Wednesday, February 29, 2012
How to generate Hydrogen from your tap water?
Hydrogen is the cleanest source of energy that can power your homes and fuel your cars. It can potentially substitute diesel and petrol or coal and clean up our environment. Hydrogen has been manufactured industrially for the past several decades and transported across thousand of kilometers by pipelines in Europe. The science and technology of Hydrogen is well known but its application to generate power and fuel a car is relatively new. The gasoline internal combustion engines that drive our gasoline cars can be modified to suit Hydrogen fuel. But the physical and chemical properties of Hydrogen gas created a necessity to alter existing gasoline engines for commercialization. But such conversion has been painfully slow for couple of reasons. There is a stiff resistance from gasoline cars to switch over to Hydrogen because they have a well established infrastructure to manufacture gasoline cars and to supply gasoline through well established distribution network. But Hydrogen cars lack both of them. Even if the cars can be modified for Hydrogen, there are no sales or distribution network for the fuel Hydrogen, similar to Gasoline. Even consumers need to be educated that Hydrogen is safe, environmentally friendly and we need not depend on import of oil and so on. It is a blessing in disguise that Hydrogen can be generated by individual homes, business and industries for their captive use from their tap water. Recently Hydrogen fuelled scooters have been introduced in the market. There are number of advertisements in the media too; that you can fit a Hydrogen generator at your car that will reduce your gasoline bills substantially and also reduce your emissions.But these Electrolyzers can generate only water gas and not a pure Hydrogen. Yet such simple devices can help reduce your petrol bills to an extend .If things are so simple why are we still struggling with high crude oil prices and increasing electricity bills? Let us examine this in detail. Water (H2O) can be split into Hydrogen (H2) and Oxygen (O2) by simply passing an electric current through water using a battery. The water disassociates as follows: 2H2O ------------- 2H2 + O2 Stochiometrically, it means 36 lits of water will generate 4 Kgs of Hydrogen and 32 kgs of Oygygen.The current PEM (Proton exchange membrane) Fuel cell car (Honda FCX clarity) can drive 100 miles with just 0.105 kgs of Hydrogen from 5000 psi Hydrogen tank. Similarly 4kgs of hydrogen can generate about 100 kws of electricity using PEM Fuel cell, based on a conservative estimate; but 4Kgs of gasoline can generate only 15 kW electricity. The gasoline engine offers only 100km mileage from 13 kgs (16lits) of gasoline. In other words, 0.105 kgs of Hydrogen at 5000 psi gives the same mileage as 16 lits of Gasoline. This is the amazing power of water, yet to be unleashed! The tap water is suitable to generate Hydrogen by adding a little amount of potash lye to improve the electrical conductivity. An Alkaline water electrolyzer can be attached to the water tank to generate required amount of Hydrogen based on the above calculation. The resulting Hydrogen has to be compressed to a required level. The power consumption to electrolyze water will be about 75-80 kwhrs per Kg of Hydrogen generated at 5000 psi.Therefore 4Kgs of Hydrogen will require a power of 300kwhrs costing about $30 for a total mileage of 3800 miles. You will require a small reverse osmosis unit to be attached to your water tap so that the water is de-ionized so that there is no precipitation in the Electrolyzer or reduction in the efficiency of electrolysis. Recently, Suzuki Bargeman introduced Hydrogen Fuel cell scooter which claims to offer a mileage of 200km from 12 lits Hydrogen (carbon composite material) tank at an elevated pressure of 10,000psi.The future of Hydrogen car is very promising and finally the world can hope to get rid of smoke and noise from our roads and cities.