At present, in order to obtain hydrogen in industrial production, the following methods are usually used: first, the steam is passed through the hot coke to obtain hydrogen, but the hydrogen obtained in this way is usually only 75% pure. The second is to get hydrogen from steam through hot iron. The purity of hydrogen obtained by this way is relatively higher, about 97%. The third is to extract hydrogen from water gas. The purity of hydrogen obtained by this way is also quite low, so few people use this way to get hydrogen. The fourth is to produce hydrogen by water electrolysis. Hydrogen production by water electrolysis is the most widely used method in industry at present, and the purity is also the highest one. The purity can reach more than 99%, which is an important method for hydrogen production in industry. In the electrolysis of sodium hydroxide (potassium) solution, oxygen is released on the anode and hydrogen is released on the cathode. Hydrogen can also be obtained when electrolyzing sodium chloride aqueous solution to produce sodium hydroxide.
The hydrogen production by water electrolysis has higher requirements for the hydrogen and purity of the cooling generator. Therefore, it is all produced by electrolysis of water.
Principle of hydrogen production by electrolyzing water
The principle of hydrogen production by water electrolysis is very simple, that is, water is decomposed into hydrogen and oxygen by electricity. The specific method is: when direct current is applied to some electrolyte aqueous solutions, the decomposed substances have nothing to do with the original electrolyte. The decomposed water is used as the solvent, and the original electrolyte remains in the water. For example, sulfuric acid, sodium hydroxide, potassium hydroxide and so on all belong to this kind of electrolyte.
In the electrolysis of water, pure water is a typical weak electrolyte due to its low ionization degree and low conductivity. Therefore, the aforementioned electrolyte needs to be added to increase the conductivity of the solution, so that water can be electrolyzed smoothly into hydrogen and oxygen.
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