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Sample records for membrane separation process

  1. A general model for membrane-based separation processes

    DEFF Research Database (Denmark)

    Soni, Vipasha; Abildskov, Jens; Jonsson, Gunnar Eigil

    2009-01-01

    behaviour will play an important role. In this paper, modelling of membrane-based processes for separation of gas and liquid mixtures are considered. Two general models, one for membrane-based liquid separation processes (with phase change) and another for membrane-based gas separation are presented....... The separation processes covered are: membrane-based gas separation processes, pervaporation and various types of membrane distillation processes. The specific model for each type of membrane-based process is generated from the two general models by applying the specific system descriptions and the corresponding...

  2. Modeling of Multicomponent Mixture Separation Processes Using Hollow fiber Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sin-Ah; Kim, Jin-Kuk; Lee, Young Moo; Yeo, Yeong-Koo [Hanyang University, Seoul (Korea, Republic of)

    2015-02-15

    So far, most of research activities on modeling of membrane separation processes have been focused on binary feed mixture. But, in actual separation operations, binary feed is hard to find and most separation processes involve multicomponent feed mixture. In this work models for membrane separation processes treating multicomponent feed mixture are developed. Various model types are investigated and validity of proposed models are analysed based on experimental data obtained using hollowfiber membranes. The proposed separation models show quick convergence and exhibit good tracking performance.

  3. Process, including membrane separation, for separating hydrogen from hydrocarbons

    Science.gov (United States)

    Baker, Richard W.; Lokhandwala, Kaaeid A.; He, Zhenjie; Pinnau, Ingo

    2001-01-01

    Processes for providing improved methane removal and hydrogen reuse in reactors, particularly in refineries and petrochemical plants. The improved methane removal is achieved by selective purging, by passing gases in the reactor recycle loop across membranes selective in favor of methane over hydrogen, and capable of exhibiting a methane/hydrogen selectivity of at least about 2.5 under the process conditions.

  4. Glovebox atmosphere detritiation process using gas separation membranes

    International Nuclear Information System (INIS)

    Le Digabel, M.; Truan, P.A.; Ducret, D.; Laquerbe, C.; Perriat, P.; Niepce, J.C.; Pelletier, T.

    2003-01-01

    The use of gas separation membranes in atmospheric detritiation systems has been studied. The main advantage of this new process is to reduce the number and/or the size of the equipment in comparison to conventional tritium removal systems. Owing to the constraints linked to tritium handling, the separation performances of several commercial hollow fiber organic membranes have been analyzed, under various operating conditions, with hydrogen/nitrogen or deuterium/nitrogen mixtures. The experiments are performed with small quantities of hydrogen or deuterium (5000 ppm). The experimental results allow to evaluate the separation efficiency of these membranes and to determine the appropriate operating conditions to apply to a membrane detritiation process

  5. Recent achievements in facilitated transport membranes for separation processes

    Directory of Open Access Journals (Sweden)

    H. C. Ferraz

    2007-03-01

    Full Text Available Membrane separation processes have been extensively used for some important industrial separations, substituting traditional methods. However, some applications require the development of new membranes. In this work, we discuss recent progress achieved in this field, focusing on gas and liquid separation using facilitated transport membranes. The advantages of using a carrier species either in a liquid membrane or fixed in a polymer matrix to enhance both the flux and the selectivity of the transport are summarized. The most probable transport mechanisms in these membranes are presented and the improvements needed to spread this technology are also discussed. As examples, we discuss our very successful experiences in air fractioning, olefin/paraffin separation and sugar recovery using liquid and fixed carrier membranes.

  6. Process, including PSA and membrane separation, for separating hydrogen from hydrocarbons

    Science.gov (United States)

    Baker, Richard W.; Lokhandwala, Kaaeid A.; He, Zhenjie; Pinnau, Ingo

    2001-01-01

    An improved process for separating hydrogen from hydrocarbons. The process includes a pressure swing adsorption step, a compression/cooling step and a membrane separation step. The membrane step relies on achieving a methane/hydrogen selectivity of at least about 2.5 under the conditions of the process.

  7. Dynamic modeling of ultrafiltration membranes for whey separation processes

    NARCIS (Netherlands)

    Saltik, M.B.; Ozkan, L.; Jacobs, M.; van der Padt, A.

    2017-01-01

    In this paper, we present a control relevant rigorous dynamic model for an ultrafiltration membrane unit in a whey separation process. The model consists of a set of differential algebraic equations and is developed for online model based applications such as model based control and process

  8. Study of Aging ion exchange membranes used in separation processes

    International Nuclear Information System (INIS)

    Bellakhal, N.; Ghalloussi, R.; Dammak, L.

    2009-01-01

    Presently, the most important application of ion exchange membranes (IEM) is the electrodialysis. This technique consists of a membrane separation using a series of anion exchange membranes alternately and cations, often used for the desalination of brackish water. These membranes are confronted with problems of aging. Indeed, the more they are used more physical and chemical properties will change. A comparative study of the behavior of both EMI and new but the same treatment is carried out by measuring a magnitude transfer characteristic: ion permeability. Ionic permeability is a physical quantity can have an idea about the selectivity of the membrane towards the charged species and the p orosity o f the membrane. It is a transport of ions (cations + anions) through the membrane. Thus, determining the ion permeability is to determine the diffusion flux of a strong electrolyte through a membrane separating two compartments (one containing electrolytes and other water initially ultrapure who will gradually electrolyte through the membrane). The measurement technique used is that by conductimetric detection because of the ease of its implementation and its accuracy. Thus, the variation of the concentration of the electrolyte is continuously monitored by measuring the conductivity of the solution diluted with time. The curves s = f (t) MEA and MEC new and used varying concentration of the electrolyte membranes show that let in less waste of strong electrolyte (NaCl and HCl) than new ones. This can be explained by: - The functional sites are combined with polyvalent ions present even in trace amounts in the solution process and become inactive. The membrane loses its hydrophilic character and turns into a film almost hydrophobic. - The chemical attacks and electrodialysis operations have degraded and eliminated much of the fixed sites leading to the same effects on the hydrophilic membrane. - These two assumptions have been reinforced by the extent of exchange

  9. Potential Applications of Zeolite Membranes in Reaction Coupling Separation Processes

    Directory of Open Access Journals (Sweden)

    Tunde V. Ojumu

    2012-10-01

    Full Text Available Future production of chemicals (e.g., fine and specialty chemicals in industry is faced with the challenge of limited material and energy resources. However, process intensification might play a significant role in alleviating this problem. A vision of process intensification through multifunctional reactors has stimulated research on membrane-based reactive separation processes, in which membrane separation and catalytic reaction occur simultaneously in one unit. These processes are rather attractive applications because they are potentially compact, less capital intensive, and have lower processing costs than traditional processes. Therefore this review discusses the progress and potential applications that have occurred in the field of zeolite membrane reactors during the last few years. The aim of this article is to update researchers in the field of process intensification and also provoke their thoughts on further research efforts to explore and exploit the potential applications of zeolite membrane reactors in industry. Further evaluation of this technology for industrial acceptability is essential in this regard. Therefore, studies such as techno-economical feasibility, optimization and scale-up are of the utmost importance.

  10. Morin-based nanofiltration membranes for organic solvent separation processes

    KAUST Repository

    Perez Manriquez, Liliana

    2018-02-26

    In this work we demonstrate the successful optimization of the interfacial polymerization reaction for the manufacture of organic solvent nanofiltration membranes by replacing the toxic amines commonly used for this method with the natural occurring bio-polyphenol morin. For the manufacture of this type of OSN membrane a crosslinked PAN support was coated by interfacial polymerization using morin as the monomer of the aqueous phase and terephtaloyl chloride as the monomer of the organic phase. These membranes showed an exceptional performance and resistance to NMP by having a a permeance of 0.3L/m2 h bar in NMP with a rejection of 96% of Brilliant Blue dye which has a molecular weight of 825.97g/mol, making these membranes attractive for harsh industrial separation processes due to their ease of manufacture, low cost, and excellent performance.

  11. Separation Process by Porous Membranes: A Numerical Investigation

    Directory of Open Access Journals (Sweden)

    Acto de Lima Cunha

    2014-07-01

    Full Text Available A major problem associated with the membrane separation processes is the permeate flux drop, limiting the widespread of industrial application of this process. This occurs due to the accumulation of solute concentration near the membrane surface. An exact quantification of the concentration polarization as a function of process conditions is essential to estimate the system performance satisfactorily. In this sense, this work aims to predict the behavior of the concentration polarization boundary layer along the length of a permeable tubular membrane, over various operation conditions. The numerical solution of the Navier-Stokes equation, coupled to Darcy's and mass transfer equations, is obtained by the commercial software ANSYS CFX 12, considering a two-dimensional computational domain. The study evaluates the effects of axial Reynolds and Schmidt numbers on the concentration polarization boundary layer thickness during the cross-flow filtration process. Numerical results have shown that the mathematical model is able to predict the formation and growth of the concentration polarization boundary layer along the length of the tubular membrane.

  12. Boundaries of the Realizability Region of Membrane Separation Processes

    Science.gov (United States)

    Tsirlin, A. M.; Akhrenemkov, A. A.

    2018-01-01

    The region of realizability of membrane separation systems having a constant total membrane area has been determined for a definite output of a final product at a definite composition of a mixture flow. The law of change in the pressure in the mixture, corresponding to the minimum energy required for its separation, was concretized for media close in properties to ideal gases and solutions.

  13. Separation of Process Water using Hydroxy Sodalite Membranes

    NARCIS (Netherlands)

    Khajavi, S.

    2010-01-01

    This thesis describes the synthesis, characterization, and application of Hydroxy Sodalite (H-SOD) membranes in selective separation of water from aqueous solutions and reaction media. The emphasis has been put on the development of a tight membrane film that could be primarily used for water

  14. Studies on hydrogen separation membrane for IS process. Membrane preparation with porous α-alumina tube

    International Nuclear Information System (INIS)

    Hwang, Gab-Jin; Onuki, Kaoru; Shimizu, Saburo

    1998-01-01

    It was investigated the preparation technique of hydrogen separation membrane to enhance the decomposition ratio of hydrogen iodide in the thermochemical IS process. Hydrogen separation membranes based on porous α-alumina tubes having pore size of 100 nm and 10 nm were prepared by chemical vapor deposition using tetraethylorthosilicate (TEOS) as the Si source. In the hydrogen separation membrane, its pore was closed by the deposited silica and then the permeation of gas was affected by the hindrance diffusion. At 600degC, the selectivity ratios (H 2 /N 2 ) were 5.2 and 160 for the membranes based on porous α-alumina tube having pore size of 100 nm and 10 nm, respectively. (author)

  15. Organic-inorganic hybrid membranes in separation processes: a 10-year review

    Directory of Open Access Journals (Sweden)

    V. C. Souza

    2013-12-01

    Full Text Available In relation to some inorganic membranes, polymeric membranes have relatively low separation performance. However, the processing flexibility and low cost of polymers still make them highly attractive for many industrial separation applications. Polymer-inorganic hybrid membranes constitute an emerging research field and have been recently developed to improve the separation properties of polymer membranes because they possess properties of both organic and inorganic membranes such as good hydrophilicity, selectivity, permeability, mechanical strength, and thermal and chemical stability. The structures and processing of polymer-inorganic nanocomposite hybrid membranes, as well as their use in the fields of ultrafiltration, nanofiltration, pervaporation, gas separation and separation mechanism are reviewed.

  16. Use of membrane separation processes for the separation of radionuclides from liquid and gas streams

    International Nuclear Information System (INIS)

    Vladisavljevic, G.T.; Rajkovic, M.B.

    1999-01-01

    Use of membranes for the separation and recovery of radionuclides from contaminated liquid and gas streams has been discussed in this paper. The special attention has been paid to the use of ion-exchange membranes for electrodialysis and Donnan dialysis, as well as the use of facilitated liquid membranes for liquid pertraction. (author)

  17. Separation membrane development

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.W. [Savannah River Technology Center, Aiken, SC (United States)

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  18. Gas separation with membranes

    International Nuclear Information System (INIS)

    Schulz, G.; Michele, H.; Werner, U.

    1982-01-01

    Gas separation with membranes has already been tested in numerous fields of application, e.g. uranium enrichment of H 2 separation. In many of these processes the mass transfer units, so-called permeators, have to be connected in tandem in order to achieve high concentrations. A most economical operating method provides for each case an optimization of the cascades with regard to the membrane materials, construction and design of module. By utilization of the concentration gradient along the membrane a new process development has been accomplished - the continuously operating membrane rectification unit. Investment and operating costs can be reduced considerably for a number of separating processes by combining a membrane rectification unit with a conventional recycling cascade. However, the new procedure requires that the specifications for the module construction, flow design, and membrane properties be reconsidered. (orig.) [de

  19. Gas separation membranes

    Science.gov (United States)

    Schell, William J.

    1979-01-01

    A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

  20. Organic separations with membranes

    International Nuclear Information System (INIS)

    Funk, E.W.

    1993-01-01

    This paper presents an overview of present and emerging applications of membrane technology for the separation and purification of organic materials. This technology is highly relevant for programs aimed at minimizing waste in processing and in the treatment of gaseous and liquid effluents. Application of membranes for organic separation is growing rapidly in the petrochemical industry to simplify processing and in the treatment of effluents, and it is expected that this technology will be useful in numerous other industries including the processing of nuclear waste materials

  1. Morin-based nanofiltration membranes for organic solvent separation processes

    KAUST Repository

    Perez Manriquez, Liliana; Neelakanda, Pradeep; Peinemann, Klaus-Viktor

    2018-01-01

    In this work we demonstrate the successful optimization of the interfacial polymerization reaction for the manufacture of organic solvent nanofiltration membranes by replacing the toxic amines commonly used for this method with the natural occurring

  2. Meniscus Membranes For Separation

    Science.gov (United States)

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2005-09-20

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  3. Meniscus membranes for separations

    Science.gov (United States)

    Dye, Robert C [Irvine, CA; Jorgensen, Betty [Jemez Springs, NM; Pesiri, David R [Aliso Viejo, CA

    2004-01-27

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  4. Membrane processes

    Science.gov (United States)

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

  5. Recent developments in membrane-based separations in biotechnology processes: review.

    Science.gov (United States)

    Rathore, A S; Shirke, A

    2011-01-01

    Membrane-based separations are the most ubiquitous unit operations in biotech processes. There are several key reasons for this. First, they can be used with a large variety of applications including clarification, concentration, buffer exchange, purification, and sterilization. Second, they are available in a variety of formats, such as depth filtration, ultrafiltration, diafiltration, nanofiltration, reverse osmosis, and microfiltration. Third, they are simple to operate and are generally robust toward normal variations in feed material and operating parameters. Fourth, membrane-based separations typically require lower capital cost when compared to other processing options. As a result of these advantages, a typical biotech process has anywhere from 10 to 20 membrane-based separation steps. In this article we review the major developments that have occurred on this topic with a focus on developments in the last 5 years.

  6. On controllability of an integrated bioreactor and periodically operated membrane separation process

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Jørgensen, Sten Bay; Jonsson, Gunnar Eigil

    the influence of membrane fouling. Previously, the REED and fermentation processes have been modeled and investigated separately (Prado- Rubio et al., 2011a; Boonmee, 2003). Additionally, a simple quasi-sequential strategy for integrated process design and control structure development has been proposed (Prado...... to understand the controlled operation of the integrated process, it is convenient to use a model based approach supported by experimental evidence. Recently, an integrated bioreactor and electrically driven membrane separation process (Reverse Electro- Enhanced Dialysis - REED) has been proposed as a method...... at a certain lactate concentration level. Hence, productivity can be enhanced by the in situ lactate removal from the cultivation broth during pH controlled fermentation. This can be done by means of ion exchange membranes and electrical potential gradients. The novelty of the integrated process lies...

  7. Gamma radiation grafting process for preparing separator membranes for electrochemical cells

    International Nuclear Information System (INIS)

    Agostino, V.F. D'; Lee, J.Y.

    1982-01-01

    An irradiation grafting process for preparing separator membranes for use in electrochemical cells, comprises contacting a polymeric base film with an aqueous solution of a hydrophilic monomer and a polymerization retardant; and irradiating said contacted film to form a graft membrane having low electrical resistivity and having monomer molecules uniformly grafted thereon. In the examples (meth) acrylic acid is grafted on to polyethylene, polypropylene and polytetrafluoroethylene in the presence of ferrous sulphate or cupric sulphate as polymerization retardants. (author)

  8. Development of Ultrafiltration Membrane-Separation Technology for Energy-Efficient Water Treatment and Desalination Process

    Energy Technology Data Exchange (ETDEWEB)

    Yim, Woosoon [Univ. of Nevada, Las Vegas, NV (United States); Bae, Chulsung [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2016-10-28

    The growing scarcity of fresh water is a major political and economic challenge in the 21st century. Compared to thermal-based distillation technique of water production, pressure driven membrane-based water purification process, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), can offer more energy-efficient and environmentally friendly solution to clean water production. Potential applications also include removal of hazardous chemicals (i.e., arsenic, pesticides, organics) from water. Although those membrane-separation technologies have been used to produce drinking water from seawater (desalination) and non-traditional water (i.e., municipal wastewater and brackish groundwater) over the last decades, they still have problems in order to be applied in large-scale operations. Currently, a major huddle of membrane-based water purification technology for large-scale commercialization is membrane fouling and its resulting increases in pressure and energy cost of filtration process. Membrane cleaning methods, which can restore the membrane properties to some degree, usually cause irreversible damage to the membranes. Considering that electricity for creating of pressure constitutes a majority of cost (~50%) in membrane-based water purification process, the development of new nano-porous membranes that are more resistant to degradation and less subject to fouling is highly desired. Styrene-ethylene/butylene-styrene (SEBS) block copolymer is one of the best known block copolymers that induces well defined morphologies. Due to the polarity difference of aromatic styrene unit and saturated ethylene/butylene unit, these two polymer chains self-assemble each other and form different phase-separated morphologies depending on the ratios of two polymer chain lengths. Because the surface of SEBS is hydrophobic which easily causes fouling of membrane, incorporation of ionic group (e,g, sulfonate) to the polymer is necessary to reduces fouling

  9. pH control structure design for a periodically operated membrane separation process

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres; Jørgensen, Sten Bay; Jonsson, Gunnar Eigil

    2012-01-01

    A bioreactor integrated with an electrically driven membrane separation process (Reverse Electro-Enhanced Dialysis – REED) is under investigation as potential technology for intensifying lactic acid bioproduction. In this contribution the pH regulation issue in the periodically operated REED module...

