Process for gas separation

The present invention relates to a process for the separation of gases which comprises putting a mixture of gases in contact with a porous material, containing a silica matrix in which one or more metal oxides are possibly uniformly dispersed, which are selected from transition metals or from metals of groups IIIA, IVA and VA, having a surface area larger than 500 m2/g, a pore volume between 0.3 and 1.3 ml/g, a pore diameter smaller than 40 Angstrom and a XRD powder spectrum which does not have a crystalline structure, does not show any peak, and has a single broad diffraction line, or, in any case, a wide¬ spread scattering at angular values not higher than 2 = 5° with CuKa radiation, without any other scattering phenomena coherent for higher angular values. By means of the process of the present invention, the selective adsorption is obtained of at least one of the gases forming the gaseous mixture. These adsorbing materials are regenerable and are particularly suitable for bulk removal operations of acid gases from natural gas.