ABSTRACT
Excluding the generally well-known atmospheric gases such as outlined previously, there is a
group of other gases, which are constantly encountered in the study of air separation. These
gases are hydrogen, carbon monoxide, ultrahigh-purity nitrogen, ultrahigh-purity oxygen,
nitrous oxide, carbon dioxide, ozone, and methane. It is important, therefore, to review these
gases, as they have become important components of the industrial gas industry.
