Introduction
Laboratory methods of preparation, properties and uses of hydrogen have already been discussed at secondary level. Here some more aspects of study of hydrogen will be considered.
Laboratory methods of preparation, properties and uses of hydrogen have already been discussed at secondary level. Here some more aspects of study of hydrogen will be considered.
Industrial Preparations of Hydrogen
In industry, hydrogen is manufactured by water, natural gas resource and ammonia. Methods are in the order of their importance:
1. Preparation of Hydrogen by Electrolysis of Water
When electricity is passed through water containing a small quantity of an electrolyte (an acid, a base or a salt), water decomposes into hydrogen and oxygen. Hydrogen collects at cathode and oxygen gas, a by -- product, is collected at anode with respect to their charges.
2H2O ----------------------> 2H2 (g)+ O2 (g)
The gases produced are in the purest form. This process is expensive and is used to produce hydrogen where electricity is available at cheaper rates.
2. Preparation of Hydrogen by Steam and Hydrocarbon Process
A mixture of steam and natural gas when passed over a nickel catalyst at 900 degree centigrades, produces a mixture of hydrogen and carbon monoxide commonly known as Water gas. Natural gas contains about 94.60%- methane.
CH4 (g)+ H2O ----------------------> 3H2 (g) + CO(g) (Water Gas)
3. Preparation of Hydrogen by action of Steam on Coal
When steam is passed over red hot coke at about 1000 Degree Centigrades, a mixture of hydrogen and carbon monoxide (Known as water gas) is formed.
C (g)+ H2O ----------------------> H2 (g) + CO(g) (Water Gas)
Hydrogen is obtained in free state by removing carbon monoxide from water gas. It is done by heating the mixture of two gases with more steam at 500 Degree Centigrades in the presence of catalyst (Iron oxide or cobalt oxide). As a result carbon monoxide is changed to carbon dioxide which can easily be separated by dissolving in water under high pressure leaving behind free hydrogen gas.
Hydrogen is obtained in free state by removing carbon monoxide from water gas. It is done by heating the mixture of two gases with more steam at 500 Degree Centigrades in the presence of catalyst (Iron oxide or cobalt oxide). As a result carbon monoxide is changed to carbon dioxide which can easily be separated by dissolving in water under high pressure leaving behind free hydrogen gas.
FeO
CO(g)+ H2 + H2O(g) ----------------------> CO2 (g) + 2H2 (g)
500 Degree Centigrades
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