Assessment of composition and calcination parameters in Fischer-Tropsch synthesis over Fe–Mn–Ce/γ-Al2O3 nanocatalyst

Ali Akbar Mirzaei,Hossein Atashi,Reza Roknabadi

doi:10.2516/ogst/2020089

Abstract

The effects of nanocatalyst composition and calcination parameters on the performance of the Fe–Mn–Ce ternary nanocatalysts supported on alumina granules in a laboratory fixed bed microreactor have been evaluated. Nanocatalysts were synthesized by incipient wetness impregnation under vacuum method (simultaneous impregnation of metal species). The samples used for hydrogenation of carbon monoxide via Fischer-Tropsch synthesis. The optimum nanocatalyst composition for production of light olefins (C=2 – C=4) from synthesis gas is 75 wt%Fe–20 wt%Mn–5 wt%Ce. The calcination parameters (temperature, time and atmosphere) were investigated and their effects on the structure and performance of the nanocatalysts were determined. The maximum ratio of olefins/(methane + paraffin) and the best activity and selectivity belonged to the nanocatalyst which was calcined in static air at 500 °C for 7 h. The nanocatalyst precursors and calcined samples (fresh and used) were characterized by XRD, N2 physisorption, FE‒SEM, EDAX, MAP, TG, DSC, and H2–TPR. The present study results confirm that the structural, morphological and physic-chemical properties of the nanocatalyst have been impressed with metal species and calcination parameters.

Highlights

Fischer-Tropsch Synthesis (FTS) as a favorite heterogeneous catalytic process for the chemical industry and research teams is the conversion of synthesis gas (H2 + CO) into a mixture of hydrocarbons with the advantages of low content of toxic and carcinogenic pollutants including sulfur and aromatics [1,2,3,4,5,6,7,8,9,10,11]
The results showed that, the sample calcined under air has identified the best selectivity to desired products C1⁄42 À C1⁄44 light olefins
As the 75 wt%Fe–20 wt%Mn–5 wt%Ce/Al2O3 nanocatalyst calcined at 500 °C for 7 h under air atmosphere was selected as the optimal system, so the optimum catalyst phase changes in different modes including precursor, fresh and used calcined were evaluated by X-Ray Diffraction (XRD) technique

Summary

Introduction

Fischer-Tropsch Synthesis (FTS) as a favorite heterogeneous catalytic process for the chemical industry and research teams is the conversion of synthesis gas (H2 + CO) into a mixture of hydrocarbons with the advantages of low content of toxic and carcinogenic pollutants including sulfur and aromatics [1,2,3,4,5,6,7,8,9,10,11]. Iron-based catalysts as affordable choice, are of interest in chemical industries they are suitable for CO-rich synthesis gas due to their activity to water gas shift reaction [11, 20]. Having benefits such as proper selectivity to the light olefins, high CO conversion, and compatibility to the operating conditions has distinguished iron-based catalysts from others [21,22,23].

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Results

Conclusion