Initial Step of Flue Gas Desulfurization-An IR Study of the Reaction of SO2 with NOx on CaO-

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• 作者：Tomohiro Ishizuka ; Hajime Kabashima ; Tsutomu Yamaguchi ; Kozo Tanabe ; and Hideshi Hattori
• 刊名：Environmental Science & Technology
• 出版年：2000
• 出版时间：July 1, 2000
• 年：2000
• 卷：34
• 期：13
• 页码：2799 - 2803
• 全文大小：78K
• 年卷期：v.34,no.13(July 1, 2000)
• ISSN：1520-5851

文摘

Flue gas desulfurization contributes much to the preventionof acid rain. In a dry-type flue gas desulfurization,promotive effect of NO on SO₂ absorption is observed. Toelucidate the reaction mechanisms for absorption ofSO₂ by a calcium compound in a dry-type flue gasdesulfurization, the states of adsorbed SO₂, NO, and NO₂on CaO and the reactivity of the adsorbed SO₂ with NO, NO₂,and O₂ were studied by IR and temperature-programmeddesorption (TPD). Sulfur dioxide (SO₂) and NO₂ were adsorbedon CaO mainly in the form of sulfite ion (SO₃^2-) andnitrato (NO₃) complex, respectively. Nitrogen oxide (NO) isadsorbed in the forms of nitrito (NO₂) complexes, freenitro, and nitro or chelating nitro complexes. The sulfiteion reacts with the adsorbed species of NO to be oxidizedto sulfate ion (SO₄^2-) but reacts neither with the nitratocomplex nor with O₂. The nitrito complexes, free nitro, andnitro or chelating nitro complexes act as an oxidizingagent toward sulfite ion on CaO to form sulfate ion. Thetransformation of SO₃^2- ion into SO₄^2- ion by NO is furtheraccelerated in the presence of O₂.