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Browsing by Author "Mendes, Patricia"

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  • Functionalization of metal-organic frameworks for hexane isomers separation
    Publication . Mendes, Patricia; Rodrigues, Alírio; Ragon, Florence; Horcajada, Patricia; Serre, Christian; Silva, José A.C.
    This work shows the effect of incorporating three different organic ligands (NH2-H2BDC, NO2-H2BDC and Br-H2BDC) into UIO-66(Zr) framework viewing the separation of hexane isomers(22DMB, 23DMB, 3MP and nHEX).
    2012Conference object Open access Show more
  • Hexane isomers sorption on a functionalized metal-organic framework
    Publication . Silva, José A.C.; Mendes, Patricia; Ragon, Florence; Rodrigues, Alírio; Horcajada, Patricia; Serre, Christian
    A series of functionalized porous Zr terephthalate MOFs of the UiO-66(Zr) structure type bearing either Br, NH2 or NO2 groups have been synthesized at the multi-gram scale through an atmospheric pressure solvothermal route with the final aim of investigating the influence of functionalization on the separation of hexane isomers (22DMB, 23DMB, 3MP and nHEX). The studies performed in a fixed bed adsorption column with equimolar mixtures at temperatures between 343 and 423 K and partial pressure up to 10 kPa have shown that the Br, NO2 and NH3 forms exhibit an uptake reaching 15%, being the sorption selectivity hierarchy on the whole comparable to the bared UiO-66 solid: 22DMB approximate to 23DMB >> 3MP nHEX. The 22DMB/nHEX selectivity reaches approximately three at low uptake while the 22DMB/3MP selectivity of UiO-66_NO2 is nearly constant (1.3).
    2013Journal article Open access Show more
  • Hexane isomers sorption on the rigid framework MOF MIL-100(Cr)
    Publication . Mendes, Patricia; Silva, José A.C.; Rodrigues, Alírio
    In this work we studied the hexane isomers sorption on the MIL-100(Cr) [1]. The first part of the study was related to the pattern MIL-100(Cr) solid, the second dealt with the MIL-100(Cr) grafted with EtAp (Ethylamine pure) and the third with MIL-100(Cr)MEDA (Methyl ethylene diamine). The synthesis and characterization of MIL-100 (Cr), MIL-100(Cr)EtAp and MIL-100(Cr)MEDA was performed at Institut Lavoisier de Versailles. The separation and adsorption capacity of each MOF were evaluated through breakthrough experiments in a chromatographic system at LSRE using an equimolar mixture of four hexane isomers: n-hexane (nHEX) (RON 25), 3-methylpentane (3MP) (RON 75), 2,3-dimethylbutane (23DMB) (RON 103) and 2,2-dimethylbutane (22DMB) (RON 94) with the objective to the develop an adsorptive process to separate hexane isomers (kinetic diameter very similar) in order to improve the quality of gasoline measured by the octane number (RON).
    2013Conference object Open access Show more
  • Multicomponent hexane isomers sorption on MOF ZIF-8
    Publication . Mendes, Patricia; Silva, José A.C.; Rodrigues, Alírio; Horcajada, Patricia; Serre, Christian
    The main goal of this research focuses on the development of an adsorptive process to separate hexane isomers (kinetic diameter very similar) in order to improve the quality of gasoline measured by the octane number (RON). In this investigation, studies of sorption equilibrium of hexane isomers: n-hexane (RON 25), 3-methylpentane (RON 75), 2,3-dimethylbutane (RON 103) and 2,2-dimethylbutane (RON 94) were performed on ZIF-8. The MOF ZIF-8 was synthesized and fully characterized by XRD, TGA, IR and surface area at the Institute Lavoisier Versailles.
