For the purpose of enlarging the utilization of the two kinds of colloidai earths, we studied the adsorptlon of S Oa fro ai SO2 system by granulated earth To elucidate the surface structure of colloidal earth, we compared the results of there system with those for the adsorbents generaly used such as silica gel, alumina gel and acti ated carbons.
The experiment was carried out by using the fixed adsorption bed and the SO2 gas whose concentration was about O.2 vol% (2000 ppm).
The obtained results are as foilows;
1) The adsorption isotherm of SO2 gas-air system is of the Freundlich type and the following relations between C and X for each colloidal earth are found;
X e.070. Ce 20g(for Imaichi C. E.), X O.044. ii2(for Terauchi C. E.)
where C is the concentration of SOti gas (vol %) and X is the adserbed amount of SO2 gas (SO2 1).
2) Trmhe ntfollowing relations are also found between R. number and (H. T. U.)dG for each colloidal earth (R. number 300, mixed gas temperature=20 C, the adsorption column diameter 61 mm and column height=1.8 m):
(H. T. U.)oG O, e20. R.25 (for lmtaichi C. E, the concentration of SO2 (O, 25 vol %)
(H. T. U.)06 O. e30. R. C, 5 (fer Terauchi C. E., the concentration of SO2 (O.30 vel %)
3) Different behavior observed with the two colloidal earths may be ascribed to a difference in the Fe20s content of both earths.
4) lt is inferred that the surface of Terauchi colloidal earth consists of alumina gel, because its break-through-curve resembles that of alumina gel. A large adsorptien capacity of lmai hi colloidal earth appears to be ascribed to the presence of removable Fe20s gel on it.
5) Both colloidal earths, , especially lmaichi colloidal earth, are usefu1 for the desulfurization of SO air system