All the equilibrium measurements were made in a manometric–chromatographic equipment operated in closed system. The pressure transducer used for total amount adsorbed measurements is Lucas Schaevitz 9000 series from 0 to 500 kPa with an error of 60.5 kPa. The scheme of the equipment is shown in Fig. 1. The system was called manometric and not volumetric because the real variable measured is the pressure [17].