Shintaro Yoshida, William J. Movick, Keisuke Obata, S. Mani Sarathy and Kazuhiro Takanabe*,
{"title":"直接注入过氧化氢,将甲烷选择性地均质转化为高级碳氢化合物","authors":"Shintaro Yoshida, William J. Movick, Keisuke Obata, S. Mani Sarathy and Kazuhiro Takanabe*, ","doi":"10.1021/acs.iecr.4c00997","DOIUrl":null,"url":null,"abstract":"<p >The impact of direct H<sub>2</sub>O<sub>2</sub> injection on the selective CH<sub>4</sub> coupling reaction at high temperatures was investigated both experimentally and by kinetic modeling to provide insight into the reaction mechanism of the catalytic oxidative coupling of methane (OCM). H<sub>2</sub>O<sub>2</sub> injection transforms CH<sub>4</sub> into C<sub>2</sub>H<sub>6</sub> and C<sub>2</sub>H<sub>4</sub> at high selectivity, confirming the effectiveness of the involvement of H<sub>2</sub>O<sub>2</sub> by generating OH radicals in OCM. For carbon oxides, there was only CO formation without CO<sub>2</sub> at CH<sub>4</sub> conversions at or below 10%, as expected from the pure contribution of the gas phase. These results were consistent with simulation results using kinetic modeling of gas-phase elementary reactions. Rate of production (ROP) analysis suggests that OH radicals formed from H<sub>2</sub>O<sub>2</sub> decomposition were responsible for the high selectivity toward C<sub>2</sub> products. The major loss of C<sub>2</sub> selectivity and CH<sub>4</sub> conversion is due to HO<sub>2</sub> radicals, a secondary product in H<sub>2</sub>O<sub>2</sub> decomposition. The HO<sub>2</sub> radicals were found to both oxidize CH<sub>3</sub> radicals and neutralize OH radicals. The kinetic model consistently overpredicted the CH<sub>4</sub> conversion and C<sub>2</sub> selectivity over the experimental results, which can be attributed to the radical quenching and overoxidation reaction on the surface of the quartz tube reactor. The findings in this work help create a better understanding of the requirements of selective C<sub>2</sub> formation under OCM conditions.</p>","PeriodicalId":39,"journal":{"name":"Industrial & Engineering Chemistry Research","volume":null,"pages":null},"PeriodicalIF":3.8000,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acs.iecr.4c00997","citationCount":"0","resultStr":"{\"title\":\"Direct Injection of Hydrogen Peroxide for Selective Homogeneous Conversion of Methane into Higher Hydrocarbons\",\"authors\":\"Shintaro Yoshida, William J. Movick, Keisuke Obata, S. Mani Sarathy and Kazuhiro Takanabe*, \",\"doi\":\"10.1021/acs.iecr.4c00997\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >The impact of direct H<sub>2</sub>O<sub>2</sub> injection on the selective CH<sub>4</sub> coupling reaction at high temperatures was investigated both experimentally and by kinetic modeling to provide insight into the reaction mechanism of the catalytic oxidative coupling of methane (OCM). H<sub>2</sub>O<sub>2</sub> injection transforms CH<sub>4</sub> into C<sub>2</sub>H<sub>6</sub> and C<sub>2</sub>H<sub>4</sub> at high selectivity, confirming the effectiveness of the involvement of H<sub>2</sub>O<sub>2</sub> by generating OH radicals in OCM. For carbon oxides, there was only CO formation without CO<sub>2</sub> at CH<sub>4</sub> conversions at or below 10%, as expected from the pure contribution of the gas phase. These results were consistent with simulation results using kinetic modeling of gas-phase elementary reactions. Rate of production (ROP) analysis suggests that OH radicals formed from H<sub>2</sub>O<sub>2</sub> decomposition were responsible for the high selectivity toward C<sub>2</sub> products. The major loss of C<sub>2</sub> selectivity and CH<sub>4</sub> conversion is due to HO<sub>2</sub> radicals, a secondary product in H<sub>2</sub>O<sub>2</sub> decomposition. The HO<sub>2</sub> radicals were found to both oxidize CH<sub>3</sub> radicals and neutralize OH radicals. The kinetic model consistently overpredicted the CH<sub>4</sub> conversion and C<sub>2</sub> selectivity over the experimental results, which can be attributed to the radical quenching and overoxidation reaction on the surface of the quartz tube reactor. The findings in this work help create a better understanding of the requirements of selective C<sub>2</sub> formation under OCM conditions.</p>\",\"PeriodicalId\":39,\"journal\":{\"name\":\"Industrial & Engineering Chemistry Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.8000,\"publicationDate\":\"2024-06-18\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://pubs.acs.org/doi/epdf/10.1021/acs.iecr.4c00997\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Industrial & Engineering Chemistry Research\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.iecr.4c00997\",\"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}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Industrial & Engineering Chemistry Research","FirstCategoryId":"5","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.iecr.4c00997","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}
Direct Injection of Hydrogen Peroxide for Selective Homogeneous Conversion of Methane into Higher Hydrocarbons
The impact of direct H2O2 injection on the selective CH4 coupling reaction at high temperatures was investigated both experimentally and by kinetic modeling to provide insight into the reaction mechanism of the catalytic oxidative coupling of methane (OCM). H2O2 injection transforms CH4 into C2H6 and C2H4 at high selectivity, confirming the effectiveness of the involvement of H2O2 by generating OH radicals in OCM. For carbon oxides, there was only CO formation without CO2 at CH4 conversions at or below 10%, as expected from the pure contribution of the gas phase. These results were consistent with simulation results using kinetic modeling of gas-phase elementary reactions. Rate of production (ROP) analysis suggests that OH radicals formed from H2O2 decomposition were responsible for the high selectivity toward C2 products. The major loss of C2 selectivity and CH4 conversion is due to HO2 radicals, a secondary product in H2O2 decomposition. The HO2 radicals were found to both oxidize CH3 radicals and neutralize OH radicals. The kinetic model consistently overpredicted the CH4 conversion and C2 selectivity over the experimental results, which can be attributed to the radical quenching and overoxidation reaction on the surface of the quartz tube reactor. The findings in this work help create a better understanding of the requirements of selective C2 formation under OCM conditions.
期刊介绍:
ndustrial & Engineering Chemistry, with variations in title and format, has been published since 1909 by the American Chemical Society. Industrial & Engineering Chemistry Research is a weekly publication that reports industrial and academic research in the broad fields of applied chemistry and chemical engineering with special focus on fundamentals, processes, and products.