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Highlights: [•] Mineral sequestration of CO2 in Columbia River Basalt under field conditions is predicted to occur within several decades. [•] Mineral sequestration of co-injected H2S is predicted to occur within several years. [•] Modeled rates are consistent with laboratory predictions. [•] Binary interaction parameters for the solubility of CO2 and H2S in pure water and brine are detailed. [Copyright &y& Elsevier]

Abstract: Adsorption of CO2 on dehydrated Prussian blue analogue CoII 3[CoIII(CN)6]2 was studied using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). An infrared peak at 2340cm−1 assigned to adsorbed CO2 was identified and used semi-quantitatively to construct an isotherm at 298K that followed the Langmuir–Freundlich equation in the low-coverage Henry''s law limit with CO2 pressure below about 25kPa. Temperature-dependence at 6.8kPa CO2 was used to determine ΔH ad =−23±3kJmol−1, in this limit as well. Deviation from the Langmuir–Freundlich model was significant at temperatures above 298K and attributed primarily to a loss of reliability of the DRIFT spectra at higher CO2 pressures, particularly at higher temperatures, and the accompanying uncertainties in the difference spectra when correcting for the presence of gaseous CO2. Based on this work, the application of DRIFTS to study CO2 adsorption on Prussian blue analogues and other adsorbents is promising, although the range of conditions over which it can be applied appears to be more limited than with other techniques. [Copyright &y& Elsevier]