Experimental evidence of reaction‐induced fracturing during olivine carbonation. Issue 18 (23rd September 2016)

• Record Type: Journal Article
• Authors: Zhu, Wenlu; Fusseis, Florian; Lisabeth, Harrison; Xing, Tiange; Xiao, Xianghui; De Andrade, Vincent; Karato, Shun‐ichiro
• Is Part Of: Geophysical research letters. Volume 43:Issue 18(2016)
• Page Start: 9535
• Page End: 9543
• Publication Date: 2016-09-23
• Subjects: mineral carbonation -- fluid‐rock interaction -- time‐resolved X‐ray microtomography -- CO2 sequestration -- reaction‐induced fracturing -- microstructure evolution; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070834
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Mineral carbonation, a process that binds CO2 in the form of carbonates by silicate weathering, is widespread on the Earth's surface. Because of the abundance of silicate rocks and the permanence of the carbonated solids, sequestering CO2 via mineral carbonation has generated lots of interests. However, it is unclear how the fluid‐rock reaction proceeds to completion in spite of an increasing solid volume. We conducted a mineral carbonation experiment in which a sintered olivine aggregate reacted with a sodium bicarbonate solution at reservoir conditions. Time‐resolved synchrotron X‐ray microtomographic images show cracks in polygonal patterns arising in the surface layers and propagating into the interior of the olivine aggregate. The nanotomography data reveal that the incipient cracks intersect at right angles. We infer that stretching due to nonuniform volume expansion generates polygonal cracking of the surfaces. Our data shed new lights on the processes that control hydration and carbonation of peridotite. Key Points: We demonstrate that fracturing of the host rock can be achieved without additional energy input We identify that nonuniform volume expansion is key to reaction‐induced cracking in olivine We provide experimental evidence that the positive volume‐changing olivine carbonation reaction can be self‐sustaining