are produced by splitting air into individual components. The cryogenic method, that doesn´t charge the environment, was found and developed by Carl von Linde before more than 100 years. The air is compressed, made free of water steam, dust and carbon dioxide, and subsequently cooled very rush to an extreme low temperature.
Subsequently, it liquefies due to pressure relieve, and is broken by a multi-stage distillation process into oxygen, nitrogen, argon and other rare gases.
Nowadays, also other physical methods are employed for splitting and cleaning the individual components of air:
- Separation: by means of membranes.
- Absorption: capturing some components of air during air flow through a certain kind of material when other components pass trouble free through.
Air splitters are built by Linde by own in the Division Construction of equipment, and they are operated in compliance with state of art technical methods.
Industrial gases - sources
Acetylene is produced by controlled calcium carbide decomposition in water surplus. Afterwards, the raw acetylene is chemically purified and filled into steel cylinders and bundles which contain porous mass with solvent; acetylene is dissolved in this solvent under pressure.
Hydrogen may be obtained by steam reforming from water steam, natural gas, or other light hydrocarbons. Gases which are rich in hydrogen also arise in refineries and during electrolytic processes that are applied by chlorine production; hydrogen is obtained from these gas mixtures. We also utilise these hydrogen production methods – for example in our plants Leuna, Buna, and Bitterfeld in Germany and in the Milazzo refinery in Sicily.
Liquid hydrogen is produced in our plant in Ingolstadt, Germany; this is the only plant for hydrogen liquefaction in Germany. Hydrogen is liquefied by the temperature of minus 253°C and is transported in the liquid state; this decreases its transportation costs.
The most economic method for helium gaining is its extraction from natural gas. Thanks to its long-term contracts, Linde has access to the natural gas sources in U.S., Europe, and North Africa.
Carbon dioxide may be obtained from its natural underground deposits. In Répcelak, Hungary, that represents the biggest natural carbon dioxide source in Europe, we obtain more than 100,000 tons of CO2 annually. Besides this, we utilise the carbon dioxide which arises in the chemical industry at other places; we purify it to the purity that is required in the food industry.