It is possible to accelerate the dissolution of CO2 injected into deep aquifers by pumping brine from regions where it is undersaturated into regions occupied by CO2. For a horizontally confined reservoir geometry, we find that it is possible to dissolve most of the injected CO2 within a few hundred years at an energy cost that is less than 20% of the cost of compressing the CO2 to reservoir conditions. We anticipate that use of reservoir engineering to accelerate dissolution can reduce the risks of CO2 storage by reducing the duration over which buoyant free-phase CO2 is present underground. Such techniques could simplify risk assessment by reducing uncertainty about the long-term fate of injected CO2, and could expand the range of reservoirs which are acceptable for storage.

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A new methodology is proposed for the acceleration of CO 2 dissolution to lower the risk of CO 2 leakage for carbon capture and storage (CCS) technology. It is called ex situ dissolution because CO 2 is being dissolved at a surface before it is injected underground. This new approach reduces or eliminates possible leakage of CO 2 from underground formation. To achieve full underground dissolution of injected pure supercritical CO 2 or gaseous CO 2 may take thousands of years because of the absence of strong mixing (convective-diffusion dominated processes). Dissolving CO 2 in brine before injection significantly increases the security of geological sequestration. The mass transfer from CO 2 droplets into brine during cocurrent (CO 2 Àbrine) horizontal pipe flow is studied mathematically to investigate the effectiveness of the proposed method. The dissolution rate of the CO 2 droplets is correlated to the variation of mean droplet diameter versus time, because the mass transfer causes shrinkage of the droplets. Empirical correlations based on Sherwood numbers were employed in the example for calculation of mass-transfer coefficients for droplets of CO 2 in the fluid flowing through a pipe.

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We report the changes in the electrical properties of the lipid-protein film of pulmonary surfactant produced by excess cholesterol. Pulmonary surfactant (PS) is a complex lipid-protein mixture that forms a molecular film at the interface of the lung's epithelia. The defined molecular arrangement of the lipids and proteins of the surfactant film gives rise to the locally highly variable electrical surface potential of the interface, which becomes considerably altered in the presence of cholesterol. With frequency modulation Kelvin probe force microscopy (FM-KPFM) and force measurements, complemented by theoretical analysis, we showed that excess cholesterol significantly changes the electric field around a PS film because of the presence of nanometer-sized electrostatic domains and affects the electrostatic interaction of an AFM probe with a PS film. These changes in the local electrical field would greatly alter the interaction of the surfactant film with charged species and would immediately impact the manner in which inhaled (often charged) airborne nanoparticles and fibers might interact with the lung interface.