アンモニアガスの吸着除去に関する研究 ＩＩ 各種ゼオライトによるアンモニアガスの吸着

Abstract

The adsorption of ammonia gas on eight kinds of zeolites was measured by the static method at 30°C and up to 70, 000ppm. The difference in the adsorption of ammonia gas on activated carbons and zeolites was examined through the results of amount adsorbed, adsorption isotherm, and rate of adsorption. The relations between the amounts of ammonia gas adsorbed on zeolites, rate of adsorption and their physical properties were discussed as to specific surface area, pore volume, and pH.The results were as follows : 1) The amount of adsorbed on each zeolite was roughly the same and was approximately 40 times as much as that on the activated carbons (No. 2, No. 3, and No. 6) at lower equilibrium concentrations up to 1, 000ppm.2) The adsorption isotherms of ammonia gas on the activated carbons and zeolites were found to follow Freundlich's equation and Langmuir's equation, respectively.3) The rate of adsorption of the zeolites of which pore diameters were 3 Å and 4 Å was much slower than that of activated carbons, and their time of reaching adsorption equilibrium was about 40-70 min, but the rate of adsorption on the zeolites of which pore diameters were 9 Å, 13 Å were the same as that of the activated carbons.4) Adsorption of ammonia gas on the zeolites seemed to be mainly physical as judged from the value of heat of adsorption.5) It may be concluded that amounts of ammonia gas adsorbed on the zeolites was determined mainly by their pH's rather than their porous structure, whereas the rate of adsorption was determined by their porous structure such as specific surface area and pore volume.