Enhanced simultaneous absorption of NOx and SO2 in oxidation-reduction-absorption process with a compounded system based on Na2SO3

• 作者: Sichao Li Wenjun Huang Haomiao Xu Kai Liu Jia-nan Wang Yaning Sun Zan Qu Naiqiang Yan
• 来源期刊: 环境科学学报（英文版）
• 年，卷（期）: 2022,（1）
• 页码范围: 1-10
• 页数: 10页
• 语种: 英文

摘要

Oxidation of sulfite and competitive absorption existed in Na2SO3 solution for simultane-ous removal of NOx and SO2,inhibited the long-term high-efficiency when used for practi-cal applications.A matching strategy was developed to solve these problems.Antioxidants combination was used to retard the oxidation of antioxidant and enhance inhibition of S(Ⅳ)(tetravalent sulfur) oxidation.Hydroquinone (HQ) and sodium thiosulfate (ST) showed a pos-itive synergistic effect on inhibition of S(Ⅳ) oxidation.When SO2 concentration was 500 and 2000 ppmV,the addition of 0.1 wt.％ HQand 1 wt.％ ST decreased the percentage of S(Ⅳ) ox-idized by oxygen by over 30％ and 40％,respectively.Alkali (Na2CO3) alleviated the competi-tive absorption between NOx and SO2.Moreover,Na2CO3 exhibited an enhancement effect on the absorption of NOx and SO2 when coupled with anti-oxidants.While the increase of oxygen pressure accelerated the oxidation of S(Ⅳ),the anti-oxidants can retard the oxida-tion.The measurement of pH suggested the removal efficiency of NOx highly depended on SO32-concentration rather than pH.The further investigation of the mechanism suggested the match effect was related to the interaction between ST and the intermediate product of HQ.The match strategy holds a potential for application of SO32-to denitration.