{"title":"Macrokinetics of ammonium sulfite oxidation inhibited by sodium thiosulfate in wet ammonium flue gas desulfurization","authors":"Jian Peng, Wen Yao, Peichao Lian","doi":"10.1002/kin.21764","DOIUrl":"https://doi.org/10.1002/kin.21764","url":null,"abstract":"<p>The oxidation of ammonium sulfite must be inhibited to improve the economy and cycle performance of the ammonia flue gas desulfurization process. A stirred bubbling reactor was used to investigate the macrokinetics of oxidation inhibition of ammonium sulfite by sodium thiosulfate in wet ammonia desulfurization. The effects of initial <span></span><math>\u0000 <semantics>\u0000 <msubsup>\u0000 <mi>SO</mi>\u0000 <mn>3</mn>\u0000 <mrow>\u0000 <mn>2</mn>\u0000 <mo>−</mo>\u0000 </mrow>\u0000 </msubsup>\u0000 <annotation>${rm SO}^{2-}_{3}$</annotation>\u0000 </semantics></math> concentration, Na<sub>2</sub>S<sub>2</sub>O<sub>3</sub> concentration, pH value, gas flow rate, and temperature on the oxidation rate were discussed. The results show that the apparent activation energy of the reaction is 37.3 kJ/mol. The macrokinetics equation of sodium thiosulfate inhibiting sulfite oxidation in the ammonia desulfurization process was established. Combined with the kinetic model, it is inferred that the rate of sodium thiosulfate inhibiting ammonium sulfite oxidation is controlled by the intrinsic chemical reaction. The results can provide a reference for the regeneration of ammonium sulfite in the wet ammonia desulfurization process.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"117-124"},"PeriodicalIF":1.5,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143116437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mads Peter Sulbaek Andersen, Josefine Ellerup Borcher, Ole John Nielsen
{"title":"Atmospheric chemistry of (Z)-CF2HCF=CHCl: Kinetics and products of reaction with Cl atoms and OH radicals","authors":"Mads Peter Sulbaek Andersen, Josefine Ellerup Borcher, Ole John Nielsen","doi":"10.1002/kin.21763","DOIUrl":"https://doi.org/10.1002/kin.21763","url":null,"abstract":"<p>Long path length FTIR-smog chamber techniques were used to study the title reactions in 650 Torr of N<sub>2</sub>, oxygen, or air diluent at 296 ± 3 K. Values of <i>k</i>(Cl + (<i>Z</i>)-CF<sub>2</sub>HCF = CHCl)═(6.6 ± 0.7) × 10<sup>−11</sup> and <i>k</i>(OH + (<i>Z</i>)-CF<sub>2</sub>HCF═CHCl)═(4.1 ± 0.7) × 10<sup>−12</sup> cm<sup>3</sup> molecule<sup>−1</sup> s<sup>−1</sup> were measured. The IR spectrum of (<i>Z</i>)-CF<sub>2</sub>HCF═CHCl is reported. The atmospheric lifetime of (<i>Z</i>)-CF<sub>2</sub>HCF═CHCl is determined by the reaction with OH and is approximately 2.8 days. Reaction of (<i>Z</i>)-CF<sub>2</sub>HCF═CHCl with Cl atoms gives HC(O)Cl and CF<sub>2</sub>HC(O)F as major primary products. Under environmental conditions, the OH radical initiated oxidation gives CF<sub>2</sub>HC(O)F and HC(O)Cl in yields of (98 ± 8)% and (100 ± 4)%, respectively. Accounting for non-uniform horizontal and vertical mixing leads to a 100-year time-horizon global warming potential value for (<i>Z</i>)-CF<sub>2</sub>HCF═CHCl of essentially zero.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"108-116"},"PeriodicalIF":1.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21763","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143113229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthew S. Johnson, Hao-Wei Pang, Mengjie Liu, William H. Green
{"title":"Species selection for automatic chemical kinetic mechanism generation","authors":"Matthew S. Johnson, Hao-Wei Pang, Mengjie Liu, William H. Green","doi":"10.1002/kin.21762","DOIUrl":"https://doi.org/10.1002/kin.21762","url":null,"abstract":"<p>Many important chemical kinetic systems require detailed chemical kinetic models to resolve. These detailed kinetic models can involve thousands of species and hundreds of thousands of chemical reactions, making them difficult to construct by hand. Modern automatic mechanism generation algorithms can mostly be divided into two classes: rule and rate based. Rule-based generators choose species based on user defined constraints on species and reaction classes. Rate-based generators generate a much larger set of potentially important species and reactions and then choose which ones to add based on running simulations of species and reactions deemed important and calculating the flux to potentially important species. In principle, the latter is preferable, as it requires the user to make far fewer assumptions about what is important in the system. However, while the effectiveness of the rate-based approach has been demonstrated in a wide variety of systems, it has also been demonstrated to have difficulty picking up important low-flux chemistries. Here we present a discussion of the challenges associated with rate-based mechanism generation and new algorithms that are able to efficiently mitigate these challenges improving species selection during mechanism generation in a set of case studies.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":"57 2","pages":"93-107"},"PeriodicalIF":1.5,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/kin.21762","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143118913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}