Comparison of Conventional and Two-Zone Fluidized Bed Reactors for Methanol to Olefins. Effect of Reaction Conditions and the Presence of Water in the Feed

The effect of water over the performance of the Methanol-to-Olefins process was studied in a conventional fluidized bed reactor (CFBR) and a two-zone fluidized bed reactor (TZFBR). Both of them contained the same SAPO-34-based catalyst, prepared by agglomeration with bentonite and alumina. In the first section of this paper, the performance was studied in the TZFBR for a wide range of temperatures (350-600 °C, ΔT = 50 °C), and two oxygen concentrations fed to the lower zone (7.5 and 10.8% for 500, 550, and 600 °C). In the second section, a comparison between the performance over the two previously mentioned reactors is presented, followed by a comparison between feeding water or not doing so to the TZFBR. Results showed that the TZFBR increased the initial yield to olefins and the production time of them, an effect that was increased by feeding a mixture of methanol-water (1:1 molar ratio) instead of pure methanol.