{"title":"Chapter III. Specificities of the Mechanism and Energy of Branching Chain Processes","authors":"V. V. Azatyan","doi":"10.1134/S002315842460127X","DOIUrl":null,"url":null,"abstract":"<p>It is shown that the features of chain processes are determined mainly by the fact that most of the internal energy of the initial reagents is converted into the energy of free valences of atoms and radicals. This results in high concentrations of active particles, which react with the initial reagents at higher rates, providing intensive self-heating, which additionally accelerates the process. It is noted that, without considering the chain nature of reactions, it is impossible to explain ignition upon heating, since the high activation energies of reactions of only molecular reagents exclude an increase in the rate during heating. Taking into account the chain nature of combustion reactions made it possible to explain ignition upon heating and develop a theory of the phenomenon. An explanation is given to the most important characteristic of gas combustion: the length of reaction chains, which determines the role of the chain mechanism in combustion, and the dependence of kinetics on temperature. A solution to the problems of the third flammability limit, confirmed by kinetic and spectroscopic experiments, was obtained, as well as the evidence of the presence of HO<sub>2</sub> radicals in the flame, their active role in the heterogeneous development of reaction chains and in combustion in general. The possibility of replacing the solution of diffusion differential equations by effective kinetic parameters when describing combustion has been experimentally proven.</p>","PeriodicalId":682,"journal":{"name":"Kinetics and Catalysis","volume":"65 1 supplement","pages":"S25 - S36"},"PeriodicalIF":1.3000,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Kinetics and Catalysis","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1134/S002315842460127X","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
It is shown that the features of chain processes are determined mainly by the fact that most of the internal energy of the initial reagents is converted into the energy of free valences of atoms and radicals. This results in high concentrations of active particles, which react with the initial reagents at higher rates, providing intensive self-heating, which additionally accelerates the process. It is noted that, without considering the chain nature of reactions, it is impossible to explain ignition upon heating, since the high activation energies of reactions of only molecular reagents exclude an increase in the rate during heating. Taking into account the chain nature of combustion reactions made it possible to explain ignition upon heating and develop a theory of the phenomenon. An explanation is given to the most important characteristic of gas combustion: the length of reaction chains, which determines the role of the chain mechanism in combustion, and the dependence of kinetics on temperature. A solution to the problems of the third flammability limit, confirmed by kinetic and spectroscopic experiments, was obtained, as well as the evidence of the presence of HO2 radicals in the flame, their active role in the heterogeneous development of reaction chains and in combustion in general. The possibility of replacing the solution of diffusion differential equations by effective kinetic parameters when describing combustion has been experimentally proven.
期刊介绍:
Kinetics and Catalysis Russian is a periodical that publishes theoretical and experimental works on homogeneous and heterogeneous kinetics and catalysis. Other topics include the mechanism and kinetics of noncatalytic processes in gaseous, liquid, and solid phases, quantum chemical calculations in kinetics and catalysis, methods of studying catalytic processes and catalysts, the chemistry of catalysts and adsorbent surfaces, the structure and physicochemical properties of catalysts, preparation and poisoning of catalysts, macrokinetics, and computer simulations in catalysis. The journal also publishes review articles on contemporary problems in kinetics and catalysis. The journal welcomes manuscripts from all countries in the English or Russian language.