초록 ▼

The present invention provides for a process for purifying atmospheric air prior to its separation by cryogenic distillation. The process utilizes three adsorbent layers, the first primarily removes water; the second primarily removes CO2; and the third layer is designed to remove displaced gas comp

The present invention provides for a process for purifying atmospheric air prior to its separation by cryogenic distillation. The process utilizes three adsorbent layers, the first primarily removes water; the second primarily removes CO2; and the third layer is designed to remove displaced gas components such as N2O and hydrocarbons which are displaced by the second layer. It has been found that CaX type adsorbents provide the removal of N2O and hydrocarbons in the third layer.

대표청구항 ▼

1. A process for the removal of impurties from a gas stream by thermal swing adsorption comprising sequentially passing said gas stream through a first adsorbent layer which will remove water from said gas stream, a second adsorbent layer comprising a sodium X zeolite thereby removing CO2 from said

1. A process for the removal of impurties from a gas stream by thermal swing adsorption comprising sequentially passing said gas stream through a first adsorbent layer which will remove water from said gas stream, a second adsorbent layer comprising a sodium X zeolite thereby removing CO2 from said gas stream, and a third adsorbent layer comprising a calcium Low Silicon X zeolite wherein the adsorbents in said second and third layers have a Si/Al elemental ratio of the zeolitic phase between 0.9 to 1.3, and 0.9 and 1.15, respectively, with a cation composition of the third layer adsorbent, on an equivalent basis, that comprises about 60 to about 100% calcium ions, and about 40 to about 0% other ions, the other ions being selected from the group consisting of Group IA ions, from Group IIA ions other than calcium, from Group IB ions other than gold, from Group IIB ions other than mercury, and from ions of the lanthanides, and mixtures of these, and said third layer adsorbent comprises about 5 to about 25 percent by weight of binder, thereby removing nitrogen oxides and hydrocarbons from said gas stream.