EFFECT OF POTASSIUM ON CARBON DEPOSITION CHARACTERISTICS OF IRON-BASED CATALYST DURING DIRECT CONVERSION OF SYNGAS TO LIGHT OLEFINS

Abstract

Abstract: The catalyst samples with different K/Fe atomic ratios were prepared by doping K on the ferric hydroxide precipitate, denoted as Kn/Fe (n represents 0, 0.02, 0.04, 0.40, 0.80 and 1.00, respectively) and characterized by XRD, FT-IR, Raman, TG-DTG, and element analysis. The effects of K/Fe on carbon deposition characteristics and reaction activity were investigated. The results show that the addition of potassium can improve the performance for CO hydrogenation to light olefins and increase the selectivity of C2=~C4=. The best K/Fe atomic ratio in this paper is n=0.04. However, excessive addition of potassium have an opposite effects. The addition of potassium is more advantageous to the generation of graphite like coke which may leads to decrease the activity and the stability of the catalyst. Meanwhile, with the increase of K/Fe atomic ratio, the amount of carbon deposition increases gradually, and the level of fat and H/C mole ratio in coke is increased.

Key words: Fe/K atomic ratio, carbon deposite, syngas, light olefins

CLC Number:

References

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