  10. A continuous membrane microbioreactor system for development of integrated pectin modification and separation processes

    DEFF Research Database (Denmark)

    Zainal Alam, Muhd Nazrul Hisham Bin; Pinelo, Manuel; Samanta, Kama

    2011-01-01

    present a continuous membrane microbioreactor prototype for development of enzyme catalyzed degradation of pectin. Membrane reactors are becoming increasingly important for the novel ‘biorefining’ type of processes that either require product removal to avoid product inhibition or rest on partial...... hydrolysis of the substrate to obtain e.g. value-added oligosaccharides from complex biopolymers. The microbioreactor prototype was fabricated from poly(methylmethacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) and designed as a loop reactor (working volume approximately 190μL) integrated...... with a regenerated cellulose membrane for separation of low molecular weight products. The main technical considerations and challenges related to establishing the continuous membrane microbioreactor are discussed. The workability of the prototype was validated by comparing the process data at microscale to those...

  11. Gas separation membrane module assembly

    Science.gov (United States)

    Wynn, Nicholas P [Palo Alto, CA; Fulton, Donald A [Fairfield, CA

    2009-03-31

    A gas-separation membrane module assembly and a gas-separation process using the assembly. The assembly includes a set of tubes, each containing gas-separation membranes, arranged within a housing. The housing contains a tube sheet that divides the space within the housing into two gas-tight spaces. A permeate collection system within the housing gathers permeate gas from the tubes for discharge from the housing.

  12. Polymide gas separation membranes

    Science.gov (United States)

    Ding, Yong; Bikson, Benjamin; Nelson, Joyce Katz

    2004-09-14

    Soluble polyamic acid salt (PAAS) precursors comprised of tertiary and quaternary amines, ammonium cations, sulfonium cations, or phosphonium cations, are prepared and fabricated into membranes that are subsequently imidized and converted into rigid-rod polyimide articles, such as membranes with desirable gas separation properties. A method of enhancing solubility of PAAS polymers in alcohols is also disclosed.

  13. The effect of silica toward polymer membrane for water separation process

    Science.gov (United States)

    Jamalludin, Mohd Riduan; Rosli, M. U.; Ishak, Muhammad Ikman; Khor, C. Y.; Shahrin, Suhaimi; Ismail, Ras Izzati; Lailina N., M.; Leng Y., L.; Jahidi, H.

    2017-09-01

    The aim of this present work was to investigate the effect of different percentage rice husk silica (RHS) particles composition towards polymer mixed matrix membrane microstructure and performance in water separation process. The polymer membranes were prepared by a phase inversion method using polysulfone (PSf), N-methyl-2-pyrrolidone (NMP) as solvent, distilled water as non-solvent and fixed RHS at 400°C as an additive. The microstructures of PSf/PEG/RHS sample were characterized by performing scanning electron microscope (SEM). The performance was measured by using pure water flux and humic acid for the rejection test. The analyzed result of SEM analysis revealed that the addition of RHS obviously improved the microstructure of the membrane especially at the top and sub layer at the range of 1 until 3 wt. %. This was proven by the pure water flux (PWF) value measured from 114.47 LMH to 154.04 LMH and rejection from value 83% to 96% at this specified range substantially higher than the mixed matrix membrane with synthetic silica. In fact, the presence of RHS particles not only improved the properties and performance of membrane but also possess biodegradable properties which can minimize the pollution and provide a membrane green technology system.

  14. NOVEL COMPOSITE MEMBRANES FOR HYDROGEN SEPARATION IN GASIFICATION PROCESSES IN VISION 21 ENERGY PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Michael Schwartz

    2004-12-01

    This report describes the work performed, accomplishments and conclusion obtained from the project entitled ''Novel Composite Membranes for Hydrogen Separation in Gasification Processes in Vision 21 Energy Plants'' under the United States Department of Energy Contract DE-FC26-01NT40973. ITN Energy Systems was the prime contractor. Team members included: the Idaho National Engineering and Environmental Laboratory; Nexant Consulting; Argonne National Laboratory and Praxair. The objective of the program was to develop a novel composite membrane structure for hydrogen separation as a key technology module within the future ''Vision 21'' fossil fuel plants. The separation technology module is targeted for use within the gasification module of the ''Vision 21'' fossil fuel plant. The high performance and low-cost manufacturing of the proposed technology will benefit the deployment of ''Vision 21'' fossil fuel plant processes by improving the energy efficiency, flexibility and environmental performance of these plants. Of particular importance is that this technology will also produce a stream of pure carbon dioxide. This allows facile sequestration or other use of this greenhouse gas. These features will benefit the U.S. in allowing for the continued use of domestic fossil fuels in a more energy efficient and environmentally acceptable manner. The program developed and evaluated composite membranes and catalysts for hydrogen separation. Components of the monolithic modules were fabricated by plasma spray processing. The engineering and economic characteristics of the proposed Ion Conducting Ceramic Membrane (ICCM) approach, including system integration issues, were also assessed. This resulted in a comprehensive evaluation of the technical and economic feasibility of integration schemes of ICCM hydrogen separation technology within Vision 21 fossil fuel plants. Several results and conclusion

  15. Membrane manufacture for peptide separations

    KAUST Repository

    Kim, Dooli; Salazar Moya, Octavio Ruben; Nunes, Suzana Pereira

    2016-01-01

    Nanostructured polymeric membranes are key tools in biomedical applications such as hemodialysis, protein separations, in the food industry, and drinking water supply from seawater. Despite of the success in different separation processes, membrane manufacture itself is at risk, since the most used solvents are about to be banned in many countries due to environmental and health issues. We propose for the first time the preparation of polyethersulfone membranes based on dissolution in the ionic liquid 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DEP). We obtained a series of membranes tailored for separation of solutes with molecular weight of 30, 5, 1.3, and 1.25 kg mol-1 with respective water permeances of 140, 65, 30 and 20 Lm-2h-1bar-1. We demonstrate their superior efficiency in the separation of complex mixtures of peptides with molecular weights in the range of 800 to 3500 gmol-1. Furthermore, the thermodynamics and kinetics of phase separation leading to the pore formation in the membranes were investigated. The rheology of the solutions and the morphology of the prepared membranes were examed and compared to those of polyethersulfone in organic solvents currently used for membrane manufacture.

  16. Membrane manufacture for peptide separations

    KAUST Repository

    Kim, Dooli

    2016-06-07

    Nanostructured polymeric membranes are key tools in biomedical applications such as hemodialysis, protein separations, in the food industry, and drinking water supply from seawater. Despite of the success in different separation processes, membrane manufacture itself is at risk, since the most used solvents are about to be banned in many countries due to environmental and health issues. We propose for the first time the preparation of polyethersulfone membranes based on dissolution in the ionic liquid 1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM]DEP). We obtained a series of membranes tailored for separation of solutes with molecular weight of 30, 5, 1.3, and 1.25 kg mol-1 with respective water permeances of 140, 65, 30 and 20 Lm-2h-1bar-1. We demonstrate their superior efficiency in the separation of complex mixtures of peptides with molecular weights in the range of 800 to 3500 gmol-1. Furthermore, the thermodynamics and kinetics of phase separation leading to the pore formation in the membranes were investigated. The rheology of the solutions and the morphology of the prepared membranes were examed and compared to those of polyethersulfone in organic solvents currently used for membrane manufacture.

  17. Membrane separation principle used for gas drying processes in fuel cells and life support systems

    International Nuclear Information System (INIS)

    Nigsch, H.A.; Fleck, W.U.

    1991-07-01

    Different membrane separation principles as applied to fuel cell powerplants and ECLSS are described. A new separator type that enables smaller weight and geometries and requires less energy than conventional mechanical separator techniques for space applications is presented. Module optimization and investigations concerning ECLSS applications are discussed. 5 refs

  18. New separation technique. Catalytically functionated separation membrane

    Energy Technology Data Exchange (ETDEWEB)

    Urgami, Tadashi [Kansai Univ., Osaka (Japan)

    1989-02-01

    This report introduces research examples, showing the fundamental principle of the membrane by separating the catalytically functionated separation membrane into enzyme fixing separation membrane, polymerized metal complex separation membrane and polymer catalyst separation membrane. This membrane can achieve both functions of separation and catalytic reaction simultaneously and has sufficient possibility to combine powerful functions. Enzyme fixing separation membrane is prepared by carrier combination method, bridging method or covering method and the enzyme fixing method with polymerized complex in which enzyme is controlled to prevent the activity lowering as much as possible and enzyme is fixed from an aqueous solution into polymer membrane. This membrane is applied to the continuous manufacturing of invert sugar from cane sugar and adsorption and removing of harmful substances from blood by utilizing both micro-capsuled urease and active carbon. Alginic acid-copper (II) complex membrane is used for the polymerized metal complex membrane and polystyrene sulfonate membrane is used for the polymer catalyst separation membrane. 28 refs., 4 figs., 1 tabs.

  19. Process efficiency of casein separation from milk using polymeric spiral-wound microfiltration membranes.

    Science.gov (United States)

    Mercier-Bouchard, D; Benoit, S; Doyen, A; Britten, M; Pouliot, Y

    2017-11-01

    Microfiltration is largely used to separate casein micelles from milk serum proteins (SP) to produce a casein-enriched retentate for cheese making and a permeate enriched in native SP. Skim milk microfiltration is typically performed with ceramic membranes and little information is available about the efficiency of spiral-wound (SW) membranes. We determined the effect of SW membrane pore size (0.1 and 0.2 µm) on milk protein separation in total recirculation mode with a transmembrane pressure gradient to evaluate the separation efficiency of milk proteins and energy consumption after repeated concentration and diafiltration (DF). Results obtained in total recirculation mode demonstrated that pore size diameter had no effect on the permeate flux, but a drastic loss of casein was observed in permeate for the 0.2-µm SW membrane. Concentration-DF experiments (concentration factor of 3.0× with 2 sequential DF) were performed with the optimal 0.1-µm SW membrane. We compared these results to previous data we generated with the 0.1-µm graded permeability (GP) membrane. Whereas casein rejection was similar for both membranes, SP rejection was higher for the 0.1-µm SW membrane (rejection coefficient of 0.75 to 0.79 for the 0.1-µm SW membrane versus 0.46 to 0.49 for the GP membrane). The 0.1-µm SW membrane consumed less energy (0.015-0.024 kWh/kg of permeate collected) than the GP membrane (0.077-0.143 kWh/kg of permeate collected). A techno-economic evaluation led us to conclude that the 0.1-µm SW membranes may represent a better option to concentrate casein for cheese milk; however, the GP membrane has greater permeability and its longer lifetime (about 10 yr) potentially makes it an interesting option. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Olefins-selective asymmetric carbon molecular sieve hollow fiber membranes for hybrid membrane-distillation processes for olefin/paraffin separations

    KAUST Repository

    Xu, Liren

    2012-12-01

    In this paper, the development of asymmetric carbon molecular sieve (CMS) hollow fiber membranes and advanced processes for olefin/paraffin separations based on the CMS membranes are reported. Membrane-based olefin/paraffin separations have been pursued extensively over the past decades. CMS membranes are promising to exceed the performance upper bound of polymer materials and have demonstrated excellent stability for gas separations. Previously, a substructure collapse phenomenon was found in Matrimid ® precursor derived CMS fiber. To overcome the permeance loss due to the increased separation layer thickness, 6FDA-DAM and 6FDA/BPDA-DAM precursors were selected as potential new precursors for carbon membrane formation. Defect-free asymmetric 6FDA-DAM and 6FDA/BPDA-DAM hollow fibers were successfully fabricated from a dry-jet/wet-quench spinning process. Polymer rigidity, glass-rubber transition and asymmetric morphology were correlated. CMS hollow fiber membranes produced from 6FDA-polymer precursors showed significant improvement in permeance for ethylene/ethane and propylene/propane separations. Further studies revealed that the CMS membranes are olefins-selective, which means the membranes are able to effectively separate olefins (ethylene and propylene) from paraffins (ethane and propane). This unique feature of CMS materials enables advanced hybrid membrane-distillation process designs. By using the olefins-selective membranes, these new processes may provide advantages over previously proposed retrofitting concepts. Further applications of the membranes are explored for hydrocarbons processes. Significant energy savings and even reduced footprint may be achieved in olefins production units. © 2012 Elsevier B.V.

  1. Oxygen permeation and thermo-chemical stability of oxygen separation membrane materials for the oxyfuel process

    Energy Technology Data Exchange (ETDEWEB)

    Ellett, Anna Judith

    2009-07-01

    The reduction of CO{sub 2} emissions, generally held to be one of the most significant contributors to global warming, is a major technological issue. CO{sub 2} Capture and Storage (CCS) techniques applied to large stationary sources such as coal-fired power plants could efficiently contribute to the global carbon mitigation effort. The oxyfuel process, which consists in the burning of coal in an oxygen-rich atmosphere to produce a flue gas highly concentrated in CO{sub 2}, is a technology considered for zero CO{sub 2} emission coal-fired power plants. The production of this O{sub 2}-rich combustion gas from air can be carried out using high purity oxygen separation membranes. Some of the most promising materials for this application are mixed ionic-electronic conducting (MIEC) materials with perovskite and K{sub 2}NiF{sub 4} perovskite-related structures. The present work examines the selection of La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58), La{sub 2}NiO{sub 4+{delta}}, Pr{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (PSCF58) and Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF50) as membrane materials for the separation of O{sub 2} and N{sub 2} in the framework of the oxyfuel process with flue gas recycling. Annealing experiments were carried out on pellets exposed to CO{sub 2}, water vapour, O{sub 2} and Cr{sub 2}O{sub 3} in order to determine the thermo-chemical resistance to the atmospheres and the high temperature conditions present during membrane operation in a coal-fired power plant. The degradation of their microstructure was investigated using Scanning Electron Microscopy (SEM) in combination with electron dispersive spectroscopy (EDS) as well as X-Ray Diffraction (XRD). Also, the oxygen permeation fluxes of selected membranes were investigated as a function of temperature. The membrane materials selected were characterised using thermo-analytical techniques such as precision thermogravimetric

  2. Separation of FFA from Partially Hydrogenated Soybean Oil Hydrolysate by Means of Membrane Processing

    DEFF Research Database (Denmark)

    Jala, Ram Chandra Reddy; Guo, Zheng; Xu, Xuebing

    2011-01-01

    Different types of commercial porous and non-porous polymeric membranes have been investigated for their capabilities to separate free fatty acids (FFA) from hydrolysate of partially hydrogenated soybean oil. A regenerated cellulose (RC, PLAC) membrane exhibited the most prominent difference...... in rejection between FFA and glycerides and the highest flux (27 kg h−1 m−2) in hydrolysate ethanol solution. The results also showed that, besides the pore size of membrane, the membrane flux depended largely on the property matching between membrane and solvent, as observed (40 kg h−1 m−2) flux was achieved...... with methanol but no flux detected with hexane for PLAC. The polyvinyl alcohol (PVA, NTR-729 HF) and Polyamide (PA, NTR-759HR) membranes gave the second and third highest flux (10.1 and 5.7 kg h−1 m−2, respectively), where solute rejections for NTR-759HR were 95.9% for triacylglycerols (TG), 83...

  3. Advanced oxidative processes and membrane separation for micropollutant removal from biotreated domestic wastewater.

    Science.gov (United States)

    Silva, Larissa L S; Sales, Julio C S; Campos, Juacyara C; Bila, Daniele M; Fonseca, Fabiana V

    2017-03-01

    The presence of micropollutants in sewage is already widely known, as well as the effects caused by natural and synthetic hormones. Thus, it is necessary to apply treatments to remove them from water systems, such as advanced oxidation processes (AOPs) and membrane separation processes, which can oxidize and remove high concentrations of organic compounds. This work investigated the removal of 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and estriol (E3) from biotreated sewage. Reverse osmosis processes were conducted at three recoveries (50, 60, and 70 %). For E2 and EE2, the removals were affected by the recovery. The best results for RO were as follows: the E2 compound removal was 89 % for 60 % recovery and the EE2 compound removal was 57 % for 50 % recovery. The RO recovery did not impact the E3 removal. It was concluded that the interaction between the evaluated estrogens, and the membrane was the major factor for the hormone separation. The AOP treatment using H 2 O 2 /UV was carried out in two sampling campaigns. First, we evaluated the variation of UV doses (24.48, 73.44, 122.4, and 244.8 kJ m -2 ) with 18.8 mg L -1 of H 2 O 2 in the reaction. EE2 showed considerable removals (around 70 %). In order to optimize the results, an experimental design was applied. The best result was obtained with higher UV dose (122.4 kJ m -2 ) and lower H 2 O 2 concentration (4 mg L -1 ), achieving removal of 91 % for E3 and 100 % for E2 and EE2.

  4. Relaxation phenomena in dense gas separation membranes

    NARCIS (Netherlands)

    Wessling, Matthias

    1993-01-01

    Solution-diffusion membranes are widely used for the separation of gaseous and liquid mixtures. The separation of air (O2/N2), landfill gas (CH4/CO2) and purge gas streams (NH3/H2) in the ammonia synthesis are examples for state-of-the-art membrane gas separation processes. For the separation of

  5. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  6. Mathematical modelling of membrane separation

    DEFF Research Database (Denmark)

    Vinther, Frank

    This thesis concerns mathematical modelling of membrane separation. The thesis consists of introductory theory on membrane separation, equations of motion, and properties of dextran, which will be the solute species throughout the thesis. Furthermore, the thesis consist of three separate mathemat......This thesis concerns mathematical modelling of membrane separation. The thesis consists of introductory theory on membrane separation, equations of motion, and properties of dextran, which will be the solute species throughout the thesis. Furthermore, the thesis consist of three separate...... mathematical models, each with a different approach to membrane separation. The first model is a statistical model investigating the interplay between solute shape and the probability of entering the membrane. More specific the transition of solute particles from being spherical to becoming more elongated...

  7. DD3R zeolite membranes in separation and catalytic processes : Modelling and application

    NARCIS (Netherlands)

    Van den Bergh, J.

    2010-01-01

    Around 2004 the annual energy consumption of the Dutch (petro-)chemical industry was estimated to be 460 PJ of which 200 PJ could be allocated to separation processes [1]. In 2009, 15% of the global energy consumption was required for separation and purification processes to produce commodities.

