Patent attributes
In order to provide a new PSA method which can concentrate simultaneously a strong adsorbate such as xenon and a weak adsorbate such as nitrogen in a high concentration with a high recovery percentage when highly valuable gas such as xenon and krypton contained in the exhaust gas from a semiconductor manufacturing equipment, etc. is recovered in a high concentration with a high recovery percentage, the present invention provides a new PSA method in which the method uses a separation apparatus comprising a lower column and a upper column which are filled with an adsorbent, a material gas storage tank for storing the material gas to be introduced into the lower column, a strong adsorbate storage tank for storing a main component which is easily adsorbed by the adsorbent, and a compressor, and the strong adsorbate which is easily adsorbed by the adsorbent and the weak adsorbate which is not readily adsorbed by the adsorbent are recovered, wherein the method comprises an (a) adsorption step, (b) rinse step, (c) low column depressurization step, (d) upper column depressurization step, and (e) purge step sequentially repeated based on a predetermined sequence.
