Treatment of NO and NO₂ with a Mg−Al oxide slurry

Abstract

A selective catalytic reduction process is generally used to treat NO_x; however, this approach results in the leakage of ammonia and requires expensive catalysts. In light of these issues, the specific objective of this study was to develop a new treatment method for a NO_x gas stream with a Mg−Al oxide slurry. In this study, we examined the ability of a Mg−Al oxide slurry to treat NO and NO₂ gas streams. The Mg−Al oxide slurry only partially removed the NO and NO₂. The ability of Mg−Al oxide to remove NO is based on the adsorption of NO molecules onto the surface of the Mg−Al oxide rather than the formation of an Mg−Al layered double hydroxide (Mg−Al LDH) intercalated with NO^– ₂. NO₂ removal was greater than NO removal because of the higher solubility of NO₂. For NO₂ removal, the Mg−Al oxide adsorbed NO^– ₂ and NO^– ₃ onto the surface and formed Mg−Al LDH intercalated with NO^– ₂ and NO^– ₃. Based on these results, we conclude that the Mg−Al oxide slurry is an effective treatment for NO_x.

Keywords:

• Mg−Al oxide slurry
• NO
• NO₂
• treatment