The factors influencing the rate of making formic acid and sodium bicarbonate by gas-liquid-liquid double decomposition are discussed. The rate controlling step is determined according to the characteristics of the system, The kinetic equation of this process is established.

This paper introduces a mathematical model for batch processes of crystallization according to the theory of population balance and uses Laplace transformation in its solution. On its basis a dynamic method to measure the kinetics of crystallization is developed and used for the determination and comparison of the change of kinetic parameters with different addition agents for the cooling and salting-out crystallization of NH4C1 in the production of alkali. A new method for selecting addition agent based upon dynamic data of crystallization is advanced. It is found to be easy, feasible and relatively precise. In the experiment the Coulter-counter was used to measure the required data of CSD from a large number of samples and the parameters for the kinetics of crystallization was fitted by the use of multi-variable nonlinear regression.

The properties of monoazo dyes containing long-chain alkyl, N-acyl used for mulberry silk were studied. The relations between the properties and the change of the length of carbon-chain of these dyes were discussed in detail. These dyes with a carbon atom number in the long chains oi 12-20 was found to have the best properties for mulberry silk.

In this paper the characteristics of flow boiling heat transfer in an annu-lus 2mm in width have been studied by using water and viscous liquid. The experimental results show that within a certain range of heat flux the flow boiling heat transfer coefficient in an annulus is larger than an empty tube by 80 %; the overall heat transfer coefficient is increased on an average by 60%. The calculated value of overall heat transfer coefficient is compared with the experimental value with water as the boiling liquid.

In this paper, the theory of Markov chain is used to discuss the behavior of bubbles in G-L-S fluidized bed. A generalized stochastic model is proposed. On the basis oi thermodynamics, the model parameters were analysed and discussed to obtain a simplified stochastic model of bubble size distribution. In addition, the distribution of bubble size in a twodimensional G-L-S three-phase fluidized bed were measured by using conductivity probe method and micro-computer sampling technique. The calculated values with the stochastic model were very close to the experimental data.

The correlation equations of gas holdup in three different types of external-circulation-loop reactors are developed for air-water system. The resistance calculation for fluid flow in the loop results in a resistance equation. The gas holdup and liquid circulating rate for a given gas injection rate can be predicted with the correlation equations and the resistance equation, providing the basis for the scaling up of this reactor.

In this paper, the anti-flocculating properties of copper phthalocyanine (CuPC) pigment are studied by measuring its viscosity in alkyd resin after different periods of time. The CuPC methylamine derivatives can improve the anti-flocculating properties of CuPC pigment in alkyd resin, and the effect of the CuPC cyclohexyiamine derivatives is more significant.

Pattern recognition method has been applied to solving the problems of the optimization of chemical processes. The basic starting-point of optimization by pattern recognition is that the technological parameters are used as feature variable to construct the pattern space and all samples are divided into a number of classes according to the production target to be optimized. In order to find out the key factors influencing the target, the method of feature extraction is adopted to reduce the dimensionality of the pattern space of technological parameters. Some specific methods are suggested to search for optimal production conditions for two kinds of optimization problems, i. e., the problem of optimal index and the problem of optimal direction, respectively. The problems of multiple targets are also discussed briefly. The methods of process optimization by pattern recognition have been applied to some factories and considerable technical-economic benefits have been achieved.

A practical method for calculating VLE of NH3-H2O-CO2-N2-H2 system under high pressure is proposed in this paper. On the basis of the NH3-H2O-CO2 system, the molecular thermodynamic principle is used for calculating liquid-phase equilibria. The hyperbolic tangent function for the activity coefficient of the NH3-H2O system developed by Prausnitz is used in establishingthe VLE calculation method ior the NH3-H2O-CO2 system over a wide concentration range(NH3 10-90%(wt.)). PHS equation of state is used to calculate the vapor phase fugacity coefficient in the NH3-H2O-CO2-N2-H2 system under high pressure. Scope oi application: Temperature 30-70℃ Pressure 5.00-11.87MPa Liquid NH3 concentration 10-90%(wt. ) Liquid CO2 concentration 0-15%(wt. ) NH3/CO2 mole ratio in liquid phase≥ 5 The calculated results of the proposed model are in good agreement with both our experimental data and those from literature sources.

