Effective Co-Al Oxide Catalysts for the Production of Synthetic Liquid Fuels from Natural and Associated Petroleum
We report the improvement of the Co-Al oxide catalysts for the synthesis of liquid hydrocarbons from synthesis gas (process gas-to-liquid) by the Fischer-Tropsch reactions. The synthesis gas (H2: CO> 2) is obtained by oxidative conversion of natural gas, coal and associated gas, peat and biomass with steam. Hydrocarbons obtained by the Fischer-Tropsch synthesis is subjected to processing into petroleum products - diesel fuel and naphtha.
It was known that Co-Al oxide catalysts are obtained by thermal treatment of hydroxo-carbonates of a hydrotalcite-type structure in an inert gas followed by the activation in hydrogen.
Recently in the Boreskov Institute of Catalysis it was found that the use of hydroxo-nitrate-carbonate of hydrotalcite-type structure as a precursor provided improved activity of CoAl catalyst . The method and the conditions of preparation determine the composition of a hydroxo-compound-precursor. The catalysts were prepared by deposition-precipitation of cobalt cations on support, γ- and δ-Al2O3, under the conditions of urea hydrolysis (UCoAl) and by precipitation (PCoAl). Table 1 shows a comparison of catalytic properties in the Fischer-Tropsch synthesis of catalysts prepared from hydroxo-nitrate-carbonates (UCoAl) and hydroxo-carbonate (PCoAl). The diagram shows the composition of hydrocarbon mixture formed.