This work presents a comprehensive analysis on the CO2 gasification of miscanthus derived biochar by using combined experimental and computational methods. The empirical formula and the 2D molecular model of the biochar were proposed based on the results from elemental analysis, Fourier infrared spectroscopy, and solid-state 13C NMR spectroscopy. The density functional theory (DFT) method was used to study the conversion of biochar to gaseous products under the CO2 condition at the B3LYP/6-31G(d,p) level. The reactants, intermediates, transition states, and products during the CO2 gasification process were analyzed, and the activation energy (ΔE) of each reaction step and thermodynamic parameters (Gibbs free energy, ΔG, and enthalpy, ΔH) were obtained. By comparison of the kinetic and thermodynamic parameters of different reaction paths, it was found that the proposed path 1 and path 5 could occur spontaneously with the changes in Gibbs free energy (ΔG) being -182.6 and -170.6 kJ/mol, respectively. The order of the reaction path was path 1 < path 5 < path 3 < path 4 < path 2, in terms of the degree of difficulty. It was also found that, for the benzene ring having a ring-opening reaction, when the substituents were located in the 2 and 3 carbon atoms or the 2, 3, and 5 carbon atoms, the C-C bond between the 1 and 6 carbon atoms was more prone to homolytic reaction than that between the 1 and 2 carbon atoms.
Bibliographical noteThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Industrial & Engineering Chemistry Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.iecr.0c04105
Funding: This work was supported by the Natural Science Foundation of
China for Young Scholars (No. 51706022), the Natural Science
Foundation of Hunan Province of China for Young Scholars
(No. 2018JJ3545), Open Fund of Key Laboratory of Renewable
Energy Electric-Technology of Hunan Province (No.
2017ZNDL007), 2019 Graduate Research and Innovation
Project at Changsha University of Science and Technology
(No. CX2019SS22), and the Innovative Team of Key
Technologies of Energy Conservation, Emission Reduction
and Intelligent Control for Power-Generating Equipment and
System at CSUST. The authors also would like to acknowledge
the funding from EU Horizon 2020 Research and Innovation
Program under the Marie Skłodowska-Curie Action (Grant
Agreement No. 823745).
- Industrial and Manufacturing Engineering
- General Chemistry
- General Chemical Engineering