The reduction of A6 ammonia synthesis catalyst under atmospheric pressure and at temperatures 435-530℃ has been studied. It is found that when the reducing temperature is below 515℃, the catalyst cant be reduced completely but only to a limited extent. At 435℃, 490℃and 515℃, the maximum extent of reduction corresponds to 22%, 82%, and 100% respectively. The result of X-ray structure analysis shows that before reduction the catalyst has a structure of spinel and changes to (a)-Fe after reduction. The portion of the spinel which appears more difficult to be reduced is smaller in its lattice constant. A series of activity tests under 300 atms for samples with different extent of reduction have been carried out, and the constant of reaction rate with Tern-kin Equation has been calculated. It is found that the portion of the catalyst which appears more difficult to be reduced possesses higher specific activity after reduction.

Dichloroacetaldehyde, an intermediate of organic insecticide, can be synthesized by the catalytic chlorination of paraldehyde or aldehyde. The selection of catalysts, the temperature of various stages of the reaction, etc., were investigated and dichloroaldehyde was obtained in good yields. The experimental results indicate that antimony trichloride is more active than sulfur for catalytic chlorination of paraldehyde or aldehyde. It is necessary to control the reaction temperature, the quantity of catalyst and the molar ratio of the reactants accurately. The product, containing 90~95% of dichloroacet-aldehyde, was obtained in 75~78% yields. Formation of tarry distillation residue due to the polymerization increases with the increasing of the reaction temperature or the quantity of antimony trichloride.

Two kinds of liq-liq. system and columns of 1-inch and 2-inches diameter have been used in this study. Correlation of all experimental data gives an equation of the type Vd/x + Vc/(1-x) = Vo (1-x)n instead of the more simple equation Vd/x + Vc/(1-x)=V0(1-x) given by J. D. Thornton. Data of kerosene-water system in 1-inch column gives n=2.2±0.2. Flooding velocities calculated by use of the equation obtained are very close to the values actually measured.

Four ternary systems have been used for the determination of mass transfer rates between single organic drops and aqueous solutions. The solutes chosen are highly in favor of organic dispersed phase so that the resistance can be considered solely in the continuous aqueous phase. In the experiments for pure systems, special attention has been paid to the purification of all substances employed and to the avoidance of possible contaminations of apparatus and both liquids, and reproducible mass transfer results can thus be obtained over the range of drop Reynolds number between 4 and 1000. These data have been used to test various correlations proposed by different authors, and it has been found that each correlation can fit only a limited range of drop Reynolds number, i.e. at Re≤50, the measured continuous phase coefficients essentially follow those of solid spheres during dissolution, at Re≥1000, nearly agree with those predicted from the equation proposed by Handles and Baron[26], and at 100

Mass transfer rates of n- and i-butanol into single water drops falling through continuous phases of these liquids have been measured using Colburn and Welch technique. The results, after having been corrected for end effects and expressed as dispersed-phase mass transfer coefficients as well as a correlation factor R, have been compared with the Kronig and Brink model and with some selected data published in literature. From the results obtained it seems reasonable to conclude that the Kronig and Brink model will apply to circulating drops up to a drop Reynolds number of 50 or 60, which is similar to the conclusion reached recently by Treybal after careful examination of Johnsons paper, and will fail to remain valid above 80. The data are generally in agreement with those given by Johnson et. al. on single drops but somewhat higher than those of Heertjis et. al. in spray towers. The i-butanol-H2O system is found to show larger deviations all the way from the theoretical values than the n-butanol-H2O system. In as much as no interfacial turbulence has been observed by Schlieren technique in both cases, the difference in mass transfer rates between two systems can only be attributed to the difference in drop behaviour caused by the difference in such properties as viscosity and interfacial tension, and shape of drops. The variation of drop terminal velocities with drop sizes has also been examined. The results are found to be lower than those predicted by the correlation of Hu and Kintner for drops without mass transfer, but they are similar in trends in that the terminal velocities show also a maximum value at a certain transition drop diameter of about 3.5mm (this is in fair agreement with the calculated values of 3.5 and 3.8 mm for n- and i-butanol, respectively). It is thus likely that the Kronig and Brink model could apply to these systems up to such a drop size, above which the results would appear to approach a model descri bing the behaviour of oscillating drops such as that of Handles and Baron.