A consecutive‐competitive reaction system for assessing homogeneous and heterogeneous liquid–liquid mixing efficiency

Self Cite

Mixing of two immiscible liquids consists of two sections that are liquid-liquid dispersion and mass transfer intraphase or interphase. It plays a crucial role in the liquid-liquid heterogeneous reactions. Here, the liquid-liquid heterogeneous mixing efficiency in RPB reactor is experimentally assessed by a consecutive-competitive chemical probe system. The diameters of dispersed phase droplets in RPB were measured and a correlation to predict the mean diameters were obtained. Based on the dispersed phase size and mass transfer characteristic, a model for predicting the segregation index of liquid-liquid heterogeneous mixing in RPB was established with a deviation <20%. Based on this model, the characteristic time of liquid-liquid heterogeneous mixing in RPB is determined to be in the range of 0.01-1 s. RPB exhibits a great process intensification potential for heterogeneous mixing process.chemical probe, heterogeneous mixing, mass transfer, rotating packed bed | INTRODUCTIONUsually, mixing plays an important role on the reaction results. When two miscible liquids mix within a fully developed turbulent reactor, the fresh feedstock is first dispersed to segregation mass at macroscale and mesoscale, and then the size of unmixed blobs of fluid is reduced by breakage and deformation. When the aggregates are reduced to the size equal to Kolmogorov length scale λ k (usually 10-100 μm), the mixture quickly reaches the molecular scale by viscous deformation and molecular diffusion. 1 The above process can be divided into three typical scales that are macromixing, mesomixing, and micromixing, respectively. 2 However, in the heterogeneous mix-

Section: Methodsmentioning

confidence: 96%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Liquid‐liquid heterogeneous mixing efficiency in a rotating packed bed reactor

Zhang

Wang

et al. 2022

Self Cite

Image‐based measurement of engulfment vortex to quantitatively assess micromixing efficiency in a gas–liquid stirred tank

Huang,

Duan,

Feng

et al. 2023

Micromixing in reactors is typically characterized by chemical test reactions. A novel image‐based measurement system of engulfment vortex (IMEV system) is developed to assess the micromixing efficiency. Over 2000 vortices were recognized from images captured under various experimental cases, and key frames for their formation, engulfment and dissipation were identified. Inspired by the engulfment model (i.e., E model), this work quantified the micromixing time and local turbulent energy dissipation rate with the vortex lifetimes. The micromixing time obtained through the IMEV method is comparable to its value estimated by the micromixing model and segregation index of the test reaction, with a deviation of less than 20%. In turbulent gas–liquid systems, bubbles play a dual role on the local micromixing due to frequent disturbance and phase interface limitation. To summarize, this work offers an alternative approach for micromixing studies and provides valuable insights into dispersed phase effects on the micromixing efficiency.

Mechanism and kinetics investigation of reaction network: 1,3‐Dichloro‐2‐propanol with alkali to prepare epichlorohydrin

Zhang,

Zhu

et al. 2023

Self Cite

Dehydrochlorination of 1,3‐dichloropropanol with alkali is a key step to industrially produce epichlorohydrin. But there are many side reactions involved in the synthesis process. In this work, a complete mechanism and kinetics investigation of the related reaction network was constructed. Density functional theory simulation method was first used to simulate the possible reactions so as to confirm the reaction mechanism and simplify the reaction network. Based on the simulation results, the complex reaction network was simplified into a three‐step consecutive reaction. The kinetic parameters of the three consecutive steps, including the order of the reaction, the pre‐exponential factor, and activation energy, were experimentally determined by conductance and other methods. All the experimental results are basically consistent with the simulation. The obtained kinetics data provide a basis for epichlorohydrin synthesis process optimization.