  8. Membrane Separation Processes for Post-Combustion Carbon Dioxide Capture: State of the Art and Critical Overview

    Directory of Open Access Journals (Sweden)

    Belaissaoui Bouchra

    2014-11-01

    Full Text Available Membrane processes have been initially seldom considered within a post-combustion carbon dioxide capture framework. More traditional processes, particularly gas-liquid absorption in chemical solvents, are often considered as the most appropriate solution for the first generation of technologies. In this paper, a critical state of the art of gas separation membranes for CO2 capture is proposed. In a first step, the key performances (selectivity, permeability of different membrane materials such as polymers, inorganic membranes, hybrid matrices and liquid membranes, including recently reported results, are reviewed. In a second step, the process design characteristics of a single stage membrane unit are studied. Purity and energy constraints are analysed as a function of operating conditions and membrane materials performances. The interest of multistage and hybrid systems, two domains which have not sufficiently investigated up to now, are finally discussed. The importance of technico-economical analyses is highlighted in order to better estimate the optimal role of membranes for CCS applications.

  9. Successive membrane separation processes simplify concentration of lipases produced by Aspergillus niger by solid-state fermentation.

    Science.gov (United States)

    Reinehr, Christian Oliveira; Treichel, Helen; Tres, Marcus Vinicius; Steffens, Juliana; Brião, Vandré Barbosa; Colla, Luciane Maria

    2017-06-01

    In this study, we developed a simplified method for producing, separating, and concentrating lipases derived from solid-state fermentation of agro-industrial residues by filamentous fungi. First, we used Aspergillus niger to produce lipases with hydrolytic activity. We analyzed the separation and concentration of enzymes using membrane separation processes. The sequential use of microfiltration and ultrafiltration processes made it possible to obtain concentrates with enzymatic activities much higher than those in the initial extract. The permeate flux was higher than 60 L/m 2 h during microfiltration using 20- and 0.45-µm membranes and during ultrafiltration using 100- and 50-kDa membranes, where fouling was reversible during the filtration steps, thereby indicating that the fouling may be removed by cleaning processes. These results demonstrate the feasibility of lipase production using A. niger by solid-state fermentation of agro-industrial residues, followed by successive tangential filtration with membranes, which simplify the separation and concentration steps that are typically required in downstream processes.

  10. Pilot-scale multistage membrane process for the separation of CO2 from LNG-fired flue gas

    KAUST Repository

    Choi, Seung Hak

    2013-06-01

    In this study, a multistage pilot-scale membrane plant was constructed and operated for the separation of CO2 from Liquefied Natural Gas (LNG)-fired boiler flue gas of 1000 Nm3/day. The target purity and recovery of CO2 were 99 vol.% and 90%, respectively. For this purpose, asymmetric polyethersulfone (PES) hollow fibers membranes has been developed in our previous work and has evaluated the effects of operating pressure and feed concentration of CO2 on separation performance. The operating and permeation data obtained were also analyzed in relation with the numerical simulation data using countercurrent flow model. Based on these results, in this study, four-staged membrane process including dehumidification process has been designed, installed, and operated to demonstrate the feasibility of multistage membrane systems for removing CO2 from flue gases. The operation results using this plant were compared to the numerical simulation results on multistage membrane process. The experimental results matched well with the numerical simulation data. The concentration and the recovery of CO2 in the permeate stream of final stage were ranged from 95-99 vol.% and 70-95%, respectively, depending on the operating conditions. This study demonstrated the applicability of the membrane-based pilot plant for CO2 recovery from flue gas. © 2013 Elsevier B.V. All rights reserved.

  11. New polymer material for CO_2 capture by membrane separation process

    International Nuclear Information System (INIS)

    Solimando, Xavier

    2016-01-01

    In this PhD thesis, two types of membrane materials were developed for CO_2 separation. The first ones associate a reference polymer material (Pebax) with new pseudo-peptidic bio-conjugates additives. These pseudo-peptide-polymer bio-conjugates were obtained by a 'grafting-to' synthetical pathway from alkyne-functionalized 1:1[a/a-Na-Bn-hydrazino] dimer and tetramer pseudopeptides. Poly(diethylene glycol acrylate) (PEDEGA) oligomeric part was synthesized under controlled conditions using Single Electron Transfer Living Radical Polymerization (SET-LRP) from an azido-functionalized initiator allowing direct coupling via CuAAC 'click' chemistry. The influence of these additives on CO_2 sorption and separation properties was analyzed in terms of properties-morphology-structure relationships. These original additives allowed to enhance CO_2 separation performances of the reference membrane, increasing CO_2 permeability by 46%, and maintaining good selectivities aCO_2/N_2 = 44 et aCO_2/CH_4 = 13. In another work, two families of poly(urethane-imide)s (PUIs) with controlled architecture were developed for obtaining membrane materials with high content in ethylene-oxide units while avoiding their crystallization. Linear multi-blocks PUIs were first synthesized by polycondensation with different sizes of Jeff amine polyether soft block, corresponding to soft block contents varying from 40 to 70%wt. To further increase the soft phase content until a very high level (85%wt), grafted multi-blocks PUIs were obtained by a 'grafting-to' strategy from an alkyne-functionalized precursor PUI and azido-PEDEGA oligomers with different molar weights. The evolution of their CO_2 separation performances were correlated to their soft phase content, morphology and CO_2 sorption ability. For the maximum soft phase content (85%wt), high performances were obtained for CO_2 separation (PCO_2 = 196 Barrer; aCO_2/N_2 = 39 et aCO_2/CH_4 = 12). Compared to the precursor PUI, the grafting strategy

  12. Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas

    Energy Technology Data Exchange (ETDEWEB)

    Kaaeid Lokhandwala

    2005-12-22

    The original proposal described the construction and operation of a 1 MMscfd treatment system to be operated at a Butcher Energy gas field in Ohio. The gas produced at this field contained 17% nitrogen. During pre-commissioning of the project, a series of well tests showed that the amount of gas in the field was significantly smaller than expected and that the nitrogen content of the wells was very high (25 to 30%). After evaluating the revised cost of the project, Butcher Energy decided that the plant would not be economical and withdrew from the project. Since that time, Membrane Technology and Research, Inc. (MTR) has signed a marketing and sales partnership with ABB Lummus Global, a large multinational corporation. MTR will be working with the company's Randall Gas Technology Group, a supplier of equipment and processing technology to the natural gas industry. Randall's engineering group first found a new site for the project at a North Texas Exploration (NTE) gas processing plant. The plant produced about 1 MMscfd of gas containing 24% nitrogen. The membrane unit was built to bring this gas to 4% nitrogen for delivery to the pipeline. The membrane skid was built by ABB. NTE ordered the required compressor and MTR made the membrane modules for a December 2004 delivery. However, the gas supply was not steady enough for field testing, and MTR/ABB have now located other sites for field testing and commercial development.

  13. Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas

    Energy Technology Data Exchange (ETDEWEB)

    Kaaeid Lokhandwala

    2005-12-15

    The original proposal described the construction and operation of a 1 MMscfd treatment system to be operated at a Butcher Energy gas field in Ohio. The gas produced at this field contained 17% nitrogen. During pre-commissioning of the project, a series of well tests showed that the amount of gas in the field was significantly smaller than expected and that the nitrogen content of the wells was very high (25 to 30%). After evaluating the revised cost of the project, Butcher Energy decided that the plant would not be economical and withdrew from the project. Since that time, Membrane Technology and Research, Inc. (MTR) has signed a marketing and sales partnership with ABB Lummus Global, a large multinational corporation. MTR is now working with the company's Randall Gas Technology Group, a supplier of equipment and processing technology to the natural gas industry. Randall's engineering group first found a new site for the project at a North Texas Exploration (NTE) gas processing plant. The plant produced about 1 MMscfd of gas containing 24% nitrogen. The membrane unit was built to bring this gas to 4% nitrogen for delivery to the pipeline. The membrane skid was built by ABB. NTE ordered the required compressor and MTR made the membrane modules for a December 2004 delivery. However, the gas supply was not steady enough for field testing, and MTR/ABB have now located other sites for field testing and commercial development.

  14. Advanced Membrane Separation Technologies for Energy Recovery from Industrial Process Streams

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J. R.; Wang, D. [Gas Technology Institute; Bischoff, B.; Ciora, [Media and Process Technology; Radhakrishnan, B.; Gorti, S. B.

    2013-01-14

    Recovery of energy from relatively low-temperature waste streams is a goal that has not been achieved on any large scale. Heat exchangers do not operate efficiently with low-temperature streams and thus require such large heat exchanger surface areas that they are not practical. Condensing economizers offer one option for heat recovery from such streams, but they have not been widely implemented by industry. A promising alternative to these heat exchangers and economizers is a prototype ceramic membrane system using transport membrane technology for separation of water vapor and recovery of heat. This system was successfully tested by the Gas Technology Institute (GTI) on a natural gas fired boiler where the flue gas is relatively clean and free of contaminants. However, since the tubes of the prototype system were constructed of aluminum oxide, the brittle nature of the tubes limited the robustness of the system and even limited the length of tubes that could be used. In order to improve the robustness of the membrane tubes and make the system more suitable for industrial applications, this project was initiated with the objective of developing a system with materials that would permit the system to function successfully on a larger scale and in contaminated and potentially corrosive industrial environments. This required identifying likely industrial environments and the hazards associated with those environments. Based on the hazardous components in these environments, candidate metallic materials were identified that are expected to have sufficient strength, thermal conductivity and corrosion resistance to permit production of longer tubes that could function in the industrial environments identified. Tests were conducted to determine the corrosion resistance of these candidate alloys, and the feasibility of forming these materials into porous substrates was assessed. Once the most promising metallic materials were identified, the ability to form an alumina

  15. Sucrose purification and repeated ethanol production from sugars remaining in sweet sorghum juice subjected to a membrane separation process.

    Science.gov (United States)

    Sasaki, Kengo; Tsuge, Yota; Kawaguchi, Hideo; Yasukawa, Masahiro; Sasaki, Daisuke; Sazuka, Takashi; Kamio, Eiji; Ogino, Chiaki; Matsuyama, Hideto; Kondo, Akihiko

    2017-08-01

    The juice from sweet sorghum cultivar SIL-05 (harvested at physiological maturity) was extracted, and the component sucrose and reducing sugars (such as glucose and fructose) were subjected to a membrane separation process to purify the sucrose for subsequent sugar refining and to obtain a feedstock for repeated bioethanol production. Nanofiltration (NF) of an ultrafiltration (UF) permeate using an NTR-7450 membrane (Nitto Denko Corporation, Osaka, Japan) concentrated the juice and produced a sucrose-rich fraction (143.2 g L -1 sucrose, 8.5 g L -1 glucose, and 4.5 g L -1 fructose). In addition, the above NF permeate was concentrated using an ESNA3 NF membrane to provide concentrated permeated sugars (227.9 g L -1 ) and capture various amino acids in the juice, enabling subsequent ethanol fermentation without the addition of an exogenous nitrogen source. Sequential batch fermentation using the ESNA3 membrane concentrate provided an ethanol titer and theoretical ethanol yield of 102.5-109.5 g L -1 and 84.4-89.6%, respectively, throughout the five-cycle batch fermentation by Saccharomyces cerevisiae BY4741. Our results demonstrate that a membrane process using UF and two types of NF membranes has the potential to allow sucrose purification and repeated bioethanol production.

  16. Integration of Bioreactor and Membrane Separation Processes: A Model Based Approach

    DEFF Research Database (Denmark)

    Prado Rubio, Oscar Andres

    and recirculated. The novelty of the process relies in the specialized design and operation of the Reverse Electro-Enhanced Dialysis module. The REED design allows removal of the lactate from the fermentation broth and simultaneously facilitates pH control in the fermenter using hydroxide. Additionally...... density constraint. Through dynamic simulations, the system behavior is investigated under current reversal conditions. Several phenomena are predicted such as preferable ion transport at the interfaces, transient flux inversion and accumulation/depletion of ions within the membranes. The combination...

  17. Gas separation membranes current status

    International Nuclear Information System (INIS)

    Puri, S.P.

    1996-01-01

    Membrane-based gas separation systems are now widely accepted and employed as unit operation in industrial gas, chemical and allied industries. Following their successful commercialization in the late Seventies to recover hydrogen from ammonia purge gas streams, membrane-based systems have gained acceptance in a wide variety of applications

  18. Metal ion separations using reactive membranes

    International Nuclear Information System (INIS)

    Way, J.D.

    1993-01-01

    A membrane is a barrier between two phases. If one component of a mixture moves through the membrane faster than another mixture component, a separation can be accomplished. Membranes are used commercially for many applications including gas separations, water purification, particle filtration, and macromolecule separations (Abelson). There are two points to note concerning this definition. First, a membrane is defined based on its function, not the material used to make the membrane. Secondly, a membrane separation is a rate process. The separation is accomplished by a driving force, not by equilibrium between phases. Liquids that are immiscible with the feed and product streams can also be used as membrane materials. Different solutes will have different solubilities and diffusion coefficients in a liquid. The product of the diffusivity and the solubility is known as the permeability coefficient, which is proportional to the solute flux. Differences in permeability coefficient will produce a separation between solutes at constant driving force. Because the diffusion coefficients in liquids are typically orders of magnitude higher than in polymers, a larger flux can be obtained. Further enhancements can be accomplished by adding a nonvolatile complexation agent to the liquid membrane. One can then have either coupled or facilitated transport of metal ions through a liquid membrane. The author describes two implementations of this concept, one involving a liquid membrane supported on a microporous membrane, and the other an emulsion liquid membrane, where separation occurs to internal receiving phases. Applications and costing studies for this technology are reviewed, and a brief summary of some of the problems with liquid membranes is presented

  19. Evaluation report on the R and D of the membrane separation process introduction technology; Makubunri process donyu gijutsu no kenkyu kaihatsu hyoka hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper reported the R and D of the membrane separation process introduction technology during a period of 1994 through 1998. The membrane separation technology is not associated with the phase change which requires large energy and expected to be an energy saving process. For the production of membranes required of high functions, the vapor deposition polymerization method was considered, and high order structure control of the membrane, control of adhesion and attachment, and control of orientation, and development of the high polymerization technology were required. For the high grade control of vapor polymerization, the substrate surface structure/quality were important. The molecular level analysis of the vapor deposition surface was also needed. Therefore, the paper took notice of STM (scanning tunneling microscopy), AFM (atomic force microscopy) and HREELS (high resolution electron energy loss spectroscopy) as surface atomic/molecular configuration analysis technology, and designed/fabricated and studied the high resolving power and high sensitivity analysis equipment using the analysis equipment which combined HREELS and STM and the analysis equipment using SFG (sum frequency generation) which can detect signals in the low frequency region. Making full use of the highest technology, technology was able to be developed for substrate surface analysis and surface reaction analysis technologies which become the basis of the high performance separation membrane fabrication technology by the vapor deposition polymerization method indispensable for introduction of the membrane separation process. The technology can be the base applicable to a lot of fields where surfaces and interfaces are concerned

  20. Membrane-based technologies for biogas separations.

    Science.gov (United States)

    Basu, Subhankar; Khan, Asim L; Cano-Odena, Angels; Liu, Chunqing; Vankelecom, Ivo F J

    2010-02-01

    Over the past two decades, membrane processes have gained a lot of attention for the separation of gases. They have been found to be very suitable for wide scale applications owing to their reasonable cost, good selectivity and easily engineered modules. This critical review primarily focuses on the various aspects of membrane processes related to the separation of biogas, more in specific CO(2) and H(2)S removal from CH(4) and H(2) streams. Considering the limitations of inorganic materials for membranes, the present review will only focus on work done with polymeric materials. An overview on the performance of commercial membranes and lab-made membranes highlighting the problems associated with their applications will be given first. The development studies carried out to enhance the performance of membranes for gas separation will be discussed in the subsequent section. This review has been broadly divided into three sections (i) performance of commercial polymeric membranes (ii) performance of lab-made polymeric membranes and (iii) performance of mixed matrix membranes (MMMs) for gas separations. It will include structural modifications at polymer level, polymer blending, as well as synthesis of mixed matrix membranes, for which addition of silane-coupling agents and selection of suitable fillers will receive special attention. Apart from an overview of the different membrane materials, the study will also highlight the effects of different operating conditions that eventually decide the performance and longevity of membrane applications in gas separations. The discussion will be largely restricted to the studies carried out on polyimide (PI), cellulose acetate (CA), polysulfone (PSf) and polydimethyl siloxane (PDMS) membranes, as these membrane materials have been most widely used for commercial applications. Finally, the most important strategies that would ensure new commercial applications will be discussed (156 references).

  1. Separation setup for the light water detritiation process in the water-hydrogen system based on the membrane contact devices

    International Nuclear Information System (INIS)

    Rozenkevich, M. B.; Rastunova, I. L.; Prokunin, S. V.

    2008-01-01

    Detritiation of light water wastes down to a level permissible to discharge into the environment while simultaneously concentrating tritium to decrease amount of waste being buried is a constant problem. The laboratory setup for the light water detritiation process is presented. The separation column consists of 10 horizontally arranged perfluorosulphonic acid Nafion-type membrane contact devises and platinum catalyst (RCTU-3SM). Each contact device has 42.3 cm 2 of the membrane and 10 cm 3 of the catalyst. The column is washed by tritium free light water (L H2O ) and the tritium-containing flow (F HTO ) feeds the electrolyser at λ = G H2 /L H2O = 2. A separation factor of 66 is noted with the device at 336 K and 0.145 MPa. (authors)

  2. Membrane separation of ionic liquid solutions

    Science.gov (United States)

    Campos, Daniel; Feiring, Andrew Edward; Majumdar, Sudipto; Nemser, Stuart

    2015-09-01

    A membrane separation process using a highly fluorinated polymer membrane that selectively permeates water of an aqueous ionic liquid solution to provide dry ionic liquid. Preferably the polymer is a polymer that includes polymerized perfluoro-2,2-dimethyl-1,3-dioxole (PDD). The process is also capable of removing small molecular compounds such as organic solvents that can be present in the solution. This membrane separation process is suitable for drying the aqueous ionic liquid byproduct from precipitating solutions of biomass dissolved in ionic liquid, and is thus instrumental to providing usable lignocellulosic products for energy consumption and other industrial uses in an environmentally benign manner.

