Not only for environmental protection, but also for process technology in itself, it is an urgent task to integrate environmental impact minimization into chemical process synthesis. This paper is trying to summarize the developments of this area over the recent ten years in order to remind chemical engineers of what can be done now and what should be done in near future from an industrial viewpoint. After discussing some original concepts and hierarchies, three aspects of process synthesis i.e. reaction path synthesis, environmental impact assessment and process integration, are highlighted for environmental impact minimization. There is no mature tool in reaction path synthesis as yet; the advances in green chemistry will play a great role in connection with finding new reaction, new raw material, new solvents, and etc. There is still a long road to go for the development of environmental performance indicators and indices; and the next step is to incorporate some generally accepted indices into flowsheeting software. Some new trends in modeling and simulation techniques and numerical optimization can readily solve problems involving environmental issues in a more natural way. All in all, due to the multi-objectivity and complexity in environmental impact minimization, the combined methodology becomes the necessity, and a promising direction is how to combine reaction path synthesis,and flowsheet with environmental impact assessment system with multi-objective programming techniques.

On the basis of the two-flux model of radiative transfer in photochemical reactor, the model was extended by considering light transmission passing through the photocatalyst, and reflection and absorption of light by the photocatalyst in the plane parallel-plate reactor. The extended model showed the dimensionless radiation intensity distribution and the dimensionless total radiative energy absorption rate in heterogeneous photoreactor. Semiconductor ultrafine TiO 2 power was widely used as the photocatalyst in heterogeneous photochemical reactor for environmental control. In order to show the usefulness of this simple method, the effects of TiO 2 power diameter and reactor depth on the dimensionless radiation intensity distribution and on the dimensionless total radiative energy absorption rate in gas-solid heterogeneous photocatalytic reactor were illustrated. The model explained that it was necessary to select reasonable reactor depth, particle diameter and density on semiconductor heterogeneous photoreactor designed.

In a vertical gas-liquid-solid fluidized bed of 4.2 cm in diameter and 130 cm in height, the axial solid concentration distribution is investigated for both particles with different properties. Two distinguishing systems can be formed upon the wettable property of particle materials. One is called as a no-attached system in which the solid holdup decreases with increasing bed height. Another is named as an attached system in which solid holdup increases with the bed height. The sedimentation-dispersion model can be employed better to describe both above systems by modifying only a model parameter, i.e.the particle terminal settling velocity, which considers the effect of an additional drag force resulting from attached up-flowing bobbles and subtracts a certain value obtained by a function formula relating to the gas velocity. It is found that the axial concentration profiles of solid particles predicted by the modified sedimentation-dispersion model are in good agreement with experimental results for both no-attached and attached systems.

A theoretical approach to forced convective condensation heat transfer coefficient of nonazeotropic mixtures inside smooth tubes was developed. Calculations were performed for R32/R134a mixtures with the R32 mass fraction ranged from 0 to 60.1%. The results revealed that there was a reduction of heat transfer coefficient for a nonazeotropic mixture when compared with that of a single component substance with the same thermophysical properties. The reduction of the heat transfer coefficient depended not only on the mass fraction of the mixture, but also on the vapor quality of fluid. Besides, minimum heat transfer coefficients were observed at mass fractions ranging from 10% to 30% for R32/R134a mixtures.

The adiabatic calorimetry is a very simple and precise means to measure the rate of polymerization.In this work the method was used to aquire the temperature-time curves of the copolymerization of styrene (St) and methyl methacrylate (MMA) in toluene initiated by 2,2′-azobis (2,4-dimethylvaleronitrile).The sums of crossed chain propagation enthaipy(-Δ H R12 )+(-Δ H R21 )were simulated based on terminal model and penultimate model of Fukuda and Inagaki. The reactor was a 1.5 litre Dewar-reactor equipped with temperature sensors (Pt-100)and a computer,with the system and surrounding temperatures being recorded and calculated on line.At 70—90 ℃ and in the atmosphere of helium,St and MMA were copolymerized and a series of temperature-time curves were obtained by varing the initial concentrations of initiator from 0.02 to 0.03 mol·L -1 with a constant total monomer concentration of 3.5 mol·L -1 ,and mole concentration ratio of St to MMA ranging from 2/8 to 8/2.The sums of crossed chain propagation enthalpy (-Δ H R12 ) +(-Δ H R21 ) were simulated as 151.03 kJ· mol -1 and 76.57 kJ· mol -1 respectively based on the terminal model and penultimate model of Fukuda and Inagaki. The results show that the value simulated based on the terminal model is coincident with the published datum (136.95 kJ·mol -1 ) ,but the value simulated according to penultimate model of Fukuda and Inagaki is much less.Besides,the great difference between (-Δ H R12 ) and (-Δ H R21 ) in the penultimate model of Fukuda and Inagaki implies that there remain some problems to be studied further.However,it is still insufficient to prove that the terminal model is better than the penulthmate model of Fukuda and Inagaki for simulating the copolymerization system.

