Continental flood basalts are extensive geologic features currently
being evaluated as reservoirs that are suitable for long-term storage of carbon
emissions. Favorable attributes of these formations for containment of injected
carbon dioxide (CO2) include high mineral trapping capacity, unique structural
features, and enormous volumes. We experimentally investigated mineral
carbonation in whole core samples retrieved from the Grand Ronde basalt, the
same formation into which ~1000 t of CO2 was recently injected in an eastern
Washington pilot-scale demonstration. The rate and extent of carbonate mineral
formation at 100 °C and 100 bar were tracked via time-resolved sampling of
bench-scale experiments. Basalt cores were recovered from the reactor after 6, 20, and 40 weeks, and three-dimensional X-ray
tomographic imaging of these cores detected carbonate mineral formation in the fracture network within 20 weeks. Under these
conditions, a carbon mineral trapping rate of 1.24 ± 0.52 kg of CO2/m3 of basalt per year was estimated, which is orders of
magnitude faster than rates for deep sandstone reservoirs. On the basis of these calculations and under certain assumptions,
available pore space within the Grand Ronde basalt formation would completely carbonate in ~40 years, resulting in solid
mineral trapping of ~47 kg of CO2/m3 of basalt.
Revised: May 22, 2018 |
Published: February 27, 2018
Citation
Xiong W., R. Wells, J.A. Horner, H.T. Schaef, P. Skemer, and D.E. Giammar. 2018.CO2 Mineral Sequestration in Naturally Porous Basalt.Environmental Science & Technology Letters 5, no. 3:142-147.PNNL-SA-133317.doi:10.1021/acs.estlett.8b00047