Effect of reaction temperature and H2/CO ratio on deactivation behavior of precipitated iron Fischer-Tropsch synthesis catalyst

In this paper, a precipitated iron Fischer-Tropsch catalyst was synthesized, which is similar to commercial CNFT-1 catalyst. The effect of reaction temperature and H2/CO feeding ratio on the deactivation behavior were throughly investigated. The results revealed that deactivation rate was significantly affected by the reaction temperature, which showed 15 times of deactivation rate constant operated at 290 ℃ than that at 270 ℃. However, deactivation rate constant had less difference with different H2/CO ratio from 2 to 5. Further characterization results demonstrated that the sintering and surface oxidation of iron carbide crystallite might be the main reason responsible for the deactivation when increased the reaction temperature. An opposite effect of iron carbide oxidizing inhibition and crystallite agglomeration was observed when increasing of H2/CO feeding ratio, which would lead to the slight deactivation of the precipitated iron catalyst.