摘要
在CO_(2)-ECBM背景下对煤的纳米孔隙结构对CO_(2)/CH_(4)选择性吸附的影响进行研究,可有效提升CO_(2)对CH_(4)驱替置换效果的预测精度。为了研究煤对CO_(2)/CH_(4)选择性吸附与其纳米孔隙结构的内在联系,以4组不同煤阶煤样为研究对象,开展低压N_(2)/CO_(2)吸附及高压CO_(2)/CH_(4)吸附试验,定量表征煤的纳米孔隙结构特征及其对CO_(2)/CH_(4)的吸附性能,探讨煤的孔隙结构对CO_(2)/CH_(4)选择性吸附的控制作用。结果表明:比表面积及孔容在1~50 nm范围随煤阶升高而降低,在0.5~1.0 nm范围随煤阶升高呈“U”型变化规律;CH_(4)和CO_(2)的吸附等温线均能被Langmuir方程较好地拟合,单分子层饱和吸附量与温度呈负相关关系,CO_(2)的吸附常数显著大于CH_(4);煤对CO_(2)/CH_(4)的选择性吸附系数介于3.89~7.97,与温度负相关而与煤的微孔D-R比表面积正相关,表明微孔分布有利于提升CO_(2)对CH_(4)的吸附选择性。
In the context of CO_(2)-ECBM,studying the influence of coal’s nanopore structure on the selective adsorption of CO_(2)/CH_(4)can effectively improve the accuracy when predicting the displacement efficiency of CO_(2)on CH_(4).To study the relationship between selective adsorption of CO_(2)over CH_(4)and nano-pore structure of coal,low pressure N_(2)/CO_(2)adsorption and high-pressure CO_(2)/CH_(4)adsorption experiments were conducted using four coals of different rank.The nano-pore structure and adsorption properties for CO_(2)/CH_(4)of the coals were quantitatively characterized.Meanwhile,the effect of pore structure on selective adsorption capacity of CO_(2)/CH_(4)was analyzed.The control effect of coal pore structure on CO_(2)/CH_(4)selective adsorption were discussed.The results indicate that the specific surface area and pore volume in 1-50 nm range decrease with coal rank,while the values in 0.5-1.0 nm range show an U-shaped trend with coal rank.In addition,the adsorption of CO_(2)and CH_(4)can be well described by Langmuir equation.The single molecular layer saturation capacity decreases with increasing temperature.The adsorption constant of CO_(2)is significantly higher than that of CH_(4).Moreover,the selectivity coefficients of CO_(2)/CH_(4)range from 3.89 to 7.97,the value of which decreases with temperature but increases with the specific surface area of micropores,indicating that micropore distribution is beneficial for improving the selectivity of CO_(2)over CH_(4).
作者
刘振建
蒲超
都喜东
嵇洋洋
涂欣雨
LIU Zhenjian;PU Chao;DU Xidong;JI Yangyang;TU Xinyu(College of Civil Engineering,Yancheng Institute of Technology,Yancheng 224051,China;School of Energy and Power Engineering,Chongqing University,Chongqing 400044,China;Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,China)
出处
《煤质技术》
2025年第3期69-75,85,共8页
Coal Quality Technology
基金
云南省基础研究计划基金资助项目(202401AT070406,202101BE070001-039)
江苏省大学生创新创业训练基金资助项目(202310305131H)。
