Studies were made with a view to obtain some method and apparatus for a high yield of chlorobenzene, preventing the formation of dichlorobenzene.
We adopted a double-tube reactor, which is actually of triple-tube when the water jacket is taken into account. The inner tube is made of iron, with some holes near the bottom to connect the inner and the annular space.
The reactor was charged with benzene up to the top of the inner tube. Chlorine, mixed with inert gas, nitrogen, was introduced into the inner tube from the bottom, by means of which the liquid was lifted with gas bubbles and circulated through the annular space. The inner iron tube was gradually reacted to form the necessary catalyst FeCl₃, which helped to chlorinate benzene.
At some intervals the liquid samples were analysed to see the concentration of chlorobenzene and dichlorobenzene. The concentration of FeCl₃ in the liquid and the composition of the exit gas were also examined. The yields of chlorobenzene and others were measured at 30°C, 50°C and 70°C, which revealed the following results.
(1) By some preliminary experiments it was found that the mixing of an inert gas was very effective for the circulation of the liquid and prevention of dichlorobenzene formation.
(2) At 30°C we obtained an extraordinarily high yield of chlorobenezen, in some cases over 98%, without any appreciable formation of dichlorobenzene.
(3) In the process, FeCl₃ was produced by the reaction of iron tube, and the actual concentration of FeCl₃ was found to be several times higher than those in the literature.
(4) The chlorination was checked by the presence of a small quantity of water.

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The authors examined the methods hitherto employed for the solution of cylindrical reactor equation in which the radial distributions are taken into account, and here they propose several new numerical methods for it.
These methods can be applied:
When the inner- or outer-catalyst- type heat exchanging reactor is employed;
When there exists non-uniformity in the flow velocity and effective thermal conductivity at the cross section of the reactor; and when the temperature of the cooling or heating path is varied.
1st Method: Previously reported.⁸⁾
2nd Method: Simultaneous first order differential equations on Ti (l) and Ci (l), i=0, 1, 2, …n, which are defined by the equations (6) and (7), are solved.
3rd Method: T and c are expanded into such equations as (10) and (11) and the simultaneous first order ordinary differential equations, containing the expansion coefficient as a function of l are solved.
4th Method: When the activation energy is small, VQ is assumed to be expressed by equation (12) in a small division. Analytical solution, satisfying the boundary condition for r and the distribution at the section l=l_o is used for determining the distribution at l=l_o+Δl.
5th Method: T and c are expanded into functional series which satisfy the boundary conditions for r. Simultaneous equations containing the expansion factor which are functions of l are derived and solved. In this case VQ is assumed to be expressed by equation (23) in a small division. The last method serves its purpose comparatively better than the rest.

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The continuous esterification of acetic acid in an excess ethanol with sulfuric acid catalyst was studied, using a packed tower. The main reaction tower, 157.8cm in height and 3.79cm in diameter, was packed with Raschig rings (5.78×8.10mm). The feed of alcohol, vaporized through the vaporizer, was led to the bottom of the tower, and the feed of acetic acid and catalyst sulfuric acid was mixed with the reflux and led to the top of the tower in a liquid form. When the reaction was completed, samples were taken and examined so as to determine the composition.
The analysis has been made on the following assumptions:
(1) The reaction is homogeneous in the liquid phase.
(2) The ester formed is rapidly removed and reverse reaction is negligible. In an excess alcohol, the reaction is that of first order in respect to acetic acid concentration.
(3) There is a certain proportional relationship between liquid composition and its equilibrium gas composition.
The general relations derived on these assumptions are expressed by Eqs. (3), (4), (9) and (10). When the rate of mass transfer is very small compared with the reaction rate, said relations can be simplified in the form of Eq. (16). From the experimental results, the calculated reaction constant is found to be proportional to the sulfuric acid catalyst concentration, as shown in Fig. 4.

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Both the theoretical and experimental studies were performed with respect to the fluidized-solids reactors for particles, whose diameters decrease with time in the fluidized bed. Starting from the kinetics of the reaction for one particle, and applying the law of elutriation for the holding time of each particle, the overall reaction kinetics of fluidized bed was studied, and the theoretical quations for the carry-over rate, bed weight and size frequency distribution functions for the bed itself and carry-over were derived.
As an example of particles having such characteristics, pitch coke particles with wide size distribution were gasified with air in the fluidized-solids reactor of inner dia. 11cm, and the elutriation velocity constants were correlated as shown in eq. (21)-(23).
Then the experimental results were analysed with the theoretical equations, by which the adequacy of these theoretical considerations to express the kinetics in the fluidized bed was proved.
Lastly the overall rate coefflcients of gasification were obtained from the experimental data, and the effects of agglomeration of particles or turbulent diffusion in the fluidized bed were discussed, considering the results of the authors' preceding experiments.⁴⁾

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The indicial response, the residence time curve and the escaping probabity of reactants from a continuous flow reactor in which the reactants are mixing have generally been expressed by Eqs. (2), (3) and (5), applying the Duhamel's integral to the system composed of a single reactor or multistage-reactors in cascade, each of which has a known indicial response and a linear characteristic.
The above general equations are applied to the analysis of the mixing characteristics of a continuous flow reactor in which the mixing is incomplete and the mean diffusivity of the reactant can be assumed.
It has become clear that the steady reaction in such a system can independently be determined by two dimensionless parameters of U and R_i (see Tab. 1) and that the reactor divided into multistages in cascade gives higher yield than the single stage reactor.
The mixing characteristics of such a continuous reactor as illustrated in Fig. 4-a are experimentally analysed using the puls-wave method… the quantitative details of this method are described in Eqs. (4), (8) and Fig. 2. The experimental results indicate that the system may well be expressed by the reactor model in which the mean diffusivity can be assumed. Behaviours of various types of such reactors are correlated as Figs. 8, 9 and Eq. (17).
Finally, the dimensionally similar scale-up of the stirred reactor which is long in the direction of fluid-flow has been discussed with respect to the fluid-mixing, steady chemical reaction and other rate coefficients, such as those of heat-transfer and mass-transfer.
Eqs. (18), (21) and Tab. III are the necessary conditions determining the characteristics of such scale-up, where the analysis is based, for convenience' sake on the Büche's hypothesis of "equal power per unit volume." The Rushton's criterion on the scale-up is also applicable to this purpose with similar procedures as above.

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化学反応装置内の反応過程をなるべく有利な条件で行わせるように装置の型式の撰定,具体的寸法および操業条件の決定などがなされなければならない。これが反応操作設計の目的である。ここではNH₃合成を例にとって,断熱型およど自己熱交換型操作の設計の概要を示す。

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