In this paper, the energy saving and optimal operation policy has been proposed for solvent recovery system of the ketone-benzene dewaxing process . It is to find the limit (or called global optimization solution) of using energy based on the pinch technology, integrate the retrofit heat exchanger network and to optimize operation conditions. The network created by using the policy is very close to global optimization solution and has made a large energy saving in refinery.

Using kinetic theory, the Ito stochastic-differential equations for the freely rotating bead-rod chain model is derived in generalized coordinates. A corresponding algorithm is then proposed to simulate the dynamic behavior and rheological properties of this model in steady shear flow and elongated flow. Computer animation of conformational transitions in polymer chains is realized with the help of MATHEMATICA software.

It is shown by the detailed analysis of its heat mass transfer mechanism that the variation of the surface temperature of scaling layer has an important influence on the scaling process. A heat mass transfer model is constructed to take the variation of the scaling layer surface temperature into consideration. With the model, simplified analyses of the scaling processes are carried out under both the constant wall temperature and the constant wall heat flux conditions. The results show that the variation of the scaling layer surface temperature is one of the major factors that cause the asymptotic tendency of scaling process. Comparisons of the model with experimental data are given. The results show that the present model can give a very good prediction of the experimental results.

The batch and fed-batch cultivation of Bacillus thuringiensis were investigated. A four-compartment structured kinetic model based on Williams model was suggested to describe the cultivation processes. The initial values were estimated from the experimental data. The model calculation was in good agreement with the batch culture experimental data. By using the parameters from the batch culture simulation, the kinetic model was capable to predict the fed-batch culture process with satisfactory results.

A Theoretical equation for nonequilibrium state of gas is here extended to the liquid state, and a theoretical equation of isobaric liquid specific heat capacity is derived. This equation can be applied to both polar and nonpolar liquids with an average error of 0.85% from 986 experimental data, 220 compounds of 32 structural types, Its accuracy is about 10 times higher than that of the Rowlinson-Bondi method, recommended by Reid, et al. It is far better than all other published methods.

On the basis of two-fluid polymer coordination solution model, an equation of state (EOS) for polymer mixtures is derived, and applied to pVT correlation of four polymer mixture systems (polyisobutene/cyclohexane,polyisobutene/benzene, polydimediylsiloxane/hexadimethyl-siloxane, polydimethyl siloxane/benzene). A satisfactory accuracy is obtained. A new concept named fluidity coefficient is proposed. It could be obtained from equilibrium properties (pVT data),and used to predict the transfer properties.

FCCU offers a unique challenge to control engineers by virtue of its complex process dynamics and the conflict between its operating constraints and the economic targets. FCCU reactor-regenerator s characteristics are analysed from process control point of view, and advanced control strategy on reactor regenerator is proposed comprising of model predictive control and coordinated monitoring layer, complemented by an industrial plant test.

An MINLP (mixed integer nonlinear programming) model for optimal design of multipurpose batch processes with multiple production routes is developed. It allows the existence of intermediate storage,parallel units in and out of phase,as well as discrete equipment sizes. By combining simulated annealing (SA) with linear programming (LP), SA/LP algorithm is proposed for solving the MINLP model. SA/LP algorithm takes advantage of both SA in the good global optimization and LP in the ability to deal with continuous variables as well as constraints equations. The illustrating examples show that SA/LP method gives better global convergence and is far more efficient in computing time compared with some published methods.

A two-reaction system composed of an absorption reactor and an electrochemical reactor has been studied to produce of hydrogen and elemental sulfur by decomposition hydrogen sul-fide.A flow absorption reactor and an electrochemical reactor with graphite or graphite fiber cloth as the anode and graphite or graphite fiber cloth loaded with Pt as the cathode has been developed.

The method of measuring catalyst surface fractal dimension was introduced. The relations of surface fractal dimension with catalyst selection, catalyst preparation method, rare earth element content and catalyst treatment process have been discussed in detail. The results showed that fractal was an effective tool.

The interactions between the transport, reaction, pore morphology and evolution process are analysed in this paper. A fractal pore model is presented. These local fractal pores are the constituents of the pore network of char particle. The Bethe network is used to describe the pore space topology of the medium. This approach provides a natural framework for characterization of the geometrical structure of the pore and modelling of pore opening , enlargement and coalescence in the evolution of porosity and internal accessible surface area with the process of char gasification. This study also considers the loss of solid fragments by percolation. So it is applicable to modelling the char gasification proceas in the industrial gasifier.

