In this work, ethylene selective oxidation reaction, as a model reaction, has been experimentally studied and simulated by computer in terms of dynamic operation and transient response to step-change in feed composition. The relations among periodic operation performance, transient response characteristics in a differential tubular reactor and the dynamic behavior of the elementary processes of this reaction system were investigated.

Forced composition cycling experiments were carried out at 0.1MPa total pressure and 250℃. A maximum in the time-averaged selectivity-period curve was found at the period of about 1 min, being higher by 5% than its optimal steady state value. A cycling operation model including all kinetic parameters of elementary steps was used to simulate the dynamic process of forced composition cycling. The results of simulation showed that this model can predict a maximum in the time-averaged selectivity-period curve but the period at which the maximum was found was much less than 1 min. It suggested that cycling operation could probably cause a slow change in the bulk phase or/and on the surface of the catalyst.

In a φ500mm cold model of radial flow moving bed reactor, the distributions of pressure and velocity in the main channels were studied under four kinds of gas flow mode: inward Z gas flow; inward gas flow; outward Z gas flow and outward II gas flow. It was found that in the outward n gas flow mode, the axial non-uniformity of gas is minimum (less than 5% under the experiment condition). Correlations about the momentum recovery factor K were proposed. The distribution of pressure in the main channel can be predicted accurately.

The axial circulation, power consumption and Metzner constant Kswere measured for 19 types of helical screw impellers with a draught tube in the laminar regime. On the basis of an analogy between this mixer and a screw extruder, the semi-theoretical correlations of the circulation number Ci, power consumption Kp and Metzner constant Ks were obtained. The influence of elasticity on circulation number Ci was also studied. The elasticity seemed to dampen the axial circulation and the circulation number Ci of viscoelastic fluids was lower than that of Newtonian fluids.

The extended Hukel theory was applied to compute molecular orbits of 17 typical components of naphtha. On this basis, a general principle of seeking the best lumping scheme was put forward by means of fuzzy analy sis. The catalytic naphtha reforming process was then studied by analysing the 17 typical components. Lumping schemes with different λ levels were obtained. Theresults of comparing these schemes with the models of catalytic naphtha reforming reported in literatures showed that the lumping schemes with different λ levels agreed well with the lumping models. According to the principle given in the paper, it can be seen that the four components lumping model of Smith corresponds to a λ level of 0.93, the 13 components lumping model of Mobil Co. corresponds to a λ level of 0.97, and the 22 components lumping model of Kmark corresponds to a λ level of 0.98.

Two types of azo dyes with p-(β-hydroxyethyl sulphonyl sulphuricester)aniline, 2-amino-6-(β-hydroxyethyl sulphonyl sulphuric ester) benzothia-zole as the diazo components and aniline with different N-substituted groups as the coupling components were synthesized. The relationship between the molecular structure and the dye distribution in the cotton and polyester portions, dye absorption spectra, the colors ot cotton and polyester portion, and lightfastness were discussed.

Two heterocyclic intermediates of 2-amino-6-(β-hydroxyethyl sul-phonyl sulphuric ester)benzothiazole and N-(β-hydroxyethyl sulphonyl ethyl)-2,2,4,7-tetramethyl-1,2,3,4-tetrahydroquinoline were synthesized, and therefrom six red-blue colors of azo reactive disperse dyes were prepared. Their dyeing behavior on nylon and polyester-cotton blend was studied.

The fermented broth with dense cell aggregated particles under aerobic conditions as a three phase system was simulated by inert ion-exchange resin particles and the gas holdup of such a system in an air-lift biore-actor was investigated. Based on the data taken from the simulated system and the measurement on a real yeast flock cultivation system, the correlation of gas holdup with superficial gas velocity, circulating velocity of suspended me-dium and interfering sedimentation velocity was obtained. The predicted values from correlation agreed well with experiments.

Standard sieves were used to grade the catharanthus roseus cell aggregate rates of the previous ten subcultures. From the experimental results of the mean diameter of the catharanthus roseus cell aggregates in sub-cultures, it was found that the size decreased first, then increased and finally reached a relatively stable value. A trial is presented here to apply fuzzy sub-cluster theory to the high degree dispersion size distribution of plant cell aggregates. A model equation of integrate size distribution of plant cell aggregates was obtained. The model parameters were estimated by Marquardt nonlinear optimal method. The model values agreed well with experimental data.

Lactic acid was produced by immobilized L. clelbruecku in a fixed-bed reactor and then separated in a column filled with poly(4-vinylpyridine) as adsorbent. The fementation process was described by a fermentation kinetics model with axial dispersion and the fixed-bed adsorption process was described by a linear-driving-force model to give satisfactory simulation results.

