Formulated Mn-promoted SAPO-34/kaolin/alumina sol micro-size catalyst with a superior performance for methanol to light olefins conversion in a fluidized bed reactor

Formulation of zeolite molecular sieves powder is necessary to prepare an excellent micro-size catalyst for methanol conversion to light olefins (MTO) in a fluidized bed reactor. In this work, new fluidizable micro-meso pore catalysts were successfully fabricated by spray drying a slurry containing Mn(x) SAPO-34 powder, kaolin filler, alumina sol binder, and HCl additive. A mixed template of TEAOH/morpholine with different amounts of Mn ion was used in primary gel during hydrothermally synthesis of the crystals. The catalytic samples were characterized utilizing different methods. A moder-ate acidity reached by catalyst formulation using kaolin and alumina sol as well as through Mn incorpo-ration into the chabazite cages was helpful for MTO performance of the final shape-selective catalyst in terms of selectivity to light olefins and lifetime. The enhancement effect of Mn promoter on ethylene pro-duction was much more than propylene because of entering Mn to the micro-pores and imposing restric-tion on heavier hydrocarbons diffusion. The uniformity and crystalinity were also appeared to be enhanced once Mn(0.05) was introduced into the gel composition. The suggested spray dried catalyst was SD-Mn(0.05)SAPO-34 (70-120 lm) in which provided a superior selectivity up to 88.4% to light ole-fins and catalytic lifetime of 330 min in a fluidized bed reactor at 450celcius, WHSV = 4 h(-1), and X-MeOH = 0.75 in the feed. (c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.