• Membrane Journal
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• v.4 no.1
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• pp.9-29
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• 1994

The development of separation technology is an important research subject as is clear from its role in the Japanese government's research and development program for basic technology for the next generation(1981~1990). Japan is poor not only in mineral resources but also in energy resources and if a sudden change occurs in oil producing facility or an accident occurs in a nuclear power plant, then energy policy must undergo changes and economic foundations may collapse. Japan has already experienced this. Although, oil prices are stable at present and Japan can import oil at low cost due to the yen appreciation, Japan needs to promote development work for any new energy crisis that may come in the future. This has been the motive for gas separation membrane development in Japan. The study of gas permeation through polymer membranes, which is the basis for membranes for gas separation, at Japanese universities began many years ago, but interest in membranes for gas separation was aroused mainly by the Government. The development of gas separation membranes in Japan started with membranes for oxygen separation on an industrial scale.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.183-186
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• 2004

Nano particles-containing CMS membranes were prepared by pyrolysis of polyimides dispersed uniformly with precursors and their gas separation performances were examined, to elucidate the permeation mechanism and to further improve the gas separation performance. Consequently, it was suggested that the separation performance could be controlled by doping nano-particles in the CMS membranes, and that optimization of various factors, such as the size, content, and dispersion state of the nano particles would contribute for further improvement of the gas separation performance.

• Membrane Journal
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• v.23 no.6
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• pp.393-408
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• 2013

Gas separation processes using polymeric membranes have been greatly developed during the last few decades due to high energy efficiency and economic advantages. To achieve optimum economic performance, gas separation membranes required high permeability and selectivity. So, a number of reports examining the various polymeric materials for gas separation membranes have been published. Among the studied materials, polyimide (PI), which exhibit high permselectivity for various gas pairs, high chemical resistance, thermal stability, and mechanical strength, have attracted much attention. This paper focuses on the basic principle of gas separation, preparation procedure of membrane along with the recent developments and research trends of PI based materials for gas separation.

• Environmental Engineering Research
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• v.25 no.4
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• pp.447-461
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• 2020

In recent years, stimuli-responsive materials have garnered interest due to their ability to change properties when exposed to external stimuli, making it useful for various applications including gas separation. Light is a very attractive trigger for responsive materials due to its speedy and non-invasive nature as well as the potential to reduce energy costs significantly. Even though light is deemed as an appealing stimulus for the development of stimuli-responsive materials, this avenue has yet to be extensively researched, as evidenced by the fewer works done on the photo-responsive membranes. Of these, there are even less research done on photo-responsive materials for the purpose of gas separation, thus, we have collected the examples that answer both these criteria in this review. This review covers the utilisation of photo-responsive materials specifically for gas separation purposes. Photo-chromic units, their integration into gas separation systems, mechanism and research that have been done on the topic so far are discussed.

• Mass Spectrometry Letters
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• v.12 no.4
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• pp.186-191
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• 2021

A new method for chemical separation of light rare-earth elements (LREEs) using gas-pressurized extraction chromatography (GPEC) is described. GPEC is a microscale column chromatography system that features a constant flow of solvents, which is created by pressurized nitrogen gas. The separation column with a Teflon tubing was packed with LN resin. The proposed GPEC method facilitates production of lesser chemical wastes and faster separation owing to the use of low solvent volume compared to traditional column chromatography. We evaluated the separation of Ba, La, Ce, and Nd using various elution solvents. The column reproducibility of the proposed GPEC system ranged from 2.4% to 4.9% with RSDs of recoveries, and the column-to-column reproducibility ranged from 3.1% to 6.3% with RSDs of recoveries. The proposed technique is robust, and it can be useful for the fast separation of LREEs.

• Membrane Journal
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• v.21 no.4
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• pp.307-320
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• 2011

Polymeric gas separation membrane is the fastest growing field in membrane separation process. Polymeric gas separation membrane process is competitive compare to cryogenic process and pressure swing adsorption process. Aromatic polymer materials such as polysulfones, polypheneylene oxides, polycarbonates and polyimides have been used for gas separation. Recently, glassy polymer likes polyimide in aromatic polymers has been developed for achievement of high selectivity and permeability coefficients. The accurate understanding on a type and structure of polymer material is very important, because the factor that polymer material affect gas separation property. In the study, trend and the development direction on synthesis and permeation properties of polyimide is confirmed.

• Membrane Journal
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• v.17 no.2
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• pp.81-92
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• 2007

Membrane-based separation processes are receiving increasing attention in the scientific community and industry since they provide a desirable alternative to processes that are not easy to achieve by conventional separation technologies. In particular, gas separation using polymeric membranes have annually grown so fast owing to advantages such as easy installation, no moving parts, small footprint and low energy process. The key element is definitely a polymer membrane exhibiting high permeability and high selectivity to compete with other gas separation technologies. Current polymer membranes used for commercial gas separation are a family of hydrocarbon polymers for hydrogen separation, air separation and carbon dioxide separation from natural gas sweetening. Relatively, gas or vapor separation properties of fluoropolymers are not known so much as compared with those of hydrocarbon polymers. Accordingly, in this study, membranes prepared from amorphous perfluoropolymers are of particular interest because of the unique properties of these polymers. The advantages offered by these amorphous perfluoropolymers for use in gas and vapor separation will be discussed. In addition, membrane properties and separation performance will be compared with other membranes available on the market.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.51-61
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• 2022

Gas separation via hollow fibre membrane modules (HFMM) is deemed to be a promising technology for natural gas sweetening, particularly for lowering the level of carbon dioxide (CO₂) in natural gas, which can cause various problems during transportation and process operation. Separation performance via HFMM is affected by membrane properties, module specifications and operating conditions. In this study, a mathematical model for HFMM is developed, which can be used to assess the effects of the aforementioned variables on separation performance. Appropriate boundary conditions are imposed to resolve steady-state values of permeate variables and incorporated in the model equations via an iterative numerical procedure. The developed model is proven to be reliable via model validation against experimental data in the literature. Also, the model is capable of capturing axial variations of process variables as well as predicting key performance indicators. It can be extended to simulate a large-scale plant and identify an optimal process design and operating conditions for improved separation efficiency and reduced cost.

• Korean Membrane Journal
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• v.7 no.1
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• pp.42-50
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• 2005

Among ceramic membranes developed to date, amorphous silica membranes are attractive for gas separation at elevated temperatures. Most of the silica membranes can be formed on a porous support by sol-gel or chemical vapor deposition (CVD) process. To improve gas permselectivity of the membrane, well-controlled pores having desired size and chemical affinity between permeates and membrane become important factors in the preparation of membranes. In this article, we review the literature and introduce our technologies on the microstructure to be solved and pore size control of silica membranes using sol-gel and CVD methods.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1866-1870
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• 2019

Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, $LiNO_3-ZrO_2$ and $LiCl-ZrO_2$ mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation.