What is the most ideal method of hydrogen production

One, electrolysis of water to produce hydrogen

More than the use of iron as the cathode surface, nickel as the anode surface of the tandem electrolyzer (the external shape of the filter press) to electrolyze the caustic potash or caustic soda aqueous solution. Oxygen is produced at the anode and hydrogen at the cathode. This method is more expensive, but the product purity is large and can directly produce hydrogen with a purity of 99.7% or more. This purity of hydrogen is often used for: ① electronics, instrumentation, instrumentation industry with the reducing agent, protective gas and heat treatment of PoMo alloy, etc., ② powder metallurgy industry, tungsten, molybdenum, cemented carbide, etc. with the reducing agent, ③ polysilicon, germanium and other semiconductor raw materials, ④ hydrogenation of fats and oils, ⑤ double-hydrogen cooled generators in the cooling gas, and so on. Like the Beijing Electronic Tube Factory and the Academy of Sciences gas plant on the water electrolysis method of hydrogen production.

Two, water gas method of hydrogen

With anthracite coal or coke as raw material and water vapor reaction at high temperature and water gas (C + H2O → CO + H2 - heat). After purification and then make it and water vapor together through the catalyst so that the CO is converted into CO2 (CO + H2O → CO2 + H2) can get the hydrogen content of more than 80% of the gas, and then pressed into the water to dissolve CO2, and then through the ammonia-containing cuprous anthranilic acid (or ammonia-containing cuprous acetic acid) solution to remove the residual CO and get the purer hydrogen, this method of hydrogen production at low cost and production of large quantities of equipment, more in the ammonia synthesis plant This method is mostly used in ammonia synthesis plants. Some also CO and H2 synthesized methanol, there are a few places with 80% hydrogen gas is not pure for artificial liquid fuels. Like the Beijing Chemical Experimental Plant and many local small nitrogen fertilizer plants use this method.

Three, by the petroleum thermal cracking of syngas and natural gas hydrogen

Petroleum thermal cracking by-products of hydrogen production is very large, commonly used in gasoline hydrogenation, petrochemicals and fertilizer plants need hydrogen, this method of hydrogen production in many countries around the world are used in China's petrochemical bases such as in the fertilizer plant in Qing, the Bohai oil fields of the petrochemical base, etc. are used in this way to make hydrogen

Also in some places (such as the United States), the United States is also used in the chemical experiment plant and many small nitrogen fertilizer plant. In some places (such as Bay, way and Batan Rougo hydrogen plant in the United States, etc.).

Four, the coke oven gas frozen hydrogen

The initial purification of the coke oven gas frozen and pressurized, so that the other gases liquefied and the remaining hydrogen. This method is used in a few places (such as Ke Mepobo plant in the former Soviet Union).

Fifth, the electrolysis of brine by-production of hydrogen

In the chlor-alkali industry by-production of a large amount of pure hydrogen, in addition to the synthesis of hydrochloric acid there is still a surplus, but also by the purification of the production of hydrogen or pure hydrogen. The hydrogen used in the second chemical plant is a by-product of the electrolysis of brine.

Six, brewing industry by-product

Corn fermentation acetone, butanol, fermentation tank exhaust gas has more than 1/3 of the hydrogen, after several times after the purification of the production of hydrogen (more than 97%), the hydrogen through the use of liquid nitrogen cooled to -100 ° C below the silica gel tubing is further removed impurities (such as a small amount of N2) can be produced pure hydrogen (more than 99.99%), like the chemical plant with the hydrogen is a by-product of electrolysis of brine. 99.99% or more), such as the Beijing brewery on the production of this by-product of hydrogen, used to burn quartz products and for foreign units.

Seven, iron and water vapor reaction hydrogen

But the quality is poorer, this is a more obsolete method is now basically eliminated.