Study On Anthraquinone Hydrogenation In Gas-Liquid-Solid Circulating Fluidized Bed

Experiments were performed in air-anthraquinone working solution-γ/Al₂O₃ particles system to the study effects of operation conditions on hydrodynamics parameters. Gas holdup increased with the increase of superficial gas velocity and superficial slurry velocity. But superficial gas velocity had more obvious effects than the superficial slurry velocity. An empirical correlation was developed to account for the gas holdup through experimental data. Axial solid distribution was studied with different superficial flow velocities. The sedimentation-dispersion model was used to describe the axial solid distribution. The maximum relative error between simulated value and experimental value was 11.68%, and the average relative error was 5.75%. The bubble rise velocity was investigated. The results showed that bubble rise velocity increased with increasing superficial gas velocity, but decreased with increasing solid concentration. Liquid circulation rate increased with increasing superficial gas velocity. Particle distribution was studied. Along the bed height, the particle distribution changed with superficial gas velocity.Hydrogenation reaction in hydrogen-anthraquinone-Pd/γ-Al₂O₃ particles three-phase system was studied. The experimental results showed that both ethylanthraquinone(EAQ) conversion and H₂O₂ space time-yield both increased with increasing superficial gas velocity and with increasing reaction temperature. Catalyst stability was analyzed in reaction time. The reaction feature in three phase fluidized bed was studied by catalyst characterization, such as XPS, XRD, SEM.Two models were used to simulate hydrogenation in three phase fluidized bed with the gas phase assumed to be in plug flow, and the liquid phase in plug flow (P-P model) or in back-mixed flow (P-M model). Comparison between calculated and experimental results showed that P-M model was more accurate than P-P model. And the influences of different parameters on reactor performance were investigated based on P-M model. The gas concentration along the bed was studied. The preference temperature of the reaction was between 60⁷0℃. EAQ conversion and H₂O₂ space time-yield both increased with increasing superficial gas velocity.