(560fc) Multi-Stage Fluidized Bed Technology for Methanol to Aromatic

A three-stage conversion technology was proposed for intensification of methanol to aromatics (MTA) by regional functionalization of fluidized bed reactor. The design is as follows considering the temperature and acidity of catalyst stream as two key factors. The reactivated catalyst from air regenerator was recycled into the middle section of the reactor for the dehydrogenation of alkane and the aromatization of light hydrocarbons (LHTA), in which strong acidity and high temperature were required. Then partial deactivated catalyst from the middle section overflowed into the bottom section for MTA, in which partial loss of acidity would limit hydrogen transfer. And then the top section filled with the olefins alkylation catalyst or olefins aromatization was coupled into the two-step aromatization for deep conversion of olefins. Model Zn/ZSM-5 was used in a three-stage fluidized bed reactor. Mold HZSM-5 chosen as the catalyst of the olefins alkylation was also compared with Zn-ZSM-5 as the catalyst of olefins aromatization in the third stage. Experimental results successfully verified the proposed process. After the three-stage conversion, the aromatics yield increased by at least 10 percentage points in comparison with the one-stage conversion. The final alkenes/alkanes ratio dropped to a small value, showing great advantage in terms of separation process in industry. Multi-stage fluidized bed technology opened a new approach to process intensification of MTA by regional functionalization design of reactor beyond catalyst design.