| On a summer day in Paris in 1783, Jaques Charles did | | | | 200 to 300 kms. |
| something as tonishing. He roared 3,000 feet above | | | | By 2010 some auto companies expect the first |
| ground in a balloon of rubber-coated silk bag filled with | | | | production of fuelcell cars to hit-the road. A hydrogen |
| lighter-than-air hydrogen gas. Though this event had no | | | | storage system must carry enough fuel for at least a |
| significance for the next two centuries, yet Charles | | | | 500 km trip and also be light enough to haul around a |
| had launched a quest to harness the power of | | | | car. For a system weighing 600 kilograms (a |
| hydrogen for transportation. | | | | reasonable~ size of a vehicle) ,six kgs. would be |
| Burned or used in fuel cells, hydrogen is an appealing | | | | stored hydrogen. Liquified stored hydrogen can |
| option for powering future automobiles. This nontoxic | | | | improve it's stored energy density and could be used in |
| gas could serve as a pollution-free energy carrier for | | | | cars, it drawbacks notwithstanding. Neverthe less, One |
| machines of many kinds. When it burns, it releases no | | | | world-renowned carmakerBMW is pushing this |
| carbon .dioxide, a potent greenhouse gas. | | | | technology onto the road. The vehicle called |
| And if hydrogen is fed into a fuel cell stack a battery | | | | HYDROGEN-7 will incorporate an ,internal combustion |
| like device that generates electricity from hydrogen | | | | engine capable of running on either gasoline for 500 |
| and oxygen it can propel an electric car or truck with | | | | Kms.or on liquid hydrogen for 250 kms. |
| only heat and water as by products. Fuel-cell powered | | | | Chemical compaction: to raise energy density scientists |
| vehicles could offer more than twice the efficiency of | | | | have been able to take advantage of the chemistry of |
| today's automobiles. Hydrogen could, therefore, help | | | | hydrogen itself. In it~ liquid phase, hydrogen molecules |
| ease environmental problems, including air pollution and | | | | contain two bound atoms each. But when hydrogen |
| its hazards. | | | | molecules are chemically bound to certain other |
| Weight for weight, hydrogen contains three times the | | | | elements, they can be packed even closer together |
| energy of gasoline (petrol) but it is impossible to store | | | | than in liquid hydrogen. |
| hydrogen gas as compactly as the conventional liquid | | | | Some researchers are focusing on a class of |
| fuel. One of the most challenging technical issues is | | | | substances called reversible metal hydrides, which |
| how to efficiently and safely store enough hydrogen | | | | were discovered by accident in 1969 at the Philips |
| onboard to provide the driving range and performance | | | | Laboratories in the Netherlands. Investigators found |
| the motorists demand. Feasible storage devices hold | | | | that a Samarium-Cobalt alloy when exposed to |
| sufficient hydrogen to support today's minimum | | | | pressurized hydrogen gas it would absorb hydrogen, |
| acceptable travel (driving range--almost 500 kms)--on | | | | somewhat like a sponge soaks up water. When the |
| a fuel tank that does not compromise on luggage | | | | pressure was then removed ,the hydrogen within the |
| room. These tanks have to be filled or recharged in a | | | | alloy reemerged in other words, the process was |
| few minutes. Lot many researchers in the U8 Internal | | | | reversible, |
| Energy Agency are expending considerable effort to | | | | In the US, scientists like Jame Reilly and Gary |
| overcome these limitations. Infact, 17 governments are | | | | Sandrock,pioneered the development of hydride alloys. |
| committed to advancing hydrogen and fuel-cell | | | | This work formed the basis for today's widely used |
| technologies. In 2005 the US Department of Energy | | | | Nickel-Metal hydride batteries.The density of hydrogen |
| provide4 $ 30 million to fund the 80 research projects. | | | | in these alloys is 150 % more than liquid hydrogen! |
| A 500 km. minimum driving range is one of the principal | | | | Such properties of metal hydrides are well suited to |
| operational aims of the auto industry. Engineers believe | | | | automobiles. Although the current metal hydrides have |
| that a~allon of gasoline is equal,on an energy basis, to | | | | limitations, many automakers see them as the most |
| a kilogram of hydrogen.(One US gallon is almost 3.8 | | | | viable low-pressure approaching the near future. |
| litres) Whereas today's automobile needs about 20 | | | | Toyota and Honda automotive engineers, are planning |
| gallons of gasoline to travel 500 km.,the typical fuel-cell | | | | a so-called hybrid approach in a system that combines |
| vehicle would need only 8 kilograms of hydrogen. | | | | a solid metal hydride with moderate pressure (lower |
| Several automakers have tested about 60 hydrogen | | | | than 10,000 psi) ,which they predict could achieve a |
| -fuelled prototypes and demonstrated driving ranges of | | | | driving range of more than 500 kms. |