Hydrogen storage methods

Hydrogen storage basically implies a reduction in the enormous volume of hydrogen gas 1 kg of hydrogen at ambient temperature and atmospheric pressure has a volume of 11 m. Three parameters allow the density of hydrogen to be increased (i) increased pressure, (ii) lower temperature and (iii) decreased oscillation amplitude of the hydrogen atoms or molecules by interaction with other materials. The crucial 

Catalysis for Sustainable Energy Production. Edited by P. Barbaro and C. Bianchini Copyright 2009 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-32095-0 

There are basically six methods in order to store hydrogen reversibly vith a high volumetric and gravimetric density. 

---

Let s briefly review the promising hydrogen storage methods by Figure 5, where the volume densities (Vd) vs weight densities (Wd) for each storage method are shown [16],... 

Table 5.9 Main hydrogen storage methods and teehniques...

Table 5.10 Characteristics of six basic hydrogen storage methods...

Zhou, L. 2005. Progress and problems in hydrogen storage methods. Renew Sustain Energy Rev 9 395 08. 

Figure 5.2 The six basic hydrogen storage methods and phenomena. From top left to bottom right compressed gas (molecular H2) liquid hydrogen (molecular H2) physisorption (molecular H2) on materials,forexample, carbon with a very large specific surface area hydrogen (atomic H) intercalation in host metals,...

As the most abundant element in the universe, hydrogen is often found in numerous chemical compounds. Some of these compounds can be used as a hydrogen storage method. The hydrogen is combined in a chemical reaction that creates a stable compound containing the hydrogen. A second reaction occurs that releases the hydrogen, which is collected and utilised by a fuel cell. 

Third, the risk of stranded investment is significant, since much of an initial compressed hydrogen station infrastructure could not be converted later if either a non-compression hydrogen storage method or a liquid fuel such as a gasoline-ethanol combination... 

Table 1. Comparison of Metal Hydrides to Other Hydrogen Storage Methods, Gasoline and Methanol...

Figure 2.56. Plateau pressure (see Fig. 2.49) for various metal hydride combinations as a function of inverse temperature. From A. Ziittel (2004). Hydrogen storage methods. Naturwissenschaften 91,157-172. Used by permission from Springer-Verlag.

Relatively high cost as compared with gaseous and liquid hydrogen storage methods. 

Neither is practical on a large scale, since these hydrogen storage methods both require large amounts of energy to either pressurise or cool the hydrogen, and present signibcant safety risks. 

We have looked at a range of hydrogen storage methods. In Section 8.9, we looked at fairly simply hydrogen in, hydrogen out systems. In Section 8.10, we looked at some more complex systems involving the use of hydrogen-rich chemicals that can be used as carriers. 

---