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International audience; The adsorption of the xylene mixture onto MIL-101(Cr) has been studied experimentally and theoretically. The adsorption isotherms of the xylene isomers show a high affinity for each isomer with MIL- 101(Cr). This is in good agreement with the enthalpies of adsorption extrapolated at zero coverage, 75 kJ mol 1, 68 kJ mol 1 and 64 kJ mol 1 for o-, m- and p-xylene respectively. The order of these values is consistent with that obtained by the computer simulations. The saturation plateau obtained with p-xylene is higher than that obtained with the adsorption of o- or m-xylene onto MIL-101(Cr). This was discussed in terms of stacking in the cavities of MIL-101(Cr). The filling of the small cavities of MIL-101(Cr) was found more difficult in the case of m-xylene which was interpreted by a weaker interaction with the cavities walls. The chromatographic separation of the xylene mixture was consistent with these results. Different retention times could be found, agreeing the different enthalpies of adsorption for the different isomers. o-Xylene was successfully separated from the xylene mixture.

The recovery of propylene and nitrogen from the stream formed during the resin degassing (70% N 2 /30% C 3 H 6 ) within the polypropylene production process is important from the economic and environmental points of view. This work proposes the use of a pressure swing adsorption process with MIL-100(Fe) as an adsorbent to carry out this separation, either for recovering only nitrogen, or recovering both nitrogen and propylene. Single and binary breakthrough curves were experimentally determined on a lab-scale set-up and simulated to validate the mathematical model. PSA simulation results showed that for the nitrogen recovery process, a product purity of 99.9% and a recovery of 81.5% could be achieved with a power consumption of only 115 Wh/kg N2 . For the nitrogen and propylene recovery process, the products purities obtained were respectively 99.9% for nitrogen and 97.9% for propylene with recoveries of 97.4% and 87.6%. The adsorbent productivity was 0.20 kg N2 /kg ads /h and 0.07 kg C3H6 /kg ads /h. The total power consumption increased to 179 W h/kg N2 or 309 W h/kg C3H6 a value that is still below the ones reported previously in the literature for other technologies.