Back to results
US 9,221,008 B2Granted
Gas prepurification process
AssigneeLinde Aktiengesellschaft
InventorsSuling Zhai, Yaping Lu
Life of this patent
Estimating the term…
Abstract
A method for removing impurities from a feed air gas stream prior to the stream being fed to a cryogenic distillation unit. The feed air gas stream contacts an ionic liquid which adsorbs the impurities from the air. The method can use one or more beds such as in pressure swing adsorption processes.
Claims6
A method for removing impurities from a feed gas stream containing impurities comprising the steps:
- a) feeding the feed gas stream to a first adsorption vessel containing an ionic liquid selected from the group consisting of imidazolium, pyridinium, pyrrooidinium, guanidinium, ammonium, phosphonium, and sulphonium-based ionic liquids, or mixtures thereof having the structures:
- wherein R1, R2, R3, and R4 are different alkyl and alkenyl groups and are selected from the group consisting of hydrogen, and straight or branched chain alkyl and alkenyl groups having from 1 to 12 carbons further comprising an amine selected from the group consisting of thiourea and amino groups being present in said ionic liquid and a hydroxyl group being incorporated into said cation wherein the impurities are removed from the feed gas stream;
- b) directing a portion of the feed gas stream free of impurities to a second bed, wherein the gas stream free of impurities regenerates the ionic liquid present in the second bed;
- and c) directing the remaining portion of the feed gas stream free of impurities to a cryogenic distillation unit.
1 more element
Dependencies are inferred from the claim text.