模拟CO_2地质埋藏条件下无烟煤微孔超微孔变化特征  

Micropore-ultramicropore changes of anthracite asscoiated with simulated CO_2 geosequestration

作　　者：刘长江[1,2] 桑树勋[2] 王国雄[3] Victor Rudolph 

机构地区：[1]中国石油大学(华东),地球科学与技术学院,山东青岛266580 [2]中国矿业大学资源与地球科学学院/煤层气资源与成藏过程教育部重点实验室,江苏徐州221008 [3]昆士兰大学,化学工程学院,澳大利亚布里斯班4072

出　　处：《西北大学学报（自然科学版）》2014年第6期954-958,969,共6页Journal of Northwest University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(41302125);山东省自然科学基金资助项目(ZR2011DL010);国家自然科学重点基金资助项目(41330638)

摘　　要：CO2地质埋藏过程中的煤体孔隙演化是影响CO2地质埋藏的主要问题之一,该研究以＂高压超临界CO2地球化学反应器＂为实验室模拟平台,对CO2在地下煤层的储存过程进行模拟;以40℃,9.8 MPa,72 h为模拟条件,通过氦比重仪和压汞仪对不同粒度的无烟煤孔隙结构变化进行研究。结果表明,在经过超临界CO2-H2O的作用后,无烟煤的真密度和视密度均呈现增大趋势,其中增幅最大的4~8 mm样品从1.500 g/cm3增加到1.590 g/cm3;总孔容变化较为明显,增加主要表现在4~8 mm样品,增幅达162%,孔隙度增幅则达196%,其余粒度样品的总孔容和孔隙度也有不同程度增高。CO2的埋藏过程对无烟煤的影响主要表现在微孔和超微孔隙的发育,不同粒度样品的超微孔隙变化均较大,从而直接导致对气体的吸附能力越来越强。Pore structure changing of coal during the CO： geo-sequestration is one of the key issues that affect the sequestration process significantly. To address this problem, the CO2 sequestration process in an anthracite coal was replicated using a high pressure supercritical CO2 （ HP-ScCO2 ） reactor. Different coal grain sizes were exposed to ScCO2 and water at around 40 ℃ and 9.8 MPa for 72 h. Helium pycnometer and mercury porosimetry provide the density, pore size distribution and porosity of the coal before and after the ScCO2 treatment. The results show that after being treated by the HP-ScCO2, the true density and bulk density both increased. The growth rate of total pore volume and porosity of 4 - 8 mm sample increased most, by 162% and 196% respectively. The influence of CO2 sequestration on anthracite pore structure is shown mainly in micropores and uhramicropores increasing, which accordingly enhance the gas adsorption.

关 键 词：无烟煤 CO2地质埋藏 微孔—超微孔隙 

分 类 号：P618.11[天文地球—矿床学]