Lately the Wilson equation has been very often used in the calculation of vapor-liquid equilibrium. However, it is not easy to obtain the parameters Λ_ij and Λ_ji which can be determined from the binary data only. This is mainly due to nonlinearity with respect to the parameters. We present some procedures to evaluate the Wilson parameters. When a large number of data points are available, the nonlinear least-squares technique coupled with the Q function as an objective function is.to be preferred over any other techniques.
Using the parameters determined from the binary data, we predicted vapor-liquid equilibria for five ternary systems at one atmosphere. The results indicate that the procedures used are of sufficient accuracy for most practical purposes.

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Vapor-liquid equilibrium relationships of four binary systems containing dioxane were measured at atmospheric pressure without using any analytical instrument. The dew-bubble point method was used for the systems methanol-dioxane and ethanol-dioxane. For other systems, benzene-dioxane and ethyl acetates-dioxane, the bubble-condensation point method was applied in the present investigation. The experimental dew, bubble and condensation point temperatures were measured by using a flow-type apparatus. As a result, a minimum azeotrope was observed in the ethanol-dioxane system. The other three binary systems measured were nonazeotropic.

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A prediction method of high pressure vapor-liquid equilibria by the BWR equation of state is presented. This method in terms of ratio of mole fractions in liquid phase can be used more easily than the usual method, and is particularly useful for multicomponent system for which experimental data are not available. This method is shown to be successful in the prediction of the ternary methane-n-pentane system and quinary methane-ethane-propanen-butane-n-pentane system.

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An experimental and theoretical study has been made of the turbulent mass transfer for large Schmidt numbers in the entrance region of a circular tube in which a turbulent boundary layer with small negative pressure gradients develops. Measurements of the local and the over-all mass transfer rates were carried out by use of an electrochemical method for Reynolds numbers of 1×10⁴, 2×10⁴ and 3×10⁴ and Schmidt number of 1561.
A method for the prediction of mass transfer rates in the turbulent boundary layers is also provided.
The equation of conservation of matter is reduced into a form of the heat conduction equation by using von Mises transformation. The equation is then solved by assuming that the distribution of the eddy diffusivity in the developing boundary layer at the entrance region of a circular tube is the same as that for fully developed tube flow and using an eigenvalue technique.
The solution agrees fairly well with the experimental results. This suggests that the above mentioned assumption for the eddy diffusivity distribution in the boundary layer is valid.

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Vapor-liquid equilibrium data at one atmosphere are studied for the system methylene chloride-acetone-salt. The salts ZnBr₂, ZnCl₂, KSCN, MnCl₂, Nal, CuCl₂, CaCl₂, NH₄NO₃ and LiNO₃ are examined to observe the salt effect on the methylene-chloride-acetone system. Effective salts are ZnBr₂, ZnCI₂ and KSCN, which are more soluble in acetone than are MnCI₂, Nal, CuCI₂, CaCI₂, NH₄NO₃ and LiNO₃. An increase of relative volatility of methylene chloride was observed by adding these salts. By extractive distillation with zinc bromide, high-purity acetone with a methylene chloride content of 0.09 (mole %) or less was obtained.

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Iterative method for the determination of stage temperatures, stage reaction rates and interstage flow rates in the problem of multicomponent distillation accompanied by a simultaneous chemical reaction is discussed, and the use of a modified Muller''s method for the convergence of the column temperature profile is proposed. Derivation of the equation is simplified by using matrix notation, which also has the advantage that any interstage flow pattern is allowed. For the solution of the linearized material balance equation, the tridiagonal matrix algorithm is employed. Some problems are discussed to demonstrate the feasibility of the calculations and the fact that quadratic convergence is obtained.

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The rapid growth of the petrochemical industry leads to a demand for highpurity acetone. However, removal of a small amount of water in acetone to less than 1400 ppm by ordinary distillation is a difficult problem. After investigation of removal of micro water in acetone, it has been found that azeotropic distillation employing ethylbromide as separating agent is effective. As basic data for the design of an azeotropic tower, the following physical properties have been measured.
1) Vapor-liquid equilibrium of the binary systems ethylbromide-water at 760mm of Hg in the region of ethylbromide-rich side and ethylbromide-acetone at 760 mm of Hg.
2) Solubility of water in ethylbromide at 0, 10, 20, 30, 34.7°C.
Using ethylbromide as separating agent, azeotropic batch distillations have been carried out through a packed tower. As a result, it has been found that micro water in the feedstock can be reduced to less than 200 ppm.

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Mixtures of m- and p-xylene can hardly be separated by an ordinary distillation technique even if extractive distillation is used.
In the present work a new method for separating the mixture is proposed. Namely p-xylene is enriched continuously by adopting a distillation accompanied by the chemical reaction of trans-alkylation on the basis of the fact that only m-xylene reacts with tert-butylbenzene.
A method of computation is also presented for this new distillation process.

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The rate coefficient of reaction between liquid C₁₈ alpha-olefin and gaseous SO₃ dissolved in it is measured by using a pulse method, developed first to measure the film coefficient of mass-transfer in packed beds. To interpret the rate data obtained from the pulse reactor, a criterion is developed based on the penetration theory to approximate the behavior of a rapid second-order irreversible reaction by that of a pseudo first-order reaction. Experimental procedures and the underlying concept of getting rate coefficient by the pulse method are given to apply it to gaseous SO₃ absorption by liquid alpha-olefins. The second-order rate coefficient k₂ of the reaction for liquid C₁₈ alpha-olefin and SO₃ dissolved in it is found to be:
k₂ = 7.7×10⁹exp(-6.2×10³/RT)

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Experimental studies of the continuous emulsion polymerization of stylene were made for the purpose of examining the consistency of the authors'' theory proposed previously1). Two kinds of seeders, a plug flow type and a backmixed type, were employed prior to the main reactor to analyze the formation of polymer particles, separately from their growth. Although the number of polymer particles obtained experimentally was less than that of the theoretical value due to the presence of a small amount of impurities introduced continuously in the system, the experimental results agreed well qualitatively with those predicted from the theory.