  3. Biomimetic membranes for sensor and separation applications

    CERN Document Server

    2012-01-01

    This book addresses the possibilities and challenges in mimicking biological membranes and creating membrane-based sensor and separation devices. It covers recent advances in developing biomimetic membranes for technological applications with a focus on the use of integral membrane protein mediated transport. It describes the fundamentals of biosensing as well as separation and shows how the two processes work together in biological systems. The book provides an overview of the current state of the art, points to areas that need further investigation and anticipates future directions in the field. Biomimetics is a truly cross-disciplinary approach and this is exemplified by the challenges in mimicking osmotic processes as they occur in nature using aquaporin protein water channels as central building blocks. In the development of a biomimetic sensor/separation technology, both channel and carrier proteins are important and examples of how these may be reconstituted and controlled in biomimetic membranes are ...

  4. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  5. Hybrid ion-exchange membranes for fuel cells and separation processes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Carretero, F.J.; Compan, V. [Departamento de Termodinamica Aplicada, ETSII, Universidad Politecnica de Valencia, 46020 Valencia (Spain); Riande, E. [Instituto de Ciencia y Tecnologia de Polimeros (CSIC), 28006 Madrid (Spain)

    2007-11-08

    This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion {sup registered} solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion {sup registered}. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion {sup registered} membranes. The conductivity of the membranes was measured at 80 C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m{sup -1} for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 C for Nafion {sup registered} hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m{sup -1}, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity. (author)

  6. Novel Zeolitic Imidazolate Framework/Polymer Membranes for Hydrogen Separations in Coal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Musselman, Inga H.

    2013-01-31

    Nanoparticles of zeolitic imidazolate frameworks and other related hybrid materials were prepared by modifying published synthesis procedures by introducing bases, changing stoichiometric ratios, or adjusting reaction conditions. These materials were stable at temperatures >300 °C and were compatible with the polymer matrices used to prepare mixed-matrix membranes (MMMs). MMMs tested at 300 °C exhibited a >30 fold increase in permeability, compared to those measured at 35 °C, while maintaining H{sub 2}/CO{sub 2} selectivity. Measurements at high pressure (up to 30 atm) and high temperature (up to 300 °C) resulted in an increase in gas flux across the membrane with retention of selectivity. No variations in permeability were observed at high pressures at either 35 or 300 °C. CO{sub 2}-induced plasticization was not observed for Matrimid®, VTEC, and PBI polymers or their MMMs at 30 atm and 300 °C. Membrane surface modification by cross-linking with ethylenediamine resulted in an increase in H{sub 2}/CO{sub 2} selectivity at 35 °C. Spectrometric analysis showed that the cross-linking was effective to temperatures <150 °C. At higher temperatures, the cross-linked membranes exhibit a H2/CO2 selectivity similar to the uncrosslinked polymer.

  7. Improvement on the concentrated grape juice physico-chemical characteristics by an enzymatic treatment and Membrane Separation Processes

    Directory of Open Access Journals (Sweden)

    PLÍNIO R.F. CAMPOS

    2016-03-01

    Full Text Available ABSTRACT In this work, the improvement on the concentrated grape juice physico-chemical characteristics by using an enzymatic treatment followed by Membrane Separation Process (MSP has been investigated. By using Novozym 33095(r and Ultrazym AFP L(r enzymes varying three operating parameters, the best result on the grape pulp characteristics was attained for the Novozym 33095(r performed at 35oC, 15 min. and 50 mgL-1. In micro/ultra filtration processes after enzymatic pretreatment, the best performance of the MSP with high permeate flux value and suitable grape juice characteristics was attained using 0.05 mm membrane pore size, 1 bar pressure and 40 oC treatment temperature. When reverse osmosis process is operated at 40 bar and 40oC, high soluble solid and low turbidity values are attained. An enzymatic treatment along with MSP has shown an alternative and efficient grape juice processing system, being possible to extend to other foods.

  8. Integrated distillation-membrane process for bio-ethanol and bio-butanol recovery from actual fermentation broths: Separation energy efficiency and fate of secondary fermentation products

    Science.gov (United States)

    A hybrid process integrating vapor stripping with vapor compression and vapor permeation membrane separation, termed Membrane Assisted Vapor Stripping (MAVS), was evaluated for recovery and dehydration of ethanol and/or 1-butanol from aqueous solution as an alternative to convent...

  9. Four-port gas separation membrane module assembly

    Science.gov (United States)

    Wynn, Nicholas P.; Fulton, Donald A.; Lokhandwala, Kaaeid A.; Kaschemekat, Jurgen

    2010-07-20

    A gas-separation membrane assembly, and a gas-separation process using the assembly. The assembly incorporates multiple gas-separation membranes in an array within a single vessel or housing, and is equipped with two permeate ports, enabling permeate gas to be withdrawn from both ends of the membrane module permeate pipes.

  10. Gas separation using porous cement membrane.

    Science.gov (United States)

    Zhang, Weiqi; Gaggl, Maria; Gluth, Gregor J G; Behrendt, Frank

    2014-01-01

    Gas separation is a key issue in various industrial fields. Hydrogen has the potential for application in clean fuel technologies. Therefore, the separation and purification of hydrogen is an important research subject. CO2 capture and storage have important roles in "green chemistry". As an effective clean technology, gas separation using inorganic membranes has attracted much attention in the last several decades. Membrane processes have many applications in the field of gas separation. Cement is one type of inorganic material, with the advantages of a lower cost and a longer lifespan. An experimental setup has been created and improved to measure twenty different cement membranes. The purpose of this work was to investigate the influence of gas molecule properties on the material transport and to explore the influence of operating conditions and membrane composition on separation efficiency. The influences of the above parameters are determined, the best conditions and membrane type are found, it is shown that cementitious material has the ability to separate gas mixtures, and the gas transport mechanism is studied.

  11. Latest development on the membrane formation for gas separation

    Directory of Open Access Journals (Sweden)

    Ahmad Fausi Ismail

    2002-11-01

    Full Text Available The first scientific observation related to gas separation was encountered by J.K Mitchell in 1831. However, the most remarkable and influential contribution to membrane gas separation technology was the systematic study by Thomas Graham in 1860. However only in 1979, membrane based gas separation technology was available and recognized as one of the most recent and advanced unit operations for gas separation processes. Membrane is fabricated by various methods and the parameters involved to a certain extent are very complicated. The phase inversion technique that is normally employed to produce membranes are dry/wet, wet, dry and thermal induced phase separation. Other techniques used to produce membrane are also reviewed. This paper reports the latest development in membrane formation for gas separation. The route to produce defect-free and ultrathin-skinned asymmetric membrane is also presented that represents the cutting edge technology in membrane gas separation process

  12. Phosphazene membranes for gas separations

    Science.gov (United States)

    Stewart, Frederick F.; Harrup, Mason K.; Orme, Christopher J.; Luther, Thomas A.

    2006-07-11

    A polyphosphazene having a glass transition temperature ("T.sub.g") of approximately -20.degree. C. or less. The polyphosphazene has at least one pendant group attached to a backbone of the polyphosphazene, wherein the pendant group has no halogen atoms. In addition, no aromatic groups are attached to an oxygen atom that is bound to a phosphorus atom of the backbone. The polyphosphazene may have a T.sub.g ranging from approximately -100.degree. C. to approximately -20.degree. C. The polyphosphazene may be selected from the group consisting of poly[bis-3-phenyl-1-propoxy)phosphazene], poly[bis-(2-phenyl-1-ethoxy)phosphazene], poly[bis-(dodecanoxypolyethoxy)-phosphazene], and poly[bis-(2-(2-(2-.omega.-undecylenyloxyethoxy)ethoxy)ethoxy)phosphazene]- . The polyphosphazene may be used in a separation membrane to selectively separate individual gases from a gas mixture, such as to separate polar gases from nonpolar gases in the gas mixture.

  13. Pilot-scale multistage membrane process for the separation of CO2 from LNG-fired flue gas

    KAUST Repository

    Choi, Seung Hak; Kim, Jeong Hoon; Lee, Yongtaek

    2013-01-01

    and permeation data obtained were also analyzed in relation with the numerical simulation data using countercurrent flow model. Based on these results, in this study, four-staged membrane process including dehumidification process has been designed, installed

  14. SEPARATION OF HYDROGEN AND CARBON DIOXIDE USING A NOVEL MEMBRANE REACTOR IN ADVANCED FOSSIL ENERGY CONVERSION PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2005-02-03

    Inorganic membrane reactors offer the possibility of combining reaction and separation in a single operation at high temperatures to overcome the equilibrium limitations experienced in conventional reactor configurations. Such attractive features can be advantageously utilized in a number of potential commercial opportunities, which include dehydrogenation, hydrogenation, oxidative dehydrogenation, oxidation and catalytic decomposition reactions. However, to be cost effective, significant technological advances and improvements will be required to solve several key issues which include: (a) permselective thin solid film, (b) thermal, chemical and mechanical stability of the film at high temperatures, and (c) reactor engineering and module development in relation to the development of effective seals at high temperature and high pressure. In this project, we are working on the development and application of palladium and palladium-silver alloy thin-film composite membranes in membrane reactor-separator configuration for simultaneous production and separation of hydrogen and carbon dioxide at high temperature. From our research on Pd-composite membrane, we have demonstrated that the new membrane has significantly higher hydrogen flux with very high perm-selectivity than any of the membranes commercially available. The steam reforming of methane by equilibrium shift in Pd-composite membrane reactor is being studied to demonstrate the potential application of this new development. A two-dimensional, pseudo-homogeneous membrane-reactor model was developed to investigate the steam-methane reforming (SMR) reactions in a Pd-based membrane reactor. Radial diffusion was taken into consideration to account for the concentration gradient in the radial direction due to hydrogen permeation through the membrane. With appropriate reaction rate expressions, a set of partial differential equations was derived using the continuity equation for the reaction system. The equations were

  15. Highly permeable double-skinned forward osmosis membranes for anti-fouling in the emulsified oil-water separation process

    KAUST Repository

    Duong, Hoang Hanh Phuoc; Chung, Neal Tai-Shung; Wei, Shawn; Irish, Lana

    2014-01-01

    Forward osmosis (FO) has attracted wide attention in recent years. However, the FO performance may be restricted due to internal concentration polarization (ICP) and fast fouling propensity that occurs in the membrane sublayer. Particularly, these problems significantly affect the membrane performance when treating highly contaminated oily wastewater. Recently, double-skinned flat sheet cellulose acetate (CA) membranes consisting of two selective skins via the phase inversion method have demonstrated less ICP and fouling propensity over typical single-skinned membranes. However, these membranes exhibit low water fluxes of <12 LMH under 2 M NaCl draw solution. Therefore, a novel double-skinned FO membrane with a high water flux has been aimed for in this study for emulsified oil-water treatment. The double-skinned FO membrane comprises a fully porous sublayer sandwiched between (i) a truly dense skin for salt rejection and (ii) a fairly loose dense skin for emulsified oil particle rejection. The former dense skin is a polyamide synthesized via interfacial polymerization, while the latter one is a self-assembled sulfonated pentablock copolymer (Nexar copolymer) layer. The resultant double-skinned membrane exhibits a high water flux of 17.2 LMH and a low reverse salt transport of 4.85 gMH using 0.5 M NaCl as the draw solution and DI water as the feed. The double-skinned membrane outperforms the single-skinned membrane with much lower fouling propensity for emulsified oil-water separation. © 2014 American Chemical Society.

  16. Highly permeable double-skinned forward osmosis membranes for anti-fouling in the emulsified oil-water separation process

    KAUST Repository

    Duong, Hoang Hanh Phuoc

    2014-04-15

    Forward osmosis (FO) has attracted wide attention in recent years. However, the FO performance may be restricted due to internal concentration polarization (ICP) and fast fouling propensity that occurs in the membrane sublayer. Particularly, these problems significantly affect the membrane performance when treating highly contaminated oily wastewater. Recently, double-skinned flat sheet cellulose acetate (CA) membranes consisting of two selective skins via the phase inversion method have demonstrated less ICP and fouling propensity over typical single-skinned membranes. However, these membranes exhibit low water fluxes of <12 LMH under 2 M NaCl draw solution. Therefore, a novel double-skinned FO membrane with a high water flux has been aimed for in this study for emulsified oil-water treatment. The double-skinned FO membrane comprises a fully porous sublayer sandwiched between (i) a truly dense skin for salt rejection and (ii) a fairly loose dense skin for emulsified oil particle rejection. The former dense skin is a polyamide synthesized via interfacial polymerization, while the latter one is a self-assembled sulfonated pentablock copolymer (Nexar copolymer) layer. The resultant double-skinned membrane exhibits a high water flux of 17.2 LMH and a low reverse salt transport of 4.85 gMH using 0.5 M NaCl as the draw solution and DI water as the feed. The double-skinned membrane outperforms the single-skinned membrane with much lower fouling propensity for emulsified oil-water separation. © 2014 American Chemical Society.

  17. Review of Membranes for Helium Separation and Purification

    Directory of Open Access Journals (Sweden)

    Colin A. Scholes

    2017-02-01

    Full Text Available Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications where helium recycling has potential. A review of the available polymeric and inorganic membranes for helium separation is provided. Commercial gas separation membranes in comparable gas industries are discussed in terms of their potential in helium separation. Also presented are the various membrane process designs patented for the recovery and purification of helium from various sources, as these demonstrate that it is viable to separate helium through currently available polymeric membranes. This review places a particular focus on those processes where membranes are combined in series with another separation technology, commonly pressure swing adsorption. These combined processes have the most potential for membranes to produce a high purity helium product. The review demonstrates that membrane gas separation is technically feasible for helium recovery and purification, though membranes are currently only applied in niche applications focused on reusing helium rather than separation from natural sources.

  18. Novel, Ceramic Membrane System For Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Elangovan, S.

    2012-12-31

    Separation of hydrogen from coal gas represents one of the most promising ways to produce alternative sources of fuel. Ceramatec, teamed with CoorsTek and Sandia National Laboratories has developed materials technology for a pressure driven, high temperature proton-electron mixed conducting membrane system to remove hydrogen from the syngas. This system separates high purity hydrogen and isolates high pressure CO{sub 2} as the retentate, which is amenable to low cost capture and transport to storage sites. The team demonstrated a highly efficient, pressure-driven hydrogen separation membrane to generate high purity hydrogen from syngas using a novel ceramic-ceramic composite membrane. Recognizing the benefits and limitations of present membrane systems, the all-ceramic system has been developed to address the key technical challenges related to materials performance under actual operating conditions, while retaining the advantages of thermal and process compatibility offered by the ceramic membranes. The feasibility of the concept has already been demonstrated at Ceramatec. This project developed advanced materials composition for potential integration with water gas shift rectors to maximize the hydrogenproduction.

  19. Anisotropic membranes for gas separation

    Science.gov (United States)

    Gollan, Arye Z.

    1987-01-01

    A gas separation membrane has a dense separating layer about 10,000 Angstroms or less thick and a porous support layer 10 to 400 microns thick that is an integral unit with gradually and continuously decreasing pore size from the base of the support layer to the surface of the thin separating layer and is made from a casting solution comprising ethyl cellulose and ethyl cellulose-based blends, typically greater than 47.5 ethoxyl content ethyl cellulose blended with compatible second polymers, such as nitrocellulose. The polymer content of the casting solution is from about 10% to about 35% by weight of the total solution with up to about 50% of this polymer weight a compatible second polymer to the ethyl cellulose in a volatile solvent such as isopropanol, methylacetate, methanol, ethanol, and acetone. Typical nonsolvents for the casting solutions include water and formamide. The casting solution is cast in air from about zero to 10 seconds to allow the volatile solvent to evaporate and then quenched in a coagulation bath, typically water, at a temperature of 7.degree.-25.degree. C. and then air dried at ambient temperature, typically 10.degree.-30.degree. C.

  20. CHRISGAS Project. WP13: Ancillary and Novel Processes. Final Report: Separation of Hydrogen with Membranes Combined with Water Gas Shift Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Hervas, J. M.; Marono, M.; Barreiro, M. M.

    2011-05-13

    Oxygen pressurized gasification of biomass out stands as a very promising approach to obtain energy or hydrogen from renewable sources. The technical feasibility of this technology has been investigated under the scope of the VI FP CHRISGAS project, which started in September 2004 and had a duration of five and a half years. The Division of Combustion and Gasification of CIEMAT participated in this project in Work Package 13: Ancillary and novel processes, studying innovative gas separation and gas upgrading systems. Such systems include novel or available high temperature water gas shift catalysts and commercially available membranes not yet tried in this type of atmosphere. This report describes the activities carried out during the project regarding the performance of high temperature water gas shift catalysts for upgrading of synthesis gas obtained from biomass gasification, the separation of H2 with selective membranes and the combination of both processes in one by means of a catalytic membrane reactor. (Author) 20 refs.

  1. CHRISGAS Project. WP13: Ancillary and Novel Processes. Final Report: Separation of Hydrogen with Membranes Combined with Water Gas Shift Reaction

    International Nuclear Information System (INIS)

    Sanchez-Hervas, J. M.; Marono, M.; Barreiro, M. M.

    2011-01-01

    Oxygen pressurized gasification of biomass out stands as a very promising approach to obtain energy or hydrogen from renewable sources. The technical feasibility of this technology has been investigated under the scope of the VI FP CHRISGAS project, which started in September 2004 and had a duration of five and a half years. The Division of Combustion and Gasification of CIEMAT participated in this project in Work Package 13: Ancillary and novel processes, studying innovative gas separation and gas upgrading systems. Such systems include novel or available high temperature water gas shift catalysts and commercially available membranes not yet tried in this type of atmosphere. This report describes the activities carried out during the project regarding the performance of high temperature water gas shift catalysts for upgrading of synthesis gas obtained from biomass gasification, the separation of H2 with selective membranes and the combination of both processes in one by means of a catalytic membrane reactor. (Author) 20 refs.

  2. Polymeric Gas-Separation Membranes for Petroleum Refining

    Directory of Open Access Journals (Sweden)

    Yousef Alqaheem

    2017-01-01

    Full Text Available Polymeric gas-separation membranes were commercialized 30 years ago. The interest on these systems is increasing because of the simplicity of concept and low-energy consumption. In the refinery, gas separation is needed in many processes such as natural gas treatment, carbon dioxide capture, hydrogen purification, and hydrocarbons separations. In these processes, the membranes have proven to be a potential candidate to replace the current conventional methods of amine scrubbing, pressure swing adsorption, and cryogenic distillation. In this paper, applications of polymeric membranes in the refinery are discussed by reviewing current materials and commercialized units. Economical evaluation of these membranes in comparison to traditional processes is also indicated.

