Microbial hydrogen consumption leads to a significant pH increase under high-saline-conditions: implications for hydrogen storage in salt caverns.

Salt caverns have been successfully used for natural gas storage globally since the 1940s and are now under consideration for hydrogen (H) storage, which is needed in large quantities to decarbonize the economy to finally reach a net zero by 2050. Salt caverns are not sterile and H is a ubiquitous electron donor for microorganisms. This could entail that the injected H will be microbially consumed, leading to a volumetric loss and potential production of toxic HS.

Characterising oil and water in porous media using correlations between internal magnetic gradient and transverse relaxation time.

A method for characterising water and oil in a rock core plug using correlations between diffusion decay in internal magnetic gradient and transverse relaxation time (DG-T) is presented. The method is evaluated at different saturation levels and is compared with the measurement of correlations between diffusion and transverse relaxation time (D-T). It is shown how signals from water and oil can be separated based on their difference in diffusion decay in internal gradients.

Characterising oil and water in porous media using decay due to diffusion in the internal field.

In the method Decay due to Diffusion in the Internal Field (DDIF), the diffusion behaviour of water molecules in the internal magnetic field makes it possible to determine a distribution of pore sizes in a sample. The DDIF experiment can also be extended to a DDIF-Carr-Purcell-Meiboom-Gill (DDIF-CPMG) experiment to measure correlations between the pore size and the transverse relaxation time, T2. In this study we have for the first time applied the DDIF experiment and the DDIF-CPMG experiment to porous materials saturated with both water and oil.

Adsorption of poly(styrene sulfonate) of different molecular weights on alpha-alumina: effect of added sodium dodecyl sulfate.

The adsorption of poly(styrene sulfonate), PSS, of different molecular weights (70,000, 500,000, and 1,000,000 mol/kg), from aqueous solutions on alpha-alumina has been investigated. PSS of the lower molecular weight adsorbs less than the others whose adsorption isotherms overlap. The adsorption is found to increase with increasing ionic strength of the solutions indicating that both electrostatic and non-electrostatic contributions are involved in the adsorption process.