How is hydrogen stored and how long does hydrogen last in the body

The traditional method is liquefaction, but this method is expensive and not easy to use, and the current cutting-edge method is to use some hydrogen storage materials, a class of materials that can reversibly absorb and release hydrogen. The first discovery was palladium metal, 1 volume of palladium can dissolve hundreds of volumes of hydrogen, but palladium is very expensive and lacks practical value. After the 70s of the 20th century, due to the increasing importance of the research and development of hydrogen energy, the safe storage and transportation of hydrogen should be solved first, and the scope of hydrogen storage materials has been increasingly expanded to transition metal alloys.

For example, lanthanum-nickel intermetallic compounds have the property of reversibly absorbing and releasing hydrogen

Each gram of lanthanum-nickel alloy can store liters of hydrogen, which can be re-released by a little heating. Lani5 is a nickel-based alloy, and iron-based alloys can be used as hydrogen storage materials such as TiFe, which can absorb and store liters of hydrogen per gram of TiFe. There are other magnesium-based alloys, such as Mg2Cu, Mg2Ni, etc., which are cheaper.

Because hydrogen is small in density and difficult to store, the gas is compressed into a liquid state and bottled.

There are two traditional hydrogen storage methods, one is to use high-pressure cylinders (hydrogen cylinders) to store hydrogen, but the volume of hydrogen stored in the cylinders is small, even if the hydrogen in the cylinder is pressurized to 150 atmospheres, the quality of the hydrogen contained is less than 1 of the mass of the hydrogen cylinder, and there is a danger of **; Another method is to store liquid hydrogen, which is cooled to 253 0C and turned into a liquid for storage, but the liquid storage tank is very large and requires excellent insulation to prevent the liquid hydrogen from boiling and vaporizing.

There is also a new and simple method of hydrogen storage, which uses hydrogen storage alloys (metal hydrides) to store hydrogen.

Compressed into a liquid state and stored in cylinders.

Use for dark green cylinder storage.

After the hydrogen gas stops**, it generally lasts no more than 60 minutes. This is mainly affected by blood circulation, the gas reduction rate of different organs in the body is different, the fastest is blood, about 30 minutes will be reduced to disappear, but other organs such as the brain are released more slowly, muscles and ** are even slower.

At room temperature and pressure, Luyuan hydrogen is a highly flammable, colorless, transparent, odorless, tasteless and insoluble gas in water. Hydrogen is the least dense gas known in the world, and the density of hydrogen is only 1 14 of air, i.e. at 0, a standard atmosphere.

, the density of hydrogen is.

So hydrogen can be used as an airship.

The filling gas of the hydrogen balloon (because hydrogen is flammable and not very safe, the airship is now mostly filled with helium). Hydrogen is the relative molecular mass.

The smallest substance, mainly used as a reducing agent.

1. Alloy hydrogen storage materials.

Intermetallic compounds that can reversibly absorb, store, and release hydrogen in large quantities at a certain temperature and hydrogen pressure.

According to the number of constituent elements of hydrogen storage alloys, it can be divided into: binary system, ternary system and multivariate system; According to the main metal elements of hydrogen storage alloy materials, it can be divided into: rare earth series, magnesium series, titanium series, vanadium-based solid solution, zirconium series, etc.; The metals that make up the hydrogen storage alloy can be divided into hydrogen absorption class (denoted by A) and non-hydrogen absorption class (denoted by B), according to which the hydrogen storage alloy can be divided into:

AB5, AB2, AB, A2B.

2. Inorganic and organic hydrogen storage materials.

Organic hydrogen storage technology began in the 80s of the 20th century. Hydrogen storage in organic matter is achieved by a pair of reversible reactions between unsaturated liquid organic matter and hydrogen, that is, by using a reversible reaction of catalytic hydrogenation and dehydrogenation. The hydrogenation reaction realizes the storage (chemical bonding) of hydrogen, and the dehydrogenation reaction realizes the release of hydrogen.

3. Nano hydrogen storage materials.

Due to the quantum size effect, small size effect and surface effect, nanomaterials exhibit many unique physical and chemical properties, and have become the frontier field of physics, chemistry, materials and other disciplines. After the nano-transformation of hydrogen storage alloys, many new thermodynamic and kinetic properties have also emerged, such as significantly improved activation performance, higher hydrogen diffusion coefficient and excellent hydrogen absorption and discharge kinetic properties.

4. Hydrogen storage in carbonaceous materials.

Adsorption hydrogen storage has the advantages of safety, reliability and high storage efficiency. Among the materials for adsorption and hydrogen storage, carbonaceous materials are the best adsorbents, which are not only insensitive to a small number of gas impurities, but also can be used repeatedly. Carbonaceous hydrogen storage materials are mainly high specific surface area activated carbon (AC), graphite nanofibers (GNF), and carbon nanotubes (CNT).

