Assessment of Kazakhstan Ultramafic-Mafic Complexes (Ophiolites and Basalts) for CO2 Sequestration: A Mineralogical and Geochemical Investigation for in situ Carbonation Processes and Implications for ex-situ applications

CHEVRON/NAZARBAYEV UNIVERSITY RESEARCH COLLABORATION Faculty-Development Competitive Research Grants Program

Mineral trapping has been studied worldwide during CO2 sequestration in underground formations, especially saline aquifers. The rate of mineralization in sedimentary rocks are typically slow (i.e. requires decadal time-slot to start and thousands of years to convert). The mineral trapping rate is controlled by the mineralogy of hosting sediments, and some of them, such as quartz rich reservoirs are characterized by minimal if any mineral reactivity. In contrast, magnesium rich minerals are highly reactive, but rarely present in significant amount in sedimentary reservoirs.
Mineral trapping rate in highly-reactive rocks can lead to higher contribution and acceleration of mineral trapping process. It is noteworthy that two field-scale projects (CarbFix in Iceland and Wallula in USA) reported considerable carbon mineralization during CO2 sequestration in basalts in less than two years. The reactivity of ophiolite peridotites is even greater than those of studied basalts.
Kazakhstan is among top 20 carbon emitters per capita and without taking new actions CO2 emission will continue to rise. The evaluation of Geological Carbon Capture and Storage opportunities are being investigated to support Kazakhstan’s ambitious “Green Economy” strategic plans which includes meeting national targets to reach Paris agreement (2014) goals. In addition to storage potential in sedimentary basins, ultramafic rocks such as magnesium rich ophiolite (peridotite / serpentanite) and basalt complexes can sequester CO2 in a low-cost, safe, and near-permanent manner . Although, ophiolite and basalt complexes are abundant in Kazakhstan their utility for carbon storage has not been considered and evaluated yet.