CO2矿物捕获能力的研究进展

全球碳存储的研究表明, CO2最稳定的存储方式是 CO2的矿物捕获, 即将 CO2注入到地下,使其以方解石、菱铁矿、白云石及片钠铝石等碳酸盐矿物的形式存在.适合 CO2矿物捕获的岩石类型主要有火山岩、砂岩和火山碎屑岩.分析了3种岩石类型的金属元素含量、金属元素的释放能力、与 CO2反应生成的矿物类型及对 CO2的捕获量,并比较了3种岩石类型对 CO2矿物捕获能力的差异.其中玄武岩等火山岩的金属离子含量高,但其孔隙空间有限,制约了成岩反应,且 CO2注入后具有逸散的风险;砂岩分布广泛,有足够的孔隙利于流体注入,但是金属离子含量相对较低,对 CO2的矿物捕获所需时间相对较长;火山碎屑岩则结合了前2种岩石类型在矿物捕获方面的优势,是一种理想的 CO2矿物捕获的岩石类型.

Research Progress of Ability of Mineral Trapping of CO2

A survey of the global carbon reservoirs suggests that the most stable, long-term storage mechanism for atmospheric CO₂ is the formation of carbonate minerals such as calcite, dolomite, magnesite and dawsonite. The suitable rocks for mineral trapping are mainly sandstones, pyroclastic rocks and volcanic rocks (basalt). Based on the two kinds of diagenetic reactions during CO₂-H₂O-rock interaction processes, the content and release ability for metal element, the types of generated minerals and the amount of CO₂ capured among these three kinds of rocks were analyzed while the differences on CO₂ capturing ablitily for these three kinds of rocks were compared. Basalt contains abundant metal ions, but restricts diagenetic reaction due to pore space limitation. As a result, the injected CO₂ has the risk of a fugitive. Sandstones are widely distributed and there is sufficient porosity conducive to fluid injection, but metal ions content is relatively low, and the time required for CO₂ capture minerals are relatively long. Pyroclastic rocks are a combination of the advantages of the two rock types and is an ideal rock type for mineral trapping of CO₂.