Production of hydrogen

Hydrogen is widely used in a variety of industries: in the synthesis of hydrogen chloride, ammonia (ammonia is further used for the production of nitrogen fertilizers), in aniline and paint production, when recovering from non-ferrous metal ores. In the food industry, it is used to produce animal fat substitutes (margarines). In connection with the above-mentioned topical issue is the production of hydrogen in industrial conditions.

This gas is considered as a future energy carrier because it is renewable, does not emit "greenhouse gas" CO₂ during combustion, gives a large amount of energy per unit weight in the combustion process and is easily converted into electricity of fuel cells.

Under laboratory conditions, most often, hydrogen is obtained by reduction by metals, which stand to the left in the electrochemical series of stresses, from water and acids:
Zn + 1HCl = ZnCl₂ + H₂ ↑: ΔH <0
2Na + 2HOH = 2NaOH + H₂ ↑: ΔH <0.

In industry, the production of hydrogen occurs, mainly by processing natural and associated gases.

1. Conversion of methane. The process consists in the interaction of methane with water vapor at 800 - 900 ° C: CH₄ + H₂O = CO ↑ + 3H₂ ↑; ΔH> 0. In addition, the process of partial oxidation of hydrocarbons with oxygen in the presence of water vapor is used: 3CH₄ + O₂ + H₂O = 3CO + 7 H. These methods will eventually lose their importance, as hydrocarbon reserves are depleted.

2. Biohydrogen can be obtained from seaweed in a bioreactor. In the late 1990s, it was discovered that if seaweed was deprived of sulfur, they would switch from producing oxygen, i.e., normal photosynthesis, to hydrogen production. Biohydrogen can also be produced in bioreactors, using, in addition to algae, household waste. The process is due to bacteria that absorb the hydrocarbon, and produce hydrogen and CO2.

3. Deep cooling of coke oven gas. During the coking process of coal, three fractions are obtained: solid - coke, liquid - coal tar - and gaseous, containing, in addition to hydrocarbons, molecular hydrogen (about 60%). This fraction is subjected to super-deep cooling after being treated with a special substance, which makes it possible to separate hydrogen from impurities.

4. Production of hydrogen from water using electrolysis is the method that gives the purest hydrogen: 2H₂O → electrolysis → 2H₂ + O.

5. Conversion of carbon. First, a water gas is produced, when water vapor passes through a hot coke: C + H₂O = CO ↑ + H₂ ↑; ΔH> 0, which is then passed in a mixture with water vapor over a catalyst heated to 400 ± 500 ° C with Fe₂O. There is interaction of carbon monoxide (II) and water vapor: CO + H₂O + (H₂) = CO₂ + 2H₂ ↑; ΔH> 0.

6. Hydrogen production by conversion of carbon monoxide (CO), based on a unique reaction using photosynthetic purple bacteria (unicellular microorganisms of a peculiar red or pink color that is associated with the presence of photosynthetic pigments). These bacteria secrete hydrogen as a result of the conversion reaction: CO + H₂O → CO₂ + H.

The formation of hydrogen comes from water, the reaction does not require high temperatures and lighting. The process takes place at room temperature in the dark.

An important industrial importance in our days is the evolution of hydrogen from gases formed during the processing of oil.

However, many do not know that it is possible to produce hydrogen at home. For these purposes, one can use the reaction of a solution of alkali and aluminum. Take a half-liter glass bottle, a stopper with a hole, a gas pipe, 10 g of copper sulfate, 20 g of salt, 10 g of aluminum, 200 g of water, a balloon.

We prepare a solution of copper sulfate: for 100 g of water we add 10 g of copper sulfate.

We prepare the brine: for 100 g of water we add 20 g of salt.

The solutions are mixed. Add the resulting mixture to aluminum. After the white suspension appeared in the bottle, we attach a ball to the tube and fill it with evolved hydrogen.

Note! This experience should be conducted only in the open air. It is necessary to control the temperature, since the reaction occurs with the release of heat and can get out of control.

It should also be remembered that hydrogen, if mixed with air, forms an explosive mixture, which is called a rattling gas (two parts of hydrogen and one part of oxygen). If such a mixture is set on fire, it will explode.