Intrinsic kinetics of the Fischer-Tropsch synthesis over an impregnated cobalt-potassium catalyst

Abstract

The optimal amount of 15 wt%Co/10 wt%K/Al₂O₃ catalyst was prepared using the impregnation technique in order to study the kinetics of the Fischer-Tropsch synthesis. The rate of synthesis was measured in a fixed-bed micro reactor with H₂/CO feed ratio of 1–3 and space velocity in the range of 2,700–5,200 h⁻¹ under reactor pressure of 8 bar and a temperature range of 210–240 °C. The experimental data were best fitted by a Langmuir-Hinshelwood-Hougen-Watson (LHHW) approach rate in the form of $- r_{CO} = (k_2 K_1 P_{CO} P_{H_2 } )/(1 + K_1 P_{CO} )$. Furthermore, the data were fitted fairly well by a power law equation in the form of $- r_{CO} = kP_{CO}^{1.32} P_{H_2 }^{1.42}$. The activation energies for LHHW approach model and power law equation were obtained as 138.5 kJ/mol and 87.39 kJ/mol, respectively.