  3. Refining of biodiesel by ceramic membrane separation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yong; Ou, Shiyi; Tan, Yanlai; Tang, Shuze [Department of Food Science and Engineering, Jinan University, Guangzhou 510632 (China); Wang, Xingguo; Liu, Yuanfa [School of Food Science and Technology, Jiangnan University, Wuxi 214112 (China)

    2009-03-15

    A ceramic membrane separation process for biodiesel refining was developed to reduce the considerable usage of water needed in the conventional water washing process. Crude biodiesel produced by refined palm oil was micro-filtered by ceramic membranes of the pore size of 0.6, 0.2 and 0.1 {mu}m to remove the residual soap and free glycerol, at the transmembrane pressure of 0.15 MPa and temperature of 60 C. The flux through membrane maintained at 300 L m{sup -} {sup 2} h{sup -} {sup 1} when the volumetric concentrated ratio reached 4. The content of potassium, sodium, calcium and magnesium in the whole permeate was 1.40, 1.78, 0.81 and 0.20 mg/kg respectively, as determined by inductively coupled plasma-atomic emission spectroscopy. These values are lower than the EN 14538 specifications. The residual free glycerol in the permeate was estimated by water extraction, its value was 0.0108 wt.%. This ceramic membrane technology was a potential environmental process for the refining of biodiesel. (author)

  4. Adsorbent filled polymeric membranes : applications to pervaporation and gas separation

    NARCIS (Netherlands)

    Duval, Jean-Marc

    1993-01-01

    Nowadays research in membrane technology aims at improving the efficiency of the separation process to make it more competitive in comparison to conventional separation techniques. The improvement of the membrane material is a way to achieve this goal, especially in the case of pervaporation and gas

  5. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Fain, D.E.; Roettger, G.E. [Oak Ridge K-25 Site, TN (United States)

    1996-08-01

    Ceramic gas separation membranes can provide very high separation factors if the pore size is sufficiently small to separate gas molecules by molecular sieving and if oversized pores are adequately limited. Ceramic membranes typically have some pores that are substantially larger than the mean pore size and that should be regarded as defects. To assess the effects of such defects on the performance of ceramic membranes, a simple mathematical model has been developed to describe flow through a gas separation membrane that has a primary mode of flow through very small pores but that has a secondary mode of flow through undesirably large pores. This model permits separation factors to be calculated for a specified gas pair as a function of the molecular weights and molecular diameters of the gases, the membrane pore diameter, and the diameter and number of defects. This model will be described, and key results from the model will be presented. The separation factors of the authors membranes continue to be determined using a permeance test system that measures flows of pure gases through a membrane at temperatures up to 275{degrees}C. A primary goal of this project for FY 1996 is to develop a mixed gas separation system for measuring the separation efficiency of membranes at higher temperatures. Performance criteria have been established for the planned mixed gas separation system and design of the system has been completed. The test system is designed to measure the separation efficiency of membranes at temperatures up to 600{degrees}C and pressures up to 100 psi by separating the constituents of a gas mixture containing hydrogen. The system will accommodate the authors typical experimental membrane that is tubular and has a diameter of about 9 mm and a length of about 23 cm. The design of the new test system and its expected performance will be discussed.

  6. Membrane separation systems---A research and development needs assessment

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. (Membrane Technology and Research, Inc., Menlo Park, CA (USA)); Cussler, E.L. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science); Eykamp, W. (California Univ., Berkeley, CA (USA)); Koros, W.J. (Texas Univ., Austin, TX (USA)); Riley, R.L. (Separation Systems Technology, San Diego, CA (USA)); Strathmann, H. (Fraunhofer-Institut fuer Grenzflaech

    1990-03-01

    Membrane based separation technology, a relative newcomer on the separations scene, has demonstrated the potential of saving enormous amounts of energy in the processing industries if substituted for conventional separation systems. Over 1 quad annually, out of 2.6, can possibly be saved in liquid-to-gas separations, alone, if membrane separation systems gain wider acceptance, according to a recent DOE/OIP (DOE/NBM-80027730 (1986)) study. In recent years great strides have been made in the field and offer even greater energy savings in the future when substituted for other conventional separation techniques such as distillation, evaporation, filtration, sedimentation, and absorption. An assessment was conducted by a group of six internationally known membrane separations experts who examined the worldwide status of research in the seven major membrane areas. This encompassed four mature technology areas: reverse osmosis, micorfiltration, ultrafiltration, and electrodialysis; two developing areas: gas separation and and pervaporation; and one emerging technology: facilitated transport. Particular attention was paid to identifying the innovative processes currently emerging, and even further improvements which could gain wider acceptance for the more mature membrane technology. The topics that were pointed out as having the greatest research emphasis are pervaporation for organic-organic separations; gas separation; micorfiltration; an oxidant-resistant reverse osmosis membrane; and a fouling-resistant ultrafiltration membrane. 35 refs., 6 figs., 22 tabs.

  7. Novel silica membranes for high temperature gas separations

    KAUST Repository

    Bighane, Neha

    2011-04-01

    This article describes fabrication of novel silica membranes derived via controlled oxidative thermolysis of polydimethylsiloxane and their gas separation performance. The optimized protocol for fabrication of the silica membranes is described and pure gas separation performance in the temperature range 35-80°C is presented. It is observed that the membranes exhibit activated transport for small gas penetrants such as He, H 2 and CO 2. The membranes can withstand temperatures up to 350°C in air and may ultimately find use in H 2/CO 2 separations to improve efficiency in the water-gas shift reactor process. © 2011 Elsevier B.V.

  8. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Adcock, K.D.; Fain, D.E.; James, D.L.; Powell, L.E.; Raj, T.; Roettger, G.E.; Sutton, T.G. [East Tennessee Technology Park, Oak Ridge, TN (United States)

    1997-12-01

    The separative performance of the authors` ceramic membranes has been determined in the past using a permeance test system that measured flows of pure gases through a membrane at temperatures up to 275 C. From these data, the separation factor was determined for a particular gas pair from the ratio of the pure gas specific flows. An important project goal this year has been to build a Mixed Gas Separation System (MGSS) for measuring the separation efficiencies of membranes at higher temperatures and using mixed gases. The MGSS test system has been built, and initial operation has been achieved. The MGSS is capable of measuring the separation efficiency of membranes at temperatures up to 600 C and pressures up to 100 psi using a binary gas mixture such as hydrogen/methane. The mixed gas is fed into a tubular membrane at pressures up to 100 psi, and the membrane separates the feed gas mixture into a permeate stream and a raffinate stream. The test membrane is sealed in a stainless steel holder that is mounted in a split tube furnace to permit membrane separations to be evaluated at temperatures up to 600 C. The compositions of the three gas streams are measured by a gas chromatograph equipped with thermal conductivity detectors. The test system also measures the temperatures and pressures of all three gas streams as well as the flow rate of the feed stream. These data taken over a range of flows and pressures permit the separation efficiency to be determined as a function of the operating conditions. A mathematical model of the separation has been developed that permits the data to be reduced and the separation factor for the membrane to be determined.

  9. Polymeric molecular sieve membranes for gas separation

    Science.gov (United States)

    Dai, Sheng; Qiao, Zhenan; Chai, Songhai

    2017-08-15

    A porous polymer membrane useful in gas separation, the porous polymer membrane comprising a polymeric structure having crosslinked aromatic groups and a hierarchical porosity in which micropores having a pore size less than 2 nm are present at least in an outer layer of the porous polymer membrane, and macropores having a pore size of over 50 nm are present at least in an inner layer of the porous polymer membrane. Also described are methods for producing the porous polymer membrane in which a non-porous polymer membrane containing aromatic rings is subjected to a Friedel-Crafts crosslinking reaction in which a crosslinking molecule crosslinks the aromatic rings in the presence of a Friedel-Crafts catalyst and organic solvent under sufficiently elevated temperature, as well as methods for using the porous polymer membranes for gas or liquid separation, filtration, or purification.

  10. Carbon Dioxide Separation Using Thermally Optimized Membranes

    Science.gov (United States)

    Young, J. S.; Jorgensen, B. S.; Espinoza, B. F.; Weimer, M. W.; Jarvinen, G. D.; Greenberg, A.; Khare, V.; Orme, C. J.; Wertsching, A. K.; Peterson, E. S.; Hopkins, S. D.; Acquaviva, J.

    2002-05-01

    The purpose of this project is to develop polymeric-metallic membranes for carbon dioxide separations that operate under a broad range of industrially relevant conditions not accessible with present membrane units. The last decade has witnessed a dramatic increase in the use of polymer membranes as an effective, economic and flexible tool for many commercial gas separations including air separation, the recovery of hydrogen from nitrogen, carbon monoxide, and methane mixtures, and the removal of carbon dioxide from natural gas. In each of these applications, high fluxes and excellent selectivities have relied on glassy polymer membranes which separate gases based on both size and solubility differences. To date, however, this technology has focused on optimizing materials for near ambient conditions. The development of polymeric materials that achieve the important combination of high selectivity, high permeability, and mechanical stability at temperatures significantly above 25oC and pressures above 10 bar, respectively, has been largely ignored. Consequently, there is a compelling rationale for the exploration of a new realm of polymer membrane separations. Indeed, the development of high temperature polymeric-metallic composite membranes for carbon dioxide separation at temperatures of 100-450 oC and pressures of 10-150 bar would provide a pivotal contribution with both economic and environmental benefits. Progress to date includes the first ever fabrication of a polymeric-metallic membrane that is selective from room temperature to 370oC. This achievement represents the highest demonstrated operating temperature at which a polymeric based membrane has successfully functioned. Additionally, we have generated the first polybenzamidizole silicate molecular composites. Finally, we have developed a technique that has enabled the first-ever simultaneous measurements of gas permeation and membrane compaction at elevated temperatures. This technique provides a unique

  11. Separation of aromatics by vapor permeation through solvent swollen membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ito, A.; Adachi, K.; Feng, Y. [Niigata University, Niigata (Japan)

    1995-12-20

    A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative salability of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide. 14 refs., 9 figs., 1 tab.

  12. Membranes as separators of dispersed emulsion phases

    OpenAIRE

    Lefferts, A.G.

    1997-01-01

    The reuse or discharge of industrial waste waters, containing small fractions of dispersed oil, requires a purification treatment for which membranes can be used. If only little oil is present, removal of the dispersed phase might be preferable to the more commonly applied removal of the continuous phase. For this purpose dispersed phase separators can be applied, which combine the features of conventional coalescers and membrane filtration. The membrane surface promotes coalescence ...

  13. Membrane separation systems---A research and development needs assessment

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. (Membrane Technology and Research, Inc., Menlo Park, CA (USA)); Cussler, E.L. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science); Eykamp, W. (California Univ., Berkeley, CA (USA)); Koros, W.J. (Texas Univ., Austin, TX (USA)); Riley, R.L. (Separation Systems Technology, San Diego, CA (USA)); Strathmann, H. (Fraunhofer-Institut fuer Grenzflaech

    1990-04-01

    Industrial separation processes consume a significant portion of the energy used in the United States. A 1986 survey by the Office of Industrial Programs estimated that about 4.2 quads of energy are expended annually on distillation, drying and evaporation operations. This survey also concluded that over 0.8 quads of energy could be saved in the chemical, petroleum and food industries alone if these industries adopted membrane separation systems more widely. Membrane separation systems offer significant advantages over existing separation processes. In addition to consuming less energy than conventional processes, membrane systems are compact and modular, enabling easy retrofit to existing industrial processes. The present study was commissioned by the Department of Energy, Office of Program Analysis, to identify and prioritize membrane research needs in light of DOE's mission. Each report will be individually cataloged.

  14. Ceramic membranes for gas separation in advanced fossil power plants

    Energy Technology Data Exchange (ETDEWEB)

    Meulenberg, W.A.; Baumann, S.; Ivanova, M.; Gestel, T. van; Bram, M.; Stoever, D. [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF)

    2010-07-01

    The reduction or elimination of CO{sub 2} emissions from electricity generation power plants fuelled by coal or gas is a major target in the current socio-economic, environmental and political discussion to reduce green house gas emissions such as CO{sub 2}. This mission can be achieved by introducing gas separation techniques making use of membrane technology, which is, as a rule, associated with significantly lower efficiency losses compared with the conventional separation technologies. Depending on the kind of power plant process different membrane types (ceramic, polymer, metal) can be implemented. The possible technology routes are currently investigated to achieve the emission reduction. They rely on different separation tasks. The CO{sub 2}/N{sub 2} separation is the main target in the post-combustion process. Air separation (O{sub 2}/N{sub 2}) is the focus of the oxyfuel process. In the pre-combustion process an additional H{sub 2}/CO{sub 2} separation is included. Although all separation concepts imply different process requirements they have in common a need in membranes with high permeability, selectivity and stability. In each case CO{sub 2} is obtained in a readily condensable form. CO{sub 2}/N{sub 2} separation membranes like microporous membranes or polymer membranes are applicable in post-combustion stages. In processes with oxyfuel combustion, where the fuel is combusted with pure oxygen, oxygen transport membranes i.e. mixed ionic electronic conducting (MIEC) membranes with mainly perovskite or fluorite structure can be integrated. In the pre-combustion stages of the power plant process, H{sub 2}/CO{sub 2} separation membranes like microporous membranes e.g. doped silica or mixed protonic electronic conductors or metal membranes can be applied. The paper gives an overview about the considered ceramic materials for the different gas separation membranes. The manufacturing of bulk materials as well as supported thin films of these membranes along

  15. NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION; SEMIANNUAL

    International Nuclear Information System (INIS)

    Jerry Y.S. Lin; Jun-ichi Ida

    2001-01-01

    This project is aimed at demonstrating technical feasibility for a lithium zirconate based dense ceramic membrane for separation of carbon dioxide from flue gas at high temperature. The research work conducted in this reporting period was focused on several fundamental issues of lithium zirconate important to the development of the dense inorganic membrane. These fundamental issues include material synthesis of lithium zirconate, phases and microstructure of lithium zirconate and structure change of lithium zirconate during sorption/desorption process. The results show difficulty to prepare the dense ceramic membrane from pure lithium zirconate, but indicate a possibility to prepare the dense inorganic membrane for carbon dioxide separation from a composite lithium zirconate

  16. Adsorption/Membrane Filtration as a Contaminant Concentration and Separation Process for Mixed Wastes and Tank Wastes - Final Report

    International Nuclear Information System (INIS)

    Benjamin, M.M.

    1999-01-01

    This project was conducted to evaluate novel approaches for removing radioactive strontium (Sr) and cesium (Cs) from the tank wastes. The bulk of the Sr removal research conducted as part of this project investigated adsorption of Sr onto a novel adsorbent known as iron-oxide-coated sand. The second major focus of the work was on the removal of cesium. Since the chemistries of strontium and cesium have little commonality, different materials (namely, cesium scavengers known as hexacyanoferrates, HCFs) were employed in these tests. This study bridged several scientific areas and yielded valuable knowledge for implementing new technological processes. The applicability of the results extends beyond the highly specialized application niches investigated experimentally to other issues of potential interest for EMSP programs (e.g., separation of chromium from a variety of wastes using IOCS, separation of Cs from neutral and acidic wastes with EC-controlled HCFs)

  17. Microporous Organic Materials for Membrane-Based Gas Separation.

    Science.gov (United States)

    Zou, Xiaoqin; Zhu, Guangshan

    2018-01-01

    Membrane materials with excellent selectivity and high permeability are crucial to efficient membrane gas separation. Microporous organic materials have evolved as an alternative candidate for fabricating membranes due to their inherent attributes, such as permanent porosity, high surface area, and good processability. Herein, a unique pore-chemistry concept for the designed synthesis of microporous organic membranes, with an emphasis on the relationship between pore structures and membrane performances, is introduced. The latest advances in microporous organic materials for potential membrane application in gas separation of H 2 , CO 2 , O 2 , and other industrially relevant gases are summarized. Representative examples of the recent progress in highly selective and permeable membranes are highlighted with some fundamental analyses from pore characteristics, followed by a brief perspective on future research directions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Improving Liquid Entry Pressure of Polyvinylidene Fluoride (PVDF Membranes by Exploiting the Role of Fabrication Parameters in Vapor-Induced Phase Separation VIPS and Non-Solvent-Induced Phase Separation (NIPS Processes

    Directory of Open Access Journals (Sweden)

    Faisal Abdulla AlMarzooqi

    2017-02-01

    Full Text Available Polyvinylidene fluoride (PVDF is a popular polymer material for making membranes for several applications, including membrane distillation (MD, via the phase inversion process. Non-solvent-induced phase separation (NIPS and vapor-induced phase separation (VIPS are applied to achieve a porous PVDF membrane with low mass-transfer resistance and high contact angle (hydrophobicity. In this work, firstly, the impacts of several preparation parameters on membrane properties using VIPS and NIPS were studied. Then, the performance of the selected membrane was assessed in a lab-scale direct-contact MD (DCMD unit. The parametric study shows that decreasing PVDF concentration while increasing both relative humidity (RH and exposure time increased the contact angle and bubble-point pore size (BP. Those trends were investigated further by varying the casting thickness. At higher casting thicknesses and longer exposure time (up to 7.5 min, contact angle (CA increased but BP significantly decreased. The latter showed a dominant trend leading to liquid entry pressure (LEP increase with thickness.

  19. Stabilized ultrathin liquid membranes for gas separations

    International Nuclear Information System (INIS)

    Deetz, D.W.

    1987-01-01

    Although immobilized liquid membranes have the desirable properties of high selectivity and permeability, their practical application to gas phase separations is hindered because of the instability of the liquid phase and the relative thickness of current membranes. The problem of liquid instability, which is due to both liquid volatilization and flooding, can be reduced, or eliminated, by immobilizing the liquid phase in pores small enough to significantly reduce the molar free energy of the solution via the Kelvin effect. The obstacle of membrane thickness can be overcome by selectively immobilizing the liquid phase into the skin of a porous asymmetric membranes

  20. Industrial separation processes : fundamentals

    NARCIS (Netherlands)

    Haan, de A.B.; Bosch, Hans

    2013-01-01

    Separation processes on an industrial scale comprise well over half of the capital and operating costs. They are basic knowledge in every chemical engineering and process engineering study. This book provides comprehensive and fundamental knowledge of university teaching in this discipline,

  1. Isotope separation process

    International Nuclear Information System (INIS)

    Cox, D.M.; Maas, E.T.