In this paper, the performance of fluid dynamics and heat transfer between continuous and dispersed phases is studied for pentane-water system in a gas-liquid-liquid three-phase vertical tube. The gas-liquid-liquid three-phase section is divided into two stages. In the first stage the droplets number density is assumed to be unvarying but the diameter increases gradually, while in the second stage the diameter of droplet is kept constant value but the droplet number density is a variable. Under this assumption some models such as one-dimensional two-fluid dynamics model, local volumetric heat transfer coefficient, average volumetric heat transfer coefficient and single droplet heat transfer coefficient are developed. These models take into account the variation of gas density due to expansion in the tube, the evaporation of continuous-phase water, the action of interfacial tension, the velocity slip and interaction between gas and liquid, and two-phase bubbles break-up. The main characteristic parameters of fluid flow are also analyzed in detail. The calculated results showed good agreement with the experimental values.

Extraction of egg yolk oil (EYO) from egg yolk powder with supercritical carbon dioxide(SC-CO 2) was performed at 45 ℃ and 32.0 MPa in a 1.2 L laboratory apparatus. The effects of particle size and flow rate of CO 2 on the extraction were investigated. The controlling steps in extraction were external diffusion of EYO and equilibrium of EYO between SC-CO 2 and matrix. A mathematical model was developed for simulating the extraction process . The model could simulate satisfactorily the process of extraction of EYO with SC-CO 2. The volumetric mass transfer coefficient K f a was directly proportional to the flow rate of CO 2 with an exponent of 0.548

The diluent solution of glyoxylic acid and oxalic acid was used as the separation object.TOA (in n - octanol) was used as the solvent. The extraction characteristics of single acid and two-acid solution were studied, and the influence of pH and the concentration of complexing agent on the distribution coefficients were measured. The suitable mathematic models were proposed to describe the relationship between TOA and carboxylic acid based on assumed extraction reaction in organic phase. The experimental results showed that the ratio of oxalic acid to TOA was 1∶1 and 1∶2 in the organic phase. The distribution coefficient of oxalic acid was larger than that of glyoxylic acid, and both of them decreased with the pH. The selectivity of oxalic acid to glyoxylic acid also decreased with pH. In the extent of this experiment, the distribution coefficients for each acid and the selectivity increased with the concentration of complexing agent , and a higher selectivity and the distribution coefficients could be obtained at higher pH for a larger concentration of complexing agent. The calculated results were close to the experimental data based on the models using the parameters K 11 and K 12 from the single acid experiment and m A and m B from the two-acid experiment in the presence of 100% n -octanol.

In this paper, tri-octylamine (in octanol) was selected as extractant to extract lactic acid and acetic acid. The effects of the extractant content and the pH on the extraction equilibrium have been investigated for lactic acid, acetic acid and their mixture. The models of the distribution coefficient were proposed for the single component and the mixture based on some assumptions. At the conditions of the experiment, the distribution coefficients for the single acid and their mixture and the separation factor increased with the content of the extractant, and decreased with the pH. The distribution coefficient models fitted in well with the experimental data, and the complexation reaction constant K 11 for single acid system can be used to predict the distribution coefficient of the mixture.

The critical temperature( T c)is a key parameter for prediction of thermodynamic and transport properties by the principle of corresponding states.However,reliable experimental measurements of T c are restricted to stable substances.As a result,numerous estimation methods have become popular for calculation of T c.Among various methods for extimating T c,the group-contribution approach has been widely used.However most methods meed T b of the compounds,and it is difficult to measure T b of unstable substances. In this paper, an estimating method using the d 20 4 for critical properties in group-contribution method was presented and assessed.For correcting the influence of adjacent group and differentiating isomers, the new methods including first-level group-contribution method and second-level group-contribution method are proposed.70 first level groups and 34 second level groups were divided, and the contribution parameters of the groups for T c were obtained by correlating the experimental critical temperature of 325 substances, which are divided into 12 types. The average correlation error of GR1 method and GR2 method for T c is 2.950% and 1.937%,respectively.If the experimental T b is not available, the new method can be used to give satisfactory estimation. The T c of 31 compounds were predicted using the new method and Constantinou-Gani method,respectively, and the results show that the new method demonstrates singnificant improvements in accuracy.

The characteristics of dynamic pressure in an impinging jet were experimentally studied. The instantaneous signals of dynamic pressure resulted from the turbulence in the jetting fluid were measured through a piezoelectric sensor and recorded by a computer. The pressure signals at central axial position of the jetting fluid were sampled at different fluid pressure. The measured signals obviously possessed periodical characteristics. After analyzing the signals with FFT method, it was found that there was an inherent frequency in the dynamic pressure signals. The inherent frequency increases with the average velocity of the jetting fluid at the nozzle outlet, which is consistent with the theoretical analysis. It was supposed that the dynamic pressure signals are transformed from the fluctuating fluid velocities resulted from the turbulence in the jetting fluid. The inherent frequency corresponds to the minimum eddy scale in the turbulent jet. The smaller the eddy scale is, the higher the inherent frequency is. Higher velocity of the fluid at the outlet leads to a stronger turbulent strength. The fluctuation velocities with high inherent frequency resulted in a strong shear force field, which enables the fluid to be micro-mixed fleetly and the agglomerate of solid particles to be dispersed effectively.

