Micro-mixing And Liquid-liquid Mass Transfer Performance Of Rotating Zigzag Bed(RZB) And Its Application

As one of the most concerned about the process intensification technology,high-gravity technology has become one hot direction and the forefront of chemical engineering disciplines.Compared with the conventional rotating packed bed,the rotating zigzag bed has many advantages.Among them,the unique dynamic and static rotor structure is beneficial to improve the end effect area of the liquid inlet,so that it is a great potential for the rotating zigzag bed that has stronger micro-mixing performance and liquid-liquid mass transfer performance in the "mass transfer and molecular mixed limited " chemical reaction to prepare for the chemical applications.For this reason,in this paper,the experiment is carried out from the micro-mixing and liquid-liquid mass transfer enhancement of the rotating zigzag bed.In the depth study and experiment,it is applied to the reinforcement of the condensation process of isovaleraldehyde and acetone for the first time.The main work and achievements of this paper are as follows:1?In this paper,the micro-mixing performance of the RZB was studied by using the iodide-iodate parallel competitive reaction system.The effects of high gravitational factor ??liquid total flow uin?H+ concentration and reactant volume ratio VA / VB on the RZB reactor separation index Xs were investigated.Moreover,the effects of RZB on the separation index Xs were compared with the traditional ordinary mixing device and rotating packed bed(RPB).Experimental result shows that: under the scope of this experiment,the segregation index XS obtained from the rotating zigzag bed experiment is between 0.01 and 0.05,which shows the superior micro-mixing performance compared with the traditional conventional hybrid reactor.In addition,the results also show that the micro-mixing performance of the RZB reactor is better than that of the RPB reactor.2?The properties of physical extraction mass transfer of the rotating zigzag bed(RZB)were studied by using soybean oil-isopropanol-water as experimental system.The effects of the main operating parameters such as the high gravitational factor ?,liquid total flow uin and the water-oil two-phase volume flow ratio ? on the extraction efficiency ? were investigated.In order to further explore the quantitative relationship between the mass transfer performance and the micro-mixing performance of the RZB,experiments of the extraction mass transfer and micro-mixing on the RZB were carried out under the same experimental system and operating conditions.Experimental result indicates that: compared with the traditional extraction mixing device,extraction mass transfer performance of the rotating zigzag bed is more excellent.RZB reactor which shows excellent micro-mixing characteristics can make the droplet size instantly reach the micron level and strengthen the mass transfer process of physical extraction effectively.In the rotating zigzag bed(RZB)reactor,the extraction mass transfer performance is closely related to its micro-mixing performance.Under the experimental operating conditions,when the super-gravitational factor ? gradually increased to 263,the separation index Xs decreased to 0.020,the corresponding extraction efficiency ? gradually increased to 94.2%.The extraction efficiency ? increases with the decrease of the segregation index Xs,which indicates that the mass transfer effect of the reactor is improved with the increase of the micro-mixing effect of the reactor,but there is no linear relationship between the two.3?The production process of methylheptenone was carried out by aldol condensation reaction with isovaleraldehyde and acetone,and the rotating zigzag bed reactor was used to strengthen the reaction process.The effects of the operation conditions,such as the high gravitational factor ?,the reaction temperature T,the alkali concentration ?and the amount of isovaleraldehyde and acetone on the yield of methylheptenone Y were investigated in order to obtain the optimum operating conditions.In order to further determine the molecular structure of methylheptenone,the target product methylheptenone(MHK)was further characterized by 1H-NMR,13 CNMR and GC-MS.Experimental result indicates that: compared with the traditional conventional strengthening device,RZB reactor can effectively strengthen isovaleraldehyde and acetone aldol condensation reaction.The optimum operating conditions were determined: the amount of alkaline catalyst was set to 40% of the material,the circulating flow rate was 150 L / h,the appropriate temperature and the ratio of isopentyrone acetone were controlled,when the concentration of basic catalyst is 4.2% and the high gravitational factor is 263,the conversion of isopentaldehyde is 88.6%,the selectivity and yield of methylheptenone are 93.3% and 82.7%,respectively.Compared with the effect of mechanical agitation under the same operating conditions,the conversion of isovaleraldehyde in RZB was increased by 20% and the selectivity was increased by 30%.