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SAPO-34 zeolite is considered to be an effective catalyst for methanol or dimethyl ether conversion to olefins. In this study,we developed the in situ synthesis technology to prepare SAPO-34 zeolite in kaolin micro-spheres as a catalyst for fluidized methanol or dimethyl ether to olefins process. The silicoaluminophosphate zeolite was first time reported to be synthesized in kaolin microspheres. The SAPO-34 content of synthesized catalyst was about 22% as measured by three different quantitative methods(micropore area,X-ray fluorescence and energy dispersive spectroscopy element analysis) . Most of the SAPO-34 zeolites were in nanoscale size and distributed uniformly inside the spheres. The catalytic performance was evaluated in fixed bed and fluidized bed reactors. Compared with the conventional spray-dry catalyst,SAPO/kaolin catalyst showed superior catalytic activities,bet-ter olefin selectivities(up to 94%,exclusive coke) ,and very good hydrothermal stability. The in situ synthesis of SAPO-34 in kaolin microspheres is a facile and economically feasible way to prepare more effective catalyst for fluidized MTO/DTO(methanol to olefins/dimethyl ether to olefins) process.
SAPO-34 zeolite is considered to be an effective catalyst for methanol or dimethyl ether conversion to olefins. In this study, we developed the in situ synthesis technology to prepare SAPO-34 zeolite in kaolin micro-spheres as a catalyst for fluidized methanol or dimethyl ether to olefins process. The silicoaluminophosphate zeolite was first time reported to be synthesized in kaolin microspheres. The SAPO-34 content of synthesized catalyst was about 22% as measured by three different quantitative methods (micropore area, X-ray fluorescence and energy dispersive spectroscopy element analysis). Most of the SAPO-34 zeolites were in nanoscale size and distributed uniformly inside the spheres. The catalytic performance was evaluated in fixed bed and fluidized bed reactors. Compared with the conventional spray-dry catalyst, SAPO / kaolin catalyst showed superior catalytic activities, bet-ter olefin selectivities (up to 94%, exclusive coke), and very good hydrothermal stability. The in situ synthesis of SAPO-34 in kaolin microspheres is a facile and economically feasible way to prepare more effective catalyst for fluidized MTO / DTO (methanol to olefins / dimethyl ether to olefins) process.