Effect of diffusion resistance on reaction by using an immobilized yeast entrapped by Ca-alginate gel was studied. Intraparticle effective diffusivity of substrate, D_e, depends upon cell density, c_c, i.e. D_e/D_o = k₂(1 - k₁c_c)². Here, D₀ is a reference diffusivity, e.g. diffusivity in water; k₁ and k₂ are constants. Overall reaction rates of ethanol production by immobilized resting-yeast were measured. Experimental rates coincide well with calculated results using the effective diffusivity and reaction rate of free cells. Diffusion seemed to be restricted by cells. Thus large cell density does hot necessarily mean high reactivity. Finally, the curvature of the Lineweaver-Burk plot is pointed out.

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Measurements of the adsorption of binary gaseous mixtures of methane-ethane, ethylene-propane, ethane-propane and propane-w-butane systems on molecular sieving carbon MSC-5A were carried out at a temperature of 303.15 K and pressures of 13.3 or 40kPa. Experimental results are compared with the predictions of the two-dimensional fluid model which takes into account the interaction effect of the adsorbate. It is shown that the model predicts values which are close to the experimental results.

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Adsorption equilibria were measured for binary systems of hydrocarbon gaseous mixtures containing polar components. Three different adsorbents were used: molecular sieve 13X, activated carbon G-2X and molecular sieving carbon MSC-5A. The experimental results were compared with results calculated according to two currently adopted prediction methods: the ideal adsorbed solution model and the two-dimensional fluid model.
The adsorption equilibria of molecular sieve 13X were in good agreement with the predictions from both models. However, neither model was found to give a good fit with the adsorption equilibria obtained with the other adsorbents.
It is shown that the adsorption equilibria of activated carbon G-2X can be well predicted by a modified twodimensional fluid model which takes into account the distribution of the local molecular concentration. The experimental results obtained from molecular sieving carbon MSC-5A are considered to be accounted for by the nonuniformity of the adsorption energy.

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The method for producing a dilute solution of hydrogen peroxide by reduction of oxygen was examined. In preliminary experiments with an H-type dual-compartment reactor, the most suitable conditions were determined to be as follows. The reaction temperature was 288 K, the cathode graphite, the anode nickel, the catholyte 1 mol•dm^-3 KCl plus 0.01 mol•dm^-3 NaOH solution and the anolyte 1 mol•dm^-3 NaOH solution. In the packedbed electrode reactor with graphite particles, the rate and the current efficiency of producing hydrogen peroxide were dependent on the initial bed overpotential, the liquid velocity in the reactor and the oxygen flow rate in the catholyte tank. The production rate of hydrogen peroxide at an initial bed overpotential of - 0.4 V was clarified by the model analysis under the limiting current condition.

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The thermal decomposition of "Taiheiyo" coal was investigated experimentally, using a thermal argon plasma. The thermal plasma was generated by an arc discharge, and the temperature was approximately 10, 000 K. The plasma and fine particles of coal were introduced into an 8 mm-i.d. tube reactor. The conversion to gasified products increased with increased plasma flow rate, and showed a maximum with the variation of input power.
The conversion of a coal particle was estimated by the energy balance. The main assumptions were that the decomposition rate was limited by heat transfer, and that the coal particle decomposed at a constant temperature. The results of this method are in good agreement with those of the experiments. The temperature profile within the particle was evaluated by numerical calculation.

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Vapor-liquid equilibria (VLE) for single electrolyte systems NH₃-H₂O, HCOOH-H₂O, CH₃COOH-H₂O and C₂H₅COOH-H₂O were measured at 101.3kPa in dilute electrolyte regions. The experimental data were compared with the results calculated by the Wilson equation or the Margules equation which were extended to the whole concentration range of weak electrolyte, and good agreement was found for the present systems.
Further, the effect of pH on VLE was measured for NH₃-H₂O and CH₃COOH-H₂O systems at 101.3 kPa and the pH effect was predicted by using the Wilson equation mentioned above. Agreement between calculated and experimental results was very good.

