Effect of the Composition of Gas Medium during Catalytic Pyrolysis of Methane on the Morphology of Carbon Deposit
E. A. RAISKAYA, S. S. SIGAEVA, P. G. TSYRULNIKOV, G. V. PLAKSIN
Institute of Hydrocarbons Processing, Siberian Branch of the Russian Academy of Sciences, Ul. Neftezаvodskаya 54, Omsk 644040 (Russia)
Keywords: волокнистый углерод, пиролиз метана, резистивный катализатор, фехраль, fibrous carbon, methane pyrolysis, resistive catalyst, Fechral
Abstract
Effect of the nature of the inert component of the gas phase (argon, nitrogen, helium) on the morphological features of deposited carbon during methane pyrolysis on the resistive catalyst (Fechral coil heated with electric current) was studied. It was shown that fibrous carbon in the form of multiplayer tubes is formed on Fechral surface during the catalytic pyrolysis of methane in mixture with argon at a temperature ≥1050 °C, Both ordered carbon fibres of different diameters with a metal particle situated at the end of the fibre and dispersed carbon deposited from the gas phase are observed in reactor walls. In methane-nitrogen mixture, carbon fibre obtained on Fechral surface is composed of oval formations; each of them consists of narrowing and broadening concentric carbon layers embedded into each other. Carbon fibres formed in helium are distinguished by less defective surface and the smallest diameter in comparison with the fibres obtained in argon and in nitrogen. It is stressed that the growth of carbon fibres proceeds mainly into the space between the coils along which the current passes into different directions.
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