Experiments in gas absorption of pure sulfur dioxide and carbon dioxide by water were carried out in a 7.0cm packed tower to obtain liquid film coefficients directly, and the absorption mechanism for both the gases were compared.
Packings used were 25mm and 15mm Raschig rings and the packed heights were 30.0cm.
Liquid film coefficients of sulfur dioxide were lower than that predicted from the carbon dioxide data by the Sherwood-Holloway correlation⁶⁾ as shown in Fig. 1 and Fig. 2.
By means of the hydrolysis hypothesis suggested by Whitney and Vivian⁹⁾, pseudo liquid film coefficients of sulfur dioxide were calculated. These coefficients were in excellent agreement with the predicted values from carbon dioxide data as shown in Fig. 3 and Fig. 4.

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We studied the so-called Ferrox process which is one of the wet processes for removing H₂S from gases by using Fe(OH)₃ suspension method.
First, we analysed the H₂S absorbing solution which is practically used in the gas factory, and confirmed that it was moderately alkaline and that thiosulfate and ferrocyanide ions existed in it.
Next, we studied the absorption velocity of H₂S by different concentrations of alkali and alkaline ferric hydroxide in suspension, and confirmed that there was scarecely any effect of alkali concentration on the H₂S absorption within the range of P.H .8-12, and that the exccess alkali retarded the regeneration of the desulfurised solution.
From these results we derived the mechanisms of desulfurization, which is shown by the following equation:
We consider that the effects of desulfurization by the method can be determined by the dissolution of H₂S in the solution and the removal of Fe₂S₃ formed in the reaction zone.

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The experiments in absorption of CO₂ gas by water were carried out by means of a perforated plate column. It was studied how the Murphree efficiency and L_x varied with the construction of the plate, gas velocity, overflow rate and the height of the weir etc.
From the results of the experiments the following conclusions were obtained.
(i) If only, the liquid film resistance exists the Murphree efficiency shows the maximum value when the gas velocity gives the maximum foaming height, with the overflow rate maintained constant.
Murfhree efficiency increases with decreasing overflow rate and with increasing weir height. The hole diameter and pitch have no appreciable influence upon the Murphree efficiency, so far as the hole diameters are 0.6 to 2.0mm and their pitch are 2 to 5 diameters.
(ii) When the concentration of gas is constant throughout a tray, Murphree liquid efficiency is calculated by the following equation,
For the abosorption of CO₂ gas by water, the length per transfer unit for liquid film is given by the following relation.

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Absorption of pure carbon dioxide (97-99%) by the city water was carried out in the wetted-wall column, which was constructed of standard 1/2″ iron pipe. The liquid film height per transfer unit, H_L, based on the log. mean driving force was calculated from the data obtained over the range from 100 to 2, 000 of (Re)_L. (Re)_G was kept constant at about 700 for the majority of runs, since it was found by the preliminary runs that it had not any effect on the rate of absorption.
The length of tube was varied from 508 to 1856mm.
The discrepancy between the experiments and the theories by Hatta and Pigford was clearly recognized as already pointed out by Sherwood and Pigford in their book. While Emmert and Pigford tried to verify the theory by the interesting experiments using wetting agent, we attempted to explain the discrepancy by other theoretical relations derived here which were based on some added assumptions. These relations are not satisfactory, but they show somewhat better agreement than the previous theoretical lines.
We recommend the experimental equations presented here for practical purposes, until a more perfect theory with due regard to the effect of turbulence is established in future.

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Absorption of CO₂ was carried out with the mixed phase flow of CO₂-air mixture gas and KOH solution in vertical glass pipes of 12.8mm and 17.8mm i.d.
The K₂CO₃ concentrations in the flowing solution were measured at various points along the pipe. This reator was, for convenience' sake, considered separately in two sections as divided according to the concentration gradients: one was the accelerating section where the concentration gradient was curved by the mixing effect, and the other was the steady flow section where the gradient was nearly linear.
Mass transfer coefficients were calculated by the next equation:
The effects of various factors on K_Ga were investigated in each flow section as follows: -
1) for the accelerating section (0.17m)
2) for the steady flow section
3) for the whole section (1.26m)
4) K_Ga was inversely proportional to the pipe diameter.
5) K_Ga was increased with the KOH concentration within the Experimental range. (0.8-2.03 N KOH)

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The present paper deals with our study on the physical absorption by pure water made for the purpose of subsequently studying the capacity characteristics of CO₂ absorption byalkaline solutions in a packing tower.
10mm glass rings were packed in a glass column of 50mm i.d. by the height of 500mm, intowhich almost pure CO₂ gas was introduced to be absorbed by distilled water.
We obtained the following two series of the results, when the temperature was reduced to 15°C.
k_La=3.30L^0.79 (1)
i.e., (H.T.U.)_L=0.303L^0.21(1a)
and k_La=4.56L^0.79 (2)
i.e., (H.T.U.)_L=0.219L^0.21 (2a)
Eq. (1) represents the results derived with the stock rings which were water washed and newly packed, therefore considered as moderately clean; while eq. (2) represents those of the repeated experiments with the same rings without repacking, which, however, were alkaline washed by being kept overnight in the same column filled with 1N-KOH solution and then water washed.
The k_La values of eq. (2) were 1.38 times that of eq. (1), mainly due to the change of the effective area; at any rate k_La was proportional to L^0.79 in both the cases.
Great differences were observed among the data of many papers in the literature concerning the capacity coefficients and the active area of packing towers. Usually no particular references have been made to the cleanliness and the preliminary treatment of the packing. According to the experiments dealt with in this paper we found that we could not neglect the effect of the cleanliness of the packings.
Also, as observed in the literative, it was difficult to obtain satisfactory data for liquor whose rate was less than 5[m³/m²·hr].

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Collecting or removing of solids or gaseous components held in gas in one of the industriallyimportant operations. Formerly we obtainedhigh washing efficiency using the Venturi scrubber for purification of blast furnace gas, and successfully replaced a cottrell by it in practical operation. The present paper is intended to report that we obtained as high as about 90% collection efficiency both in the case of pyridine bases and arsenious acid, using successively the Venturi scrubber for recovering pyridine bases and naphthalene in coke oven gas, and for removing arsenious acid in waste gas produced in dearsenization of iron ore by sintering. Thus it was found that the Venturi scrubber was not only effective as a separating apparatus for gas-solid system, but also as an absorption equipment. However many problems in chemical engineering are left unsolved yet as to the Venturi scrubber and further studies will be necessary before it is put to use for physical absorption, etc. The Venturi scrubber has a weak point in its large pressure drop, but its superiority in low installation cost, low operating cost, simple operation, etc. will more than make up the above-mentioned drawback, and in future it will be profitably employed in various fields of chemical engineering.

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