scholarly journals Optical Analysis of the Internal Void Structure in Polymer Membranes for Gas Separation

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 328
Author(s):  
Chiara Muzzi ◽  
Alessio Fuoco ◽  
Marcello Monteleone ◽  
Elisa Esposito ◽  
Johannes C. Jansen ◽  
...  
Keyword(s):  
Image Recognition ◽  
Co2 Capture ◽  
Membrane Separation ◽  
Modern Society ◽  
Structural Features ◽  
Dynamics Simulation ◽  
Rapid Screening ◽  
Separation Processes ◽  
Membrane Materials ◽  
Automatic Image Recognition

Global warming by greenhouse gas emissions is one of the main threats of our modern society, and efficient CO2 capture processes are needed to solve this problem. Membrane separation processes have been identified among the most promising technologies for CO2 capture, and these require the development of highly efficient membrane materials which, in turn, requires detailed understanding of their operation mechanism. In the last decades, molecular modeling studies have become an extremely powerful tool to understand and anticipate the gas transport properties of polymeric membranes. This work presents a study on the correlation of the structural features of different membrane materials, analyzed by means of molecular dynamics simulation, and their gas diffusivity/selectivity. We propose a simplified method to determine the void size distribution via an automatic image recognition tool, along with a consolidated Connolly probe sensing of space, without the need of demanding computational procedures. Based on a picture of the void shape and width, automatic image recognition tests the dimensions of the void elements, reducing them to ellipses. Comparison of the minor axis of the obtained ellipses with the diameters of the gases yields a qualitative estimation of non-accessible paths in the geometrical arrangement of polymeric chains. A second tool, the Connolly probe sensing of space, gives more details on the complexity of voids. The combination of the two proposed tools can be used for a qualitative and rapid screening of material models and for an estimation of the trend in their diffusivity selectivity. The main differences in the structural features of three different classes of polymers are investigated in this work (glassy polymers, superglassy perfluoropolymers and high free volume polymers of intrinsic microporosity), and the results show how the proposed computationally less demanding analysis can be linked with their selectivities.

Membrane Separation of CO2 from Natural Gas: A State-of-the-Art Review on Material Development

2013 ◽  
Vol 333 ◽  
pp. 135-147 ◽  
Author(s):  
Ahmad Abdul Latif ◽  
Jimoh K. Adewole ◽  
Suzylawati Binti Ismail ◽  
Leo Choe Peng ◽  
Abdullah S. Sultan
Keyword(s):  
Natural Gas ◽  
Large Scale ◽  
Membrane Separation ◽  
Primary Source ◽  
Reference Source ◽  
Separation Performance ◽  
Separation Processes ◽  
Membrane Materials ◽  
Material Development ◽  
Separation Of Gas Mixtures

Natural gas (NG) processing and membrane technology are two very important fields that are of great significance due to increasing demand for energy as well as separation of gas mixtures. While NG is projected to be the number one primary source of energy by 2050, membrane separation is a commercially successful competitor to other separation techniques for energy efficient gas separation processes [1]. Most of the NG produced in the world is coproduced with acid gases such as CO2which need to be removed to increase the caloric value of NG. A comprehensive review of research efforts in CO2separation from natural gas is required to capture details of the current scientific and technological progresses on the development of new membrane materials with better separation performance, and the improvement of properties of the existing ones. This paper presents the progress that has been achieved in eliminating the limitations that dominate the large scale application of membrane materials at the present time. Various polymers that have been developed to resist plasticization and the method employed to fabricate these polymers are highlighted. Also the range of plasticization pressures (together with corresponding selectivities and permeabilities at these pressures) that have so far been achieved by these fabrication methods is presented. It is believed that this review will serve as a good reference source especially for research in design and development of membrane materials with better resistance to CO2-induced plasticization.

Research Trends of Carbon Dioxide Capture using Ionic Liquids and Aqueous Amine-Ionic Liquids Mixtures

2016 ◽  
Vol 13 (1) ◽  
pp. 53
Author(s):  
Siti Nabihah Jamaludin ◽  
Ruzitah Mohd Salleh
Keyword(s):  
Ionic Liquids ◽  
Co2 Capture ◽  
Membrane Separation ◽  
Carbon Dioxide Capture ◽  
Global Climate ◽  
Research Trends ◽  
Co2 Absorption ◽  
Absorption Process ◽  
Chemical Absorption ◽  
Factors Influencing

Anthropogenic CO2 emissions has led to global climate change and widely contributed to global warming since its concentration has been increasing over time. It has attracted vast attention worldwide. Currently, the different CO2 capture technologies available include absorption, solid adsorption and membrane separation. Chemical absorption technology is regarded as the most mature technology and is commercially used in the industry. However, the key challenge is to find the most efficient solvent in capturing CO2. This paper reviews several types of CO2 capture technologies and the various factors influencing the CO2 absorption process, resulting in the development of a novel solvent for CO2 capture.

