A Comparative study of catalytic activity and lifetime of novel micro-meso porous catalysts in MTO process

Recently, two kinds of mesoporous catalysts with high propylene selectivity in propane dehydrogenation (PDH) process has been successfully synthesized. The first proposed catalyst is SAPO-34 molecular sieve with hierarchical tuned nanostructure. The second catalyst is a novel bi-phase SAPO-34/ZSM-5 zeolite hierarchical composite utilized with TPA-SAPO-34 exchanged core cystals being wrapped by ZSM-5 zeolite particles. In this contribution, the physico-chemical properties of the catalysts were analyzed by XRD, FESEM and N2 adsorption-desorption techniques and their catalytic activity and life time were investigated in MTO process. The results show that hierarchical SAPO-34 has a significant lifetime and selectivity to the light olefins compared with SAPO-34/ZSM-5. It shows a full conversion of MeOH during the first 200 min of reaction while composite sample conversion starts under 90 % and decreases during the time. However the deactivation phenomenon is hindered by using core-shell catalyst; hence the robustness can be named as a privilege employing composite zeolitic catalysts.