Hydrogen Storage Using Mg-Mixed Metal Hydrides

Monday, November 8, 2010: 10:35 AM
Seminar Theater (Hilton)
Canan Acar and Hamid Arastoopour, Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL

Hydrogen Storage Using Mg-Mixed Metal Hydrides

To minimize the adverse effect of ever increasing global energy consumption per capita, there is a need for significant energy production from renewable resources and non carbon molecules such as hydrogen to become energy carrier. The lack of satisfactory hydrogen storage systems which are safe, cheap and simple is one of the main problems for the transition to a hydrogen-based energy carrier system. Mg-based alloys show potential as hydrogen storage material because of the high gravimetric density of MgH2 (7.6 wt. %), as well as its abundant supply and low cost as a raw material. However, they exhibit high enthalpies of formation, poor hydrogenation/dehydrogenation kinetics, poor charge/discharge cycling stability and high temperature requirements. Literature studies showed that the addition of LaNi5 to MgH2 reduces hydrogen absorption temperature and accelerates the kinetics at room temperature and yields higher hydrogen storage capacity at elevated temperatures. Furthermore, literature showed that Nb2O5 is the most effective catalyst for the hydrogen sorption reaction of Mg.

In this work, Mg-LaNi5 and Mg-Nb2O5 composite systems were prepared and studied to obtain a better understanding of hydrogen storage capacity, adsorption/desorption rates. Hydrogen storage capacities of our sorbent were measured by performing adsorption/desorption experiments at different temperatures.

The results of the experiments were analyzed and compared with available data from the literature. The results of our experiments showed that our sorbent (MgH2 - 20 wt. % LaNi5 - 7.3 wt. % Nb2O5) has higher capacity for absorption and higher rate of absorption and desorption at different temperatures than the available sorbents in the literature today.

 


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