Patent ID: 8246721

Claim:
A method for purifying exhaled anesthesia gas containing oxygen and at least 20% by volume of N 2 O, wherein: (a) at a temperature between 20° C. and 40° C. and at a pressure between 0.80 bar and 1.30 bar, the exhaled anesthesia is placed in contact with a main adsorbent, comprising at least one zeolite exchanged to over 50% by one or more metal cations, wherein the main adsorbent has an adsorption kinetics of less than 10 sec −1 , and having a N 2 O adsorption capacity higher than 80 Ncm 3 /g, measured at 1 bar and 20° C., in order to adsorb at least part of the N 2 O from the stream and to produce a purified gas stream, and (b) a purified gas stream is recovered, having a N 2 O content lower than the N 2 O content of the exhaled anesthesia gas placed in contact with the main adsorbent in step a).