Separation of Biologically Active Compounds by Membrane Operations

2017 ◽  
Vol 23 (2) ◽  
pp. 218-230 ◽  
Author(s):  
Xiaoying Zhu ◽  
Renbi Bai
Keyword(s):  
Energy Consumption ◽  
Bioactive Compounds ◽  
Membrane Fouling ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
High Energy ◽  
Separation Processes ◽  
Membrane Processes ◽  
Separation Technology ◽  
Pressure Driven

Background: Bioactive compounds from various natural sources have been attracting more and more attention, owing to their broad diversity of functionalities and availabilities. However, many of the bioactive compounds often exist at an extremely low concentration in a mixture so that massive harvesting is needed to obtain sufficient amounts for their practical usage. Thus, effective fractionation or separation technologies are essential for the screening and production of the bioactive compound products. The applicatons of conventional processes such as extraction, distillation and lyophilisation, etc. may be tedious, have high energy consumption or cause denature or degradation of the bioactive compounds. Membrane separation processes operate at ambient temperature, without the need for heating and therefore with less energy consumption. The “cold” separation technology also prevents the possible degradation of the bioactive compounds. The separation process is mainly physical and both fractions (permeate and retentate) of the membrane processes may be recovered. Thus, using membrane separation technology is a promising approach to concentrate and separate bioactive compounds. Methods: A comprehensive survey of membrane operations used for the separation of bioactive compounds is conducted. The available and established membrane separation processes are introduced and reviewed. Results: The most frequently used membrane processes are the pressure driven ones, including microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). They are applied either individually as a single sieve or in combination as an integrated membrane array to meet the different requirements in the separation of bioactive compounds. Other new membrane processes with multiple functions have also been developed and employed for the separation or fractionation of bioactive compounds. The hybrid electrodialysis (ED)-UF membrane process, for example has been used to provide a solution for the separation of biomolecules with similar molecular weights but different surface electrical properties. In contrast, the affinity membrane technology is shown to have the advantages of increasing the separation efficiency at low operational pressures through selectively adsorbing bioactive compounds during the filtration process. Conclusion: Individual membranes or membrane arrays are effectively used to separate bioactive compounds or achieve multiple fractionation of them with different molecule weights or sizes. Pressure driven membrane processes are highly efficient and widely used. Membrane fouling, especially irreversible organic and biological fouling, is the inevitable problem. Multifunctional membranes and affinity membranes provide the possibility of effectively separating bioactive compounds that are similar in sizes but different in other physical and chemical properties. Surface modification methods are of great potential to increase membrane separation efficiency as well as reduce the problem of membrane fouling. Developing membranes and optimizing the operational parameters specifically for the applications of separation of various bioactive compounds should be taken as an important part of ongoing or future membrane research in this field.

Application of membrane separation processes in phosphorus recovery: A review

2021 ◽  
Vol 767 ◽  
pp. 144346
Author(s):  
Xiang Li ◽  
Shuting Shen ◽  
Yuye Xu ◽  
Ting Guo ◽  
Hongliang Dai ◽  
...  
Keyword(s):  
Membrane Separation ◽  
Phosphorus Recovery ◽  
Separation Processes

MOLECULAR DYNAMICS SIMULATION ON HYDROGEN STORAGE IN METALLIC NANOPARTICLES

2009 ◽  
Vol 08 (01n02) ◽  
pp. 39-42 ◽  
Author(s):  
HIROSHI OGAWA ◽  
AKINORI TEZUKA ◽  
HAO WANG ◽  
TAMIO IKESHOJI ◽  
MASAHIKO KATAGIRI
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Storage ◽  
Metallic Nanoparticles ◽  
Structural Modification ◽  
Structural Features ◽  
Dynamics Simulation ◽  
Metallic Nanoparticle ◽  
Hydrogen Atoms ◽  
Diffusion Of Hydrogen ◽  
Storage Properties

Hydrogen storage in a metallic nanoparticle was simulated by classical molecular dynamics. Distribution of hydrogen atoms inside nanoparticle was investigated by changing length and energy parameters of metal– H bonds. Hydrogen atoms diffused into the particle and distributed homogeneously in case of weak metal– H bonds. In case of strong metal– H bonds, a hydrogen-rich surface layer was observed which suppresses the inward diffusion of hydrogen atoms. Structural modification of nanoparticle accompanied by grain boundary formation due to hydrogen loading was also observed. These variations in dynamical and structural features are considered to affect the hydrogen storage properties in nanoparticles.

scholarly journals Analysis of ethanol dehydration using membrane separation processes

2020 ◽  
Vol 15 (1) ◽  
pp. 122-132 ◽  
Author(s):  
Carolina Conde-Mejía ◽  
Arturo Jiménez-Gutiérrez
Keyword(s):  
Capital Investment ◽  
Membrane Separation ◽  
Biomass Pretreatment ◽  
Ethanol Dehydration ◽  
Purification Step ◽  
Silica Membrane ◽  
Separation Processes ◽  
Fermentation Processes ◽  
Vapor Permeation ◽  
Type Zeolite

AbstractAfter the biomass pretreatment and fermentation processes, the purification step constitutes a major task in bioethanol production processes. The use of membranes provides an interesting choice to achieve high-purity bioethanol. Membrane separation processes are generally characterized by low energy requirements, but a high capital investment. Some major design aspects for membrane processes and their application to the ethanol dehydration problem are addressed in this work. The analysis includes pervaporation and vapor permeation methods, and considers using two types of membranes, A-type zeolite and amorphous silica membrane. The results identify the best combination of membrane separation method and type of membrane needed for bioethanol purification.

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