The requirement of much longer duration of startup is an important characteristic of a close-boiling fractionating column, and consequently the search for ways to shorten this period have been received much concern and attention. The conventional method of starting up a column is under the condition of constant vapor velocity, while in this paper, the authors propose another way of operation, i. e. startup with stepwise lowering of vapor velocity. The mathematical models of those two methods of startup are developed and solved to obtain the analytical solutions of exponential type to represent the change of concentration profile. The derived equations are in agreement with the experimental data. Both theoretical study and experimental work show that, when the same final concentration is reached, the duration of startup required for proposed operation is less than that for the conventional. This result may have some significance to the operation a close-boiling fractionating or batch distillating column.

Following the work on gas lift reactor (Pachuca tank) for gas-liquid-suspended solid 3-phase reaction, multideck gas lift reactors have been developed. This type of reactor has many unique advantages such as achieving of counter-current operation between gas and slurry, decreasing of gas consumption and small amount of volatile component of liquid required to recovery from the exit gas. The stability of the overflow tube of the reactor was studied. Semi-empirical equation was derived to calculate the flooding point of the reactor. The operating range of the overflow tube was also determined. This multideck reactor has been operated successfully in a pilot plant of ammonia leaching of copper ore. Results agree reasonably with those predicted from small scale batch experiments. The extraction of vanadium from soda roasted steel slag in a 5-deck reactor with carbon dioxide in the gas phase was also satisfactory. Experimental results obtained from the continuous flow 5-deck reactor and those calculated from the batch experimental data using CSTR model were in agreement.

Based on Eyrings theory of viscosity of pure liquids, an equation for the calculation of the viscosity of liquid mixtures was proposed from the concept of local molar composition: where V represents the viscosity, V molar volume, ga interaction energy between the molecules of the same kind, ga interaction energy between the molecules of the defferent kinds, n, R, T, x have their conventional meaning, and the subscripts i, j denote -component and j-component respectively. By the use of this equation, thirty binary systems and five ternary systems were tested with satisfactory agreement between calculated and experimental values. This equation is, therefore, valid both for correlate viscosities of binary systems and predict those of multicomponent systems from binary parameters.

A direct method for evaluating equilibrium vapor compositions from measurements of the vapor pressure or boiling point of the solutions is presented. The basic differential equations are derived from Gibbs-Duhem equation and can be solved easily by iterative method. This method can be successfully used for binary systems, and in principle can also be applied to multicomponent systems. Several examples of binaries and ternaries are presented for demonstration. Calculated results are in good agreement with experimental data.

Multi-effect multi-stage flash process is one of the evaporation processes in chemical engineering, yet it is somewhat different from conventional multi-effect evaporation. To meet the new problems encountered methods of analysis and formulas for calculation are presented here from the theoretical aspect. First, the multi-stage flash is analyzed in order to get the stagewise changes in flash variables such as flow rate, concentration, pressure etc. Schemes of circulation of concentrated solution in each effect are then analyzed for the determination of circulation parameters and terminal variables in each effect. The peculiarities such as double-streams, multi-stages and combination of flash and condensation in a section are then analyzed, stagewise changes in source and sink temperatures are determined, and various solutions both for design and operation problems are presented. The results thus obtained have been checked with the published data of a desalination unit and they agree well. It is suggested that these methods of analysis are applicable to all flash vapourization technologies.

The process producing propylene oxide by epoxidation of propylene with ethylbenzene hydroperoxide is one of the most promising methods in recent years. In order to select and achieve an optimum reaction equipment technologically, the mathematical models of the epoxidation reactor for plug flow, single-stage backmix and multi-stage equal-sized backmix in series have been founded in this paper based on the kinetic model and the effects of various flow patterns on the reaction have also been discussed. It is shown that multistage backmix reactor is a more perfect one for industrial equipment, and the optimum operating conditions are suggested. The mathematical model for multi-stage backmix flow has been verified experimentally in four-stage reactors. The experimental and calculated values agreed quite well with each other.

An internal recycle gradientless reactor had been designed for studying gas/solid catalytic reaction kinetics. The construction of the reactor is simple. The electromagnetic stirrer was employed in order to overcome the difficulties of the radial sealing of the rotating shaft. The catalyst may be put on the perforated fixed plate or in the rotating basket moving with the shaft. It enables to accommodate catalyst size from a few tenth of a milimeter to commercial size. Residence time distribution measurements showed that the gas flow pattern was ideal mixing flow. The axial and radial temperature differences in the reactor were very small. The reactor may be operated up to 800(C). The relation between residence time distribution and the stirring speed for various gas volumetric rate was studied. In order to reach perfect mixing state, higher stirring speed were required for higher gas flow rate. The re-actant concentrations in reactor effluent were measured under various stirring speed. The compositions were unchanged after the stirring speed had been increased to a certain value.

A series of ultrastable Y zeolite samples have been prepared under various conditions. The samples show a considerable unit cell shrinkage and have a high degree of thermal stability and hydrothermal stability. The degree of crystallinity is largely over 80%. The samples also exhibit a strong acidic property involving both Bronsted acid and Lewis acid and have cracking activities comparable with LaHY zeolite. Studies of the hydrothermal stability of the acidic sites of the ultrastable Y zeolite demonstrated that 100% steam treatment at temperatures over 780℃ it eliminate almost all stronger acidic sites. Cation exchange experiment showed that Al cations formed in the stabilization step can be exchanged by NH4+.Finally the general regularities of preparation and the properties of the ultrastable Y zeolite were discussed.

Based on a proposed model that the growth of mean bubble diameter along the height of bed is proportional to average degree of bubble separation in the level, and a lot of existent experimental data, it has derived that the following calculation equation for bubble growth along the height of bed In addition, based on a simplified model of initial bubble diameter that is proportional to vertical centric distance of two adjacent bubbles, and the existent experimental data, the calculation equation of initial bubble diameter DBO was obtained- According to the obtained equation and the assumption that the bed expansion in a bubbling fluidised bed caused by existence of bubble only, the calculation equation of expansive height of bubbling fluidised bed was presented.

With the consideration of all the reactions involved in the polyesterification of BHET (bis-β-hydroxyethyl terepliathalate) such as the primary forward polycondensation reaction, its reverse reaction and the cracking reaction, a kinetic equation was derived. As the concentration of ethylene glycol (EG) appeared as a term in the derived equation is difficult to determine, it was empirically correlated with the speed of stirring, R, the specific surface of the reacting system, etc. Finally a semiempirical equation correlating the average degree of polyesterification ( DP )with both the operating parameters (such as the temperature T, pressure p and the time of residence ) and the constructional parameters of the industrial reactors(such as R and ε)has been obtained as follows: