Abstract:Membrane separation is based on selective transport through the membrane. Increasingly, membrane technology has developed and is currently being used in a broad range of industrial applications. This article provides an overview of the fundamentals of membrane technology, the fabrication of various membranes, and the use of membranes in scaled‐up modules of various geometries for industrial applications.
Different membrane processes are introduced: (i) microfiltration and ultrafiltration; (ii) nanofi… Show more
“…8): It is a clean technology with operational ease, also known as one of the green technology systems. 7–9…”
Section: Introductionmentioning
confidence: 99%
“…The selective layer thickness can be controlled below 10 μm, but practically fabricating thickness below 1 μm is quite a challenging task. 9,12 Figure 2.Schematic diagram of solution casting fabrication method. 9,12 …”
Section: Introductionmentioning
confidence: 99%
“…The main parameters to control the thickness of the coating layer are as mentioned below:(a) Polymeric solution concentration.(b) Dipping time.(c) The speed for the withdrawal of porous substrate.(d) Evaporation rate and environmental impact.Figure 3.Schematic diagram of dip-coating fabrication method. 9,14 …”
Section: Introductionmentioning
confidence: 99%
“…In this mechanism, the gas components of the mixture separate on the basis of their difference in permeability through the membrane. 9,19…”
Section: Introductionmentioning
confidence: 99%
“…Its unit is GPU = 10 −6 (cm 3 (STP)/cm 2 s.cmHg). 9,19 The performance of different DLC membranes is compared using these GS performance factors as given in Table S2, which are discussed in the next section of this review.Figure 8.Schematic diagram of MBGS system applied on gas mixture. 13 …”
The separation of air (O2/N2) via a polymeric membrane has recently piqued the interest of academic researcher as well as the industrial sector. Because of its remarkable characteristics, the polymeric membrane has emerged as one of the innovative and fast growing technology. However, two major problems faced by membrane technology, which hinder its growth in the commercial sector are, 1): The trade-off between permeability and selectivity. 2): Maintaining physical and chemical structural stability in a long-term commercial scale process. Recent advancements in membrane material, structural, and process design have enabled the development of dual-layer composite (DLC) membranes. This concept combines the benefits of both thinner mixed matrix membranes (MMMs) based active layer and porous support substrate. Due to these properties, the membrane exhibits higher perm-selectivity with enhanced mechanical strength as compared to single layer polymeric membrane. This review article mainly focused on the developmental progress of DLC membrane throughout the years. In which membrane structural details, selection criteria, fabrication methodologies, application [e.g., air (O2/N2) separation] were critically reviewed. In addition, challenges arising in the DLC membrane production and future prospects for the development of these membranes were also thoroughly discussed in this literature. This creates a paradigm for future research in the commercial development of these membranes for the air (O2/N2) separation process, which can be utilized in both medical and industrial sectors. [Formula: see text]
“…8): It is a clean technology with operational ease, also known as one of the green technology systems. 7–9…”
Section: Introductionmentioning
confidence: 99%
“…The selective layer thickness can be controlled below 10 μm, but practically fabricating thickness below 1 μm is quite a challenging task. 9,12 Figure 2.Schematic diagram of solution casting fabrication method. 9,12 …”
Section: Introductionmentioning
confidence: 99%
“…The main parameters to control the thickness of the coating layer are as mentioned below:(a) Polymeric solution concentration.(b) Dipping time.(c) The speed for the withdrawal of porous substrate.(d) Evaporation rate and environmental impact.Figure 3.Schematic diagram of dip-coating fabrication method. 9,14 …”
Section: Introductionmentioning
confidence: 99%
“…In this mechanism, the gas components of the mixture separate on the basis of their difference in permeability through the membrane. 9,19…”
Section: Introductionmentioning
confidence: 99%
“…Its unit is GPU = 10 −6 (cm 3 (STP)/cm 2 s.cmHg). 9,19 The performance of different DLC membranes is compared using these GS performance factors as given in Table S2, which are discussed in the next section of this review.Figure 8.Schematic diagram of MBGS system applied on gas mixture. 13 …”
The separation of air (O2/N2) via a polymeric membrane has recently piqued the interest of academic researcher as well as the industrial sector. Because of its remarkable characteristics, the polymeric membrane has emerged as one of the innovative and fast growing technology. However, two major problems faced by membrane technology, which hinder its growth in the commercial sector are, 1): The trade-off between permeability and selectivity. 2): Maintaining physical and chemical structural stability in a long-term commercial scale process. Recent advancements in membrane material, structural, and process design have enabled the development of dual-layer composite (DLC) membranes. This concept combines the benefits of both thinner mixed matrix membranes (MMMs) based active layer and porous support substrate. Due to these properties, the membrane exhibits higher perm-selectivity with enhanced mechanical strength as compared to single layer polymeric membrane. This review article mainly focused on the developmental progress of DLC membrane throughout the years. In which membrane structural details, selection criteria, fabrication methodologies, application [e.g., air (O2/N2) separation] were critically reviewed. In addition, challenges arising in the DLC membrane production and future prospects for the development of these membranes were also thoroughly discussed in this literature. This creates a paradigm for future research in the commercial development of these membranes for the air (O2/N2) separation process, which can be utilized in both medical and industrial sectors. [Formula: see text]
A bipolar membrane (BPM) can be used to accelerate water dissociation to maintain a pH gradient in electrochemical cells, providing freedom to independently optimize the environments and catalysts used for paired reduction and oxidation reactions. The two physical layers in a BPM, respectively, selective for the exchange of cations and anions, should ideally reject ion crossover and facilitate ionic current via water dissociation in an interfacial layer. However, ions from the electrolyte do cross over in actual BPMs, competing with the water dissociation reaction and negatively affecting the stability of the electrolytes. Here, we explore the mechanisms of ion crossover as a function of pH and current density across a commercial BPM. Our unique series of experiments quantifies the ion crossover for more than 10 electrolyte combinations that cover 10 orders of magnitude in acid dissociation constant (K a ) and current densities spanning over more than 2 orders of magnitude. It was found that the ion crossover is dominated by diffusion for current densities up to a maximum of 10−40 mA cm −2 depending on the electrolyte, while migration is of higher importance at high current densities. The influence of the electrolyte pK a or pH on the ion crossover is not straightforward. However, ions with a higher valence or ion size show significantly lower crossover. Moreover, high current densities are the most favorable for high water dissociation efficiencies for all electrolyte combinations. This operational mode aligns well with practical applications of BPMs in electrolysis at industrial relevant current densities.
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