Removal of HCl, SO₂, and NO by treatment of acid gas with Mg-Al oxide slurry.
Although effective treatment of acid gases such as HCl, SO(x), and NO(x) is essential for preventing air pollution, current methods pose other environmental problems such as CaCl₂ leaching, reduced landfill lifetimes, and solid waste production. Here we show that acid gases can be treated simply with a Mg-Al oxide slurry. The contribution of Mg-Al oxide to HCl and SO₂ removal increased as a function of the quantity and temperature of Mg-Al oxide. HCl was removed by the reconstruction of Mg-Al layered double hydroxide (Mg-Al LDH) intercalated with Cl⁻ dissociated from HCl in the slurry. SO₂ was oxidized into SO₃ by oxygen in the air flow, dissolved in an aqueous solution, and removed by the reconstruction of Mg-Al LDH intercalated with dissociated SO₄²⁻. Although less pronounced because of surface adsorption, NO was nonetheless removed by Mg-Al oxide. Our results suggest that simultaneous removal of HCl, SO₂, and NO using a Mg-Al oxide slurry may be possible without the concomitant problems of conventional treatment methods.
Tohoku University, Aramaki, Aoba-ku, Sendai, Japan. kameda@env.che.tohoku.ac.jp
Tomohito
T
Kameda
Naoya
N
Uchiyama
Toshiaki
T
Yoshioka
D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control; D017607:Aluminum Compounds / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry*; D017616:Magnesium Compounds / Q000737:chemistry*; D009569:Nitric Oxide; D013458:Sulfur Dioxide / Q000737:chemistry*; D014961:X-Ray Diffraction
D000393:Air Pollutants; D017607:Aluminum Compounds; D017616:Magnesium Compounds; D013458:Sulfur Dioxide; C110424:aluminum magnesium oxide; D009569:Nitric Oxide; D006851:Hydrochloric Acid