The equilibrium solubility and sorption/desorption curves for alcohol and water in a kind of polyimide membrane with and without crosslinking agent at 298. 15 K, 308. 15 K and 313. 15 K are measured by quartz-springs weighing method. Results show that both adsorbed and dissolved states of alcohol and water exist in this kind of polyimide membrane. Fickian diffusion or anomalous diffusion are found under different conditions. Crosslinking agent added to membrane can enhance the solubility of water and decrease the desorption rate of alcohol. It is shown that the crosslinking agent can improve the separation properties of polyimide membrane.

The equilibrium solubility of alcohol and water in two polyimide membranes measured in a previous work is correlated by the dual - mode theory with Flory-Huggins solution model and Langmuir adsorption model. Diffusion coefficient - concentration relations are evaluated from experimental sorption and desorption curves. Solubility coefficients, permeabilities are then obtained. The infinite dilution ideal separation factor is used for the appraisal of separation performance of pervaporation membrane. It is shown that the diffusion coefficients and permeabilities of alcohol and water in the membrane containing crosslinking agent are less than in that without crosslinking agent. However, the infinite dilution ideal separation factors in the former are larger than that in the latter. The results indicate that the crosslinking agent can improve the performance of polyimide membrane for the separation of alcohol and water.

In the present study the Lu-Maurer model (1993,1996)for aqueous electrolyte solutions was used to correlate solubility products Ksp of 18 salts including MgSO4, KCaCl3, NH4NO3, MgSO4·H2O, MgSO4·4H2O,MgSO4·5H2O,MgSO4·6H20,MgSO4·7H2O,CaCL2·2H2O,CaCL2-4H2O, CaCl2·6H2O,KMgCl3·6H2O,KaCaCl4·2H2O, CaMg2Cl6·12H2O, K2Mg2(SO4)3, K2Mg(SO4)2·2H2O, K2Mg(SO4)2·4H2O and K2Mg(SO4)2·6H2O. With no additional parameters this model was used to predict solubilities of 13 systems including MgCl2-CaCl2-H2O, KCl-HCl-H20, NaCl-HCl-H20, NH4Cl-HCl-H20,CaCl2-KCl-H20,MgCl2-KCl-H20,CaCl2-NaCl-H20,MgCl2-NaCl-H20,MgS04-K2S04-H20, NH4N03-NH4C1-H2o, NaNO3-NH4NO3-H2O, NaCl-KCl-MgCl2-H2O and NaCl-KCl-CaCl2-H2O in the temperature range from 273.15 K to 378.15 K. It was shown that this model is capable of predicting solubilities in mixed electrolyte aqueous solutions at elevated temperatures and up to very high ionic strength. It could be used to predict the composition of solid liquid phase equilibria for determining the technical conditions for the separation and manufacture of the interest inorganic salts.

A new equation of state based on the two - fluid coordination model for polymer solutions was applied to correlate the experimental pVT data of three copolymer melts [P(VAC/E), P(S/MMA) and (PEP)] and two blend systems (PVME/PS and PPO/PS) with high accuracy, and a new assumption considering a copolymer melt as a blend system was proposed to define the segment length of random copolymer. By correlation of the pVT data of the copolymer melts and the blends, it was found that thecross energetic parameter η12 and average hard - core volume V*12 have certain summation relationships with their corresponding homopolymer model parameters respectively. So a simple mixing rule was proposed to estimate the cross parameters to predict the pVT data. It shows that the predicted results are in good agreement with the experimental data.

A novel algorithm of neural network structure optimization is described in this paper. The capabilities of the algorithm are demonstrated by application in steady-state process, dynamic process and industrial process. The recognized results of neural network structure show that the optimal neural network can be widely used for modelling and simulation of chemical processes.

A novel fuzzy-neural network (FNN) was proposed in this paper. A new type of neural network construction incorporating fuzzy rules was formed, in which the fuzzy sub - space was designed by homogenized design and could be adjusted. The ability of the fuzzy-neural network to simulate and predict was improved, and the time for training was shortened correspondingly. The kind of network could be used to simulate or optimize bioprocesses. In this paper, the fuzzy-network was used to predict the glutamic acid production by fed - batch fermentation, which gave satisfactory results.

The method to humidify Fee catalyst is taken to simulate the change of properties of cohesive particles. The model presented in this paper is conformed by the measurement of the width of the static arching in hopper against negative pressure gradient. The effect of various factors, such as the unconfined yield strength of powder, the shape of a hopper , operation condition and the time of consolidation on the width of static arching is discussed in detail . The method to determine the minimal size of out - let of standpipe is presented. for the design of standpipe in industry.

The kinetics of gas phase ozonation of trichloroethylene was investigated at 101.3 kPa and 298 K in a batch,tank reactor with circulation of reaction mixture within the reactor system.The regression analysis of experimental data indicated that the overall kinetics is two and one - half order, first order in ozoneand three - halves order in trichloroethylene,and the average rate constant is 57.3 mol-1.5·L1.5·s-1.

The kinetics for the reactive system of propanoic acid and methanol was investigated over a temperature range 313 K-343 K under ambient pressure, and in the presence of the catalyst of sulfuric acid (0.5%-3% mass concentration). Chemical and vapor- liquid equilibria for the esterification system containing propanoic and methyl propionate with sulfuric acid (l%-2% mass concentration ) as catalyst were measured. Experimental results were correlated and estimated with good accuracy by using the stoichiometric approach.

