Modeling the influence of changes in aliphatic structure on char surface area during coal pyrolysis |
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Authors: | He Yang Thomas H. Fletcher Yang Li Lijun Jin Sufen Li Yan Shang Haoquan Hu |
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Affiliation: | 1. State Key Laboratory of Fine Chemicals, Institute of Coal Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian, China;2. Chemical Engineering Department, Brigham Young University, Provo, Utah;3. School of Energy and Power Engineering, Dalian University of Technology, Dalian, China |
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Abstract: | The influence of changes in aliphatic structure on char surface area during coal pyrolysis was modeled, and the effect was introduced to a previous char surface area model for lignite pyrolysis established based on the chemical percolation devolatilization (CPD) model. The modified model can predict not only the N2 and CO2 char surface area during rapid pyrolysis of three lignites but also the CO2 char surface area of two high-volatile bituminous coals; the agreement of the modified model with experiments is improved at high temperatures. The decrease in aliphatic chain length can reduce adsorption positions around aromatic core, and decrease char surface area. When mass release is more than 55% at about 1,100 K, the predicted N2 char surface area starts to decrease with further generation of volatiles, and the increase of predicted CO2 char surface area with increasing generation of volatiles also become slow at the end of mass release. |
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Keywords: | aliphatic structure char surface area coal pyrolysis modeling |
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