Study of preparation methods and their effect on the morphology and texture of SAPO-34 for the methanol to olefin reaction

In our present study, the effects of different parameters on the synthesis of silicoaluminophosphate, SAPO-34, were investigated and the product selectivity and catalytic performance of this catalyst were studied for the reaction of methanol to olefins in a fixed bed reactor. In spite of examining the conventional parameters effective in the hydrothermal preparation of SAPO-34, such as templating agents or mixed templating agents with different ratios, different alumina and silica sources, aging time and hydrothermal reaction in static state, we have investigated the effect of the mixing method and the addition of crystal growth inhibitors on the morphology and particle size of the prepared zeolites. The synthesized catalysts have been characterized with several methods such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, BET and X-ray powder diffraction. Under our experimental conditions, the prepared SAPO-34 has shown better selectivity to propylene, minimum paraffinic byproducts and a higher percentage of total olefins compared to a commercial ZSM-5 catalyst.