Experiment And Simulation Of Gas-Liquid-Liquid Three-Phase Reactive Extraction Process For Hydrogen Peroxide Production Via Anthraquinone

The intergrated reactive extraction process of anthrahydroquinone oxidation and hydrogen peroxide extraction was investigated in a sieve plate column with air-organic phase-water three-phase system under pressure. Anthrahydroquinone conversion increased with the increase of operation pressure, but negligible varision in extraction efficiency was observed. Antrahydroquinon conversion increased as a result of increasing gas superficial velocity, while extraction efficiency of hydrogen peroxide reached up a maximum of 72.94%. When the oxygen content in the gaseous phase increased, antrahydroquinone conversion increased but extraction efficiency of hydrogen peroxide decreased. The negative influence of the increasing ratio of superficial velocity of organic phase to aqueous phase on extraction efficiency of hydrogen peroxide was also observed.An equilibrium (EQ) stage model was developed to simulate the gas-liquid-liquid three-phase reactive extraction process considering the effects of pressure and reaction on gas superficial velocity. The simulation data were well consistent with the experiments. The maximal and average relative error for antrahydroquinone conversion was 18.01% and 7.56%, while for extraction efficiency of hydrogen peroxide was 14.23% and 6.95%, reapectively. The simulation results indicated that both antrahydroquinone conversion and extraction efficiency of hydrogen peroxide decreased with increasing superficial velocity of organic phase.A nonequilibrium (NEQ) stage model was also developed for gas-liquid-liquid three-phase reactive extraction process. The maximal and average relative error of antrahydroquinone conversion was 14.21% and 4.41%, while for extraction efficiency of hydrogen peroxide was 9.03% and 4.13%, reapectively. The conclusions were drawn based on the NEQ model simulations. With the increase of pressure, both reactive rate and liquid-liquid mass transfer rate increased, and reaidence time of organic phase unchanged. With increasing gas superficial velocity, both reactive rate and reaidence time of organic phase increased, but liquid-liquid mass transfer rate decreased. With increasing superficial velocity of organic phase, reactive rate and liquid-liquid mass transfer rate increased, but reaidence time of organic phase decreased. Axis diatribution of reactive rate, mass transfer rate, residence time of organic phase, liquid-liquid mass transfer rate, and concentration of hydrogen peroxide in the two liquid phase and the films were simulated using the NEQ model.The hydrodynamics characters of gas-liquid-liquid three-phase system in a sieve plate column were calaculated by Fluent. The average relative error of the holdup of gaseous phase and organic phase was 17.10% and 6.78%, reapectively. The CFD modeling also led to the following conclusions. The increase of gas superficial velocity was propitious to the mass transfer among three phases. The increasing superificial velocity of organic phase and aqueous phase improved the phase distribution in the column, but increased the probability of dead zone. The superficial velocities of each phase sharply increased the turbulence intensity in the column.