This paper presents a polynomial model for the characteristic curves of the synthesis gas compressor of Kellogg-type ammonia plants and a regression model for vapor-liquid equilibria in ammonia separation as well as for loop pressure drop based on plant data. The refrigeration required for separation of ammonia is also estimated. Steady state simulation of the ammonia synthesis loop by combining the sequential modular approach and the equation-solving approach, is carried out. Case studies on the basis of design conditions indicate that the simulation results match well with plant operation. Effects of the main operation variables on loop performance are studied by simulation analysis under 53 operation conditions. Multi-objective and multilevel optimization, with minimal compressor power and maximal production rate as object, and optimal temperature profiles of the ammonia synthesis converter as constraint, is explored.

Dense phase voidage can be estimated by cutting gas flow and following the rate of bed collapse. Abrupt cessation of flow is not possible when excess gas in the wind box can only discharge through the bed. The magnitude of this problem is examined experimentally.

The global reaction rates for industrial high-temperature shift reaction catalyst WB-2 of size φ9 × 7 mm have been investigated in an internal recycle gradientless reactor at pressures of 7 × 105 Pa (gauge) and 13 × 105 Pa(gauge). The pore-size distribution and the tortuosity factor of the catalyst have been measured. In this part, by using the intrinsic kinetic equation obtained at atmospheric pressure, the numerical solutions of the global rates have been computed according to the simplified multicomponent diffusion model presented in the second part of this paper, and have been compared with the experimentally observed values. The average absolute deviations between the calculated effectiveness factors by, the simplified multicompohent modeland thekey-component model, and the experimental values, are 11.72% and 11.88%, respectively. Therefore, the results of comparison are satisfaetory. It is proposed therefrom in this part, that the experiments of global rates under pressure are not necessary to investigate kinetic behavior under pressure for reactions for which operating pressures are not high such as the high-temperature shift reaction. The effectiveness factors and global reaction rates under pressure can be obtained by using the mathematical model of effectiveness factors presented in this paper on the basis of the intrinsic kinetic equation obtained at atmospheric pressure.

Radial profiles of local gas and solid holdups and liquid interstitial velocities are measured in a large-diameter three-phase fluidized bed, and systematic studies are based on a comparison with data obtained in small-diame-ter fluidized beds. It is shown that radial profiles of gas holdup conform to the parabolic form equation. The distributions of solid particles holdup may be expressed by Eq. (7).Liquid velocities are well described by the modified circulating flow model.

The Markov process with discrete state and discrete time is used to simulate the distribution of liquid flow in a packed column. The agreement between the- theoretical prediction and experimental data found in relevant literature and obtained in our experimental columnindicates that the random flow of the liquid in a packed column can be well described by a stochas-tical process.

The flow pattern and velocity distribution for the flow of highly viscous fluid in an agitated vessel with an anchor impeller were studied by means ofstreak photography using selective illumination of polystyrene pearls as tracer particles. Equations for velocity distribution, shear rate r and energy dissipation function Φ, were obtained by using the least square method. The shear rate r in the vicinity of the vessel wall and the Metzner constant ks, were compared with the shear rate averaged over the vessel and the parameter C3 of agitator performance, respectively, that ks and C3 reflect mainly the mean shear rate in the high shear area and the average shear rate over the vessel, respectively, and that, for a uniform shear field, C3 is equal to ks. The per-unit-volume parameter v may be used to characterize the shear rate distribution. The variation of flow pattern and velocity distribution with Reynolds number was also studied. The flow pattern was shown to be symmetrical at low Reynolds number, but asymmetrical at high Reynolds number.

Reaction characteristics of the oxidation of SO2 with vanadium catalyst in molten liquid phase was studied. A new mechanism was proposed for this liquid phase reaction. Based on the proposed mechanism, an intrinsic rate model was derived. Taking the effect of mass transfer in the liquid intoconside ration avoiding the tedious solution of the effectness factor, a"micro-kinetic" models relating to the intrinsic rate model were formulated. It was further pointed out that different model were necessary for different levels of temperatures. In the development of the macrokinetic models for the SHU commercial catalyst pellets, simplified models for porous diffusion were used. Experimented data regression suggested that the macrokinetics models over the different temperature ranges could be written as follows, At higher temperature levels (460-580℃): and at lower temperature levels(400 -460℃):

An association model applicable to calculating the solubilities of low-volatile substances in supercritical fluids was derived and compared with experimental data available in the literature, showing good agreement over wide ranges of temperatures and pressures: 1.01≤Tr≤1.23; 0.96≤Pr≤9.66 On the basis of this model, the solvability of supercritical fluids and its changing tendency with other variables over the range likely to be encountered in supercritical fluid extraction were discussed. Some deductions derived from the model showed good agreement with experimental results.

