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Journal of Thermal Science

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2024 , Vol. 33 >Issue 5: 1961 - 1973

DOI: https://doi.org/10.1007/s11630-024-2006-0

Evolution Mechanism of Carbon Covalent Bond during Coal Activation Using Mixed Atmosphere of H2O and CO2

  • WANG Mingyue ,
  • ZHANG Siyuan ,
  • HAN Shaobo ,
  • ZHANG Chi ,
  • REN Qiangqiang
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  • 1. Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. State Key Laboratory of Coal Conversion, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China

网络出版日期: 2024-09-09

基金资助

This work was supported by the CAS Project for Young Scientists in Basic Research (YSBR-028).

版权

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2024
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Evolution Mechanism of Carbon Covalent Bond during Coal Activation Using Mixed Atmosphere of H2O and CO2

  • WANG Mingyue ,
  • ZHANG Siyuan ,
  • HAN Shaobo ,
  • ZHANG Chi ,
  • REN Qiangqiang
Expand
  • 1. Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. State Key Laboratory of Coal Conversion, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China

Online published: 2024-09-09

Supported by

This work was supported by the CAS Project for Young Scientists in Basic Research (YSBR-028).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2024
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摘要

充分破坏煤炭中的芳香环结构是减少污染物排放的关键。本工作应用立式管式炉实验台，对神木煤粉进行了活化反应研究。通过改变活化气氛中H2O与CO2的比例，研究活化过程中碳共价键的演化机制并通过密度泛函理论进行验证。两种气体分子遵循不同的途径来增强碳的反应性：CO2主要通过参与交联反应，而H2O和煤粉的吸附能垒较低，更容易生成含氧官能团。气体分子在混合气体气氛中存在活性位点的竞争，但两者之间存在协同作用。这种协同作用可以归结为两种可能性：H2O的加入在一定程度上减缓了五元环的生成，同时促进了含氧官能团的生成；引入含氧官能团可以有效减少气体分子与碳之间相互作用的吸附能垒。

关键词： activation reaction; carbon structure; char; CO2/H2O atmosphere; density functional theory

本文引用格式

WANG Mingyue , ZHANG Siyuan , HAN Shaobo , ZHANG Chi , REN Qiangqiang . Evolution Mechanism of Carbon Covalent Bond during Coal Activation Using Mixed Atmosphere of H2O and CO2[J]. 热科学学报, 2024 , 33(5) : 1961 -1973 . DOI: 10.1007/s11630-024-2006-0

Abstract

Adequate destruction of the aromatic structure in coal is key to further reducing the emission of pollutants. In this research, activation reactions of Shenmu coal powder were carried out in a vertical tube furnace. The study investigated the evolution mechanism of carbon covalent bonds during the activation process by altering the ratio of H2O to CO2 in the activation atmosphere. The theoretical validation was conducted through density functional calculations. The two gas molecules follow different pathways to increase the reactivity of char. CO2 mainly participates in the cross-linking reaction by intensifying branching, while H2O and char have lower adsorption energy barriers and are more likely to generate oxygen-containing functional groups. Gas molecules partially compete for active sites in a mixed gas atmosphere, but there is a synergism between the two effects. The synergism can be attributed to two possibilities. The inclusion of H2O mitigates the generation of five-membered rings to a limited extent, while concurrently enhances the development of oxygen-containing functional groups. Introducing oxygen-containing functional groups can effectively diminish the adsorption energy barrier associated with the interaction between gas molecules and char, consequently leading to a reduction in the energy demand for subsequent bond cleavage.

Key words： activation reaction; carbon structure; char; CO2/H2O atmosphere; density functional theory

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