More than 30 air separation units and 24 carbon dioxide liquefaction plants in the US
Industrial gases are used in almost every industrial production process to improve safety, productivity, environmental compliance or product quality. Industrial gases include gases recovered from the atmosphere (including oxygen, nitrogen, argon, krypton and xenon) and gases recovered as a byproduct of other processes (including carbon dioxide, carbon monoxide, hydrogen and helium).
Oxygen, nitrogen and argon are recovered from air using a cryogenic method developed by the founder of Linde, Dr. Carl von Linde, more than 100 years ago. Particulates are removed from the incoming air, which is then repeatedly compressed and cooled.
Water, hydrocarbons and carbon dioxide are then removed. With further processing, the air eventually becomes a liquid and the individual gases are separated by distillation. These plants are called air separation units, or ASUs. Many of the world's ASUs have been built by Linde's engineering division.
Carbon dioxide is produced as a by-product of chemical processes, such as hydrogen manufacture, ammonia manufacture, ethanol fermentation, ethylene oxide and natural gas processing. Carbon dioxide is also produced naturally from some high purity natural reserves.
Helium is produced along with natural gas in some, but not all, natural gas production, making helium a rare and expensive gas.
Each of these gases has its own unique properties, and Linde provides solutions that use the industrial gases’ properties to improve our customers' operations. These properties can include chemical reactivity or inertness, or the physical properties (temperature or pressure).