The employment of Valentin-Guiochon equation in the chromatographic slope method has been studied. Results of the thirteen binary systems studied show that predictions of vapor-liquid equilibria depend not only on whether the experimental temperature is around the boiling point of the solute or not, but also on the selection of excess Gibbs energy model. Satisfactory prediction results can be obtained at 0-5.5℃ below the boiling point of the solute for UNIQUAC, while, for the Wilson equation, it will be 3-5℃ below the boiling point of the solute if multiple roots do not show up. When multiple roots do appear, the least root will be one of the pair of parameters which can give the satisfactory vapor-liquid equilibr ium prediction.

LLE (liquid-liquid equilibria) data have been determined for the n-butyl alcohol-water-butyl acetate ternary system and the related binary systems at20℃, 30℃ and 40℃. The experimentally determined LLE data for the n-butyl alcohol-water binary system have been found to be in satisfactory agreement with available literature data. The correlation and prediction of the LLE data have been done by using NRTL and UNIQUAC models. The model parameters of binary systems have been identified with a thermodynamic criterion. In the correlation of ternary LLE data, two objective functions (mole fraction and distribution constant) have been used for purpose of comparison. The effect of weighting in the first objective function has been examined. In predicting the ternary LLE with different sets of parameter values obtained for each of the constitutent binary systems, improved prediction results have been obtained by comparing the results of different combinations of the sets of parameter values and choosing those giving the best results.

In order to employ stripping urea melt to react with NaCl- to produce soda, the phase diagram of the Na+, NH4+/HCO3-, Cl-, (NH2)2CO-H2O system has been studied. In comparison with Na+, NH4+/HCO3-, Cl-, H2O system, the amout of water involved is much less for the urea saturated system. At the NaHCO3-NH4HCO3-NH4Cl saturated point, if there is no urea present, Na-uti-lization coefficient UNa = 83.1%. However, when saturated with urea, UNa= 85.80%. The NaHCO3 mother liquor contains 8.30 moles of water for one mole of NH4C1 in urea free system and contains 5.80 moles of water in urea saturated one. Therefore, 30% of H2O evaporation load would be saved for producing the same quatity of NH4Cl in urea saturated system. As urea wouldset out together with the ammonium chloride, consumption of steam for evaporation would be much less. For the purpose of separating the urea-NH4Cl compound fertilizer from the NaHCO3 mother liquor, it is necessary to investigate the phase diagram of the(NH2)2CO-NaCl-NH4Cl-H2O system at different temperatures.Experiments conducted show that at both 35℃ and 100℃, no double salts are formed, while at 25℃, solid phase of (NH2)2CO. NaCl. H2O is being observed. A NaHCO3-urea-NH4Cl production process is, thereby, being proposed, and a material balance calculation has been made. Theoretically speakly, with this process, for every ton of soda, produced 4.462 tons of urea-NH4Cl compound fertilizers may be produced simultaneously, and the fertilizer thus obtained contains 42.0%N, with 14% in NH4C1 included.

In this paper, a pseudo one-dimensional model comprising different coaxial mixing is proposed and used to study the liquid phase mixing in packed columns. The model parameters are estimated by the optimal method of nonlinear programming, and the equivalent mixing coefficient is regressed in a dimensionless equation.

A two-dimensional model involving both radial and axial mixing under the condition of steady tracer injection from a point source is presented. The model parameters are estimated by the optimal method of nonlinear programming, using the two dimensional RTD experimental data obtained in a. one meter diameter packed column. Dimensionless equations for the evaluation of axial and radial Peclet numbers are regressed.

Studies on the kinetics of extracting copper from chloride medium (CuCl2-NaCl-HCl)with HS-LIX65N(Escaid 100 as the diluent)in a Lewis cell was carried out. In this article, the effect of the different compositions of the two phases on the extraction rate of copper was studied. Considering that the controlling regime of copper extraction in such a system was the interfacial chemical reaction related with adsorption and de-sorption, our experimental results indicated that the formation of 1 - 2 complex (i. e., CuR2), was the controlling reaction step, and species of CuCl+ were the main extracted species under the experimental conditions employed. Theoretical analysis led to the development of the following model: where, [RH]i - concentration of species at the interface; a- The activity of species in the bulk phase. The average deviation of computed results from experimental data were found to be 5.29% only.