Eight Chinese oil shales were extracted under nonisothermal conditions with supercritical toluene and toluene-tetralin mixtures. Optimum extraction conditions for high liquid yield and high conversion were determined by systematic variation of extraction parameters: pressure, final extraction temperature, oil shale particle size, solvent flow rate, and H-donor content of the solvent. The results indicate that supercritical extraction of oil shale with toluene gives about twice as much oil yield as conventional retorting. With supercritical hydroextraction, where an H-donor is added to the supercritical toluene, nearly complete recovery of organic matters in the oil shale is possible with a high proportion of liquid products. From the concentration of extract in solution at different temperatures, the kinetics of supercritical extraction of oil shale was shown to be first order in rate, divided into two regions, with corresponding activation energies of about 120 and 180 kJ/mol, respectively.

In this investigation, a diffusion-reaction equation of the desorption of carbon dioxide from hot catalyzed potash solution was derived from the film model, as follows The effects of the concentration of promoter, temperature and rotor speed on the desorption rate are discussed. The theoretical predictions are in close agreement with experiments using hot potash promoted by a vanadate.

Under certain specific conditions, a zone of recirculation may be formed in confined jet. Confined jets are often used for tubular reactors, evolution of recirculation will creat backmixing of fluids disturbing reactor performance. The authors of this paper conducted experiments involving recirculation phenomena in confined jets. Factors affecting the occurence of recirculation were studied. The initial and ending points of recirculation were identified. Based on the model for free turbulent round jets, a correlation formula was derived for estimating the initial point of recirculation in confined jets.

This paper focuses on the evaluation of the linear VLE model for systems containing C5 hydrocarbons and acetonitrile by use of an experimental column with 22 sieve-plates (d = 32mm) operated at total reflux and total solvent recirculation. As reported previously[6], the linear VLE model, which have been used for C5 hydrocarbons DMF systems, is as follows: (1) (2) According to the good agreement of the calculated results using this linear model with expermental results, the conclusion can be made that these linear equilibrium relations are suitable for systems containing C5 hydrocarbons and acetonitrile for technical purposes. The average deviation in concentration between experimental and calculated values is 0.45% (mole) and the temperature deviation is 3.6℃ and 0.7℃ (after correction). The model parameters M and B are also reported,

An additional line of correlation lor mass transfer is introduced into the "Generalized Correlation Diagram for Semi-experimental Pressure Drops in Packed Towers" which was published by the same anther. At an earlier date, the diameter of the tower, the pressure drop, and the packed height can be worked out with the proposed diagram. This modified diagram mav serve also as a "Generalized Capacity Diagram for Packed Tower" for design work as well as for operational purposes.

The extractive rectification of butadiene has been investigated by pattern recognition. The condition of optimization for two response variables has been found, and confirmed in production practice.

A new computation procedure is proposed for multicomponent distillation columns processing non-ideal solutions. The Newton-Raphson method in whichliquid mole fractions are chosen as independent variables is used to solve the tridiagonal matrix equation, and a block tridiagonal matrix algorithm is developed. Successful applications of the new method to some non-ideal distillation systems are demonstrated with features of more insensitiveness to the initial values fewer C. P. U. memories, fewer partial derivatives more rapid and more stable than others.

A modified information index ID in molecular graphs has been developed to predict molar excess enthalpy, HE, of binary mixtures composed by non-electrolytes. The calculated HE values of 60 binary systems compare reasonably well with their corresponding experimental values. It is shown that this approach can be used to evaluate the HE of binary mixtures that contain hetero-atoms as well as those composed by hydrocarbons.

The porous electrodes were made by admixing PTFE emulsion with carbon black. In the electrolytic cell the cathode and the anode were separated by a ration exchange membrane. The current efficiency of HO2- exceeded 90% at the temperature of 20℃, when the concentration of KOH was greater than 0.3mol/l, the power consumption was 2.2kW·h per kg of H2O2. The steadystate polarization curve was measured.