West Lafayette (IN) - Researchers at Indiana's Purdue University have further developed a recently described technology that can break down water directly into hydrogen and oxygen without input power.
The announced process drives water across a plate which splits the water into its gas components. The collected gases can then be piped off and burned efficiently in a hydrogen powered engine. This process is claimed to produce absolutely no pollution whatsoever and can be used in a wide range of vehicles, even replacing the nuclear power plants in submarines, according to the researchers.
The original process was first announced by Purdue researchers in May of this year. It was based on the idea of taking an aluminum/gallium alloy and flowing water across it. The aluminum splits the water into hydrogen and oxygen without any input power. Basically, the oxygen is drawn to the aluminum and the hydrogen bubbles away to be collected. The gallium is present to prevent normal oxidation on the aluminum's surface, thereby keeping the source free from almost immediate contamination which normally occurs on aluminum during electrolysis. It's an interesting use of the material because gallium is even a waste byproduct of aluminum manufacturing.
Their newest research will be presented in a paper scheduled for release on September 7 at the 2nd Energy Nanotechnology International Conference in Santa Clara, California. It outlines an alloy capable of exposing even more aluminum to the water, thereby making the process more efficient. The original process used a 72% aluminum, 28% gallium (by weight) ratio. The reaction produced hydrogen, alumina (aluminum oxide) and heat. The new process increases the ratio to 80%-20%.
This technology's greatest potential asset is the ability to create hydrogen on demand. If the researchers vision becomes a reality, this means that a vehicle's fuel tanks can be filled with safe water. Only one device near the engine compartment is required to actually produce the explosive hydrogen.
The research result indicates that two of the major barriers to hydrogen adoption could be eliminated: The first is the current difficulty in manufacturing and distributing the fuel in hydrogen form. The second is the dangerous requirement of storing hydrogen in high-pressure fuel tanks in the vehicle itself. The concern is that if a tank is ruptured during a crash, or if there is some kind of leak during refueling, an explosion can occur. This has happened in early tests and is a foremost concern on any would-be adopter's mind.
Since this technology produces hydrogen on demand via a simple plate-like device, it can also be scaled to meet any volume requirements. This means that everything from mopeds to submarines can be powered by completely clean hydrogen combustion, the result of which is heat and water vapor (which can even be recycled into the fuel tank).
Hydrogen burns in internal combustion engines at a very high temperature. Most of the current problems with hydrogen powered engines are heat related. Special combustion chamber materials and cooling have to be used in these engines. There are several prototypes from companies like Toyota, Honda and GM on the road racking up test miles today.
These pilot vehicles all prove that the power source does work, is completely clean (at least within the cars) and could be put into production once the issue of finding safe and efficient ways to create and store hydrogen are found. With a system that stores only water and creates very small quantities of hydrogen on demand, the risk of explosion falls to very low levels.
In a somewhat related technology, Australian researchers discovered in April a way to produce hydrogen and oxygen by flowing raw seawater over a similar type of plate in the presence of direct sunlight.
The combined gas was created and collected in a similar way and could be burned by nearby power generation facilities. The Australian scientists postulated that a 40 square km area of Australia's desert would be sufficient to incorporate enough power-generation devices that the power grid they would drive from this technology could provide enough electricity for every citizen in the entire country. The researchers suggested that, in 5-10 years, the production capacities necessary to create enough material for such an endeavor could actually make the idea feasible.