The kinetics of stripping copper from loaded HS-LIX 65N with NaCl-HC1 solution was carried out in a Lewis cell. Experimental results showed that the stirring speed of agitators in the two phases did not seem to have any significant effect on the stripping rate of copper. However, the stripping rate of copper was apparently almost proportional to the interfacial area between the two phases. In addition a relatively high value of apparent activation energy was apparent for the stripping process, featuring interfacial chemical reaction characteristics. Mathematical models were developed with experimental results obtained of which a typical one was given below: where, concentration was expressed in mol/l, and computational deviation was found to be around 0.5%. It was concluded, therefore, that the controlling regime in the system was the interfacial chemical reaction related with adsorption and desorption.

The Peng-Robison equation of state is used for predicting vapor-liquid equilibria of hydrogen containing systems at low temperature and high pressure. Quantum correction and the effect of ortho-para conversion of hydrogen were introduced into the P-R equation. Several ways of incorporating these effects into the original P-R equation were studied and the calculated results were compared. The incorporation of these effects led to a more accurate description of VLE than the original P-R equation of state.

A method of coupling a pseudo-binary model with equation of state was presented for the calculation of the gas-liquid equilibrium(GLE)data of a CO2-CnAlCl4(C6H5CH3)n system at elevated pressure. The apparent critical parameters and the apparent eccentric factors obtained by the pseudo-unitary model were used as characteristic parameters of these non-aqueous salt-containing solutions. Regressions of two adjustable parameters of P-R EOS were obtained by the experimental GLE data. Taking the effect of the mixing rule on the accuracy of calculation into consideration, it was found that the P-R equation was greatly improved by employing the modified mixing rule. Results obtained showed that the pseudo-binary model coupled with the EOS method could be used for the GLE of the type of system under study.

This paper discusses the static model of a 1000 t/day ammonia plant, which uses natural gas as the raw material. Calculated values of compositions, temperature, etc., are in good agreement with actual measurements. A new optimization method called the decomposition-coordination method for large sized systems is presented in this paper. The method has been verified experimentally. An on-line computer control stratery is also illustrated.

The reduction and passivation behaviour of low pressure methanol CuO-ZnO-Al2O3-V2O5, catalysts have been studied with thermal analysis technique. along with XRD, IR, SEM and activity evaluation. Results show that the industrial catalyst contains about 25% basic carbonate, which is beneficial for getting better selectivity, activity and stability. Catalysts precalcined at 350℃ will lead to the formation of unfavourable structure. Direct reduction of industrial catalysts at low H2 concentration with high gas flow rate and at low temperature cascade rising rate will give good thermal stability and catalytic activity. It is attributed to the fact that some carbonate and hydroxyl groups are retained in the structure. They are assumed to be the necessary coordination species to form active sites, while the precalcined catalysts have lost most of these functional groups. Catalyst passivated under extremely low O2 concentration (0.01%)can restore its activity almost completely after re-reduction. A mathematical model of reduction kinetics has been set up from the thermo-gravimetric curve.

Eight different Kenics static mixers were investigated with the aim to identify the structural parameters for augmenting heat transfer through reduced flow resisitance. By changing the twist ratio and the twist angle of standard elements, as well as the distance between the elements, such a goal might he attained. Comparative tests with air in vertical Kenics devices weremade in the region of Reynold numbers from 2300 to 20000 to establish f-Re and Nu-Re correlations. Results obtained indicated that heat transfer could be augmented through reduced flow resistance, by appropriately increasing the twist ratio and twist angle of a standard Kenics static mixer However ample distance between the elements was also necessary lor attaining the better in heat transfer performences.

A sensitive apparatus for measuring the thickness of dynamic liquid film under various conditions is being presented. The fluctuation curve of film thickness can be determined continuously by employing this apparatus. The film thickness is proportional to the height of its amplitude generated on the fluctuation curve. This would provide simpler calibration and more accurate measurement. The error is less than 2.2% within the measurement range of around 1 mm. A study on annular gas-liquid two-phase flow, using this apparatus as a measuring means, is being chosen as an example to prove its validity.

Three new types of Φ25mm perforated metal grid Intalox Saddle(for short, perlorlox) were being made, and experiments were conducted tor their fluid dynamic characterestics. Experimental results showed that lower pressure drop. higher flooding velocity and greater capacity among other advantages were claimed tor perforlox. They showed better performance, when compared with metal Pall Kings and metal Casscade-Mini Rings.