We investigate the dynamics of a liquid droplet in contact with a surface of a porous structure by means of the pore-scale level, fully resolved numerical simulations. The geometrical details of the solid porous matrix are resolved by a sharp interface immersed boundary method on a Cartesian computational grid, whereas the motion of the gas-liquid interface is tracked by a mass conservative volume of fluid method. The numerical simulations are performed considering a model porous structure that is approximated by a 3D cubical scaffold with cylindrical struts. The effect of the porosity and the equilibrium contact angle (between the gas-liquid interface and the solid struts) on the spreading behavior, liquid imbibition, and apparent contact angle (between the gas-liquid interface and the porous base) are studied. We also perform several simulations for droplet spreading on a flat surface as a reference case. Gas-liquid systems of the Laplace number, La = 45 and La = 144 × 103 are considered neglecting the effect of gravity. We report the time exponent (n) and pre-factor (C) of the power law describing the evolution of the spreading diameter (S = Ctn) for different equilibrium contact angles and porosity. Our simulations reveal that the apparent or macroscopic contact angle varies linearly with the equilibrium contact angle and increases with porosity. Not necessarily for all the wetting porous structures, a continuous capillary drainage occurs, and we find that the rate of the capillary drainage very much depends on the fluid inertia. At La = 144 × 103, numerically we capture the capillary wave induced pinch-off and daughter droplet ejection. We observe that on the porous structure the pinch-off is weak compared to that on a flat plate.

Electrochemical Hydrogen Compression presents solutions to realizing a hydrogen infrastructure and thus providing a sustainable energy network. This technology enables typical bottlenecks of purification and compression to be surpassed simultaneously, but functions only for hydrogen gas specifically. HyET has developed a membrane for electrochemical hydrogen compression showing superior proton conductivity in combination with minimal hydrogen back-diffusion characteristics, to be able to compress to pressures as high as 100 MPa with a competitive energy requirement.

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Ing. Joachim Werther on the occasion of his 80th birthday Liquid injection in fluidized beds is used to add reactants or to improve the heat management in the reactor. This injection will increase the complexity of reactor due to the formation of agglomerates. In this work the effect of the injection on the particle temperature distribution in a fluidized bed of porous particles is determined experimentally using particle image velocimetry and infra-red thermography. The main property of the porous particles influencing the distribution is the specific surface area. In addition, the porosity has a large effect on the defluidization of the fluidized bed.

The company HyET pioneers Electrochemical Hydrogen Compression (EHC) with strong focus on advancing our rate capability and energy efficiency for compression and simultaneous purification. Additional advantages over mechanical pumping are: isothermal compression vs. adiabatic, no moving parts, instantaneous, variable pump rate, included metering, and bi-directional control (de-/compression). Previously, HyET demonstrated a compression record showing pressures as high as 100MPa are feasible in one single stage using EHC. Simple scalability of the ‘active’ membrane area enabled us to produce stacks with a pumping capacity around 2 kg per day. Stand-alone systems are designed in ongoing JTI funded programs containing multiple parallel stacks and delivering up to 100 kg per day upon request. Only hydrogen gas is transported through the solid, proton-conducting membrane through conversion at the catalysed membrane surface according to the following reaction equation: H2 = 2 H+ + 2 e- Other gases that may be present in the mixture stay behind because these cannot follow this pathway. Proprietary membranes have been developed at HyET to minimise passive permeation of all gases. The primary reason is the reduction of hydrogen back-diffusion, which goes at the expense of the energy efficiency. Secondary, our bespoke membranes automatically show better selectivity towards hydrogen and deliver enhanced purification ability, especially in combination with positive pressure differential. This presentation will provide insight in EHC working principles, current abilities and potential solutions made available for building a viable hydrogen infrastructure, enabling market application such as: Automotive (Home) refuelling Distributed energy storage from sustainable supply Harvesting from impure hydrogen gas sources Hydrogen injection and selective extraction from natural gas pipelines