said second temperature, and said first period is shorter than said second period.  
     
     
         11 . A process as claimed in  claim 7  wherein said catalyst is a porous metal comprising a transition metal or an alloy thereof.  
     
     
         12 . A process as claimed in  claim 1  wherein said catalyst-comprises a leached intermetal.  
     
     
         13 . A process as claimed in  claim 1  wherein said catalyst comprises at least one of nickel, iron and cobalt.  
     
     
         14 . A process as claimed in  claim 1  wherein said gas comprises methane.  
     
     
         15 . A process as claimed in  claim 1  wherein said temperature is in the range 350 to 1200° C.  
     
     
         16 . A process as claimed in  claim 1  wherein the catalytically produced carbon product is further treated or formulated.  
     
     
         17 . A process as claimed in  claim 16  wherein said carbon product is fragmented.  
     
     
         18 . A process as claimed in  claim 16  wherein said carbon product is compacted.  
     
     
         19 . A process as claimed in  claim 16  wherein said carbon product is treated to reduce the metal content thereof.  
     
     
         20 . A carbon article formed from carbon generated in a process as claimed in  claim 1 .  
     
     
         21 . An article comprising a metal substrate bearing on a surface thereof carbon generated in a process as claimed in  claim 1 .  
     
     
         22 . An article as claimed in  claim 21  in the form of a hydrogen reservoir.  
     
     
         23 . A metal catalyst comprising particles of a carbon-containing metal having deposits of carbon on the surfaces thereof, prepared by exposure of said metal to a gas comprising methane and/or carbon monoxide for a period of 1 to 60 minutes at a temperature of 400 to 600° C. and a pressure of 5 to 10 bar, said gas containing less than 2% mole of hydrogen.