5. Coordination hydride hydrogen storage.

Coordination hydride hydrogen storage is the property that alkali metals (Li, Na, K, etc.) or alkaline earth metals (Mg, Ca, etc.) and the third principal group elements can form coordination hydrides with hydrogen. The main difference between it and metallic hydrogen is the transition to ionic or covalent compounds during hydrogen absorption, while the hydrogen in metallic hydrides is stored in an atomic state in the alloy.

6. Hydrate hydrogen storage.

Gas hydrate, also known as pore hydrate, is an ice-like crystal consisting of a host hole formed by hydrogen bonding of water molecules containing a guest molecule under a very weak van der Waals force.

In order for hydrogen to be used as a conventional energy source, it is not only necessary to solve the problem of cheap hydrogen production technology, but more importantly, it is also necessary to overcome the problems of safe and convenient storage and transportation.

Liquid hydrogen. The density of gaseous hydrogen is small, which is not conducive to storage. At a pressure of 15 megapascals, only 0 5 kg of hydrogen can be filled in a 40 cubic decimeter cylinder.

Compressing gaseous hydrogen into liquid hydrogen consumes almost 1 3 1 4 of its combustion energy, which is not only high in energy consumption, but also unsafe. It's no wonder that when tank trucks loaded with liquid hydrogen first appeared on American roads, red "carried" jeeps.

Calling forward and hugging back, as if facing a great enemy. Therefore, for a widely used fuel, it is necessary to find a more ideal, safe and convenient storage and transportation method.

Various attempts have been made to scientifically study hydrogen storage methods, and the metal hydrogen storage method has become a promising method.

It may be a little strange to say, how can solid metal, not a container, hold gas? It turns out that certain metals or alloys, because of their catalytic or active action on the surface, can break down hydrogen molecules into hydrogen atoms.

The phenomenon of entering the metal lattice and forming the metal reed hydride was first discovered by American scientists at the end of the 60s of the 20th century. At present, a variety of hydrogen storage alloys have been successfully studied in the world. The hydrogen storage of hydrogen storage alloys is like a sponge absorbing water.

The reaction between metal and hydrogen is a reversible process, which can absorb a large amount of hydrogen and release it reversibly under certain temperature and pressure conditions. For example, lanthanum-nickel alloys can absorb hydrogen to form metal hydrides, which is an exothermic reaction.

Hydrogen storage alloys are used to store hydrogen, and hydrogen gas will emerge from the alloy as long as it is heated slightly. This hydrogen inhalation and release can be repeated over a fairly long period of time. In this hydrogen storage alloy, hydrogen storage capacity can be as high as 88 kilograms of cubic meters, which is higher than that of kilograms of liquid hydrogen.

At present, the most practical ones are lanthanum-nickel alloys and iron-titanium alloys.

Each kilogram of lanthanum-nickel alloy can store 153 liters of hydrogen, which is more than 1,000 times its own volume, and the hydrogen storage capacity per kilogram of iron-titanium alloy is four times larger than the former, and ** is also low. The development of hydrogen storage materials with excellent performance has opened up a new way of hydrogen storage and transportation, and has shown a broad application prospect.

Hydrogen water cannot be stored at room temperature, and at room temperature and pressure, the solubility of hydrogen in water is very small and does not react, so it can coexist.

The density of liquid hydrogen is about 70 kilograms per cubic meter, and it is important to know the incompressibility of liquids, and the general pressure cannot be compressed to the density of water. To press the density of water, it is necessary to overcome the strong intermolecular force, and the pressure cannot be calculated at present, and the energy cannot be calculated, but it can only be said to be extremely large.

Hydrogen (H2):

It was first prepared artificially in the early 16th century by placing the metal in a strong acid. 1766 In 1781, Henry Cavendish discovered the element hydrogen.

Hydrogen is burned to produce water, and Lavoisier named the element "hydrogenium" (meaning "substance that produces water", "hydro" means "water", "gen" means "generated", "ium")."is a universal suffix for elements).

In the 50s of the 19th century, when the British physician Hexin (1855) wrote the "New Edition of Naturalism" (1855), he translated "hydrogen" as "light gas", which means the lightest gas.

The hydrogen and oxygen machine dissolves hydrogen and oxygen into water and becomes hydrogen-rich, how long can water be stored and the hydrogen will not run away?

1. Liquefaction hydrogen storage (the cost is too high for the fracturing source, and it requires high energy to maintain its liquefaction); Compressed hydrogen storage (low gravimetric and bulk density).

2. Metal hydride hydrogen storage (high volume storage density, but low weight density), and the other is the carbon nanotube adsorption hydrogen storage that is now being studied (it has been proved that at room temperature and less than 1bar (about one atmosphere) pressure, single-walled carbon tubes can adsorb 5%-10%, and multi-walled carbon nanotubes can store hydrogen up to 14%, but some reports from this source hall have been questioned, because there is no world-recognized detection standard for carbon nanotube hydrogen storage in the world's recognized disperse state).

The main methods are:

1. The cost of liquefaction hydrogen storage is too high, and it requires high energy to maintain its liquefaction;

2. Compressed hydrogen storage, weight density and chain Chang or volume density are very low;

3. Metal hydride stores hydrogen, with high volume storage density but low weight density.