Liquid hydrogen as a fuel
The hydrogen atom has become a model for the structure of atom. Hydrogen as a substance however, has an equally important place in chemistry. Hydrogen is normally a colourless, odourless gas composed of H2 molecules. Approximately 40% of the hydrogen produced commercially is used to manufacture ammonia and about the same amount is used in petroleum refining. But the future holds an even greater role for hydrogen as a fuel.
Liquid hydrogen, H2, is a favourable rocket fuel. On burning, it produces more heat per gram than any other fuel. In its gaseous form, hydrogen may become the favourite fuel of the twenty first century. When hydrogen burns in air, the product is simply water. Therefore, the burning of hydrogen rather than fossil fuels (natural gas, petroleum, and coal) has important advantages.
The burning of fossil fuels is a source of environmental pollutants. They become the source of acid rain and discharge a large amount of toxic gases like SO2 and CO2.
Controlling carbondioxide emissions into the atmosphere is a difficult challenge, but the answer might lie in the conversion to a hydrogen economy, hydrogen would become a major energy barrier. Automobiles, for example may be modified to burn hydrogen. At present, in USA they use car using a modified piston engine and has a hydrogen storage unit in the tank. This proves that it is possible to develop hydrogen-burning cars.
Hydrogen in not a primary energy source. But it is a convenient and non-polluting fuel, but it would have to be obtained from other energy sources.
1) It is produced by heating propane and steam at high temperature and pressure in presence of the catalyst nickel.
C3 H8(g) + 3H2O(g) --- (Ni) -- > 3 CO(g) + 7H2(g)
2.Pure hydrogen may be produced by reacting carbonmonoxide with steam in the presence of a catalyst to fix CO2 and H2. The CO2 is removed by dissolving it in a basic aqueous solution.
3.Hydrogen can be obtained directly from water that is decomposed by some form of energy. For example, electricity from solar photovoltic collectors can be used as a source of energy to decompose water by electrolysis. Researchers use solar energy to convert water directly to hydrogen and oxygen.