Propylene/Propane Separation in Fixed‐Bed Adsorber and Membrane Permeation

Abstract

Die metallorganische Gerüstverbindung Mg2(dhtp) mit dem Linker Dihydroxyterephthalat ist als MOF‐74 oder CPO‐27 bekannt. Mg2(dhtp) wurde in Pulverform für die Messung von Durchbruchskurven im Festbettadsorber und Adsorptionsisothermen sowie als geträgerte dünne Membranschicht für Permeationsmessungen synthetisiert. Die Messung der Durchbruchskurven des binären Propylen/Propan‐Gemisches zeigt, dass eine Trennung im Festbettadsorber möglich ist. Es zeigt sich hier eine höhere Affinität des Propylens zum Adsorbens Mg2(dhtp). Obwohl der Einzelgasfluss von Propan höher als der von Propylen ist, weist die Mg2(dhtp)‐Membran für das binäre Gemisch kein Trennverhalten auf.

Metal–Organic Framework UiO-66 Layer: A Highly Oriented Membrane with Good Selectivity and Hydrogen Permeance

“…13−17 When looking at the diversity of available MOFs, structures with 3D geometry and pore apertures of a few Å are of particular interest, since they allow an unhindered gas permeation regardless of the crystal orientation within the membrane 18 unlike 1D geometries. 19 Our group already published results with MOF layers as molecular sieve membranes prepared by microwave synthesis, 14 by reactive seeding, 20 or by covalent bonding to the support. 21 Nevertheless, for application in membrane-based separation processes, the materials have to feature a good mechanical and chemical stability.…”

“…Despite some pioneering activities and plenty of work in the development of supported MOF-based membranes, the scale up and reproducibility of defect-free MOF membranes are still major challenges. , Nevertheless, there are several publications with promising approaches to enhance the reproducibility and membrane quality by synthesis modifications or new membrane architectures. − When looking at the diversity of available MOFs, structures with 3D geometry and pore apertures of a few Å are of particular interest, since they allow an unhindered gas permeation regardless of the crystal orientation within the membrane unlike 1D geometries . Our group already published results with MOF layers as molecular sieve membranes prepared by microwave synthesis, by reactive seeding, or by covalent bonding to the support …”

Propane/propene permeation through Na-X membranes: The interplay of separation performance and pre-synthetic support functionalization

“…This is due to a few easily underestimated but none the less very serious disadvantages of MOFs, which are in most cases directly related to their said advantages. For example, separation membranes made out of materials with 1D pore systems like MOF-74 suffer from very specific problems like adsorption founded blockage/self-hindrance and disadvantageous channel orientation [8]. The latter one is especially crucial because of the special geometric requirements in membranes (pores perpendicular to the support) and the very limited possibilities to control the crystal/pore growth orientation.…”

Coordinated Water as New Binding Sites for the Separation of Light Hydrocarbons in Metal–Organic Frameworks with Open Metal Sites

“…A significant body of work dealing with the sorption properties of the M 2 (dobdc) series exists, most notably utilizing the OMSs to discriminate between saturated and unsaturated light hydrocarbons (cf. refs ,− ). Independent from the chosen metal, the general trend of the selectivities toward olefins (e.g., ethene, propene) over paraffins (e.g., ethane, propane) was observed.…”