{"title":"Investigation on the removal of NO from marine exhaust gas using the Na2S2O8-urea redox system in seawater carrier","authors":"Xiangwen Xing, Jingxuan Jiang, Jing Liu, Pei Zhao, Lin Cui, Yong Dong","doi":"10.1007/s11705-025-2533-6","DOIUrl":null,"url":null,"abstract":"<div><p>The sodium persulfate (Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub>)-urea system has been proven to be an excellent scrubbing solution for the wet removal of NO. Commonly, seawater is used as a wet carrier in marine applications. To further explore the feasibility of marine denitrification using Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub>-urea system, this study proposed the Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub>-urea-seawater composite redox system for NO removal from the marine exhaust gas. The effects of seawater carrier, reaction temperature, Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub> concentration, urea concentration, pH value, and NO concentration on NO removal were investigated. Additionally, the NO<sub>3</sub><sup>−</sup> concentration in the solution was measured. Results showed that the lowest normalized NO concentration was 0.099, with the corresponding mass of NO absorbed per unit volume of solution reaching 0.108 g·L<sup>−1</sup>. The addition of seawater carrier and incremental reaction temperature, Na<sub>2</sub>S<sub>2</sub>O<sub>8</sub>, and urea concentration promoted the NO removal performance. When the pH value increased within the range of 4–7, the NO removal performance decreased. The NO removal performance increased as the pH value further increased to 8, but decreased again when the pH value increased to 11. An increase in NO concentration was detrimental to NO removal. The Cl<sup>−</sup>, HCO<sub>3</sub><sup>−</sup>, and CO<sub>3</sub><sup>2−</sup> in seawater could augment the total concentration of active free radicals to improve denitrification performance.\n</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":571,"journal":{"name":"Frontiers of Chemical Science and Engineering","volume":"19 4","pages":""},"PeriodicalIF":4.3000,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Frontiers of Chemical Science and Engineering","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11705-025-2533-6","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The sodium persulfate (Na2S2O8)-urea system has been proven to be an excellent scrubbing solution for the wet removal of NO. Commonly, seawater is used as a wet carrier in marine applications. To further explore the feasibility of marine denitrification using Na2S2O8-urea system, this study proposed the Na2S2O8-urea-seawater composite redox system for NO removal from the marine exhaust gas. The effects of seawater carrier, reaction temperature, Na2S2O8 concentration, urea concentration, pH value, and NO concentration on NO removal were investigated. Additionally, the NO3− concentration in the solution was measured. Results showed that the lowest normalized NO concentration was 0.099, with the corresponding mass of NO absorbed per unit volume of solution reaching 0.108 g·L−1. The addition of seawater carrier and incremental reaction temperature, Na2S2O8, and urea concentration promoted the NO removal performance. When the pH value increased within the range of 4–7, the NO removal performance decreased. The NO removal performance increased as the pH value further increased to 8, but decreased again when the pH value increased to 11. An increase in NO concentration was detrimental to NO removal. The Cl−, HCO3−, and CO32− in seawater could augment the total concentration of active free radicals to improve denitrification performance.
期刊介绍:
Frontiers of Chemical Science and Engineering presents the latest developments in chemical science and engineering, emphasizing emerging and multidisciplinary fields and international trends in research and development. The journal promotes communication and exchange between scientists all over the world. The contents include original reviews, research papers and short communications. Coverage includes catalysis and reaction engineering, clean energy, functional material, nanotechnology and nanoscience, biomaterials and biotechnology, particle technology and multiphase processing, separation science and technology, sustainable technologies and green processing.