    1982-01-01

    Processes are disclosed for the separation of isotopes of an element comprising vaporizing uranyl compounds having the formula (UO2a2)n, where a is a monovalent anion and n in an integer from 2 to 4, the compounds having an isotopically shifted infrared absorption spectrum associated with uranyl ions containing said element which is to be separated, and then irradiating the uranyl compound with infrared radiation which is preferentially absorbed by a molecular vibration of uranyl ions of the compound containing a predetermined isotope of that element so that excited molecules of the compound are provided which are enriched in the molecules of the compound containing that predetermined isotope, thus enabling separation of these excited molecules. The processes disclosed include separation of the excited molecules by irradiating under conditions such that the excited molecules dissociate, and also separating the excited molecules by a discrete separation step. The latter includes irradiating the excited molecules by a second infrared laser in order to convert the excited molecules into a separable product, or also by chemically converting the excited molecules, preferably by reaction with a gaseous reactant

  2. Separation of Hydrogen Isotopes by Palladium Alloy Membranes Separator

    International Nuclear Information System (INIS)

    Jiangfeng, S.; Deli, L.; Yifu, X.; Congxian, L.; Zhiyong, H.

    2007-01-01

    Full text of publication follows: Separation of hydrogen isotope with palladium alloy membranes is one of the promising methods for hydrogen isotope separation. It has several advantages, such as high separation efficiency, smaller tritium inventory, simple separation device, ect. Limited by the manufacture of membrane and cost of gas transportation pump, this method is still at the stage of conceptual study. The relationship between separation factors and temperatures, feed gas components, split ratios have not been researched in detail, and the calculated results of cascade separation have not been validated with experimental data. In this thesis, a palladium alloy membrane separator was designed to further study its separation performance between H 2 and D 2 . The separation factor of the single stage was affected by the temperature, the feed gas component, the split ratio and the gas flow rate, etc. The experimental results showed that the H 2 -D 2 separation factor decreased with the increasing of temperature. On the temperature from 573 K to 773 K, when the feed rate was 5 L/min, the separation factor of 66.2%H 2 - 33.8%D 2 decreased from 2.09 to 1.85 when the split ratio was 0.1 and from 1.74 to 1.52 when the split ratio was 0.2.The separation factor also decreased with the increasing of split ratio. At 573 K and the feed rate of 5 L/min, the separation factor of 15.0%H 2 and 85.0%D 2 decreased from 2.43 to 1.35 with the increasing of split ratio from 0.050 to 0.534,and for 66.2%H 2 -33.8%D 2 , the separation factor decreased from 2.87 to 1.30 with the increasing of split ratio from 0.050 to 0.688. When the separation factor was the biggest, the flow rate of feed gas was in a perfect value. To gain a best separation performance, perfect flow rate, lower temperature and reflux ratio should be chosen. (authors)

  3. Immobilized fluid membranes for gas separation

    Science.gov (United States)

    Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

    2014-03-18

    Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

  4. Ceria Based Composite Membranes for Oxygen Separation

    DEFF Research Database (Denmark)

    Gurauskis, Jonas; Ovtar, Simona; Kaiser, Andreas

    2014-01-01

    Mixed ionic-electronic conducting membranes for oxygen gas separation are attracting a lot of interest due to their promising potential for the pure oxygen and the syngas production. Apart from the need for a sufficiently high oxygen permeation fluxes, the prolonged stability of these membranes...... under the large oxygen potential gradients at elevated temperatures is decisive for the future applications. The gadolinium doped cerium oxide (CGO) based composite membranes are considered as promising candidates due to inherent stability of CGO phase. The CGO matrix is a main oxygen ion transporter......; meanwhile the primary role of a secondary phase in this membrane is to compensate the low electronic conductivity of matrix at intended functioning conditions. In this work thin film (15-20 μm) composite membranes based on CGO matrix and LSF electronic conducting phase were fabricated and evaluated...

  5. Recent Membrane Development for Pervaporation Processes

    KAUST Repository

    Ong, Yee Kang; Shi, Gui Min; Le, Ngoc Lieu; Tang, Yu Pan; Zuo, Jian; Nunes, Suzana Pereira; Chung, Neal Tai-Shung

    2016-01-01

    Pervaporation has been regarded as a promising separation technology in separating azeotropic mixtures, solutions with similar boiling points, thermally sensitive compounds, organic–organic mixtures as well as in removing dilute organics from aqueous solutions. As the pervaporation membrane is one of the crucial factors in determining the overall efficiency of the separation process, this article reviews the research and development (R&D) of polymeric pervaporation membranes from the perspective of membrane fabrication procedures and materials.

  6. Recent Membrane Development for Pervaporation Processes

    KAUST Repository

    Ong, Yee Kang

    2016-03-11

    Pervaporation has been regarded as a promising separation technology in separating azeotropic mixtures, solutions with similar boiling points, thermally sensitive compounds, organic–organic mixtures as well as in removing dilute organics from aqueous solutions. As the pervaporation membrane is one of the crucial factors in determining the overall efficiency of the separation process, this article reviews the research and development (R&D) of polymeric pervaporation membranes from the perspective of membrane fabrication procedures and materials.

  7. Hybrid and Mixed Matrix Membranes for Separations from Fermentations

    Directory of Open Access Journals (Sweden)

    Christopher John Davey

    2016-02-01

    Full Text Available Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s, Greater understanding of the compatibility between the polymer and inorganic phase(s, Improved methods for homogeneously dispersing the inorganic phase.

  8. Hybrid and Mixed Matrix Membranes for Separations from Fermentations.

    Science.gov (United States)

    Davey, Christopher John; Leak, David; Patterson, Darrell Alec

    2016-02-29

    Fermentations provide an alternative to fossil fuels for accessing a number of biofuel and chemical products from a variety of renewable and waste substrates. The recovery of these dilute fermentation products from the broth, however, can be incredibly energy intensive as a distillation process is generally involved and creates a barrier to commercialization. Membrane processes can provide a low energy aid/alternative for recovering these dilute fermentation products and reduce production costs. For these types of separations many current polymeric and inorganic membranes suffer from poor selectivity and high cost respectively. This paper reviews work in the production of novel mixed-matrix membranes (MMMs) for fermentative separations and those applicable to these separations. These membranes combine a trade-off of low-cost and processability of polymer membranes with the high selectivity of inorganic membranes. Work within the fields of nanofiltration, reverse osmosis and pervaporation has been discussed. The review shows that MMMs are currently providing some of the most high-performing membranes for these separations, with three areas for improvement identified: Further characterization and optimization of inorganic phase(s), Greater understanding of the compatibility between the polymer and inorganic phase(s), Improved methods for homogeneously dispersing the inorganic phase.

  9. Isotope separation process

    International Nuclear Information System (INIS)

    1976-01-01

    The invention relates to a process for separating a given material into two or more parts, in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in the said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase UF 6 by infrared photon absorption followed by selective reaction of said excited UF 6 with atomic chlorine, bromine, or iodine to form a product which may be separated by means known in the art

  10. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1976-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. In one embodiment, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by selective dissociation of said excited molecules by the absorption of a single photon of visible or ultraviolet light. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 11 Claims, 2 Drawing Figures

  11. Polymeric membranes containing silver salts for propylene/propane separation

    Directory of Open Access Journals (Sweden)

    L. D. Pollo

    2012-06-01

    Full Text Available The separation of olefin/paraffin mixtures is one of the most important processes of the chemical industry. This separation is typically carried out by distillation, which is an energy and capital intensive process. One promising alternative is the use of facilitated transport membranes, which contain specific carrier agents in the polymer matrix that interact reversibly with the double bond in the olefin molecule, promoting the simultaneous increase of its permeability and selectivity. In this study, polyurethane (PU membranes were prepared using two different silver salts (triflate and hexafluorantimonate. The membranes were structurally characterized and their performance for the separation of propylene/propane mixtures was evaluated. The results of the characterization analyses indicated that the triflate salt was the most efficient carrier agent. The membranes containing this salt showed the best performance, reaching an ideal selectivity of 10 and propylene permeability of 188 Barrer.

  12. Development of compact tritium confinement system using gas separation membrane

    International Nuclear Information System (INIS)

    Hayashi, Takumi; Okuno, Kenji

    1994-01-01

    In order to develop more compact and cost-effective tritium confinement system for fusion reactor, a new system using gas separation membranes has been studied at the Tritium Process Laboratory in the Japan Atomic Energy Research Institute. The preliminary result showed that the gas separation membrane system could reduce processing volume of tritium contaminated gas to more than one order of magnitude compared with the conventional system, and that most of tritiated water vapor (humidity) could be directly recovered by water condenser before passing through dryer such as molecular sieves. More detail investigations of gas separation characteristics of membrane were started to design ITER Atmospheric Detritiation System (ADS). Furthermore, a scaled polyimide membrane module (hollow-filament type) loop was just installed to investigate the actual tritium confinement performance under various ITER-ADS conditions. (author)

  13. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1977-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 15 claims, 1 figure

  14. Isotope separation process

    International Nuclear Information System (INIS)

    Thomas, W.R.L.

    1979-01-01

    The instant invention relates to an improved process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same element in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than non-excited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  15. Functionalized Mesoporous Silica Membranes for CO2 Separation Applications

    Directory of Open Access Journals (Sweden)

    Hyung-Ju Kim

    2015-01-01

    Full Text Available Mesoporous silica molecular sieves are emerging candidates for a number of potential applications involving adsorption and molecular transport due to their large surface areas, high pore volumes, and tunable pore sizes. Recently, several research groups have investigated the potential of functionalized mesoporous silica molecular sieves as advanced materials in separation devices, such as membranes. In particular, mesoporous silica with a two- or three-dimensional pore structure is one of the most promising types of molecular sieve materials for gas separation membranes. However, several important challenges must first be addressed regarding the successful fabrication of mesoporous silica membranes. First, a novel, high throughput process for the fabrication of continuous and defect-free mesoporous silica membranes is required. Second, functionalization of mesopores on membranes is desirable in order to impart selective properties. Finally, the separation characteristics and performance of functionalized mesoporous silica membranes must be further investigated. Herein, the synthesis, characterization, and applications of mesoporous silica membranes and functionalized mesoporous silica membranes are reviewed with a focus on CO2 separation.

  16. Fabrication of PVDF-based blend membrane with a thin hydrophilic deposition layer and a network structure supporting layer via the thermally induced phase separation followed by non-solvent induced phase separation process

    Science.gov (United States)

    Wu, Zhiguo; Cui, Zhenyu; Li, Tianyu; Qin, Shuhao; He, Benqiao; Han, Na; Li, Jianxin

    2017-10-01

    A simple strategy of thermally induced phase separation followed by non-solvent induced phase separation (TIPS-NIPS) is reported to fabricate poly (vinylidene fluoride) (PVDF)-based blend membrane. The dissolved poly (styrene-co-maleic anhydride) (SMA) in diluent prevents the crystallization of PVDF during the cooling process and deposites on the established PVDF matrix in the later extraction. Compared with traditional coating technique, this one-step TIPS-NIPS method can not only fabricate a supporting layer with an interconnected network structure even via solid-liquid phase separation of TIPS, but also form a uniform SMA skin layer approximately as thin as 200 nm via surface deposition of NIPS. Besides the better hydrophilicity, what's interesting is that the BSA rejection ratio increases from 48% to 94% with the increase of SMA, which indicates that the separation performance has improved. This strategy can be conveniently extended to the creation of firmly thin layer, surface functionalization and structure controllability of the membrane.

  17. GAS SEPARATION MEMBRANES COMPRISING PERMEABILITY ENHANCING ADDITIVES

    NARCIS (Netherlands)

    Wessling, Matthias; Sterescu, D.M.; Stamatialis, Dimitrios

    2007-01-01

    The present invention relates to polymer compositions comprising a (co)polymer comprising (a) an arylene oxide moiety and (b) a dendritic (co)polymer, a hyperbranched (co)polymer or a mixture thereof, and the use of these polymer compositions as membrane materials for the separation of gases. The

  18. Process for isotope separation

    International Nuclear Information System (INIS)

    Emile, B.F.M.

    1983-11-01

    A process is claimed for isotopic separation applied to isotopes of elements that can be placed in at least a physicochemical form in which the isotopic atoms or the molecules containing these atoms can be easily displaced and for which there are selective radiations preferentially absorbed by the isotopes of a certain type or by the molecules containing them, said absorption substantially increasing the probability of ionization of said atoms or molecules relative to the atoms or molecules that did not absorb the radiation. The process consists of placing the isotopic mixture in such a form, subjecting it in a separation zone to selective radiations and to an electrical field that produces migration of positive ions toward the negative electrodes and negative ions toward the positive electrodes, and withdrawing from certain such zones the fractions thus enriched in certain isotopes

  19. Membranes for Environmentally Friendly Energy Processes

    Science.gov (United States)

    He, Xuezhong; Hägg, May-Britt

    2012-01-01

    Membrane separation systems require no or very little chemicals compared to standard unit operations. They are also easy to scale up, energy efficient, and already widely used in various gas and liquid separation processes. Different types of membranes such as common polymers, microporous organic polymers, fixed-site-carrier membranes, mixed matrix membranes, carbon membranes as well as inorganic membranes have been investigated for CO2 capture/removal and other energy processes in the last two decades. The aim of this work is to review the membrane systems applied in different energy processes, such as post-combustion, pre-combustion, oxyfuel combustion, natural gas sweetening, biogas upgrading, hydrogen production, volatile organic compounds (VOC) recovery and pressure retarded osmosis for power generation. Although different membranes could probably be used in a specific separation process, choosing a suitable membrane material will mainly depend on the membrane permeance and selectivity, process conditions (e.g., operating pressure, temperature) and the impurities in a gas stream (such as SO2, NOx, H2S, etc.). Moreover, process design and the challenges relevant to a membrane system are also being discussed to illustrate the membrane process feasibility for a specific application based on process simulation and economic cost estimation. PMID:24958426

  20. Membranes for Environmentally Friendly Energy Processes

    Directory of Open Access Journals (Sweden)

    Xuezhong He

    2012-10-01

    Full Text Available Membrane separation systems require no or very little chemicals compared to standard unit operations. They are also easy to scale up, energy efficient, and already widely used in various gas and liquid separation processes. Different types of membranes such as common polymers, microporous organic polymers, fixed-site-carrier membranes, mixed matrix membranes, carbon membranes as well as inorganic membranes have been investigated for CO2 capture/removal and other energy processes in the last two decades. The aim of this work is to review the membrane systems applied in different energy processes, such as post-combustion, pre-combustion, oxyfuel combustion, natural gas sweetening, biogas upgrading, hydrogen production, volatile organic compounds (VOC recovery and pressure retarded osmosis for power generation. Although different membranes could probably be used in a specific separation process, choosing a suitable membrane material will mainly depend on the membrane permeance and selectivity, process conditions (e.g., operating pressure, temperature and the impurities in a gas stream (such as SO2, NOx, H2S, etc.. Moreover, process design and the challenges relevant to a membrane system are also being discussed to illustrate the membrane process feasibility for a specific application based on process simulation and economic cost estimation.

  1. Metallic Membranes for High Temperature Hydrogen Separation

    DEFF Research Database (Denmark)

    Ma, Y.H.; Catalano, Jacopo; Guazzone, Federico

    2013-01-01

    membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm3/m/h/bar0.5 and greater......Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water-gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd...... than 1000, respectively. This chapter describes in detail composite Pd-based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400...

  2. Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

    KAUST Repository

    Alshehri, Ali; Lai, Zhiping

    2014-01-01

    As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions

  3. Development and modification of glass membranes for aggressive gas separations

    Energy Technology Data Exchange (ETDEWEB)

    Lindbraaten, Arne

    2004-07-01

    Chlorine as a chemical is widespread in industry and found in a great variety of processes ranging from water purification to plastic production. In this thesis, a magnesium production factory was chosen as an example because it involved both chlorine - air separation and hydrogen -hydrogen chloride separation. Previously, various types of membrane materials have been tested out for their applicability in the chosen process. The materials previously tested either lacked sufficient membrane performance or sufficient membrane stability. As an attempt to improve both the membrane performance and stability, glass membranes are used in this thesis. Glass membranes are prepared from a borosilicate glass, via a phase separation followed by an acid leaching route. By choosing the appropriate phase separation temperature and acid to glass ratio, the membrane can be produced with an average pore diameter of 2 nm (or 4 nm). However, the 2 nm average pore size is still too large to separate gases with separation selectivities beyond the selectivities predicted from Knudsen diffusion theory. If the pores are narrowed, the selectivity may be raised while the flux hopefully is maintained. The narrowing of the pores was done by a silane coupling to the surface OH-groups on the glass. The silane coupling agent is of the dimethyl-acyl-chlorosilane type, where the length of the acyl chain varies from 1 carbon up to 18 carbons. Glass fibres are also tested in this work, which are produced without phase separation and their average pore size is smaller than the surface-modified glasses. To be able to compare the performance of the various membranes, performance measurements are performed and these measurements are evaluated by the separation power (product of the selectivity and the permeability of the fastest permeating compound). Because of the harsh chlorine or hydrogen chloride environment, to which the membranes are exposed in this work, the membrane stability is at least as

  4. On the use of ultrafiltration membranes in oily water separators

    Energy Technology Data Exchange (ETDEWEB)

    Tremblay, A.Y.; Nottegar, M. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering; Veinot, D.E. [Defence Research Establishment Atlantic, Halifax, NS (Canada)

    2000-07-01

    Laboratory studies were conducted on the use of ultrafiltration membranes for oil water purification from ships bilges. Bilge water is a complex and highly variable mixture of several components such as seawater, lubricating oil, greases, marine diesel fuel, hydraulic oil, detergents, metal oxides, corrosion inhibitors, asbestos and other wastes. This laboratory study examined the performance of ultrafiltration membranes when separating oily waste water of similar composition to that of bilge water. Ultrafiltration membranes are nanoporous materials produced from ceramic, polymeric or metallic substrates. The ability of the membrane to retain macromolecules, colloids, sub-micron particles and oil emulsions depends on the size of the nanopores. The best results in this study occurred when upper and lower bounds on the membrane pore size were found to exist. It was determined that ultrafiltration is a viable separation process for the treatment of bilge water for compliance with overboard discharge regulations. 7 refs., 1 tab., 3 figs.

