Removal of nitrogen oxide (NOx) from stationary sources was studied by adsorption of NO, formed by the catalytic oxidation of nitrogen monoxide (NO). The adsorption measurements were carried out by using flow reactors (U-shaped glass tube, ID : 10 mm, and glass tube, ID : 21 mm) under atmospheric pressure and at 19~65°C. The adsorption of NO2 (about 500 ppm level) on some commercially available adsorbents was measured by a continuous method. For practical use, some zeolities adsorbed a sufficient amount of NO2, that is, 1.41~5.78 g NO2/100 g solid (Table 2). The zeolite of mordenite system was acid-stable. The oxidation of NO adsorbed on zeolite surface was retarded by H2O, CO2, and NO2. The effective oxidation of NO occurred when the concentration of H2O in effulent gas was less than ca. 0.04%. The oxidation of NO was not affected by the presence of SO2 (200 ppm level), and was simultaneously removed. Desorption of NOx, from zeolite surface was carried out at 200~500°C. It has been shown that NOx was adsorbed in the form of NO, NO2, and (NO)x.(NO2)v as a result of the interaction between NO and NO2. © 1979, The Chemical Society of Japan. All rights reserved.
