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In this study, the mass transfer and reaction kinetics of soybean oil epoxidation using concentrated hydrogen peroxide in a formic acidautocatalyzed reaction system were studied in detail. Studying the mass transfer of formic acid showed that the influence of reactant diffusion near the interface is eliminated when the stirring rate is > 120 rpm in a double-stirred cell, and the mass transfer rate decreases greatly with the conversion of double bonds and a decrease of reaction temperature. A temperature increase has little impact on the equilibrium of formic acid in the oil/water system, while an increase of epoxidized soybean oil significantly increases the value of the partition coefficient of formic acid. Another important aspect in the kinetic study is the decomposition of performic acid, which can cause the reduction of H 2 O 2 and formic acid during the reaction. Finally, a biphasic model, which considers all reactions in oil and aqueous phases, the equilibrium and mass transfer of reagents and products between the phases, and the evolution of proton concentrations with time, was developed to describe the epoxidation process.

Isobaric vapor-liquid equilibrium (VLE) data were measured for three ternary systems containing ionic liquids (ILs): water + 2-propanol + 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF 4 ]), water + 1-propanol + [emim][BF 4 ], and water + 1-propanol + 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF 4 ]). The measurements were performed at P ) 100 kPa and at several constant IL mass fractions. Activity coefficients of the volatile components were obtained without the need of a thermodynamic model of the liquid phase. The effect of the ILs on the relative volatility of the volatile components was depicted separately by their effect on the activity coefficients. Results of the activity coefficients showed that [emim] + has a stronger interaction with water than [bmim] + ; however, it has a weaker interaction with 1-propanol or 2-propanol. Boiling temperature data were also measured at 100 kPa for the six binary systems containing ILs. Ternary VLE data were also calculated from binary NRTL parameters, which were obtained from correlations of the binary boiling temperature data.

Vapor−liquid equilibrium (VLE) data were measured for the ternary system water (1) + ethanol (2) + 1-hexyl-3-methylimidazolium chloride ([hmim]Cl) (3) at p = 100 kPa. Six sets of complete T, x, y data were reported. While the mole fraction of ethanol on an ionic liquid (IL)-free basis was fixed, respectively, at 0.1, 0.2, 0.4, 0.6, 0.8, and 0.98, measurements were performed in a way in which the IL mass fraction varied from 0.8 to 0.1, in an interval of 0.1. The NRTL equation was used for correlation and was revealed as adequate for the ternary system in the experimental composition range. The quality of correlation appeared to be sensitive to the parameters used for water + ethanol. The ternary VLE behavior was also modeled by correlation of two data sets, in which the ethanol mole fraction on an IL-free basis is, respectively, at 0.1 and 0.98. In this way, the six data sets were reproduced satisfactorily, with root-mean-square deviations of 0.49 K for temperature and 0.0042 for vapor phase mole fraction. Owing to the regular distribution of the experimental compositions, the feasibility of the correlation−prediction procedure was graphically presented, and in some sense visualized, in terms of relative volatility, activity coefficient, and bubble temperature, showing good agreement between experiment and calculation.

Developed from rotating zigzag bed (RZB), the counterflow concentric-ring rotating bed uses a rotor composed of stationary–rotating discs, a set of concentric circular rotating rings with perforations, and a liquid distribution at the eye of the rotor, preserving the outstanding characteristics of RZBs consisting of intermediate feeding and multirotors coaxially installed in series in a casing. A mass-transfer model was proposed from which the local gas- and liquid-side mass-transfer coefficients, gas–liquid effective interfacial area, and height equivalent to theoretical plate (HETP) can be calculated. Total reflux distillation experiments were conducted in a counterflow concentric-ring rotating bed at atmospheric pressure using an ethanol–water system, and the mass-transfer end effects were also investigated. The experimental values of overall volumetric gas-side mass-transfer coefficient and HETP agree with the calculated values very well. Obvious end effects exist in the distillation process, and a correlation which takes inner and outer end effects into consideration is given. Compared with RZB, the counterflow concentric-ring rotating bed has lower mass-transfer efficiency, but it has gas–liquid throughput at least 5.576 times greater than that of RZB. Compared with rotating packed bed, the concentric-ring rotating bed has a much higher local gas-side mass-transfer coefficient.

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