available sites in faujasite are exchanged with silver which corresponds to material having 0 1 3 weight percent silver the molecular sieve in our adsorbent is one of the mfi type molecular sieves with a si al ratio of at least 10 i e silica alumina is at least 20 and preferably greater than about 20 examples of suitable molecular sieves include zsm 5 zsm 12 zsm 23 and silicalite generally the faujasite and molecular sieve will be used in a weight ratio from about 1 3 to about 3 1 although normally the exact ratio of components is not critical to the success of our invention we have found that molecular sieves with a pore diameter in the 4 6 angstrom range are especially suitable in the practice of our invention the foregoing mixture of adsorbents has been found to be well suited for the removal of sulfur compounds especially hydrogen sulfide and hydrocarbons which are likely to be found as impurities in gaseous carbon dioxide we also have found that zeolites such as 3a 4a and 5a also may be used optionally as a prebed especially to remove other impurities such as water whether other zeolites or molecular sieves are used.