Qunsheng Li

Modeling of the solubility of solid solutes in supercritical CO2 with and without cosolvent using solution theory

In this work, regular solution theory was applied to study the solubility of solids in a supercritical fluid (SCF) with and without cosolvent, and a new model for binary and ternary systems was proposed. The activity coefficient can be obtained from the model and the solubility can then be calculated easily. For a binary system there are two adjustable parameters and for a ternary system, four adjustable parameters; the parameters are related to the interactions between molecules in solution. The proposed model was compared with the HSVDW1 and HSVDW2 models. The calculated results show that the proposed model is more accurate, and the AAD for the three models is 4.5%, 7.9% and 18.5%, respectively. The model was further used to correlate the solubility data of 2-naphthol in SC CO2 with and without cosolvent measured by us before, and the overall AAD is 3.23%.

An Equilibrium Model for the Correlation of the Solubility of Solids in Supercritical Fluids with Cosolvent

Solubility of solids in supercritical fluids was studied by chemical association reaction method in this work, where both cases of with and without cosolvent were considered. Based on the thermodynamic and association reaction equilibrium theories, a model for the solubility of solids in supercritical fluids under association reactions was developed, which reduces to normal solubility calculation model when there are no cosolvent and association reactions. The model was tested with the experimental data collected from the literature, and the results show that it is more accurate than other models.

Tray Efficiency in the Air-Water-Solid System without Reaction and Its Application

This work deals with the investigation of tray efficiency with the gas-liquid-solid three phases and its application in the suspension catalytic distillation (SCD) process. The experimental data of tray efficiency under different conditions were measured by utilizing the desorption of oxygen dissolved in water by air. A method of estimation of tray efficiency for the gas-liquid-solid three phases was put forward and its suitability was also verified. This method was developed on the basis of the AIChE method for gas-liquid two phases. As an application example of this modified AIChE method, the SCD process for synthesizing cumene, based on equilibrium stage (EQ) model incorporating tray efficiency, was simulated.

Isobaric vapor-liquid equilibrium for methanol+benzene+1-octyl-3-methylimidazolium tetrafluoroborate

Isobaric vapor-liquid equilibrium (VLE) data for {methanol (1)+benzene (2)+1-octyl-3-methylimidazolium tetrafluoroborate (3)} where 3 is an ionic liquid ([OMIM]+[BF4]−) at atmospheric pressure (101.32 kPa) were measured with a modified Othmer still. The results showed that the ionic liquid studied can transfer the azeotropic point and eliminate the azeotropic phenomena when its concentration is up to x3=0.30. This means that [OMIM]+[BF4]− can be used as a promising entrainer in the application of extractive distillation. The measured ternary data were correlated using the NRTL model.

High purity separation of eutectic mixtures in a continuous moving crystal bed column crystallization

This paper presents new experimental results on the separation of an o -dichlorobenzene/ p -dichlorobenzene mixture in a continuous moving crystal bed crystallization column under the top-fed operation mode. Local concentration distributions of the binary eutectic mixture were investigated as a function of the feed composition, reflux ratio, crystal bed height, and internal stirring speed. It is demonstrated that the key factor that is decisive to the separation capability of column crystallization is the reflux ratio. The experiments showed that product purities can easily exceed 99.0% over a wide range of feed compositions, 68–94 wt%, reflux ratios, 1.0–4.7, and crystal bed heights, 200–900 mm within a column of 50 cm i.d.