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

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 CO2 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. © 2022 Chinese Society of Civil Engineering. All rights reserved.