CO2 transport and carbonate precipitation in the coupled diffusion-reaction process during CO2 storage. (15th February 2023)

• Record Type: Journal Article
• Authors: Chen, Mingkun; Zhang, Yi; Liu, Shezhan; Zhao, Changzhong; Dong, Shuang; Song, Yongchen
• Is Part Of: Fuel. Volume 334(2023)Part 2
• Publication Date: 2023-02-15
• Subjects: Mineral carbonation -- Natural olivine -- CO2 storage -- Geochemical gradient -- In situ sampling -- Mineral dissolution and precipitation; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126805
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: The local geochemical concentrations along the depth are obtained in situ. The effective diffusion coefficients are calculated via the modified model. The reaction could improve CO2 transport through the geochemical gradients. Pressure decay favors the carbonation in the deep zone without much free water. Abstract: During geological CO2 storage and utilization, CO2 plume migration forms widespread static retention regions including the dead-end fractures and pores in the host rock, where the mass transfer is dominated by diffusion. A series of packed column experiments with natural olivine were conducted to investigate how the coupled CO2 diffusion–reaction process influences the CO2 transport and the temporal-spatial evolution of carbonate precipitation in diffusion-limited zones. The carbonate precipitations were mainly magnesite, and some dolomite due to the combined effect of carbonate precipitation kinetics and the low Ca content of the solution with Mg enrichment. Compared with the pure diffusion in porous media, the geochemical gradients in the pore solution resulting from the coupled diffusion–reaction interaction promoted mass transfer and broad migration, which led to an increase in effective diffusion coefficients of CO2 by approximately-one order of magnitude. The free water layer and pressure mode could affect the distribution of carbonate precipitation and the overall sequestration capacity. In particular, the coupled CO2 diffusion–reaction interaction under pressure decay mode could accelerate the carbonation in the deep region in the water-saturated column. This study advances the fundamental understanding on the transport and reaction of injected CO2 for mafic and ultramafic formations.