Fig. 1 . Schematic diagram of a circulating fluidized bed
scaled-up reactor.
3. Results anddiscussion
3.1 Laboratory scale-up experiment
We used the Fe-Mo/ZSM-5 dual-function catalyst in the
circulating fluidized bed
scaled-up reactor to verify the reaction effect after 3 filling cycles
and continuous feeding under the same reaction conditions(reaction
temperature = 390 °C, methanol/air ratio = 0.5, reaction space velocity
= 15000 h-1). The performance of the Fe-Mo/ZSM-5
catalyst in the micro-reactor and the circulating fluidized bed
scaled-up reactor were compared in Table1. It can be seen from Table 1
that the methanol conversion rate of the three scaled-up reactors is
better than that of the micro fluidized bed reactor. We believe this was
because the regenerated catalyst brings more catalytic active centers
and accelerates the methanol reaction rate. At the same time, the
selectivity decreased for DMM and increased for FA. This was because the
regenerated catalyst brings too many oxidation active centers to promote
the adsorption of more methanol to form methoxy groups, but it is not
desorbed in time for the next polycondensation reaction. Compared with
the micro-fluidized bed reactor, the pilot-scale test results showed a
better conversion rate, indicating that the pilot scale-up experiment of
the process was successful. The yield of DMM was as high as 79.6%,
which is the best reported in the literature so far(as shown in Table
S1). These results indicate that the successful completion of the
laboratory micro-reaction to the pilot scale-up process experiment has
laid a foundation for the in-depth development, popularization and
application of new process technologies.
Table. 1. Catalytic activity of Fe-Mo/ZSM-5 catalyst in micro
fluidized bed and Circulating
fluidized bed scaled-up reactor.