Study of Methanol Conversion to Olefin and Study of Lanthanum Loading and Si/Al Ratio Parameters on HZSM-5 Catalyst

Document Type : Research Article


1 Chemical Engineering Department, Sirjan Branch, Islamic Azad University Sirjan,, I.R. IRAN

2 Mechanical Engineering Department, University of Hormozgan, Bandar Abbas, I.R. IRAN


Recently, catalytic technologies for the conversion of methanol to olefins have been very much considered. In the present paper, the effect of lanthanum loading parameters and Si/Al ratios at different temperatures on the catalytic function of HZSM-5 in the methanol-olefin conversion process was investigated. In this paper, the catalytic base of HZSM-5 with different Si/Al ratios was modified using the lanthanum metal and wet impregnation method. After loading of lanthanum metal by wet impregnation, the modified catalysts were subjected to XRD, SEM, BET, and FT-IR analysis for accurate determination of their specification and evaluation. The results of XRD and FT-IR analysis showed that the addition of lanthanum metal to HZSM-5 zeolite did not cause structural damage. The structure after the addition of lanthanum metal still had high crystallinity. The design of the Box-Behnken test was used to investigate the effect of lanthanum parameters, Si/Al ratio, and temperature, and investigate the effect of interactions between them for the production of ethylene and propylene in the methanol-olefin process. For this purpose, loading of lanthanum in the range of 0-10% by weight, the Si/Al ratio in the range of 180-160 °C, and temperature in the range of 350-450 °C were used as input variables of the Box-Behnken method. Using the results of the design of the Box-Behnken test, it was found that the highest ethylene yield was achieved on a catalyst that was at the highest level of loading of lanthanum, low Si/Al ratio and high temperature. For optimum propylene production, there was an optimal mode for three variables: Si/Al ratio, temperature, and loading rate of lanthanum, which initially increased the propylene yield and then decreased with increasing of these variables.


Main Subjects

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