Effect of surface composition of Fe catalyst on the activity for the production of high-calorie synthetic natural gas (SNG)

Abstract

An Fe2O3 catalyst was applied to the production of high-calorie synthetic natural gas (SNG). With this catalyst, the product distribution changed as the surface composition of the Fe2O3 catalyst changed. The effect of these changes on the catalytic activity was investigated. The active phases of the Fe2O3 catalyst were a mixture of low-carbon FeCx and Fe3C, which was maintained for 10 h, accompanied by the regeneration of Fe3O4. The surface Fe concentration increased after 10 h reaction, and this increased the CO conversion. In addition, the amounts of adsorbed C2H4 and C3H6 increased, which resulted in an increase in carbon chain growth. The surface concentration of oxygen also increased due to the regeneration of Fe3O4, thus reducing the C3H6 adsorption strength; in contrast, C2H4 adsorption increased, resulting in an enhanced paraffin-to-olefin (p/o) ratio for C-2 hydrocarbons and reduced p/o ratio for C-3 hydrocarbons.