Thermophysical properties of the energy carrier methanol under the influence of dissolved hydrogen

The present experimental work focuses on revealing the influence of hydrogen (H2) on the interfacial tension, viscosity, density, and thermal diffusivity of the liquid phase of the energy carrier methanol under saturation conditions, which has been only fragmentarily investigated so far, and on providing corresponding H2 solubility and Fick diffusion coefficient data. For this, conventional methods, dynamic light scattering from the liquid bulk and from the liquid-gas interface as well as Raman spectroscopy were used at temperatures up to 393 K and pressures up to 8 MPa. The results show that with H2 under saturation conditions, the viscosity and density of liquid methanol are nearly pressure-independent, whereas the interfacial tension is reduced by about 6% at 8 MPa. The latter effect is temperature-independent despite the increasing H2 concentration with increasing temperature, which may be associated with a counteracting influence of temperature on a presumed surface enrichment of H2.