A multi-stage fluidized bed strategy for the enhanced conversion of methanol into aromatics

• Published in: Chemical engineering science Vol. 204; pp. 1 - 8
• Main Authors: Chen, Zhaohui, Hou, Yilin, Yang, Yifeng, Cai, Dali, Song, Wenlong, Wang, Ning, Qian, Weizhong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 31.08.2019
• Subjects: Aromatization; Dehydrogenation; Methanol; Multi-stage fluidized bed; Paraffins; ZSM-5 zeolite; Paraffins; Aromatization; ZSM-5 zeolite; Dehydrogenation; Multi-stage fluidized bed; Methanol
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2019.04.013

•A three-stage fluidized bed strategy was proposed to enhance methanol to aromatics.•Different temperatures were used to convert methanol or intermediates in different stages.•Aromatics yield increased step by step, independently of catalyst deactivation of catalysts over time. A three-stage fluidized bed strategy was proposed to enhance the conversion of methanol into aromatics (MTA) with Zn/ZSM-5 catalyst, where the 1st stage (near the bottom) served the aromatization of methanol, the 2nd stage (in the middle) served the aromatization of C3-C5 paraffins and the 3rd stage (near the exit) served mainly the aromatization of C2-C4 olefins in sequence. The yield of aromatics in the 2nd stage increased by 7.0–9.0% compared with the 1st stage. And the final yield of aromatics at the exit of 3rd stage was kept at 62–66% for a long time, 8.0–15.0% higher than that of the exit of 1st stage. The effect of coke deposition in different stages on the evolution of aromatics, olefins and alkanes was investigated to clarify the consecutive reaction chain during MTA. As fully meeting the requirements of the different conversion characteristics of methanol and their intermediates, very high-yield production of aromatics by the single-pass conversion of methanol was achieved with this strategy.