摘要
【目的和方法】煤层气的吸附与解吸过程不仅会诱发煤体宏观变形,还显著改变煤的大分子结构特征,不同气体的作用机制与影响程度存在明显差异。基于自主研发的在线激光拉曼光谱测试系统,从分子尺度揭示无烟煤在CO_(2)、CH_(4)和N_(2)注入条件下的结构响应差异特征及作用机制。【结果和结论】气体注入导致煤微晶结构的D_(4)、D、D_(3)和G峰呈现明显蓝移,解吸时则表现为红移,且解吸过程结构无法完全恢复。随着吸附压力的增加,峰面积比(AD/AG)、峰强比(ID/IG)及D峰半高宽(FWHM)均显著增大,反映出微晶尺寸减小、结构有序度下降及缺陷增加,其中CO_(2)诱导结构变化最显著,影响程度排序为CO_(2)>CH_(4)>N_(2)。这一微观结构变化规律,为深部煤层CO_(2)/N_(2)强化煤层气开发和CO_(2)地质封存提供了分子层面的理论依据。
[Objective and Methods]The adsorption/desorption of coalbed methane(CBM)not only induces the macroscopic deformations of coals but also significantly alters their macromolecular structures,with different gases exhibiting greatly varying mechanisms and influence degrees.Utilizing an independently developed in situ laser Raman spectroscopy system,this study revealed the differential structural responses and mechanisms of anthracite under CO_(2),CH_(4),and N_(2)injection.[Results and Conclusion]Experimental results indicate that gas injection led to notable blue shifts in the D_(4),D,D_(3),and G peaks characterizing the microcrystalline structures of coals.In contrast,red shifts were observed during desorption,with the structures failing to recover completely.With an increase in the adsorption pressure,the A-to-G area and intensity ratios(AD/AG and ID/IG,respectively),as well as the full width at half maximum(FWHM)of the D peak,increased significantly.These results indicate reduced microcrystalline sizes,decreased degrees of structural order,and increased defects.Among the studied gases,CO_(2)induced the most substantial structural variations,with the influence degrees of the three gases decreasing in the order of CO_(2),CH_(4),and N_(2).These microstructural variation patterns provide a molecular-scale theoretical basis for enhanced CBM recovery in deep coal seams via CO_(2)/N_(2)injection and the geological sequestration of CO_(2).
作者
王天
潘结南
李猛
王凯
唐助云
程南南
侯泉林
WANG Tian;PAN Jienan;LI Meng;WANG Kai;TANG Zhuyun;CHENG Nannan;HOU Quanlin(School of Resources and Environment,Henan Polytechnic University,Jiaozuo 454003,China;No.156 Coalfield Geologic Exploration Team,Coalfield Geology Bureau of Xinjiang Uygur Autonomous Region,Urumqi 830009,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《煤田地质与勘探》
北大核心
2025年第8期42-51,共10页
Coal Geology & Exploration
基金
国家自然科学基金面上项目(42072195)
中原科技创新领军人才项目(254000510044)
新疆维吾尔自治区重大科技专项(2023A01004-4-2,2023A01004-3-1)。
关键词
无烟煤
吸附变形
在线激光拉曼光谱
气体注入
大分子结构
膨胀/收缩
anthracite
adsorption deformation
Raman spectrum
gas injection
macromolecular structure
expansion/contraction
作者简介
第一作者:王天,1998年生,女,河南焦作人,硕士研究生。E-mail:15038316090@163.com;通信作者:潘结南,1972年生,男,安徽怀宁人,博士,教授,博士生导师。E-mail:panjienan@163.com。
