Effect of the Type of the Cobalt-Containing Component of a Composite Catalyst on the One-Stage Synthesis of Liquid Hydrocarbons from СО and Н2

Abstract

The effect of the type of the cobalt-containing component (Со-Al₂O₃/SiO₂, Co-Re/Al₂O₃, and Co-Re/TiO₂) of a composite catalyst on the combined synthesis and hydroconversion of hydrocarbons by the Fischer–Tropsch process are investigated. The catalytic properties of catalyst samples are studied in a flow reactor with a fixed catalyst layer at 2 MPa and GHSV of 1000 h^–1 within a the temperature range of 240–280°С for 40–90 h of continuous operation. The highest values of output and selectivity to C₅₊ hydrocarbons are obtained for composite catalyst Со-Al₂O₃/SiO₂(35%)/ZSM-5(30%)/Al₂O₃(30%) at a temperature of 240°C and are 106 kg/(\({\text{m}}_{{{\text{cat}}}}^{3}\) h) and 67.1%, respectively. It is shown that using Co-Re/Al₂O₃ instead of Со-Al₂O₃/SiO₂ catalyst produces comparable values of catalytic activity, but considerably fewer unsaturated hydrocarbons are found in the products of synthesis. Using Co-Re/TiO₂ catalyst and raising the temperature (to 280°С) shifts the molecular weight distribution of the products of synthesis toward the formation of a gasoline fraction. It is found that the rate of catalyst deactivation grows in the order Со-Al₂O₃/SiO₂ > Co-Re/Al₂O₃ > Co-Re/TiO₂.