Hydride Storage of Hydrogen



BHydrogen is a potential fuel for various types of power sources, such as fuel cells, internal combustion engines, gas turbines, etc. However, a major problem is the difficulty encountered in its storage and bulk transport. A possible solution to the problem lies in the use of a metal hydride as a hydrogen storage medium. The material most near to practical application is iron titanium hydride (FeTiH1.95). This material can be synthesized through the direct union of hydrogen with the inter metallic compound, FeTi, in a two step reaction.

Hydrogen and the inter metallic compound FeTi react to produce iron titanium hydride. The decomposable nature of iron titanium hydride makes it a suitable hydrogen storage medium, and it has the advantage over other hydrides of reacting reversibly at ordinary temperatures and thus it is compatible for storing on board a automobile. It also can be made from a low cost material.

The long-term supply and the thermal behavior of test beds of the iron titanium hydride
have been assessed

Particular attention has given to micro fissuring and particle attrition during the activation of a decomposable hydride. Attention has been given to the reaction rates during hydriding and dehydriding to discover the effect on material temperature and composition. Modeling studies have been carried out to assess the dynamic behavior of a hydride bed and establish the effect of system variables on the hydriding and dehydriding rates of the metal. The results of these tests are encouraging and suitable for optimizing the design of larger units.

A stationary hydrogen storage reservoir has been built and is undergoing performance tests. The reservoir will be used in an experimental unit to examine the feasibility of storing electrical energy through the production, storage and reconversion of hydrogen. Iron titanium hydride is also of interest as a source of hydrogen fuel for automotive use. The energy density of FeTiH1.95, on the basis of available hydrogen, is 268 whr/lb; a value that compares favorably with even the most advanced battery systems suggested for automotive use. Plans are made for optimizing the design of larger units with a design for partial dissolving of Iron in situ. This will make it possible to produce a commercially viable component. commercially viable component.

Hydrides are formed when elements or
compounds absorb Hydrogen

Many elements on the periodic table of elements absorb hydrogen, most are situated in the transition group metals. One element, palladium, can absorb up to 900 times its own weight in H2. Incredible as this sounds, it is a fact that 1 pound of palladium will hold 900 lbs of Hydrogen. That is the equivalent to having enough fuel to drive your average car across the U.S. several times.

Titanium also makes a good hydride, (absorbs up to 60% of it's weight) and is more available than pricey palladium.

Some companies are working on hydrogen storage with other materials. The major goal is to meet or exceed the gasoline equivalent fuel tank for transportation needs.

Slow Moving Water has made patented advances toward completion of a worldwide delivery system of cheap, reliable hydrogen to fuel, heat, and power a safe, clean, and sustainable world.

Hydrides outperform all other types of hydrogen storage. The chart below compares hydrides to liquid and pressurized hydrogen. Not only can you store more energy in a smaller space hydrogen can be stored it off the shelf propane and gasoline containers. This makes converting to hydrogen an easy retrofit for today's energy systems.

* The hydride shown on graph is not Palladium but Titanium, and holds 200 grams of hydrogen per liter.

* The Palladium hydride holds 900 times its weight in hydrogen or 2000 grams per liter!

* Even compressing Hydrogen to 10,000 psi to get more hydrogen in less space does not compete with hydrides that only require less than 200 psi to obtain greater storage capacity.

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