According to the fact that the fluid in fluidized bed crystallizer is in turbulent motion, a turbulent mass transfer model was proposed by applying the multi-phase turbulent theory to crystal growth process. The comparison of the calculated values for the model with the experimental data indicated that this model is reliable for diffusion controlled crystal growth.

The mathematical model for the gas-solid adsorption mass transfer in a cocurrent downflow circulating fluidized bed(CDCFB) reactor is proposed in this paper. Experiments were conducted for measuring the axial tracer concentration distribution by using the steady-state tracer method. The model parameters, mass transfer coefficient and axial diffusion coefficient were obtained by non-linear retrive method (Marquardt method).The empirical correlations of experimental data for model parameters were obtained, as given by the following equationsPe2 =The model can predict the characteristics of gas ?solid mass transfer and fit the experimental results very well. So the model proposed in this paper could be used to describe the mass transfer in CDCFB.

Liquid dispersion was experimentally studied in the gas-liquid-solid three phase riser. The effects of operating factors, such as gas velocity, liquid velocity and solids circulation rate, on axial and radial dispersion coefficients of liquid were determined. Axial and radial dispersion coefficients of liquid increase with the increase of gas velocity; axial dispersion coefficients of liquid remains constant, but radial dispersion coefficients of liquid decrease with respect to liquid velocity. Axial and radial dispersion coefficients of liquid increase with solids circulation rate. Compared with the traditional expanded bed, the gas-liquid-solid three phase riser is closer to the plug flow reactor.

The simplified physical models for falling liquid film breakdown were presented by the flooding mechanisms in annular two phase flow and experiment observations. Under the state of surface evaporation, the forces of gravity, viscosity and capillary pressure in falling liquid film breakdown down vertical dimpled plate play a dominant role. Based on simplified theory analyses,film breakdown criteria Kα1/3 B was obtained. The correlations describing critical states on temporary and permanent breakdown were obtained to predict falling film breakdown conditions. In falling film flow, there were three regions: full wetted region, temporary breakdown region and permanent breakdown region, and two critical states: from fully wetted to temporary breakdown and from temporary breakdown to permanent breakdown.

The geometry of intermeshing co- rotating twin- screw, especially the shape and volume of the tetrahedral gap of the equipment were studied throughly and the mathematical model of the volume of the gap was proposed. The results in this paper clear up a lot of misunderstanding of the shape of the tetrahedral gap and provide a fairly exact model for the design of twin-screw extruders.

The data of equilibrium decomposition pressure of bisphenol A - phenol adduct and saturated vapore pressure of bisphenol A and phenol solution were measured. Comparing the curves of the saturated vapor pressure of phenol and bisphenol A - phenol solution with the equilibrium decomposition pressure of bisphenol A-phenol adduct , it was found that the latter is higher than the former two. This discovery provided the experimental basis for direct dephenolization from the crystal adduct of bisphenol A-phenol using the solid decomposition reaction principle to obtain the bisphenol A whith high quality.

A new process of condensation reaction ?separation of phenol and acetone in multi-stages trickle bed reactor has been developed. The problems of the fixed bed reactor with resin catalyst in production of BPA were resolved successfully. The influence of the technological conditions on condensation effect, such as reaction temperature, molar ratio of phenol to acetone, residence time and nitrogen flow rate was analyzed. The produced water was stripped and separated by nitrogen, the reaction temperature and molar ratio of phenol to acetone in the multistages trickle bed reactor were well distributed. By even mixing of the granulated packing with the catalyst, the transfer processes were intensified and the pressure drop of catalyst layers was cut down. Model experiment showed that the reaction and separation process in production of BPA with the multistages trickle bed reactor caused high concentration of condensation product, high conversion, high selectivity and high capacity of catalyst. The applicable range of reaction-separation process was extended.

Combining the Higbie s penetration theory and Kolmogorov s theory of isotropic turbulence , a small scale isotropic mass transfer model for local gas-liquid mass transfer coefficients in the self-aspirated reversed flow jet loop reactor has been developed. Good agreement was obtained between this model predications and experimental results in this reactor.

The paper analyzes the heat transfer and friction characteristics of spirally corrugated tubes, sets up the equations of heat transfer and friction based on the flow regime. Comparison of the calculated values and the experimental data shows should be considered as fairly good agreement at the small height of corrugation. The results also shows nonsynchronous nature between heat transfer and friction.