  5. New Developments in Membrane-Based Chemical Separations

    National Research Council Canada - National Science Library

    Jirage, Kshama

    1998-01-01

    Membrane based chemical separations is an emerging field of research. This is because membrane-based separations are potentially less energy intensive and more cost effective than competing separation methods...

  6. Metal oxide membranes for gas separation

    Science.gov (United States)

    Anderson, Marc A.; Webster, Elizabeth T.; Xu, Qunyin

    1994-01-01

    A method for permformation of a microporous ceramic membrane onto a porous support includes placing a colloidal suspension of metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane having mean pore sizes less than 30 Angstroms and useful for ultrafiltration, reverse osmosis, or gas separation.

  7. Preparation of hollow fiber membranes for gas separation

    NARCIS (Netherlands)

    Li, Shu-Guang

    1994-01-01

    Today, immersion precipitation is the most often used process for the preparation of gas separation membranes from polymeric materials. In this process a polymer solution in the form of a thin liquid film or hollow fiber is immersed in a nonsolvent bath where the polymer precipitates and forms a

  8. Adsorptive molecularly imprinted composite membranes for chiral separation of phenylalanine

    Directory of Open Access Journals (Sweden)

    Shah Nasrullah

    2016-09-01

    Full Text Available Two types of composite imprinted membranes, i.e., composite membrane comprised of D-Phe imprinted beads and D-Phe imprinted membrane or DCM and composite membrane comprised of L-Phe imprinted beads and L-Phe imprinted membranes or LCM, were synthesized by phase inversion technique after a uniform dispersion of beads within the polymeric solutions using simple physico-mechanical process. The assemblies of the prepared DCM, LCM and control membranes were employed in ultrafiltration for chiral separation of D, L-Phenylalanine racemate solution. DCM and LCM showed an improved adsorption capacity (0.334 mg g-1 and 0.365 mg g-1 respectively, and adsorption selectivity (2.72 and 2.98 respectively. However, the percent rejection of the template and counter enantiomer were lower than that of control membranes. Compared to control membrane, the DCM and LCM showed inverse permselectivity. These composite membranes having better adsorption and separation ability for Phenylalanine racemate solution will be suitable in the future for various other applications.

  9. The effects of processing conditions on the surface morphology and hydrophobicity of polyvinylidene fluoride membranes prepared via vapor-induced phase separation

    Science.gov (United States)

    Peng, Yuelian; Fan, Hongwei; Ge, Ju; Wang, Shaobin; Chen, Ping; Jiang, Qi

    2012-12-01

    The present investigation reveals how the surface morphology and the hydrophobicity of polyvinylidene fluoride (PVDF) membranes, which were prepared via a vapor-induced phase separation method, were affected by the initial PVDF content in the casting solution and the air temperature. The surface morphology was characterized with scanning electron microscopy. A ternary phase diagram of PVDF/N, N-dimethylacetamide/water was constructed to explain the formation mechanism of the different morphologies. The results show that different membrane morphologies and hydrophobicities can be obtained by changing the processing conditions. Low air temperature and high PVDF contents facilitate the crystallization process, resulting in the formation of a porous skin and particle morphology, which increases the hydrophobicity of the surface. High air temperature and low PVDF contents are favorable for the formation of a net-like surface morphology via spinodal decomposition and lead to a superhydrophobic surface. Theoretical calculations were performed to testify that the net-like surface was more favorable for superhydrophobicity than the particle-based surface.

  10. Separation of tritiated water using graphene oxide membrane

    Energy Technology Data Exchange (ETDEWEB)

    Sevigny, Gary J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Motkuri, Radha K. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Gotthold, David W. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Frost, Anthony P. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Bratton, Wesley [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

    2015-06-28

    In future nuclear fuel reprocessing plants and possibly for nuclear power plants, the cleanup of tritiated water will be needed for hundreds of thousands of gallons of water with low activities of tritium. This cleanup concept utilizes graphene oxide laminar membranes (GOx) for the separation of low-concentration (10-3-10 µCi/g) tritiated water to create water that can be released to the environment and a much smaller waste stream with higher tritium concentrations. Graphene oxide membranes consist of hierarchically stacked, overlapping molecular layers and represent a new class of materials. A permeation rate test was performed with a 2-µm-thick cast Asbury membrane using mixed gas permeability testing with zero air (highly purified atmosphere) and with air humidified with either H2O or D2O to a nominal 50% relative humidity. The membrane permeability for both H2O and D2O was high with N2 and O2 at the system measurement limit. The membrane water permeation rate was compared to a Nafion® membrane and the GOx permeation was approximately twice as high at room temperature. The H2O vapor permeation rate was 5.9 × 102 cc/m2/min (1.2 × 10-6 g/min-cm2), which is typical for graphene oxide membranes. To demonstrate the feasibility of such isotopic water separation through GOX laminar membranes, an experimental setup was constructed to use pressure-driven separation by heating the isotopic water mixture at one side of the membrane to create steam while cooling the other side. Several membranes were tested and were prepared using different starting materials and by different pretreatment methods. The average separation result was 0.8 for deuterium and 0.6 for tritium. Higher or lower temperatures may also improve separation efficiency but neither has been tested yet. A rough estimate of cost compared to current technology was also included as an indication of potential viability of the process. The relative process costs were based on the rough size of facility to

  11. Comparison of gas membrane separation cascades using conventional separation cell and two-unit separation cells

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    The adoption of two-unit separation cells in radioactive rare gas membrane separation equipment enhances the separation factor, but increases the required membrane area and compressive power. An analytical economic evaluation was undertaken to compare the conventional separation cell with the two-unit separation cells, adopting as parameters the number of cascade stages, the membrane area and the operating power requirements. This paper describes the models used for evaluating the separation performance and the economics of cascade embodying these different concepts of separation cell taken up for study, and the results obtained for the individual concepts are mutually compared. It proved that, in respect of the number required of cascade stages, of operating power requirements and of the annual expenditure, better performance could always be expected of the two-unit separation cells as compared with the conventional separation cell, at least in the range of parameters adopted in this study. As regards the minimum membrane area, the conventional separation cell and the series-type separation cell yielded almost the same values, with the parallel-type separation cell falling somewhat behind. (auth.)

  12. Retrofit with membrane the Paraffin/Olefin separation

    Energy Technology Data Exchange (ETDEWEB)

    Motelica, A.; Bruinsma, O.S.L.; Kreiter, R.; Den Exter, M.J.; Vente, J.F. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2012-10-15

    Olefins, such as ethylene, propylene, and butadiene, are among the most produced intermediates in petrochemical industry. They are produced from a wide range of hydrocarbon feedstocks (ethane, propane, butane, naphtha, gas oil) via a cracking process. The last step in this process is the separation of olefins from other hydrocarbons, which is traditionally performed with distillation. As the physicochemical properties, such as volatility and boiling point, of the compounds are very similar, the purification becomes capital and energy intensive. For example, the top of an ethylene/ethane distillation column needs to be chilled to -30C and this requires large amount of electric energy consumption. The separation of butadiene from the C4-fraction is performed with the aid of an additional solvent. This solvent has to be regenerated at the cost of additional high temperature steam. To overcome these separation disadvantages of olefin/paraffin separation, different separation methods have been investigated and proposed in recent years. Suggested options are based on better heat integration of the overall process, or on novel separation systems such as Heat Integrated Distillation Columns, membrane separation, adsorption-desorption systems or on hybrid separation methods, for example, distillation combined with membrane separation.

  13. Application of membrane processes to alcohol-water separation: Improving the energy efficiency of biofuel production(Singapore)

    Science.gov (United States)

    The prospect of dwindling oil supplies, concern over the carbon balance of the planet, and the availability of waste and non-waste biomass materials has generated renewed interest in the use of fermentation processes to produce commodity chemicals and fuels. The economics of fer...

  14. Liquid membranes: an emerging area in separation science

    International Nuclear Information System (INIS)

    Mohapatra, P.K.; Manchanda, V.K.

    2010-01-01

    Full text: With the ever increasing energy demands, nuclear energy is poised to make a significant contribution as one of the major clean energy resources. The public acceptability of the nuclear energy programme, however, depends largely on the management of radioactive waste by mitigating its long term adverse impact on the environment. Separation of long-lived radionuclides such as actinides and fission products from high level radioactive waste is a challenging task for the chemists involved at the back end of the nuclear fuel cycle. Amongst the various separation techniques, liquid membrane based separation methods are becoming increasingly popular due to factors such as ligand economy, high efficiency and low power consumption. Techniques such as emulsion liquid membrane (ELM) and hollow fibre supported liquid membrane (HFSLM) methods are reported to be more efficient than the solvent extraction based separation methods which have limitations of emulsion/third phase or crud formation. HFSLM technique offers the advantages of active transport, possible usage of exotic carriers and easy scale-up. For the past few years, Radiochemistry Division has been actively involved in the development of HFSLM separation processes for actinide partitioning, lanthanide/actinide separation, Sr/Y separation as well as recovery of radio-cesium from nuclear waste solutions. Similarly, ELM has major advantages of fast processing and large volume reduction factors. This lecture will give an overview of the HFSLM and ELM work carried out at Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai

  15. Electrically Driven Ion Separations in Permeable Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bruening, Merlin [Michigan State Univ., East Lansing, MI (United States)

    2017-04-21

    Membranes are attractive for a wide range of separations due to their low energy costs and continuous operation. To achieve practical fluxes, most membranes consist of a thin, selective skin on a highly permeable substrate that provides mechanical strength. Thus, this project focused on creating new methods for forming highly selective ultrathin skins as well as modeling transport through these coatings to better understand their unprecedented selectivities. The research explored both gas and ion separations, and the latter included transport due to concentration, pressure and electrical potential gradients. This report describes a series of highlights of the research and then provides a complete list of publications supported by the grant. These publications have been cited more than 4000 times. Perhaps the most stunning finding is the recent discovery of monovalent/divalent cation and anion selectivities around 1000 when modifying cation- and anion-exchange membranes with polyelectrolyte multilayers (PEMs). This discovery builds on many years of exciting research. (Citation numbers refer to the journal articles in the bibliography.)

  16. Fullerene and dendrimer based nano-composite gas separation membranes

    NARCIS (Netherlands)

    Sterescu, D.M.

    2007-01-01

    This thesis describes the development of new materials for membrane based gas separation processes. Long-term stable, loosely packed (high free volume) amorphous polymer films were prepared by introduction of super-molecular pendant groups, which possess hardsphere properties to avoid dense

  17. Membrane processes in nuclear technologies

    International Nuclear Information System (INIS)

    Zakrzewska-Trznadel, G.

    2006-01-01

    The treatment of radioactive wastes is necessary taking into account the potential hazard of radioactive substances to human health and surrounding environment. The choice of appropriate technology depends on capital and operational costs, wastes amount and their characteristics, appointed targets of the process, e.g. the values of decontamination factors and volume reduction coefficients. The conventional technologies applied for radioactive waste processing, such as precipitation coupled with sedimentation, ion exchange and evaporation have many drawbacks. These include high energy consumption and formation of secondary wastes, e.g. the sludge from sediment tanks, spent ion exchange adsorbents and regeneration solutions. There are also many limitations of such processes, i.e. foaming and drop entrainment in evaporators, loses of solvents and production of secondary wastes in solvent extraction or bed clogging in ion exchange columns. Membrane processes as the newest achievement of the process engineering can successfully supersede many non-effective, out-of-date methods. But in some instances they can also complement these methods whilst improving the parameters of effluents and purification economy. This monograph presents own research data on the application of recent achievements in the area of membrane processes for solving selected problems in nuclear technology. Relatively big space was devoted to the use of membrane processing of low and intermediate radioactive liquid wastes because of numerous applications of these processes in nuclear centres over the world and also because of the interests of the author that was reflected by her recent research projects and activity. This work presents a review on the membrane methods recently introduced into the nuclear technology against the background of the other, commonly applied separation techniques, with indications of the possibilities and prospects for their further developments. Particular attention was paid

  18. Zirconium isotope separation process

    International Nuclear Information System (INIS)

    Peterson, S.H.; Lahoda, E.J.

    1988-01-01

    A process is described for reducing the amount of zirconium 91 isotope in zirconium comprising: forming a first solution of (a) a first solvent, (b) a scavenger, and (c) a zirconium compound which is soluble in the first solvent and reacts with the scavenger when exposed to light of a wavelength of 220 to 600 nm; irradiating the first solution with light at the wavelength for a time sufficient to photoreact a disproportionate amount of the zirconium compound containing the zirconium 91 isotope with the scavenger to form a reaction product in the first solution; contacting the first solution, while effecting the irradiation, with a second solvent which is immiscible with the first solvent, which the second solvent is a preferential solvent for the reaction product relative to the first solvent, such that at least a portion of the reaction product is transferred to the second solvent to form a second solution; and separating the second solution from the first solution after the contacting

  19. Sustainable process design & analysis of hybrid separations

    DEFF Research Database (Denmark)

    Kumar Tula, Anjan; Befort, Bridgette; Garg, Nipun

    2016-01-01

    Distillation is an energy intensive operation in chemical process industries. There are around 40,000 distillation columns in operation in the US, requiring approximately 40% of the total energy consumption in US chemical process industries. However, analysis of separations by distillation has...... shown that more than 50% of energy is spent in purifying the last 5-10% of the distillate product. Membrane modules on the other hand can achieve high purity separations at lower energy costs, but if the flux is high, it requires large membrane area. A hybrid scheme where distillation and membrane...... modules are combined such that each operates at its highest efficiency, has the potential for significant energy reduction without significant increase of capital costs. This paper presents a method for sustainable design of hybrid distillation-membrane schemes with guaranteed reduction of energy...

  20. RECENT PROGRESS OF OXYGEN/NITROGEN SEPARATION USING MEMBRANE TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    K. C. CHONG

    2016-07-01

    Full Text Available The oxygen-enriched air is highly demanded for various industrial applications such as medical, chemical and enhanced combustion processes. The conventional oxygen/nitrogen production is either cryogenic distillation or pressure swing adsorption (PSA. Both of these techniques possess the production capability of 20 to 300 tonnes of oxygen per day and oxygen purity of more than 95%. However, these techniques are energy intensive. Alternatively, membrane technology is an emerging technology in gas separation as it requires low energy consumption and relatively moderate production volume, if compared to the conventional gas production techniques. These advantages have spurred much interest from industries and academics to speed up the commercial viability of the O2/N2 separation via membrane technology. In this review, the conventional and membrane technologies in O2/N2 separation, as well as recent development of membrane fabrication techniques and materials are reviewed. The latest membrane performance in O2/N2 separation is also tabulated and discussed.

  1. Process for isotope separation

    International Nuclear Information System (INIS)

    Schuster, E.; Kersting, A.; Gebauhr, W.

    1980-01-01

    Isotope separation in UF 6 gas takes place on the principle of selective excitation by laser irradiation and separation by chemical conversion with a partner in a reaction. Atomic H, N or O or the CH 3 or CHO radicals are suitable partners in the reaction. The recombination takes place by catalytic acceleration on leaving the reaction area. (DG) [de

  2. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1979-01-01

    A method is described for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption after which more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  3. The effect of pretreatment on the performance of membrane separation processes in the circulation water systems of paper production; Esikaesittelyiden vaikutus kalvoerotusprosessien toimintaan paperinvalmistuksen vesikierroissa - EKT 01

    Energy Technology Data Exchange (ETDEWEB)

    Nuortila-Jokinen, J; Nystroem, M [Lappeenranta Univ. of Technology (Finland). Dept. of Chemical Technology

    1999-12-31

    The aim of this project is to establish an optimized membrane filtration process for internal water treatment in the pulp and paper industry. In membrane filtration fouling reduces the capacity of a plant, and frequent or ineffective membrane washing reduces the membrane lifetime. These factors affect directly the feasibility of the process. Moreover, the retentates have to be economically destroyed. In this project effective pretreatment systems for membrane filtration processes will be developed. The pretreatments studied will be chemical, biological (thermophilic aerobic or anaerobic processes), oxidative (ozonation or other AOP methods) or enzymatic methods or their combinations. The target is to increase capacity and/or reduce fouling in the membrane process. In addition, the effect of the different pretreatment methods on the washability of the membranes will be studied and an optimized washing routine will be developed. The composition of the forming retentates are also affected by the pretreatment used and additionally the same methods can be used for developing a sensible and economically feasible retentate posttreatment method, which will also be developed in the project. (orig.)

  4. The effect of pretreatment on the performance of membrane separation processes in the circulation water systems of paper production; Esikaesittelyiden vaikutus kalvoerotusprosessien toimintaan paperinvalmistuksen vesikierroissa - EKT 01

    Energy Technology Data Exchange (ETDEWEB)

    Nuortila-Jokinen, J.; Nystroem, M. [Lappeenranta Univ. of Technology (Finland). Dept. of Chemical Technology

    1998-12-31

    The aim of this project is to establish an optimized membrane filtration process for internal water treatment in the pulp and paper industry. In membrane filtration fouling reduces the capacity of a plant, and frequent or ineffective membrane washing reduces the membrane lifetime. These factors affect directly the feasibility of the process. Moreover, the retentates have to be economically destroyed. In this project effective pretreatment systems for membrane filtration processes will be developed. The pretreatments studied will be chemical, biological (thermophilic aerobic or anaerobic processes), oxidative (ozonation or other AOP methods) or enzymatic methods or their combinations. The target is to increase capacity and/or reduce fouling in the membrane process. In addition, the effect of the different pretreatment methods on the washability of the membranes will be studied and an optimized washing routine will be developed. The composition of the forming retentates are also affected by the pretreatment used and additionally the same methods can be used for developing a sensible and economically feasible retentate posttreatment method, which will also be developed in the project. (orig.)

  5. Effect of stabilization temperature during pyrolysis process of P84 co-polyimide-based tubular carbon membrane for H2/N2 and He/N2 separations

    Science.gov (United States)

    Sazali, N.; Salleh, W. N. W.; Ismail, A. F.; Ismail, N. H.; Aziz, F.; Yusof, N.; Hasbullah, H.