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For the kinetic analysis of non-catalytic solid-gas reaction by thermogravimetry, the rate equation f=1- exp[- a(T- c)^b], (f= fractional conversion of reactive solid, T=temperature, a, b, c = constants) was proposed to follow precisely the experimental TGA curve (f vs. T) obtained by a temperature-programed run at heating-up speed φ = dT/dθ (θ = reaction time). Assuming the reaction to be first-order with respect to weight of reactive solid, a method based on data-fitting process was derived to determine the rate constant kφ and kinetic parameters (activation energy E and preexponential factor A) of the Arrhenius-type rate constant, from only a single temperature-programed run.
The proposed method was applied to experimental data on the gasification of coal chars with steam and carbon dioxide at temperatures up to 1000°C, and was confirmed to be valid and useful for the quantitative evaluation of kinetic parameters and the comparison of gasification reactivity of coal char.

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A kinetic study of sulphur dioxide capture by calcined limestone at 1123K was conducted by thermogravimetric analysis over a relatively wide range of diameter of limestone particles and concentrations of oxygen as well as sulphur dioxide. The experimental conditions were chosen by taking into consideration the practical operating conditions of a fluidized-bed coal combustor. Results are reported in particular on the effects of oxygen concentration on the rate of sulphur dioxide retention; these effects are of practical importance for staged air firing operation of the bed. A formula which took into account the oxygen and sulphur dioxide concentrations could predict the rate of sulphur dioxide retention at various degree of utilization of sulphur sorbent by defining an approximate maximum utilization level as solid reactivity. This parameter could be expressed by a linearly and monotonously decreasing function of the rate. Detailed effects of particle size on the expression were investigated.

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The relationship between the mixing process in a swirling jet and operational parameters Re and Re_θ, which are respectively the general Reynolds number based on cross-sectional average velocity in a jet nozzle and the newly defined swirl Reynolds number based on characteristic angular velocity of swirling motion at a nozzle exit, was investigated by measuring concentration distributions of expanding tracer puffs.
It is clarified that the increase of Re promotes both radial and axial mixing, and that the increase of Re_θ greatly promotes radial mixing but suppresses the axial mixing. Considering the effects of Re_θ on the Peclet number, it is made clear that the mixing process is remarkably changed by the generation of reverse flow in a swirling jet.

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In the solvent extraction of nickel from aqueous ammonium nitrate solution with anti-2-hydroxy-5-nonylacetophenone oxime in MSB 210, measurements of initial extraction rate using a stirred transfer cell were carried out at 30°. The extraction rate was found to be described by the rate expressionIn the solvent extraction of nickel from aqueous ammonium nitrate solution with anti-2-hydroxy-5-nonylacetophenone oxime in MSB 210, measurements of initial extraction rate using a stirred transfer cell were carried out at 30°. The extraction rate was found to be described by the rate expression
N=1.1×10^-10[Ni²⁺][HR]/[H⁺]/1+1.1×10_-6[Ni²⁺]/[H⁺]

which was derived on the assumption that the elementary reaction step between the intermediate complex adsorbed at the interface and free extractant molecule in the aqueous phase is rate-determining. The reason why this step is rate-determining was inferred.

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An asymmetric pressure distribution in a pair of rolls rotating at equal and unequal speed for Newtonian fluid was obtained by lubrication model analysis and was compared with experimental values. The work was carried out with a pair of rolls of radius R = 8.2cin in the range of fluid viscosity μ = 1.5-15 Pa•s, half of minimum nip clearance h₀ = 35-390μ/m, mean roll speed u_m = 0.26-1.56 m/s and roll speed ratio N_r = 0.5-7.
The experimental pressure profiles and force separating rolls are well represented by the calculated values in the region of N''_ca (= μu_f(R/h₀)²/γ)<2.5 × 10⁷, where γ is liquid surface tension. In the range of N''_ca>2.5 × 10⁷, the absolute values of the minimum pressure decrease with increasing N''_ca. The theoretical pressure distribution can be well corrected by considering that the liquid film separating point predicted by the theory comes near to the minimum nip.

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Samples from a used automotive tire were subjected to sub- and supercritical extraction with w-pentane, toluene and nitrogen. Solvent effectiveness for extraction was greatest for toluene and least for nitrogen. When the extraction with toluene was completed at temperature 653 K and pressure 5.2 MPa, for instance, 57 % (by weight) of the sample was converted to liquid oils and 40 % remained as solid residue. Rate constants for extraction with n-pentane, assuming that the process is first-order, increase with both temperature and pressure. Scanning electron microscope pictures show that many cavities are produced inside the solid during extraction with toluene and n-pentane. From this evidence a qualitative explanation of the process is suggested.

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