I'm doing a research on weathering of ultramafic rocks, e.g. peridotites and dunites, as a means towards effectively fight climate change and especifically CO2 emissions.
What I would like to know is if there are improvements, updates and any news about this type of technology.
Thanks in advance.
José Carlos Celi López
There is a paper here:
Köhler, P., Hartmann, J. and Wolf-Gladrow, D. A. (2010) ‘Geoengineering potential of artificially enhanced silicate weathering of olivine’, Proceedings of the National Academy of Sciences, vol. 107, no. 47, pp. 20228–20233 [Online]. DOI: 10.1073/pnas.1000545107 (Accessed 18 March 2019).
which discusses the subject
and a more recent paper here: Strefler, J., Amann, T., Bauer, N., Kriegler, E. and Hartmann, J. (2018) ‘Potential and costs of carbon dioxide removal by enhanced weathering of rocks’, Environmental Research Letters, vol. 13, no. 3, p. 034010 [Online]. DOI: 10.1088/1748-9326/aaa9c4 (Accessed 18 March 2019) which cites Koehler et al. (2010)
Li, J., and M. Hitch (2018) Mechanical activation of magnesium silicates for mineral carbonation, a review. Minerals Engineering. Vol. 128, pp. 69-83.
Li, J., M. Hitch, I. Power, and Y. Pan (2018) Integrated Mineral Carbonation of Ultramafic Mine Deposits – A Review. Minerals. Vol.8, No. 4.
Power, I., A.L. Harrison, G.M. Dipple, S.A. Wilson, P.B. Kelemen, M. Hitch, G. Southam (2013) Carbon mineralization: From natural analogues to engineered systems. Reviews in Mineralogy & Geochemistry, Mineralogical Society of America, Vol. 77, pp. 305-360.
Hitch, M. and G.M. Dipple (2012) Economic feasibility and sensitivity analysis of integrating industrial-scale mineral carbonation into mining operations. Minerals Engineering. Vol. 39, pp. 268-275.
May be useful
Saran, R. K., Arora, V., & Yadav, S. (2018). CO2 sequestration by mineral carbonation: a review. GLOBAL NEST JOURNAL, 20(3), 497-503.
Wang, F., Dreisinger, D. B., Jarvis, M., & Hitchins, T. (2018). The technology of CO2 sequestration by mineral carbonation: current status and future prospects. Canadian Metallurgical Quarterly, 57(1), 46-58.
Be sure to do a full life cycle assessment of CO2 in the process (e.g., if chemicals are used consider the CO2 emissions of production, if grinding is used what is the energy source, etc.). You can easily emit more CO2 than you mineralize, even just in the grinding process.
You might also want to consider if the Ca, Mg is being directly mineralized, or if it is being leached into the waterways and depending on mineralization in the ocean system.
The below paper looks only at gas-solid mineralization for iron/steel slags under specific conditions (30 C, relative humidity 90%, 5-20% CO2). But, the CO2 diffusivity for many of the major minerals in natural weathering are analyzed. For these specific conditions, Mg-silicates and Ca-aluminosilicates are shown to be comparatively poor targets for mineralization. This suggests that you would do better to focus on Ca-silicates instead of Mg-silicates to enhance natural weathering. You'll find this goes against the common assumption that Mg-silicates are better due to their higher CO2 capacity per kilogram of material (Mg is lighter than Ca).
Myers, C.A., Nakagaki, T. and Akutsu, K., 2019. Quantification of the CO2 mineralization potential of ironmaking and steelmaking slags under direct gas-solid reactions in flue gas. International Journal of Greenhouse Gas Control, 87, pp.100-111.