Improvement of Catalyst Activity in Methanol-to-Olefin Conversion via Metal (Sr/La) Impregnation over ZSM-5 Catalyst

Abstract

The use of methanol over ZSM-5 and modified catalysts for the production of light olefins has emerged as an effective new strategy for this industry. In the methanol-to-olefin (MTO) process, the challenges are maintaining product selectivity and prolonging the lifetime of the catalyst catalyst manufacturing become.  The effect of strontium (Sr) and lanthanum (La) impregnated over the ZSM-5 catalyst on MTO conversion was investigated in this study. The results showed that the metals impregnated on ZSM-5 had influenced its acidity strength and improved catalyst activity and lifetime in the MTO process. When a metal strontium of 5 wt.% was impregnated, the quantity of Bronsted acid sites (BAS) in the parent ZSM-5 was reduced to 81.53%. The catalyst 5La-ZSM-5 modified improved the selectivity of light olefin ca. 88% and high conversion methanol 100% for 15 h time-on-stream. The sequence of catalyst activity was 5La-ZSM-5 > 3La-ZSM-5 > 5Sr-ZSM-5 > 3Sr-ZSM-5 > parent-ZSM-5. The role of metal (Sr/La) impregnated over ZSM-5 is important for reducing acidity and prolonging activity catalyst from 7 to 14 h.

Keywords

• catalyst lifetime
• impregnated
• lanthanum
• olefin
• strontium