Mass Transfer Characteristics Of Gas-Liquid In A Slurry Bubble Column Reactor Under High Temperature And High Pressure

Slurry Bubble Column Reactor(SBCR)has been widely used in petrochemical, metallurgical, environmental, such as Fischer-Tropsch synthesis, LPMeOH, LPDME and so on. It offers many advantages over other multiphase reactors — simple construction, no mechanically moving parts, good mass transfer properties, high thermal stability, low energy supply and hence low construction and operation costs understood. So SBCR has become one of the most promising multiphase reactors. It has enormous significance and potential application value to study mass transfer of bubble column. Mass transfer characteristics affect reaction rates and product distribution for chemical processes. Thus, they play an important role in designing and scaling-up the slurry bubble column reactors.According to the characteristic of p-xylene oxidation reactor, A slurry bubble column reactor operating with water and organic liquid under high temperature and high pressure was set up. The effects of temperature, pressure, superficial gas velocity, solid concentration and diameter of reactors on the volumetric mass transfer coefficients using dynamic method are studied systematically. Moreover, the gas holdup and bubble rise velocities are measured using dynamic gas disengagement technique, which is used to calculate and estimate the Sauter mean bubble diameter and the gas-liquid interfacial area. Experimental study has resulted in the following conclusions:Gas-liquid volumetric mass transfer coefficients increase with the increase of system pressure, temperature and superficial gas velocity, and decrease with the increase of solid concentration under the ranges of temperature (293K~473K), pressure (1.0Mpa~3.0Mpa), gas velocity (0.03m/s~0.1m/s) and solid concentration (0%(w)~20%(w)). For different reactors, values in bigger reactor are slightly larger than those in smaller one. values are much more affected by pressure, superficial gas velocity and solid concentration, but less by temperature. However, values are much more affected by temperature, solid concentration, but less by pressure and superficial gas velocity. Based on analysis of the experimental data, two experiential correlations for predicting values of gas in different liquids are obtained.For Air-water- arenaceous quartz system: For gas- paraffin- arenaceous quartz system:In this paper, mass transfer characteristics are illustrated on the disciplinarian of hydrodynamics, which makes us understand mass transfer deeply in mass transfer behaviors of SBCR under high temperature and high pressure. The results of the experiment can provide some basic data to the design and scale-up of SBCR.