煤层对CO_2处置能力评价的修正方法与应用  

A CORRECTED METHOD FOR THE EVALUATION OF CARBON DIOXIDE SEQUESTRATION IN THE COAL SEAMS AND ITS APPLICATION

作　　者：周来[1,2] 冯启言[1,2] 陈中伟[3] 刘波[1,2] 李向东[1,2] 

机构地区：[1]中国矿业大学环境与测绘学院,江苏徐州221116 [2]江苏省资源环境信息工程重点实验室,江苏徐州221008 [3]中国矿业大学理学院,江苏徐州221116

出　　处：《地球与环境》2008年第4期363-367,共5页Earth and Environment

基　　金：江苏省自然科学基金项目(BK2007034);江苏省研究生培养创新工程项目(2006);中国矿业大学青年科研基金项目(2006)

摘　　要：煤等温吸附气体实验中的煤体变形效应会造成CO2在煤层中吸附量评价结果的偏差，通过对气体吸附模拟方法进行修正，应用修正的Langmuir和Dubinin—Astakhov模型对CO2、CH4吸附实验结果进行重新拟合，获得准确的吸附量计算方法。结果表明，吸附实验中煤主要表现为膨胀变形，且煤吸附CO2的膨胀量高于吸附CH4的膨胀量，煤膨胀造成CO2实测过剩吸附量较真实过剩吸附量偏低4．4％～43．8％，修正后CO2吸附拟合效果大大提高，Langmuir和D-A模型拟合曲线与实测数据吻合的相关系数分别从0．978、0．995提高到修正后的0．997、0．999，D-A模型对CO2吸附数据的拟合效果优于Langmuir模型，CH4吸附模拟效果的改善程度不及CO2。A certainty of isothermal gas adsorption experimentation is subject to the volumetric deformation in and around coal samples, from which the deviation of CO2 adsorption capacity engaged in the evaluation of CO2 geological sequestration in a coal seam will arise in the isothermal adsorption measurement. A correction fitting method for gas adsorption measurement has been established by implanting the coal volumetric uncertainties into the traditional models. Experimental data of CO2 and CH4 isothermal sorption were refitted by both corrected Langmuir model and corrected Dubinin-Astakhov model. According to the refitting results, coal swelling due to gas absorption and dissolution in the coal during gas adsorption experimentation accounts for the main volumetric uncertainty. Larger volumetric deviation of coal swelling is found in CO2 adsorption than in CH4 adsorption, Measured excess adsorption of CO2 is usually underestimated by 4.%4-43.8% owing to the coal swelling. The refitting isothermal curves of CO2 adsorption with the corrected model tally with experimental results much more satisfactorily although the fit is better for D-A. The correlation of Langmuir fitting and D-A fitting with isothermal experimental data of CO2 adsorption increases from 0. 978 and 0. 995 to 0. 997 and 0. 999, respectively. Improvement on modeling of CH4 adsorption is comparatively lower.

关 键 词：二氧化碳 甲烷 等温吸附 煤膨胀 地质处置 

分 类 号：P618.11[天文地球—矿床学]