Hydrogen is the lightest gas known in the world, and its chemical formula is H2. Hydrogen is a combustible gas with high combustion heat and high efficiency. In addition, hydrogen has a wide range of uses. The largest amount of hydrogen is used as an important petrochemical raw material for the production of synthetic ammonia, methanol and hydrogenation reactions in petroleum refining processes. In addition, it is also used in electronic industry, metallurgical industry, food industry, aerospace industry and other fields. Since the demand for hydrogen is very large, the extraction method of hydrogen is more important!
Conventional hydrogen extraction methods are divided into two categories, one is laboratory extraction of hydrogen, and the other is industrial extraction of hydrogen. The method of extracting hydrogen in the laboratory, a chemical raw material is metal, generally zinc and iron. Any metal whose activity is higher than that of hydrogen can be used to produce hydrogen. Generators are commonly used when producing more hydrogen in the laboratory. Generators can be used to react block solids (insoluble in water) with liquids, without heating during the reaction, and the generated gas is hardly soluble in water. The generator is composed of spherical funnel, container and airway. When in use, the piston of the airway is twisted, and the acid liquid flows from the spherical funnel to the bottom of the container, and then rises to the middle to touch the zinc particles to react, and the hydrogen gas produced is released from the airway. When not in use, close the piston on the air guide tube, the hydrogen pressure in the container will increase, and the acid will be hydraulically returned to the spherical funnel, so that the acid liquid will be out of contact with the zinc particles, and the reaction will stop automatically. The Hydrogen extraction methods there are four main methods for industrial extraction of hydrogen (excluding hydrogen recovery from industrial waste gas):
1. Hydrogen production by steam reforming of natural gas (including naphtha, heavy oil, refinery gas and coke oven gas, etc.);
2. Coal (including coke and petroleum coke, etc.) conversion to hydrogen production;
3. Hydrogen production by cracking methanol or ammonia;
4. Hydrogen production by water electrolysis;
Hydrogen extraction methods mainly include the above methods. Of course, we must pay attention to safety when extracting and using hydrogen. The details are as follows: 5.1 Due to production needs, gas cylinders must be used on site (indoors). The following requirements should be met: 5.1.1 The room must be well ventilated to ensure that the maximum hydrogen content in the air does not exceed 1% (volume ratio). The same below. The top of the building or the upper part of the outer wall is provided with a transom (floor) or an exhaust hole. The exhaust hole should face the safe zone, the number of indoor air changes should not be less than three times per hour, and the number of air changes per hour for emergency ventilation should not be less than seven times. 5.1.2 The distance between hydrogen cylinders and containers and cylinders containing flammable, explosive, combustible substances and oxidizing gases should not be less than 8 meters. 5.1.3 The distance from open flames or common electrical equipment should not be less than 10 meters.
