50th Anniversary Perspective: Polymers and Mixed Matrix Membranes for Gas and Vapor Separation: A Review and Prospective Opportunities

Abstract

Membrane gas separation is a mature and expanding technology. However, the availability of better membrane materials would promote faster growth. In this Perspective we analyze the state of the art of membrane materials, including polymers and hybrid materials, as well as the current issues and barriers, and finally, we outline future research directions in membrane science. Development of new membrane materials for large scale separations will rely on a multidisciplinary approach that embraces the broad fields of chemical and materials engineering, polymer science, and materials chemistry.

Mixed‐Matrix Membranes Formed from Multi‐Dimensional Metal–Organic Frameworks for Enhanced Gas Transport and Plasticization Resistance

“…[1,2] Approximately half of this energy is used for separations, most notably distillation and absorption. [3,4] Presently,c ommercial gas-separation membranes are made almoste xclusively from polymeric materials. [3,4] Presently,c ommercial gas-separation membranes are made almoste xclusively from polymeric materials.…”

“…[3] As af iller,m etal-organic frameworks (MOFs) are an attractive class of crystalline materials, which are composed of metal ions or metal clusters bridgedb yo rganic ligands. [3] As af iller,m etal-organic frameworks (MOFs) are an attractive class of crystalline materials, which are composed of metal ions or metal clusters bridgedb yo rganic ligands.…”

“…[3,26] The two basic assumptions of the model are: 1) the filler particless hould be uniformly dispersed in ac ontinuous matrix;a nd 2) the filler particles are spherical so that a geometrical shape factor (n)o f1 /3 can be used. [3,26] The two basic assumptions of the model are: 1) the filler particless hould be uniformly dispersed in ac ontinuous matrix;a nd 2) the filler particles are spherical so that a geometrical shape factor (n)o f1 /3 can be used.…”

Highly Compatible Hydroxyl-Functionalized Microporous Polyimide-ZIF-8 Mixed Matrix Membranes for Energy Efficient Propylene/Propane Separation

“…The current sales of membrane-based gas separation systems is in the range of US$ 1-1.5 billion per year with a 90% market share for: (i) hydrogen recovery from various off-gas streams, (ii) onsite nitrogen production from air, (iii) carbon dioxide removal from natural gas, and (iv) olefin recovery from nitrogen-containing petrochemical vent gas streams. 8 However, current commercial polymer membrane materials used in these processes suffer from several severe drawbacks for viable propylene/propane separation: (i) low C 3 H 6 permeability (< 10 barrer -1 barrer = 1 x 10 -10 cm 3 (STP) cm cm -2 s -1 cmHg -1 ), (ii) low C 3 H 6 /C 3 H 8 selectivity (< 10), and (iii) poor plasticization resistance under challenging high-pressure mixed-gas conditions that leads to reduction of selectivity. 9,10 One of the most promising membrane materials for propylene/propane separation is based on a chemically and thermally stable ultramicroporous zeolitic imidazolate framework (ZIF-8) with sodalite topology made by synthesis of zinc nitrate hexahydrate and 2-methylimidazole.…”

Defektfreie Mixed‐Matrix‐Membranen aus Matrimid® und Aktivkohle für die Gastrennung

“…Anwendungsbeispiele für die Gastrennung sind z. [6] Eine weitere Möglichkeit sind Mixed-Matrix-Membranen (MMM) [7 -9] Die REM-Untersuchungen zeigen, dass die Aktivkohle-Partikel gut in der Polymermatrix integriert sind und weiterhin ist eine spezielle Morphologie sichtbar, die als Krater-Morphologie bezeichnet wird. Für die verschiedenen Anwendungen in Trennprozessen stehen eine Vielzahl von Membranen aus unterschiedlichen Materialien zur Verfügung.…”