Wenfei Yue , Wenli Song , Chuigang Fan , Songgeng Li
{"title":"低CO2分压下CaCO3在真空固定床中的分解动力学","authors":"Wenfei Yue , Wenli Song , Chuigang Fan , Songgeng Li","doi":"10.1016/j.ces.2023.118646","DOIUrl":null,"url":null,"abstract":"<div><p>Calcium looping often suffers from sintering during CaCO<sub>3</sub> decomposition process, and CaCO<sub>3</sub> decomposition in vacuum is a potential solution. Kinetic analysis of CaCO<sub>3</sub> decomposition in vacuum is seldom, and most of the kinetics in the literature is obtained from thermogravimetric analyzer in atmospheric pressure. In addition, the reported kinetic data seems scattered, and varies depending on the analyzer employed. This study is focused on the intrinsic kinetics of isothermal CaCO<sub>3</sub> decomposition in a vacuum fixed bed from 700 °C to 850 °C. Besides conventional internal/external mass transfer elimination via reducing size/increasing gas velocity, the effect of CO<sub>2</sub> partial pressure is specially discussed under vacuum condition. It is found that, this influence could be eliminated only when the relative difference between equilibrium pressure and maximum CO<sub>2</sub> partial pressure (<em>P<sub>eq</sub> -P*<sub>CO2</sub></em>)/<em>P<sub>eq</sub></em> was higher than 0.98. Tests at atmospheric pressure were also conducted with the same particle size and gas volumetric feeding rate for comparison. The intrinsic reaction rate constants of CaCO<sub>3</sub> decomposition in vacuum are 1.05 × 10<sup>-3</sup> s<sup>−1</sup>– 4.76 × 10<sup>-3</sup> s<sup>−1</sup> between 700 °C and 850 °C, and the activation energy of this reaction is 92.58 kJ/mol.</p></div>","PeriodicalId":271,"journal":{"name":"Chemical Engineering Science","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Kinetics of CaCO3 decomposition at low CO2 partial pressure in a vacuum fixed bed\",\"authors\":\"Wenfei Yue , Wenli Song , Chuigang Fan , Songgeng Li\",\"doi\":\"10.1016/j.ces.2023.118646\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Calcium looping often suffers from sintering during CaCO<sub>3</sub> decomposition process, and CaCO<sub>3</sub> decomposition in vacuum is a potential solution. Kinetic analysis of CaCO<sub>3</sub> decomposition in vacuum is seldom, and most of the kinetics in the literature is obtained from thermogravimetric analyzer in atmospheric pressure. In addition, the reported kinetic data seems scattered, and varies depending on the analyzer employed. This study is focused on the intrinsic kinetics of isothermal CaCO<sub>3</sub> decomposition in a vacuum fixed bed from 700 °C to 850 °C. Besides conventional internal/external mass transfer elimination via reducing size/increasing gas velocity, the effect of CO<sub>2</sub> partial pressure is specially discussed under vacuum condition. It is found that, this influence could be eliminated only when the relative difference between equilibrium pressure and maximum CO<sub>2</sub> partial pressure (<em>P<sub>eq</sub> -P*<sub>CO2</sub></em>)/<em>P<sub>eq</sub></em> was higher than 0.98. Tests at atmospheric pressure were also conducted with the same particle size and gas volumetric feeding rate for comparison. The intrinsic reaction rate constants of CaCO<sub>3</sub> decomposition in vacuum are 1.05 × 10<sup>-3</sup> s<sup>−1</sup>– 4.76 × 10<sup>-3</sup> s<sup>−1</sup> between 700 °C and 850 °C, and the activation energy of this reaction is 92.58 kJ/mol.</p></div>\",\"PeriodicalId\":271,\"journal\":{\"name\":\"Chemical Engineering Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2023-06-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Chemical Engineering Science\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0009250923002026\",\"RegionNum\":2,\"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":"Chemical Engineering Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009250923002026","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
Kinetics of CaCO3 decomposition at low CO2 partial pressure in a vacuum fixed bed
Calcium looping often suffers from sintering during CaCO3 decomposition process, and CaCO3 decomposition in vacuum is a potential solution. Kinetic analysis of CaCO3 decomposition in vacuum is seldom, and most of the kinetics in the literature is obtained from thermogravimetric analyzer in atmospheric pressure. In addition, the reported kinetic data seems scattered, and varies depending on the analyzer employed. This study is focused on the intrinsic kinetics of isothermal CaCO3 decomposition in a vacuum fixed bed from 700 °C to 850 °C. Besides conventional internal/external mass transfer elimination via reducing size/increasing gas velocity, the effect of CO2 partial pressure is specially discussed under vacuum condition. It is found that, this influence could be eliminated only when the relative difference between equilibrium pressure and maximum CO2 partial pressure (Peq -P*CO2)/Peq was higher than 0.98. Tests at atmospheric pressure were also conducted with the same particle size and gas volumetric feeding rate for comparison. The intrinsic reaction rate constants of CaCO3 decomposition in vacuum are 1.05 × 10-3 s−1– 4.76 × 10-3 s−1 between 700 °C and 850 °C, and the activation energy of this reaction is 92.58 kJ/mol.
期刊介绍:
Chemical engineering enables the transformation of natural resources and energy into useful products for society. It draws on and applies natural sciences, mathematics and economics, and has developed fundamental engineering science that underpins the discipline.
Chemical Engineering Science (CES) has been publishing papers on the fundamentals of chemical engineering since 1951. CES is the platform where the most significant advances in the discipline have ever since been published. Chemical Engineering Science has accompanied and sustained chemical engineering through its development into the vibrant and broad scientific discipline it is today.