Discovery of a New Mixed Methane-Hydrogen Hydrate Phase with Very High Hydrogen Storage Capacity

Monday, November 8, 2010: 10:10 AM
Seminar Theater (Hilton)
Maaike C. Kroon1, Hugh Docherty2, Peter T. Cummings2, Cor J. Peters3 and Wendy L. Mao4, (1)Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, Netherlands, (2)Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, (3)Process and Energy, Delft University of Technology, Faculty of Mechanical, Maritime and Materials Engineering, Delft, Netherlands, (4)Geological and Environmental Sciences, Stanford University, Stanford, CA

Hydrogen is considered to be a promising alternative to fossil fuels. Unfortunately, due to the difficulty in finding a practical storage medium, its use as a fuel, for instance for application in the automotive sector, is currently limited. In order to be considered practical, a hydrogen storage material should satisfy a number of requirements, including a high storage capacity (high hydrogen content by mass and volume), ambient storage temperature and pressure, a fast uptake of hydrogen, and reversible hydrogen release. So far, a material that meets these requirements is does not exist. In this work, we discovered a new hydrate phase that fulfills most of the above-mentioned requirements as a high capacity hydrogen storage material. The newly discovered mixed hydrate phase consists of water + methane + hydrogen. It is formed by addition of water to the Van der Waals compound tetrahydrogenmethane (CH4(H2)4), which contains as much as 33.4 wt% molecular hydrogen and is only stable at high pressures (5.4 GPa). Here, it is show that the required pressure can be decreased by more than 95% when water is added. Although the addition of a promoter molecule decreases the overall storage capacity, it still contains as much as 10-20 wt% hydrogen, making it a very interesting hydrogen storage material. The structure of the mixed hydrate phase was determined next using a combined experimental-theoretical approach. Results will be presented at the conference.

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See more of this Session: Hydrogen Separation and Storage
See more of this Group/Topical: Engineering Sciences and Fundamentals