Various physico-chemical properties of high strength spherical catalyst A110-5Q, i. e., the densities, porosity, void fraction, specific pore volume, crushing strength and Mossbauer spectroscopy in the oxidized state, and the porosity, specific pore volume, specific surface area, average pore radius, pore size distribution, catalytic activity and kinetic parameters in the reduced state have been studied. In the oxidized state the crystal grains of the high strength catalyst with pore size of-1000A are packed more closely and the bulk and particle densities are 10-12% higher than those of the low strength catalyst with pore size of 1-5μm. In the reduced state the average pore radius and the most probable pore radius in the high strength catalyst are larger than those in the low strength catalyst, and there are three systems of pores in the former. Besides a twofold increase of the crushin gstrength, the high strength catalyst still maintaisn high activity and low flow resistance. The values of freuqency factor(ko)and activation energy(E) for ammonia synthesis are higher than those of the low strength spherical catalyst and the compensation effect equation, lnko = B+ f·E, applies.

Catalyst particles with nonuniform activity distribution may exhibit higher activity, selectivity and improved poison and deactivation stability as com-pared with those which uniform distribution. Theoretical and experimental work in this area prior to 1986 has been reviewed by Dougherty and Verykios, but expect Juang and Weng, the papers of Chinese scientists have not been included. In this paper, the literatures on the intra-particle behavior of nonuni-formly distributed catalysts are reviewed, covering the theoretical models of single and complex reaction networks under isothermal and nonisothermal conditions, experimental studies and analytical approach of activity profile optimization. Papers of Chinese authors and more recent achievements up to 1989 are also reviewed. The review tries to systematize the expressions of local rate constant and activity distribution used in the literature, and give a general theoretical model which can be applied to any single or complex reaction network the Thiele modulus is also expressed in a generalized form.

Good linear relationships between the logarithm of diffusivities and dav defined as equation (1) are obtained for low carbon n-alkanes in zeolites 4A, 5A, silicalite and NaX. There is also a good linear relationship between the logarithm of diffusivities and the pore diameter of zeolite (dp) for low carbon w-alkanes. So the diffusivity for a diffusate in a zeolite can be described by the equation as follows: a and b are constants. This relation could be used to estimate the pore diameter of new zeolite molecular sieves from the measurements of diffusivities of low carbon n-alkanes in them.

The friction and heat transfer tests of 16 different structural parameter (e/d= 0.022-0.058; t/e=9.09-36.36) of transversally corrugated tubes were made with water as working medium, Reynolds number 5000-50000. The fluid flow patterns were observed by using several transparent models of hydrogen bubble flow tracers. The general correlations for friction factor and Stanton number were obtained with a semi-theoretical and semi-statistical method. Prediction of Fanning friction factor and Stanton number were given with the errors within ±12% as compared with experimental data.A transversally corrugated tube of optimal structural parameters was obtained under certain operation condition. The heat transfer performance of transversally corrugated tube was superior to the spiral grooved tube recommended by previous studies.

The heat transfer of a small heating device can be augmented by gas impingement in a liquid coolant bath. The mechanism of its heat transfer augmentation was studied. Theoretical analysis and experimental investigation showed that besides the increasing heat transfer by the agitation of liquid caused by gas jet impingement there existed a heat sink caused by liquid coolant vaporization at the impinging gas-liquid coolant interphase. Due to such a quick vaporisation, the temperature at the gas-liquid interphase dropped notably, increasing the effective heat transfer driving force and in turn the heat transfer. From such a point of view, a physical model of simultaneous heat and mass transfer was proposed to reveal the mechanism of this particular heat transfer phonomenon, and the convective heat transfer coefficient and mass transfer coefficient can be calculated.

Analysis of heat transfer coefficient in fluidized bed, gives the critical velocity of transition from fast fluidization to pneumatic transport. For four kinds of particles the transition velocity upt can be correlated asfollows:

A computer Monte Carlo simulation program for square well potential mixture fluids is developed. It can effectively remove the overlaps between moleculas to produce the initial configuration at high densities. Distribution functions and coordination numbers at ρ*>0.9, and σ22/σ11= 5.0 for binary systems, and ternary systems models are obtained. Comparisons between simulated and calculated results from current models show that would lead to our simulation data.

An activity coefficient model for surface phases of liquid mixtures is presented on the basis of the solution theory and the theory of surface thermodynamics. Its combination with Bulter equation of surface tensions makes possible the prediction of binary solution surfaces tensions. More than twenty binary solution systems containing alkane, aromatics, alcohol, ketone, water, CS2, halogen compounds etc, are tested. The results prove that the prediction is successful and the activity model is effective.

A physical model is developed to describe the velocity distribution in an agitated vessel with helical ribbon impellers. The relationships among power consumption, Metzner constant and circulation number are derived from the model. The predicted results show good agreement with the experimental data from the literature The proposed model provides a better understanding of such vessels, which will be helpful for design and scaling-up.