TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The calcined Fe-containing catalyst may be reduced at elevated temperatures, after calcining. The calcined Fe-containing catalyst is reduced in the presence of a reducing agent, which is hydrogen. The elevated temperature is 800 degrees C or higher. Preferred Components: The Fe-containing catalyst comprises stainless steel, carbon steel, rare earth doped stainless steel, low carbon stainless steel or iron-containing metal alloys. The Fe-containing catalyst is an iron-containing metal alloy with a catalytic activator. The catalytic activator is nickel, molybdenum, ruthenium, tantalum, lanthanide metals or titanium. The Fe-containing catalyst has a high surface area and may be mesh-like, filamentous, perforated or porous. The Fe-containing catalyst is a stainless steel mesh. The molybdenum-nickel (MoNi)-type catalyst is of formula (MoxNiyMgzO). The lanthanum-nickel (LaNi)-type catalyst is of formula (LaxNiyMgzO) (where x = 0.05-0.1, y = 0.01-0.1, and z = 0.8-0.9). (a) is supported on a substrate which displays catalytic activity. The substrate is mesh-like, filamentous, perforated or porous. (a) is supported on stainless steel mesh. The substrate comprises a calcined Fe-containing catalyst.z = 0.4-0.5.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The hydrocarbon gas is contacted with the calcined Fe-containing catalyst at 500-1200 (preferably 800-1100) degrees C. The hydrocarbon gas is contacted with the calcined Fe-containing catalyst at a pressure of 1.75-10 bar. In the process, the catalyst is calcined at a temperature greater than 700 degrees C for one to two hours, prior to bringing the hydrocarbon gas into contact with the Fe-containing catalyst. The calcined Fe-containing catalyst may undergo reduction with methane contained in the hydrocarbon gas concurrently with the catalytic conversion of hydrocarbon gas into hydrogen and solid carbon. The light hydrocarbon is catalytically converted to hydrogen and carbon by contacting the light hydrocarbon with the supported (a) at 400-950 (preferably 500-850) degrees C. The process further comprises contacting the hydrocarbon gas with a catalyst comprising a calcined Fe-containing catalyst and/or (a) supported on a substrate at elevated pressure to catalytically convert the hydrocarbon gas to hydrogen and solid carbon. The solid carbon is generated as graphitic particles. The graphitic particles are readily separated from the supported catalyst. The graphitic particles are recovered in a gaseous stream comprising hydrogen and the graphitic particles. The process comprises the further step of thermally treating the recovered graphitic particles and converting any ambient amorphous carbon material to high quality graphite. The process further comprises providing hydrogen feedstock for ammonia synthesis (Haber process). Preferred Components: The light hydrocarbon is chemical compounds containing only carbon and hydrogen, having a carbon number of 6 or less. The light hydrocarbon is methane. The graphitic particles are substantially spherical or onion-like. The graphitic particles are of substantially uniform size. The graphitic particles have a mean diameter of less than 200 nm. The mean diameter of the spherical graphitic particles is 0.4-4 mu m. EXAMPLE - Mesh 316SS having a 0.16mm aperture and 0.1mm wire diameter was cut into 20x 40mm sections and rolled width-wise. The mesh was then ultra-sonicated in ethanol for 15 minutes and then in distilled water for 5 minutes. Loading syrup was made up by dissolving lanthanum(III) nitrate hexahydrate (2.0563 g), magnesium nitrate hexahydrate (0.0658 g), nickel(II) nitrate hexahydrate (1.1652 g), and cobalt(II) nitrate hexahydrate (0.2926 g) into distilled water (50 ml) at 90 degrees C and 60 revolutions per minute, and once dissolved, citric acid (25 g) was added. The solution was heated until it became syrup-like (approximately 30 ml), and then poured into a large ceramic dish (30 ml) in which 8 meshes were placed, which was the loaded catalyst. The catalyst was placed in a reactor tube and heated to 900 degrees C whilst under the flow of 20 standard cubic centimeters per minute (sccm) of nitrogen for 2 hours. The temperature of the furnace was reduced to 800 degrees C, and methane was passed into the reactor at 1.5 sccm.