A single microdroplet was suspended in an electrodynamic balance and adjusted in a polarized laser beam. The scattered light from the micro-droplet was detected by a photodiode array and stored in a microcomputer. In addition, the optical resonance spectra were continuously recorded by a PMT at 0 = 90°. Comparing the light-scattering profile (intensity versus scattering angle) and the resonance spectra with Mie theory, the size of the micro-droplet and the change of its size as a sphere can be determined precisely.

An iron/chromium redox flow cell system (270W) was constructed with polyarylonitrile graphite felt electrodes. Its bipolar plates were graphite plates soaked with paraffin. The positive and negative compartments were separated by the cation exchange membranes made of polystyrene sulfonic acid. The electrocatalyst for negative electrode was Pb-Bi combination electrodepos-ited before the operation of the system, which was also a negative electrode hydrogen evolution inhibitor. The measurements of the redox system showed its high stability in performance during the period of about 120 charging and discharging cycles. The current, voltage and energy efficiencies of the system were 93%, 78% and 72% respectively.

Preliminary studies of the backmixing coefficients of the continuous phase in a liquid-liquid Kuhni extraction column using a steady state tracer injection technique and backflow model have been carried out for the system of MIBK-deionized water in two-phase countercurrent operation. The experimental data indicated that the backmixing coefficients oi the continuous phase increased with the impeller speeds under normal conditions of agitation. An increase in the flow rates of the continuous and dispersed phases caused remarkable and slight reduction in the extent of backmixing respectively. An empirical correlation for backmixing coefficients αc was developed.

The real state of vapor liquid equilibria is considered as a combination of three fictitious states. From the relation between the real state and three fictitious states, the approximatep, y, x relationship can be obtained from these fictitious states with the help of the Gibbs-Duhem equation. This method was used to calculate isothermal high (low) pressure vapor liquid equilibria with satisfactory results, while no equations of state or equations of activity coefficients were needed.

This paper proposed an absorption heat pump cycle of the type-II using water/diglycol as the working pair. Based on the principles of thermodynamics, a mathematical model describing this heat pump was established. The theoretical model was tested experimentally, and the calculated results agreed with the experimental results. The effects of operating conditions, such as heat source and sink temperatures, reflux ratio and heat transfer effectiveness of the solution heat exchanger on the performance of the heat pump were studied and analysed.

Electromotive force measurements of the cell Na ion-selective elec-trode(glass) |NaBr(m), MeOH(w), H2O(100-w)|Br ion-selective electrode (solid state)were made at molalities of NaBr ranging from 0.01 to 3.0 in the mixed solvent of methanol-water containing 0, 10, 20, 40, 60, 80, 90, and 100 weight% methanol, respectively, at 298. 15K. Calculations of standard cell potential were made by using the Pitzer equation, and then the mean activity coefficient values of NaBr were evaluated. The association constant of NaBr in methanol were evaluated from the experimental E. M. F. data by using the Pitzer-Simonson equation extended to the binary systems containing ion pairing. The weak association of NaBr in methanol was shown. At each fixed solvent composition, the mean activity coefficients of NaBr first decreased and then increased with rising NaBr molality. At each fixed NaBr molality, they decreased with an increase of methanol in solvent mixtures.

The synthesis of α,ω-di-chloropolyisobutylene has been accomplished by cationic polymerization using 2, 10-dimethylundecane-2, 10-diacetate initiator in conjunction with BC13 co-initiator in CH2Cl2 solvent at -30℃. The polymers with high conversions, low molecular weight (Mw= 1185 - 1799) and narrow molecular weight distribution (Mw/Mn = 1.59-1.68) could be obtained. Furthermore, the formation of undesirable indanyl structures during initiation could be avoided by using this aliphatic tert-diacetate initiator.

The effects of pressure, mass flow rate and heat flux were studied in detail on the maximum temperature rise of the tube wall and the corresponding steam quality as well as the minimum heat transfer coefficient when heat transfer crises happened. The experimental results showed that these effects were quite great. The prediction correlations for the post dryout heat transfer parameters mentioned above were established. They coincided well with the experimental data obtained in the range of pressures from 5MPa to 18.5MPa, mass flow rates from 800kg/(m2·s) to 2000kg/(m2·s) and inner wall heat fluxes from 320kW/m2 to 700kW/m2.

Based on a theoretical analysis for the heat transport of nylon 6 melt in a tube reactor (VK column), various charts of radial temperature distribution and heat graphs in connection with three typical flow profiles are presented in this paper. For plug flow, the residence time of the fluid in the reactor is uniform. However, plug flow does not demonstrate significant superi-ority over others in terms of radial temperature difference. Therefore, a good baffle must have the best radial mixing and the minimum axial mixing effect, so as to insure uniformity for both physical properties across a section and residence time of fluid through VK column. The radial temperature distribution and heat graph in this work can reflect this combined effect to some extent. Results show that the radial temperature differences will increase greatly with scaling-up.