Patent ID: 7935177
Filing Date: 2011-05-03
Classification: B01D,B01J,Y02C,Y10S

Abstract:
1. A method of purifying a gas stream from both carbon dioxide and at least one other impurity chosen from among hydrocarbons and nitrogen oxides, said method comprising: A—bringing the gas stream to be purified into contact with at least one adsorbent in aggregated form either comprising at least 85% by weight of zeolite LSX having at least 90% of the exchangeable sites occupied by sodium ions, and the rest of the cations optionally being-potassium and up to 5% by weight of a binder that is inert to the adsorption, or 5-25 parts by weight of a zeolitized clay binder per 100 parts of final aggregate (type A aggregate); or comprising at least 70%, by weight of a blend of at least 20% of zeolite X and of at most 80%, by weight of zeolite LSX, said blend having at least 90%, of the exchangeable sites of the said zeolites X and LSX of which are occupied by sodium ions, the rest of the cations optionally being, potassium cations, and up to 5% by weight of a binder that is inert to the adsorption or 5-25 parts by weight of a zeolitized clay binder per 100 parts of final aggregate and optionally up to 25% of one or more other zeolites (type B aggregate); and wherein the number average size of zeolite LSX crystals in aggregate A and aggregate B is less than 4 microns; B—adsorbing at least some of the carbon dioxide, and at least some of the hydrocarbons and/or N C—desorbing the impurities adsorbed on the said adsorbent; and D—regenerating the adsorbent.