Kinetic modeling of deoiled asphaltene particle pyrolysis in thermogravimetric analysis

详细信息    查看全文

• 作者：Yan Cheng ; Binhang Yan ; Tianyang Li…
• 刊名：Journal of Thermal Analysis and Calorimetry
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：124
• 期：3
• 页码：1661-1670
• 全文大小：1,440 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Sciences
  Polymer Sciences
  Physical Chemistry
  Inorganic Chemistry
  Measurement Science and Instrumentation
  
• 出版者：Akad茅miai Kiad贸, co-published with Springer Science+Business Media B.V., Formerly Kluwer Academic
• ISSN：1572-8943
• 卷排序：124

文摘

The pyrolysis behavior of deoiled asphaltene particles was experimentally studied by thermogravimetric analysis. Considering that the activation energy would change with the evolution of pyrolysis reactions, a modified competition model was proposed to appropriately describe the pyrolysis kinetics. The model parameters were fitted with experimental results. Compared with the original two-stage model, the modified competition model showed the capability of predicting the asphaltene pyrolysis at various heating conditions using fixed kinetic parameters. The results exhibited that the modified competition model can well simulate the asphaltene pyrolysis in the main mass loss temperature range from 500 to 900 K as well as the slow decomposition at the temperatures greater than 900 K during the devolatilization process of asphaltene particles at hundred micrometer size. The modified competition model was further coupled with a heat transfer model at particle scale, including the heat exchange between the particle and the surrounding atmosphere as well as the heat transfer inside the particle. It is found that during the thermogravimetric analysis, the particle surface temperature was close to that of atmosphere, and the heat transfer effect inside the particle could be ignored for hundred-micron-sized particles. However, the temperature gradient inside particles should be considered for millimeter-sized particles. Thus, the particle samples should be sieved to hundred micron sized or smaller when studying the basic pyrolysis behaviors in order to acquire kinetic parameters for asphaltene pyrolysis by thermogravimetric analysis.KeywordsAsphaltenePyrolysis kineticsThermogravimetric analysisSingle-particle modeling