Abstract: CO₂ sequestration in deep coal seams with enhanced coal-bed methane(CH₄)recovery(CO₂-ECBM)is acknowledged as a potential way. Hitherto,it is concluded that the adsorption performance of coal matrix is the main mechanism for CH₄ accumulation and CO₂ sequestration,and the functional groups on the coal matrix surface have potential effect on the adsorption capacity of CO₂ and CH₄. Therefore,the effect and mechanism of functional groups on coal matrix surface dependences of CO₂ and CH₄ adsorption were elucidated in this work. The modified and analytical methods of the functional groups on the coal matrix surface were summarized. The research trends of functional groups on the coal matrix surface dependences of CO₂ and CH₄ adsorption were also indicated. It is found that the oxygen-containing and nitrogen-containing functional groups are the two main functional groups influencing the adsorption performance of coals. In general,the oxygen-containing functional groups are in favor of CO₂ adsorption,whereas the oxygen-containing functional groups dependence of CH₄ adsorption is still controversial. The nitrogen-containing functional groups contribute to both CO₂ and CH₄ adsorption. Hitherto,the methods used to characterize the functional groups mainly incorporate chemical titration,temperature programmed desorption(TPD),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectrum(FTIR)and nuclear magnetic resonance spectroscopy(NMR). In future work,the following aspects should be carried out to further explore the functional groups on the coal matrix surface dependences of CO₂ and CH₄ adsorption. On the one hand,the more realistic coal structure model to enhance the predictive accuracy of the research work based on theory simulation should be built. On the second hand,the more experimental work is needed to make up for the deficiency of theory simulation. Finally,the pretreatment method of coal samples is optimized to improve the existing methods used to functional groups contained in coal matrix analysis.

Key words: coal matrix, functional groups, methane, carbon dioxide, adsorption

摘要： 强化煤层气CH₄开采的深部煤层封存CO₂技术能够有效减少CO₂的排放。由于煤基质具有的吸附性能是煤体吸附CH₄及封存CO₂的主要机理，且煤基质表面官能团对于煤体CO₂和CH₄吸附能力具有潜在的影响，因此本文阐述了表面官能团对煤体CO₂和CH₄吸附性能的作用及机理，归纳了煤基质表面官能团的修饰及表征方法，指出了煤基质表面官能团对CO₂和CH₄吸附作用规律的研究趋势。分析表明：影响煤体CO₂和CH₄吸附性能的官能团主要包括含氧和含氮官能团；整体上，含氧官能团有利于CO₂吸附，含氧官能团对CH₄的吸附作用仍存在一定争议，含氮官能团均有利于提升煤体CO₂和CH₄吸附能力；官能团表征方法包括化学分析法、程序升温脱附、X射线光电子能谱、傅里叶变换红外光谱和核磁共振波谱。为了深入研究煤基质表面官能团对其吸附性能的作用规律，后续需开展以下工作：建立更为真实的煤体结构模型，提高理论模拟研究工作的预测精度；强化实验科学研究，弥补目前主要以理论模拟为研究手段的不足；优化煤体预处理方法，提高现有官能团表征方法用于煤基质官能团分析的精确度。

关键词: 煤基质, 官能团, 甲烷, 二氧化碳, 吸附