    2013Conference object Open access Show more
  • Reverse shape selectivity in the adsorption of hexane and xylene isomers in MOF UiO-66
    Publication . Silva, José A.C.; Rodrigues, Alírio; Bárcia, Patrick da Silva; Guimarães, Daniela; Mendes, Patricia; Chevreau, Hubert; Serre, Christian; Guillerm, Vincent
    An adsorption study of hexane and xylene isomers mixtures was addressed in a rigid zirconium terephthalate UiO-66 (UiO for University of Oslo) with octahedral and tetrahedral cavities of free diameter close to 1.1 nm and 0.8 nm, respectively. Multicomponent equimolar breakthrough experiments show that the adsorption hierarchy of structural isomers in UiO-66 is opposite to the one observed in conventional adsorbents. For hexane isomers, it was found that the amount adsorbed increases with the degree of branching, being 2,2-dimethylbutane (22DMB) and 2,3-dimethylbutane (23DMB) the more retained molecules. Regarding the xylene isomers, the results show that the adsorption of the bulkier ortho-xylene(oX) is favoured compared to its homologues. The structural similarity between MOF UiO-66 and zeolite MCM-22 suggests that the reverse shape selectivity observed in the adsorption of hexane and xylene isomers might be attributed to the rotational freedom of the molecules inside the small cavities.
    2011Journal article Open access Show more
  • Separation of hexane isomers in metal-organic frameworks
    Publication . Mendes, Patricia; Rodrigues, Alírio; Silva, José A.C.
    In this work we study the effect of the functionalization of UiO-66(Zr) architecture with three different organic ligands: 2-aminoterephthalic acid (NH2-H2BDC), 2-nitroterephthalic acid (NO2-H2BDC) and 2-bromoterephthalic acid (Br-H2BDC) on the separation of hexane isomers by adsorption viewing the upgrading of TIP processes. The functionalized MOFs were synthesized and fully characterized applying established techniques: X-ray powder diffraction (XRPD), Infra-Red spectroscopy (IR), Thermo Gravimetric analysis (TGA) and nitrogen adsorption measurement. The potential of separation of the hexane isomers in the synthesized MOFs has been assessed by ISBN: 988-84-695-3536-3 T12-7 performing several screening studies in a breakthrough apparatus exploiting the effect of temperature and partial pressure, demonstrating that functionalization changes sorption behavior improving the separation between 22DMB and the other isomers. Figure 2 shows an experimental breakthrough curve performed in a bed packed with amino functionalized UiO-66 (UiO-66_NH2) where it can be seen that this material is able to separate high RON di-branched isomers (22DMB) from the low RON parents mono (3MP) and linear (nHEX) ones.
    2012Conference object Open access Show more
  • Separation of hexane isomers on rigid porous metal carboxylate-based metal-organic frameworks
    Publication . Mendes, Patricia; Rodrigues, Alírio; Horcajada, Patricia; Eubank, Jarrod; Devic, Thomas; Serre, Christian; Silva, José A.C.
    Screening separation studies with equimolar quaternary mixtures of hexane isomers, namely, n-hexane/3-methylpentane/2,3-dimethylbutane/2,2- dimethylbutane (n-HEX/3MP/23DMB/22DMB), in the temperature range of 343–423 K and partial pressures up to 10 kPa have been performed using three rigid porous metal (III/IV) carboxylate-based metal–organic frameworks (MOFs) with different composition and topology. These carboxylate-based MOFs are denoted as MIL-100(Cr), MIL-125(Ti)-NH2 and MIL-127(Fe). Adsorption study results revealed that all the isomers were adsorbed on MIL-100(Cr) and MIL-125(Ti)-NH2, with adsorption amounts reaching 24 and 12 wt%, respectively, and the order of adsorption being similar to the normal boiling point of the compounds, that is, n-HEX > 3MP > 23DMB > 22DMB, with selectivity of adsorption never exceeding three (i.e. selectivities between the extreme compounds n-HEX and 22DMB). It is worth noting that adsorption of branched isomers is practically excluded on MIL-127(Fe), which exhibits a strong molecular sieve effect of the adsorbed n-HEX with the loading capacity reaching a maximum of 7 wt%. Finally, an alternative strategy, which involved probing the effect of post-synthetic functionalization on the coordinatively unsaturated metal sites of the MIL-100(Cr) using functional group ethylamine or N-methylethylenediamine showed no significant differenc
    2014Journal article Restricted access Show more