Hydrogen Storage in Gas Hydrate Using Natural Gas-Hydrogen Mixture
Abstract:
Commercial exploitation of hydrogen-rich natural gas (CH4/C2H6/H2, HRNG) requires the development of a technology platform for safe and economical gas transportation and storage.
Recent discoveries confirm that HRNG gas mixtures can be stored in HRNG hydrates under moderate pressure and temperature conditions. Here, we demonstrate enhanced uptake of HRNG gas mixture in clathrate hydrate catalysts by two different classes of promoters in three different configurations for different H2 mol% (33%–80%) in the HRNG feed gas.
The experimental study confirmed the positive effect of promoters on HRNG hydrate formation kinetics and further indicates that promoter selection should be based on H2 mol% in the HRNG mixture.
The experimental observations showed that the kinetic promoters (KP) were effective at low H2 concentration (33 mol%), while the thermodynamic promoters (TP) were effective at high H2 concentration (70–80 mol%) in the HRNG mixture.
This difference in formation kinetics (in the presence of promoters) suggests that the CH4 /C2H6 mixture controls formation kinetics and crystal structure, H2 mol% affects H2 cage occupancy, and overall uptake in hydrates is influenced by competition between liquid and gaseous TP.