MICP技术用于地质碳封存的微观机理研究初探

Preliminary study on microscopic mechanisms of MICP used for geological carbon sequestration

微生物诱导碳酸钙沉淀(MICP)技术通过生物化学反应生成碳酸钙矿物,可用于密封地质碳封存盖层大孔隙和微裂缝,减少CO_(2)泄露。地质碳封存地层常处于高温状态,而目前对高温条件下MICP的机理研究尚不多见。使用巴氏芽孢杆菌,借助微流控观测平台,研究了50℃条件下MICP矿化晶体的特性及生长规律。此研究阐释了MICP技术在高温下应用的可能,合理增加菌液和胶结液的注射次数可有效提高MICP化学转化率,显著降低岩土体渗透系数。研究结果加深了高温条件下MICP矿化机理的理解,有助于推进MICP技术在地质碳封存领域的应用。

The microbially-induced carbonate precipitation(MICP)can fill the pores and fractures of soil and rock.Therefore,the MICP can potentially be used in geological carbon sequestration(GCS)to the seal pores and microfractures that may result in CO_(2) leakage.The GCS requires a high temperature environment.However,few researches have focused on the behavior of MICP at high temperatures.The characteristics and growth of calcium carbonate crystals in the MICP at 50℃are studied by a microfluidic observation platform.The results indicate that increasing the injection numbers of bacterial suspension and cementation solution can increase the chemical transform efficiency of MICP,reduce the permeability coefficient of soils and enhance the capability of MICP.The results of this study help to advance the application of MICP in the field of GCS.