Fabrication of attrition-resistant nanostructured catalyst by spray dryer for methanol to light olefins reaction in a fluid bed reactor and coke formation

Abstract

Abstract The aim of this research is to investigate the performance of three micro-spherical sprayed dried samples with SAPO-34 of different particle sizes. Physiochemical properties of the catalysts were identified by XRD, FESEM, EDX, BET and FTIR techniques. Furthermore, TGA and FTIR techniques were implemented to characterize the coke deposition. Methanol to olefins performance tests were carried out to study the activity of the catalysts in fixed bed reactor. The optimized catalyst was also tested in a fluidized bed reactor. The results of XRD analysis exhibit typical SAPO-34 and kaolinite phase for all the three formulated catalysts. It represents the successful spray drying that crystallite structure of the shaped samples by the spray dryer is composed of both kaolinite and SAPO-34 phase. With the comparison of FESEM results of the samples, the larger and more spherical particles are obtained for the sample spray dried with SAPO-34 of the smallest size. Furthermore, rapid diffusion of the products prohibiting subsequent transformations of them to heavier products occurs for the sample shaped with the SAPO-34 having the smallest particle size. Furthermore, the optimal shaped sample showed excellent activity of near 5 h during methanol to olefins reaction in fluidized bed reactor. S-T-TDT-F catalyst which was selected for more studies in fluidized bed reactor has lower coking rate and longer life time. It can be explained in a way that pore blockage and acid sites coverage were postponed in the mentioned catalyst.