The use of vacuum ultraviolet irradiation to oxidize SO₂ and NO_x for simultaneous desulfurization and denitrification

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• 作者：Junhui Ye ; Jing Shang ; ^{shangjing@pku.edu.cn" class="auth_mail} ; Qian Li ; Weiwei Xu ; Jia Liu ; Xiang Feng ; Tong Zhu ; ^{tzhu@pku.edu.cn" class="auth_mail}
• 关键词：VUV ; Desulfurization ; Denitrification ; Flue gas treatment ; Reactive oxygen species
• 刊名：Journal of Hazardous Materials
• 出版年：30 April, 2014
• 年：2014
• 卷：271
• 期：Complete
• 页码：89-97
• 全文大小：1255 K

文摘

A simple and efficient method for simultaneous desulfurization and denitrification via vacuum ultraviolet (VUV) irradiation and with no additional chemicals is presented. The simultaneous removal of 90% SO₂ and 96% NO_x (NO + NO₂) was achieved from the simulated flue gas under the irradiation from a low-pressure mercury lamp with main wavelengths of 185 and 254 nm, respectively. The composition, flow rate, and temperature of the simulated flue gas, as well as the VUV light intensity, were evaluated as the factors impacting on the efficiency of SO₂ and NO_x removal. The OH, HO₂, O, and O₃ produced from the photolysis of H₂O and O₂ were concluded as the major reactive oxygen species that oxidized SO₂ and NO_x. The additional OH and HO₂ generated through the reactions of NO + HO₂ and SO₂ + OH/HO₂ improved treatment efficiency, while the oxidation products of NO_x, e.g., NO₂, HNO₂, HNO₃, and HNO₄, consumed massive reactive oxygen species (such as O, OH, and HO₂) and thereby reducing the removal efficiencies. The main reaction products were characterized as H₂SO₄ and HNO₃ by ion chromatography, which could be used as chemical or fertilizer raw materials.