New Spectrophotometric Method for Quantitative Characterization of Density-Driven Convective Instability

• Main Authors: Ying Teng, Pengfei Wang, Lanlan Jiang, Yu Liu, Yang Wei
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Polymers
• Subjects: convective dissolution; dissolved CO₂ mass measurements; spectrophotometric method; CO₂ storage in saline formations
• Online Access: https://www.mdpi.com/2073-4360/13/4/661

CO₂ convective dissolution has been regarded as one of the fundamental mechanisms to accelerate the mass transfer of CO₂ into brine. We present a new spectrophotometric method to characterize the convective instability and measure the dissolved CO₂ mass, which enables the real-time quantitative visualization of CO₂/brine transport mechanisms. Successive images were captured to identify the finger development regimes, and the convection morphologies were analyzed by the fingers length and affected area. CO₂ solubility was experimentally studied, and the results are in agreement with the theoretical calculations. CO₂mass transfer flux was investigated as the Sherwood number changed. The increase in salinity and temperature has a negative effect on CO₂dissolution; here, numerical simulation and experimental phenomena are qualitatively consistent. In general, these findings confirm the feasibility of the method and improve the understanding of the physical process of CO₂ convective dissolution, which can help assess the CO₂ solubility trapping mass.