We report the solubility of carbon dioxide in CaCl 2 (aq) and MgCl 2 (aq) at molalities of (1, 3, and 5) mol•kg −1 , temperatures of (308 to 424) K and pressures up to 40 MPa. We also report the solubility of CO 2 in a synthetic formation brine containing 0.910 mol•kg −1 NaCl and 0.143 mol•kg −1 KCl over the same ranges of temperature and pressure. The expanded uncertainties at 95 % confidence are 0.03 K in temperature, between (0.08 and 0.15) MPa in bubble pressure and 0.00015 in the mole fraction of CO 2 in the solution at its bubble point. The results show a strong salting-out effect, whereby the solubility declines with increasing molality of salt, which is some (20 to 30) % greater in CaCl 2 (aq) or MgCl 2 (aq) than in the synthetic formation brine at the same molality.

Solid metal oxides for carbon capture exhibit reduced adsorption capacity following high-temperature exposure, due to surface area reduction by sintering. Furthermore, only low-coordinate corner/edge sites on the thermodynamically stable (100) facet display favorable binding toward CO, providing inherently low capacity. The (111) facet, however, exhibits a high concentration of low-coordinate sites. In this work, MgO(111) nanosheets displayed high capacity for CO, as well as a ∼65% increase in capacity despite a ∼30% reduction in surface area following sintering (0.77 mmol g @ 227 m g vs 1.28 mmol g @ 154 m g). These results, unique to MgO(111), suggest intrinsic differences in the effects of sintering on basic site retention. Spectroscopic and computational investigations provided a new structure-activity insight: the importance of high-temperature activation to unleash the capacity of the polar (111) facet of MgO. In summary, we present the first example of a faceted sorbent for carbon capture and challenge the assumption that sintering is necessarily a negative process; here we leverage high-temperature conditions for facet-dependent surface activation.

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Vapor-liquid equilibrium data are reported for the binary systems (CO2 + H2) and (CO2 + N2) at temperatures between (218.15 and 303.15) K at pressures ranging from the vapor pressure of CO2 to approximately 15 MPa. These data were measured in a new analytical apparatus which is described in detail. The results are supported by a rigorous assessment of uncertainties and careful validation measurements. The new data help to resolve discrepancies between previous studies, especially for the (CO2 + H2) system. Experimental measurements of the three-phase solid-liquid-vapor locus are also reported for both binary systems.The vapor-liquid equilibrium data are modelled with the Peng-Robinson (PR) equation of state with two binary interaction parameters: one, a linear function of inverse temperature, applied to the unlike term in the PR attractive-energy parameter; and the other, taken to be constant, applied to the unlike term in the PR co-volume parameter. This model is able to fit the experimental data in a satisfactory way except in the critical region. We also report alternative binary parameter sets optimized for improved performance at either temperatures below 243 K or temperatures above 273 K. A simple predictive model for the three-phase locus is also presented and compared with the experimental data.

We report measurements of the thermodynamic properties of liquid di-isodecyl phthalate