Improvement of light olefins selectivity and catalyst lifetime in MTO reaction; using Ni and Mg-modified SAPO-34 synthesized by combination of two templates

Abstract

SAPO-34 catalysts were synthesized by the hydrothermal method using morpholine and/or TEAOH templates. The sample prepared by the combination of TEAOH and morpholine exhibited more crystallinity and smaller particle size. Furthermore, SAPO-34 was modified with Ni and Mg to improve its performance for conversion of methanol to olefin. These catalysts were characterized by XRD, SEM, EDX, BET, FTIR and NH 3-TPD techniques. The catalytic performance of catalysts was studied in MTO reaction at 673 K and atmospheric pressure by a feed WHSV of 8.7 h −1 in a fixed bed reactor. The modified catalysts showed higher selectivity to light olefins and longer lifetime. NiAPSO-34 catalyst showed the best performance; the yield of ethylene and propylene was determined to be 94 wt.% with 100% methanol conversion.