In this paper, a two-dimensional mathematical model discribing the radial concentrations and temperature profiles in the catalytic bed of triple tube type ammonia synthesis reactor was established in the cylindrical coordinate system. The concentrations and temperature profiles in an irregular cross section of catalyst bed between cold tubes were calculated by the mesh -point method. The calculation is not time-consuming,so that the method is an effective one.

Based on the study with air- water and air-#0 diesel oil in heat exchanger, results on the effects of fluid properties on void fraction and frictional pressure drop in the shell-side two-phase flow with air - 30% (by weight) water glycerine solution was presented. The results showed that the void fraction increases with the increase of liquid viscosity when the mass fraction and mass velocity are maintained unaltered. Surface tension has also effect on the void fraction. Combining these two effects, a void fraction correlation is obtained which can be used in different air-liquid systems. The experimental results show that the data of frictional multiplier increases with the increase of liquid viscosity. A comparison between the data of air - glycerine water solution and air - water system shows that different frictional multipliers approach to 1 as the value of Martinelli number increases. A new two-phase frictional drop correlation is presented. The average error is about 15% .

The domain division method for determining effectiveness factors of porous catalyst pellet is presented. By applying this method, the entire one - dimensional domain is divided into several equidistant subdomains and the nonlinear diffusion - reaction problems in a porous catalyst pellet are solved by using the one - point collocation method within each subdomain. In using the domain division method to determine the effectiveness factors of porous catalysts, a lot of calculations are made with power law type kinetic expressions and Langmuir - Hinshelwood kinetic expressions for three catalyst pellets. The agreement of the calculated results of this method with orthogonal collocation solution is satisfactory. The domain division method is simple for use and is not time consuming. The radius of dead zone can also be determined by using the domain division method, and the calculated results are reasonable.

In this work, the variation of the shell-side gas flow velocity vs. radial distance in a φ 103×1300mm permeator was characterized by using a thermo -anemograph. It was shown that the gas flowmaldistribution increases with the decrease of the average gas flow velocity. Simulation results based on the gas flow distribution shows that shell -side flow maldistribution can adversely affect the permeator performance.

Different conclusions exist about whether dropwise condensation can be maintained on chromium. Condensation of steam was carried out on vertical tubes , coated with chromium by three kinds of methods: ion-plating, electroplating and ion - plating with ion beam combination technology. The results indicated that these chromium surfaces have different heat transfer properties when steam is condensed on them.

An experimental apparatus was established for determining extremel - low vapor pressure by Knudsen torsion-effusion method. The torsion - effusion constant K of the instrument were experimentally determined by vaporizing n - hexadecane which is chosen as a standard substance. To check the reliability of the K values, vapor pressures of 1 - octadecene were measured and compared with the values selected. Vapor pressures of 5 esters including dimethyl adipate, diethyl adipate, dibutyl maleate, diethyl sebacate, dipentyl phthalate were determined at temperatures from 293 K to 373 K and correlated by the Antoine equation.

An experimental investigation is made on the condensation heat exchanger with spirally corrugated tubes in this paper.The result shows that spirally corrugated tubes can enhance both the convective heat transfer inside tubes and the condensation heat transfer outside tubes. Correlations of convective heat transfer and friction factor inside tubes and condensation heat transfer outside tubes are obtained. The application of spirally corrugated tubes to industry condensation heat exchanger is satisfying.

This article summarizes the application of ultrasonic wave in nucleation of organic systemssuch as sucrose, monosodium glutamate, glutamic acid, monohydrate α-glucose, etc. and analyzesits principle . The necessary nucleation conditions for isomers of allomorphic organic system under the effect of ultrasonic wave were obtained by studying glucose. When ultrasonic wave is used to promote nucleation of organic system supersaturate solution, a nucleation solvent is usually needed. The nucleation solvent for one isomer of allomorphic organic system should be favourable to separating out the isomer. The nucleation of amphoteric substance such as antibiotic and amino acid can be achieved by only applying ultrasonic wave at its isoelectric point or by using ultrasonic wave and nucleation solvent when the system viscosity is high.

The two-probe sensor and rapid changing color high speed photograghy techniques were used in the determination of the initial projection velocities of droplets on sieve trays operating in spray regime. The experimental results confirm that the photographic method can be complemented by the dual probe sensor method in the measurement of the initial projection velocities. A new correktion was obtained to predict the relationship between the initial projection velocities, droplet diameters and gas hole velocities.

The efficiency and kinetics of the destruction of nitrogen - containing organic compounds in waste water by Supercritical Water Oxidation at 673. 2 K-823.2K and 24 MPa-30 MPa was investigated. The removal efficiencies are lower than 10% below 673.2K, and higher than 90% above 823.2 K. The increasing of the temperature, pressure or reaction time will result in the higher removal efficiency. Under the conditions of the experiments, the rate of removal of Kjeldahls Nitrogen is first order,and independent of the concentration of oxygen. The effect of temperature on the rate constant can be expressed by Arrherrius equation. The rate constant depends on the pressure especially near the critical point of water.