27. Industrial Gases

Industrial gases may actually be used as gases, liquids, or cryogenic liquids. Industrial users generally accept them as those gases used primarily in their pure form in large quantities. Most of the gases we consider to be industrial gases have been in use for many years. Processes for the cryogenic separation of the air gases were developed as early as 1895, with commercial production of oxygen beginning in 1902. Nitrous oxide was used as an anesthetic as early as 1799. Carbon dioxide had been identified as a specific substance by 1608. Methane has been used as an energy source since the 1700s. Other gaseous compounds commonly used today for specific manufacturing processes (e.g., electronics/semiconductors, plastics) are discussed in other chapters of this Handbook related to those processes.