In this paper, an on-line ultrasonic H 2O 2 concentration meter operating according to the relationship between the concentration, temperature and ultrasonic velocity in H 2O 2 solution is introduced. The ultrasonic velocities in H 2O 2 solution are measured at different concentrations and temperatures.The velocity-concentration coefficients and velocity-temperature coefficients of H 2O 2 solution are calculated. In the on-line ultrasonic H 2O 2 concentration meter, the ultrasonic transducer installed outside the H 2O 2 solution pipeline generates an ultrasonic wave pulse. The ultrasonic wave travels through the pipeline of H 2O 2 solution. The computer transfers the ultrasonic travel time into ultrasonic velocity. The platinum resister is installed inside the H 2O 2 solution pipeline. The resistor variation caused by temperature is sent to the computer through the interface. The computer calculates the ultrasonic velocity and H 2O 2 temperature by means of velocity-concentration coefficients and velocity-temperature coefficients. It displays and prints the value of the instant H 2O 2 solution concentration, and meantime displays the 8 hour curve for H 2O 2 solution concentration variation in the screen. It also can give alarm and output a 4—20 mA analogue signal for automatic control in the production process.

An immobilized metal ion affinity membrane was prepared by plasma-induced graft polymerization of glycidyl methacrylate (GMA) onto a porous polypropylene(PP), followed by chemical conversion of epoxide group of the GMA grafted membrane into an iminodiacetate(IDA) group, and chelation with copper ion. The effect of plasma discharge condition, GMA monomer concentration and grafting time on the degree of GMA grafting was studied and the optimum condition for plasma treatment of membrane was:10 W for 30 s, and that for grafting is 30 h at a concentration of 1 mol· L -1 GMA.Under this condition, a maximum grafting degree of 13.28% was obtained. The spectra of IR and XPS shows that GMA and IDA had been attached to the PP membrane after grafting and coupling. The nonselective adsorption of PP membrane had been significantly reduced after the H 2SO 4 treatment of the IDA coupled membrane. Finally, the isotherm adsorption of bovine serum albumin (BSA) on the immobilized metal ion affinity membrane was measured and the adsorption capacity of BSA increased with the degree of grafting. When BSA concentration was 1080 μg·ml -1 ,the adsorption ability of the affinity membrane with a grafting degree of 5.3% was nearly twice as much as that membrane with a grafting degree of 4.66%.

Solid catalyst suitable for treatment of cyanide containing wastewater is synthesized,and its stablity,activity as well as the process of wastewater treatment are investigated.The results show that this kind of hydroquine redox resin has better stability and catalyst activity and can be used as the catalyst for aeration process of wastewater treatment.

Irregular shape catalysts with through-holes are new type catalysts developed recently. They are helpful to modify heat transfer character and to decrease the pressure drop of the fixed bed. This paper studied the influence of irregular shape catalysts with through-holes on the pressure drop of the fixed bed and determined the equivalent diameter of irregular shape catalysts with through-holes. The equivalent diameter can be obtained by determining the pressure drop of the fixed bed packed with a certain catalyst. Equipment used to determine the equivalent diameters of catalysts is established. The equivalent diameters of three irregular shape catalysts were determined by Ergun equation.

In this paper the effect of magnetron sputtering with DLC (diamond like carbon), DLC-F and AC on CaSO 4 scale formation was investigated. Fouling run were carried out under flow boiling conditions. The results showed that surface sputtering with DLC et. reduces CaSO 4 scale formation significantly.

Adsorption model of metal ion on imprinting chitosan resin was studied. The chemical and the physical properties such as pore size distribution and heat stability were discussed and the imprinting chitosan resin can be used many times without losing adsorption capacity. The adsorption isotherms and adsorption mechanism were studied and a new model was suggested to correlate relation of adsorption with pH and metal ion concentration,which could explain mechanism of adsorption.

An individual cell is a chemical reactor with thousands of reactions operated under a highly sophisticated control system,and it is a self-regulated reactor that can alter its biosynthetic machinery to meet its demands in a changing environment.A simple mathematical model for the growth of a single cell of hybridoma is presented in this work in which the cell is divided into structural and genetic compartments.This model can describe the changes in cell component,cell shape,cell size,substrate uptake, byproduct release and other temporal events during the cell division cycle.Some model parameters were regressed with experimental gross data of hybridoma in continuous culture,and specific uptake rate of glucose and glutamine of hybridoma in continuous culture were predicted.The predicted values were in good agreement with experimental data.The average relative deviation is 13.8%.

In this paper,the preparation of phenylpyruvic acid by hydrolysis of 5-benzalhydantoin and its dynamic behavior were studied. The optimized condition of hydrolysis was: reaction in the presence of sodium hydroxide as hydrolyte proceeding for two hours at 100?℃.The degradation of 5-benzalhydantoin was close to 100%.