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Average number of radicals per polymer particle was studied theoretically, considering the process for radical to escape from particles and the retardation process in or on polymer particles. Moreover, the physical meaning of the rate coefficient of the former process was analyzed theoretically, on the assumption that radical of lower molecular weight was able to escape from particles. The validity of the above analysis was clarified, using the published data for several monomers. For the average number of radicals, the solubility of monomer in water and the reactivity of monomer are both important factors.

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The scatter of data due to the size distribution and the number of particles to be required in an experiment in a particulate process are discussed in detail. The process dealt with in this paper is that represented by:y = KD^α_P. If the log-normal size distribution is valid, the number of particles required in an experiment and the amount of scatter can be determined by use of only one parameter, calculable from the standard geometric deviation of population-particles, basis number β (β = 0 for the count basis and β=3 for the mass basis), the exponent α, and the magnitude of error required in the experiment. Conversely, the error can be estimated from the number of particles used in an experiment.

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To make clear the local flow around each blade of an agitator, tomographic observations and measurements were carried out with a rotating camera and a plane-light source.
As the result, the profiles of local flow around an impeller look like a saw-tooth wave from a rotating coordinate projected on a horizontal plane, while the profiles of flow along top and bottom sides of each blade seems to be a pair of helicoids.
Two flow models, named vorfex seef model and single vortex model are proposed to explain the action of agitator blade and the flow characteristics near the impeller.

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The authors ascertained the applicability of the method proposed by Metzner to correlate agitation power for pseudoplastic liquids. For a ribbon impeller that is effective for highly viscous liquids this method is also useful. It was found by the authors that the proportionality constant between average shear rate and impeller speed for pseudoplastic liquids can be estimated by using experimental constants of the power equation for Bingham plastic liquids. Correlated results by using estimated values showed good agreement with data for various impellers. For ribbon and anchor impellers, a correlation curve similar to that for Newtonian liquids was observed throughout the whole region of Reynolds number. For turbines and paddles, however, curves for pseudoplastic liquids deviate from Newtonian in the transition region. These phenomena were explained by the spreading of the discharge flow range as in the case of Bingham plastic liquids.

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In the redundancy system of chemical process plants, the author proposes a new type hybrid, or combination of active parallel and standby type in this paper. The author also discusses in this paper which type of redundancy system is most economically profitable for a specific case.
Generally speaking, the standby type is preferable for smaller subsystems, and the active parallel type is preferable for larger subsystems. Quantitative criteria for the above are derived under some assumptions.
Example; Total plant cost is 10 MM and efficiency of subsystem without redundancy is 0.95. Efficiency increase through active parallel and standby redundancy is 0.03 and 0.05, respectively. In this case, for the ratio of subsystem investment cost without redundancy to total investment cost,
0-1.8% standby type is preferable.
1.8%-9% active parallel type is preferable.
Accordingly, a big compressor (0.5 MM) must be of 2 streams and a pump (10 M$) must be of standby redundancy.
Connecting piping system between equivalent parallel systems is also discussed in this paper.

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To display actual values of non-linear reaction in a continuous chemical reactor, micromixing models by Weinstein et al.¹¹⁾ and by the authors⁹⁾ are applied and compared. These models are able to represent the values of micromixing effect by combining the effect of complete segregation and maximum mixedness in proper proportion.
Next, as it might be thought more proper to represent the micromixing effect directly by a mixing model, taking into consideration the flow pattern of the reactor, this is attempted with the mixing model proposed in the previous paper⁷⁾. As a result, it is recognized that the model represents experimental values fairly well, as shown in Fig. 7.

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One of uncertainties in system design is the inevitable estimated error of system parameters. The experimental conditions spherizing the parameter confidence region and minimizing the volume of the parameter confidence region have been proposed to obtain more accurate estimation of parameters. In this paper, a practical method is proposed based on the concepts of the parameter confidence region and its sensitivity to process design. This method can lessen the influence of estimated error of parameters on process design. An example explains the usefulness of this method.

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Values of diffusion coefficients are reported for carbon dioxide and propane into ethanol, heptanol and octanol and for carbon dioxide into methyl cellulose ether solutions at 25°C.
A comparison of the alcohol values with published data for mono-, di-, and tri-hydric alcohols and hydrocarbon mixtures is discussed in terms of the dependence of diffusivity on viscosity.
An anomalous dependence is confirmed in the polymeric solutions examined.

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This paper presents an approximate solution of Neumann''s problem for a semi-infinite solid, taking account of the convection at the surface and of the density change for the solidifying substance. For a special case where heat transfer coefficient at the surface is infinite or very large, a proposed procedure of the approximate solution to the exact solution is discussed mathematically.
Applying the above approximate solution, position of solidifying front as well as temperature distribution in both phases are calculated numerically for an illustrative example, including the dilatation of bulk on solidification.

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The free boundary present in a class of Stefan''s problems in spherical geometries introduces a nonlinearity and thus imposes a formidable obstacle to exact solutions inspite of a number of recent studies claiming the contrary. The degree of approximation affected by the so-called pseudo-steady-state solution is still undetermined.

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