{"title":"新塑料和废塑料的热降解:使用无模型等转换法估算动力学和热力学参数","authors":"Rohit Kumar Singh, Prithviraj Gupta, Biswajit Ruj, Anup Kumar Sadhukhan, Parthapratim Gupta","doi":"10.1002/kin.21692","DOIUrl":null,"url":null,"abstract":"<p>Kinetic triplets—apparent activation energy (<i>E<sub>a</sub></i>), pre-exponential factor (<i>A</i>), and the reaction model—were estimated for the thermal degradation of three primary virgin and waste plastics, as well as mixed plastics waste. Model-free iso-conversional FWO, KAS, Starink, Kissinger and Vyzovkin and Friedman methods were employed for the kinetic analysis. The apparent activation energy was determined by the integral methods as 206.5-209.1 kJ mol<sup>−1</sup> and 195.6-198.8 kJ mol<sup>−1</sup> for the virgin and waste high-density polyethylene (HDPE), 211.6-214.1 kJ mol<sup>−1</sup> and 183.1-186.6 kJ mol<sup>−1</sup> for the virgin and waste polypropylene (PP), 144.0-163.1 kJ mol<sup>−1</sup> and 159.7-167.1 kJ mol<sup>−1</sup> for the virgin and waste polystyrene (PS), and 173.6-178.9 kJ mol<sup>−1</sup> for the mixed plastics waste respectively. <i>E<sub>a</sub></i> was found to follow the trend HDPE > PP > PS with higher values for HDPE and PP virgin samples than that for their waste and marginally smaller for the virgin PS than its waste. Degradation of all plastic samples followed Avrami-Erofeev equation with <i>n</i> varying between 1.0 and 1.8. The effect of conversion on <i>E<sub>a</sub></i> suggested the degradation of both virgin and waste HDPE to consist of multiple parallel reactions while that of others to be more complex. FTIR analysis of the evolved gases was used to explain the possible reaction mechanism. A small difference between the enthalpy change and the apparent activation energy (6-7 kJ mol<sup>−1</sup>) for all plastic samples indicated favourable pyrolysis reactions. The estimated kinetic parameters and thermodynamic properties showed the stability of different plastics as HDPE > PP > PS.</p>","PeriodicalId":13894,"journal":{"name":"International Journal of Chemical Kinetics","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Thermal degradation of virgin and waste plastics: Estimation of kinetic and thermodynamic parameters using model-free iso-conversional methods\",\"authors\":\"Rohit Kumar Singh, Prithviraj Gupta, Biswajit Ruj, Anup Kumar Sadhukhan, Parthapratim Gupta\",\"doi\":\"10.1002/kin.21692\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Kinetic triplets—apparent activation energy (<i>E<sub>a</sub></i>), pre-exponential factor (<i>A</i>), and the reaction model—were estimated for the thermal degradation of three primary virgin and waste plastics, as well as mixed plastics waste. Model-free iso-conversional FWO, KAS, Starink, Kissinger and Vyzovkin and Friedman methods were employed for the kinetic analysis. The apparent activation energy was determined by the integral methods as 206.5-209.1 kJ mol<sup>−1</sup> and 195.6-198.8 kJ mol<sup>−1</sup> for the virgin and waste high-density polyethylene (HDPE), 211.6-214.1 kJ mol<sup>−1</sup> and 183.1-186.6 kJ mol<sup>−1</sup> for the virgin and waste polypropylene (PP), 144.0-163.1 kJ mol<sup>−1</sup> and 159.7-167.1 kJ mol<sup>−1</sup> for the virgin and waste polystyrene (PS), and 173.6-178.9 kJ mol<sup>−1</sup> for the mixed plastics waste respectively. <i>E<sub>a</sub></i> was found to follow the trend HDPE > PP > PS with higher values for HDPE and PP virgin samples than that for their waste and marginally smaller for the virgin PS than its waste. Degradation of all plastic samples followed Avrami-Erofeev equation with <i>n</i> varying between 1.0 and 1.8. The effect of conversion on <i>E<sub>a</sub></i> suggested the degradation of both virgin and waste HDPE to consist of multiple parallel reactions while that of others to be more complex. FTIR analysis of the evolved gases was used to explain the possible reaction mechanism. A small difference between the enthalpy change and the apparent activation energy (6-7 kJ mol<sup>−1</sup>) for all plastic samples indicated favourable pyrolysis reactions. The estimated kinetic parameters and thermodynamic properties showed the stability of different plastics as HDPE > PP > PS.</p>\",\"PeriodicalId\":13894,\"journal\":{\"name\":\"International Journal of Chemical Kinetics\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.5000,\"publicationDate\":\"2023-09-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Chemical Kinetics\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/kin.21692\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Chemical Kinetics","FirstCategoryId":"92","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/kin.21692","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Thermal degradation of virgin and waste plastics: Estimation of kinetic and thermodynamic parameters using model-free iso-conversional methods
Kinetic triplets—apparent activation energy (Ea), pre-exponential factor (A), and the reaction model—were estimated for the thermal degradation of three primary virgin and waste plastics, as well as mixed plastics waste. Model-free iso-conversional FWO, KAS, Starink, Kissinger and Vyzovkin and Friedman methods were employed for the kinetic analysis. The apparent activation energy was determined by the integral methods as 206.5-209.1 kJ mol−1 and 195.6-198.8 kJ mol−1 for the virgin and waste high-density polyethylene (HDPE), 211.6-214.1 kJ mol−1 and 183.1-186.6 kJ mol−1 for the virgin and waste polypropylene (PP), 144.0-163.1 kJ mol−1 and 159.7-167.1 kJ mol−1 for the virgin and waste polystyrene (PS), and 173.6-178.9 kJ mol−1 for the mixed plastics waste respectively. Ea was found to follow the trend HDPE > PP > PS with higher values for HDPE and PP virgin samples than that for their waste and marginally smaller for the virgin PS than its waste. Degradation of all plastic samples followed Avrami-Erofeev equation with n varying between 1.0 and 1.8. The effect of conversion on Ea suggested the degradation of both virgin and waste HDPE to consist of multiple parallel reactions while that of others to be more complex. FTIR analysis of the evolved gases was used to explain the possible reaction mechanism. A small difference between the enthalpy change and the apparent activation energy (6-7 kJ mol−1) for all plastic samples indicated favourable pyrolysis reactions. The estimated kinetic parameters and thermodynamic properties showed the stability of different plastics as HDPE > PP > PS.
期刊介绍:
As the leading archival journal devoted exclusively to chemical kinetics, the International Journal of Chemical Kinetics publishes original research in gas phase, condensed phase, and polymer reaction kinetics, as well as biochemical and surface kinetics. The Journal seeks to be the primary archive for careful experimental measurements of reaction kinetics, in both simple and complex systems. The Journal also presents new developments in applied theoretical kinetics and publishes large kinetic models, and the algorithms and estimates used in these models. These include methods for handling the large reaction networks important in biochemistry, catalysis, and free radical chemistry. In addition, the Journal explores such topics as the quantitative relationships between molecular structure and chemical reactivity, organic/inorganic chemistry and reaction mechanisms, and the reactive chemistry at interfaces.