    2018-04-01

    In this study, the effect of stabilization temperature on the performance of tubular carbon membrane was being investigated. P84 co-polyimide-based tubular carbon membrane will be fabricated through the dip-coating technique. The tubular carbon membrane performance can be controlled by manipulating the pyrolysis conditions which was conducted at different stabilization temperatures of 250, 300, 350, 400, and 450°C under N2 environment (200 ml/min). The prepared membranes were characterized by using scanning electron microscopy (SEM), x-ray diffraction (XRD), and pure gas permeation system. The pure gas of H2, He, and N2 were used to determine the permeation properties of the carbon membrane. The P84 co-polyimide-based tubular carbon membrane stabilized at 300°C demonstrated an excellent permeation property with H2, He, and N2 gas permeance of 1134.51±2.87, 1287.22±2.86 and 2.98±1.28GPU, respectively. The highest H2/N2 and He/N2 selectivity of 380.71±2.34 and 431.95±2.61 was obtained when the stabilization temperature of 450°C was applied. It is concluded that the stabilization temperatures have protrusive effect on the carbon membrane properties specifically their pore structure, and eventually their gas separation properties.

  6. Bendable Zeolite Membranes: Synthesis and Improved Gas Separation Performance.

    Science.gov (United States)

    Wang, Bo; Ho, W S Winston; Figueroa, Jose D; Dutta, Prabir K

    2015-06-23

    Separation and sequestration of CO2 emitted from fossil energy fueled electric generating units and industrial facilities will help in reducing anthropogenic CO2, thereby mitigating its adverse climate change effects. Membrane-based gas separation has the potential to meet the technical challenges of CO2 separation if high selectivity and permeance with low costs for large-scale manufacture are realized. Inorganic zeolite membranes in principle can have selectivity and permeance considerably higher than polymers. This paper presents a strategy for zeolite growth within the pores of a polymer support, with crystallization time of an hour. With a thin coating of 200-300 nm polydimethylsiloxane (PDMS) on the zeolite-polymer composite, transport data for CO2/N2 separation indicate separation factors of 35-45, with CO2 permeance between 1600 and 2200 GPU (1 GPU = 3.35 × 10(-10) mol/(m(2) s Pa)) using dry synthetic mixtures of CO2 and N2 at 25 °C. The synthesis process results in membranes that are highly reproducible toward transport measurements and exhibit long-term stability (3 days). Most importantly, these membranes because of the zeolite growth within the polymer support, as contrasted to conventional zeolite growth on top of a support, are mechanically flexible.

  7. Isotope separation process

    International Nuclear Information System (INIS)

    Cabicar, J.; Stamberg, K.; Katzer, J.

    1983-01-01

    A process for separating isotopes by the method of controlled distribution is claimed. A first phase is either a solution of isotopic components and a ligand (from 10 - 6 M to a saturated solution), or a gaseous mixture of isotopic components, or a gaseous mixture of isotopic components and an inert gas. The isotopes are in the starting mixture in molar ratio from 1:10 5 to 1:10 - 5 . The second phase is a solid sorbent such as styrene-divinylbenzene ion exchangers, or bio-sorbents on the basis of mycelium of lower fungi and sorbents on the basis of cellulose, or an extraction agent such as tributyl phosphate and trioctyl amine, if need be, kept by a carrier such as teflon, silica gel and cellulose. The two-phase system exhibits non-linear equilibrium isotherm for sorption and/or desorption or for extraction and/or re-extraction. After bringing both phases into contact the rate of transport of isotopic components from one phase into another is not equal. Retardation of isotopic exchange takes place by complexation of isotopes with ligands such as cabonate, sulphate, citrate, chloride and ethylenediamine tetraacetate ions, or by using sorbents and extraction agents with chelating functional groups such as carboxyl and hyroxyl groups, groups on the basis of phosphorus, nitrogen and sulphur and/or by operating in darkness, or in the light having wave length between 2.5x10 2 and 10 9 nm. The contact time is between 10 - 2 and 10 6 s, temperature between 10 2 and 10 3 K, the number of stirrer revolutions between 10 - 2 and 10 4 revolutions per s, flow rate at column arrangement between 10 - 6 and 10 - 1 m/s and the size of particles of sorbent between 10 - 6 and 10 - 2 m

  8. Membranes, methods of making membranes, and methods of separating gases using membranes

    Science.gov (United States)

    Ho, W. S. Winston

    2012-10-02

    Membranes, methods of making membranes, and methods of separating gases using membranes are provided. The membranes can include at least one hydrophilic polymer, at least one cross-linking agent, at least one base, and at least one amino compound. The methods of separating gases using membranes can include contacting a gas stream containing at least one of CO.sub.2, H.sub.2S, and HCl with one side of a nonporous and at least one of CO.sub.2, H.sub.2S, and HCl selectively permeable membrane such that at least one of CO.sub.2, H.sub.2S, and HCl is selectively transported through the membrane.

  9. Functionalized inorganic membranes for gas separation

    Science.gov (United States)

    Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Molaison, Jennifer Lynn [Marietta, GA; Schick, Louis Andrew ,; Ramaswamy, Vidya [Niskayuna, NY

    2008-07-08

    A porous membrane for separation of carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity. The porous membrane comprises a porous support layer comprising alumina, silica, zirconia or stabilized zirconia; a porous separation layer comprising alumina, silica, zirconia or stabilized zirconia, and a functional layer comprising a ceramic oxide contactable with the fluid stream to preferentially transport carbon dioxide. In particular, the functional layer may be MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3 or a mixture thereof; wherein A is Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; and A.sup.3 is Sr or Ba.

  10. Membrane Modeling, Simulation and Optimization for Propylene/Propane Separation

    KAUST Repository

    Alshehri, Ali

    2015-06-01

    Energy efficiency is critical for sustainable industrial growth and the reduction of environmental impacts. Energy consumption by the industrial sector accounts for more than half of the total global energy usage and, therefore, greater attention is focused on enhancing this sector’s energy efficiency. It is predicted that by 2020, more than 20% of today’s energy consumption can be avoided in countries that have effectively implemented an action plan towards efficient energy utilization. Breakthroughs in material synthesis of high selective membranes have enabled the technology to be more energy efficient. Hence, high selective membranes are increasingly replacing conventional energy intensive separation processes, such as distillation and adsorption units. Moreover, the technology offers more special features (which are essential for special applications) and its small footprint makes membrane technology suitable for platform operations (e.g., nitrogen enrichment for oil and gas offshore sites). In addition, its low maintenance characteristics allow the technology to be applied to remote operations. For these reasons, amongst other, the membrane technology market is forecast to reach $16 billion by 2017. This thesis is concerned with the engineering aspects of membrane technology and covers modeling, simulation and optimization of membranes as a stand-alone process or as a unit operation within a hybrid system. Incorporating the membrane model into a process modeling software simplifies the simulation and optimization of the different membrane processes and hybrid configurations, since all other unit operations are pre-configured. Various parametric analyses demonstrated that only the membrane selectivity and transmembrane pressure ratio parameters define a membrane’s ability to accomplish a certain separation task. Moreover, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is only defined by the feed composition

  11. Air Separation Using Hollow Fiber Membranes

    Science.gov (United States)

    Huang, Stephen E.

    2004-01-01

    The NASA Glenn Research Center in partnership with the Ohio Aerospace Institute provides internship programs for high school and college students in the areas of science, engineering, professional administrative, and other technical areas. During the summer of 2004, I worked with Dr. Clarence T. Chang at NASA Glenn Research Center s combustion branch on air separation using hollow fiber membrane technology. . In light of the accident of Trans World Airline s flight 800, FAA has mandated that a suitable solution be created to prevent the ignition of fuel tanks in aircrafts. In order for any type of fuel to ignite, three important things are needed: fuel vapor, oxygen, and an energy source. Two different ways to make fuel tanks less likely to ignite are reformulating the fuel to obtain a lower vapor pressure for the fuel and or using an On Board Inert Gas Generating System (OBIGGS) to inert the Central Wing Tank. goal is to accomplish the mission, which means that the Air Separation Module (ASM) tends to be bulky and heavy. The primary goal for commercial aviation companies is to transport as much as they can with the least amount of cost and fuel per person, therefore the ASM must be compact and light as possible. The plan is to take bleed air from the aircraft s engines to pass air through a filter first to remove particulates and then pass the air through the ASM containing hollow fiber membranes. In the lab, there will be a heating element provided to simulate the temperature of the bleed air that will be entering the ASM and analysis of the separated air will be analyzed by a Gas Chromatograph/Mass Spectrometer (GC/MS). The GUMS will separate the different compounds in the exit streams of the ASM and provide information on the performance of hollow fiber membranes. Hopefully I can develop ways to improve efficiency of the ASM. different types of jet fuel were analyzed and data was well represented on SAE Paper 982485. Data consisted of the concentrations of over

  12. Multifunctional nanocomposite hollow fiber membranes by solvent transfer induced phase separation.

    Science.gov (United States)

    Haase, Martin F; Jeon, Harim; Hough, Noah; Kim, Jong Hak; Stebe, Kathleen J; Lee, Daeyeon

    2017-11-01

    The decoration of porous membranes with a dense layer of nanoparticles imparts useful functionality and can enhance membrane separation and anti-fouling properties. However, manufacturing of nanoparticle-coated membranes requires multiple steps and tedious processing. Here, we introduce a facile single-step method in which bicontinuous interfacially jammed emulsions are used to form nanoparticle-functionalized hollow fiber membranes. The resulting nanocomposite membranes prepared via solvent transfer-induced phase separation and photopolymerization have exceptionally high nanoparticle loadings (up to 50 wt% silica nanoparticles) and feature densely packed nanoparticles uniformly distributed over the entire membrane surfaces. These structurally well-defined, asymmetric membranes facilitate control over membrane flux and selectivity, enable the formation of stimuli responsive hydrogel nanocomposite membranes, and can be easily modified to introduce antifouling features. This approach forms a foundation for the formation of advanced nanocomposite membranes comprising diverse building blocks with potential applications in water treatment, industrial separations and as catalytic membrane reactors.

  13. CO2-Philic polymer membrane with extremely high separation performance

    KAUST Repository

    Yave, Wilfredo

    2010-01-12

    Polymeric membranes are attractive for CO2 separation and concentration from different gas streams because of their versatility and energy efficiency; they can compete with, and they may even replace, traditional absorption processes. Here we describe a simple and powerful method for developing nanostructured and CO2-philic polymer membranes for CO2 separation. A poly(ethylene oxide)-poly(butylene terephthalate) multiblock copolymer is used as membrane material. Smart additives such as polyethylene glycol dibutyl ether are incorporated as spacers or fillers for producing nanostructured materials. The addition of these specific additives produces CO2-philic membranes and increases the CO2 permeability (750 barrer) up to five-fold without the loss of selectivity. The membranes present outstanding performance for CO2 separation, and the measured CO2 flux is extremely high ( > 2 m3 m -2 h-1 bar-1) with selectivity over H2 and N2 of 10 and 40, respectively, making them attractive for CO 2 capture. © 2009 American Chemical Society.

  14. CO2-Philic polymer membrane with extremely high separation performance

    KAUST Repository

    Yave, Wilfredo; Car, Anja; Funari, S.; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

    2010-01-01

    Polymeric membranes are attractive for CO2 separation and concentration from different gas streams because of their versatility and energy efficiency; they can compete with, and they may even replace, traditional absorption processes. Here we describe a simple and powerful method for developing nanostructured and CO2-philic polymer membranes for CO2 separation. A poly(ethylene oxide)-poly(butylene terephthalate) multiblock copolymer is used as membrane material. Smart additives such as polyethylene glycol dibutyl ether are incorporated as spacers or fillers for producing nanostructured materials. The addition of these specific additives produces CO2-philic membranes and increases the CO2 permeability (750 barrer) up to five-fold without the loss of selectivity. The membranes present outstanding performance for CO2 separation, and the measured CO2 flux is extremely high ( > 2 m3 m -2 h-1 bar-1) with selectivity over H2 and N2 of 10 and 40, respectively, making them attractive for CO 2 capture. © 2009 American Chemical Society.

  15. Functionalized membranes for environmental remediation and selective separation

    Science.gov (United States)

    Xiao, Li

    Membrane process including microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) have provided numerous successful applications ranging from drinking water purification, wastewater treatment, to material recovery. The addition of functional moiety in the membranes pores allows such membranes to be used in challenging areas including tunable separations, toxic metal capture, and catalysis. In this work, polyvinylidene fluoride (PVDF) MF membrane was functionalized with temperature responsive (poly(N-isopropylacrylamide), PNIPAAm) and pH responsive (polyacrylic acid, PAA) polymers. It's revealed that the permeation of various molecules (water, salt and dextran) through the membrane can be thermally or pH controlled. The introduction of PAA as a polyelectrolyte offers an excellent platform for the immobilization of metal nanoparticles (NPs) applied for degradation of toxic chlorinated organics with significantly increased longevity and stability. The advantage of using temperature and pH responsive polymers/hydrogels also includes the high reactivity and effectiveness in dechlorination. Further advancement on the PVDF functionalization involved the alkaline treatment to create partially defluorinated membrane (Def-PVDF) with conjugated double bounds allowing for the covalent attachment of different polymers. The PAA-Def-PVDF membrane shows pH responsive behavior on both the hydraulic permeability and solute retention. The sponge-like PVDF (SPVDF) membranes by phase inversion were developed through casting PVDF solution on polyester backing. The SPVDF membrane was demonstrated to have 4 times more surface area than commercial PVDF MF membrane, allowing for enhanced nanoparticles loading for chloro-organics degradation. The advanced functionalization method and process were also validated to be able to be scaled-up through the evaluation of full-scale functionalized membrane provided by Ultura Inc. California, USA. Nanofiltration (NF

  16. Two-dimensional materials for novel liquid separation membranes

    Science.gov (United States)

    Ying, Yulong; Yang, Yefeng; Ying, Wen; Peng, Xinsheng

    2016-08-01

    Demand for a perfect molecular-level separation membrane with ultrafast permeation and a robust mechanical property for any kind of species to be blocked in water purification and desalination is urgent. In recent years, due to their intrinsic characteristics, such as a unique mono-atom thick structure, outstanding mechanical strength and excellent flexibility, as well as facile and large-scale production, graphene and its large family of two-dimensional (2D) materials are regarded as ideal membrane materials for ultrafast molecular separation. A perfect separation membrane should be as thin as possible to maximize its flux, mechanically robust and without failure even if under high loading pressure, and have a narrow nanochannel size distribution to guarantee its selectivity. The latest breakthrough in 2D material-based membranes will be reviewed both in theories and experiments, including their current state-of-the-art fabrication, structure design, simulation and applications. Special attention will be focused on the designs and strategies employed to control microstructures to enhance permeation and selectivity for liquid separation. In addition, critical views on the separation mechanism within two-dimensional material-based membranes will be provided based on a discussion of the effects of intrinsic defects during growth, predefined nanopores and nanochannels during subsequent fabrication processes, the interlayer spacing of stacking 2D material flakes and the surface charge or functional groups. Furthermore, we will summarize the significant progress of these 2D material-based membranes for liquid separation in nanofiltration/ultrafiltration and pervaporation. Lastly, we will recall issues requiring attention, and discuss existing questionable conclusions in some articles and emerging challenges. This review will serve as a valuable platform to provide a compact source of relevant and timely information about the development of 2D material-based membranes as

  17. Two-dimensional materials for novel liquid separation membranes.

    Science.gov (United States)

    Ying, Yulong; Yang, Yefeng; Ying, Wen; Peng, Xinsheng

    2016-08-19

    Demand for a perfect molecular-level separation membrane with ultrafast permeation and a robust mechanical property for any kind of species to be blocked in water purification and desalination is urgent. In recent years, due to their intrinsic characteristics, such as a unique mono-atom thick structure, outstanding mechanical strength and excellent flexibility, as well as facile and large-scale production, graphene and its large family of two-dimensional (2D) materials are regarded as ideal membrane materials for ultrafast molecular separation. A perfect separation membrane should be as thin as possible to maximize its flux, mechanically robust and without failure even if under high loading pressure, and have a narrow nanochannel size distribution to guarantee its selectivity. The latest breakthrough in 2D material-based membranes will be reviewed both in theories and experiments, including their current state-of-the-art fabrication, structure design, simulation and applications. Special attention will be focused on the designs and strategies employed to control microstructures to enhance permeation and selectivity for liquid separation. In addition, critical views on the separation mechanism within two-dimensional material-based membranes will be provided based on a discussion of the effects of intrinsic defects during growth, predefined nanopores and nanochannels during subsequent fabrication processes, the interlayer spacing of stacking 2D material flakes and the surface charge or functional groups. Furthermore, we will summarize the significant progress of these 2D material-based membranes for liquid separation in nanofiltration/ultrafiltration and pervaporation. Lastly, we will recall issues requiring attention, and discuss existing questionable conclusions in some articles and emerging challenges. This review will serve as a valuable platform to provide a compact source of relevant and timely information about the development of 2D material-based membranes as

  18. Optimal operation of batch membrane processes

    CERN Document Server

    Paulen, Radoslav

    2016-01-01

    This study concentrates on a general optimization of a particular class of membrane separation processes: those involving batch diafiltration. Existing practices are explained and operational improvements based on optimal control theory are suggested. The first part of the book introduces the theory of membrane processes, optimal control and dynamic optimization. Separation problems are defined and mathematical models of batch membrane processes derived. The control theory focuses on problems of dynamic optimization from a chemical-engineering point of view. Analytical and numerical methods that can be exploited to treat problems of optimal control for membrane processes are described. The second part of the text builds on this theoretical basis to establish solutions for membrane models of increasing complexity. Each chapter starts with a derivation of optimal operation and continues with case studies exemplifying various aspects of the control problems under consideration. The authors work their way from th...

  19. Development of thin film inorganic membranes for oxygen separation

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Hyo Jeong

    2012-08-22

    Membrane-based gas separation systems are noteworthy among technological options for carbon capture and storage (CCS), which is an important strategy to reduce CO{sub 2} emitted from point sources, e.g. mainly fossil power plants. In Oxyfuel-Combustion and Pre-Combustion of CCS power plant concepts oxygen separation from air is required. To meet this requirement oxygen transport membranes (OTM) consisting of gastight mixed ionic electronic conductors (MIEC) are proposed, which are associated with significantly lower efficiency losses compared with conventional air separation technologies. For cost effective application a maximum oxygen flux has to be achieved to reduce the membrane area. This can be met by reduction of membrane thickness. Therefore, the reduction of the membrane thickness to the micrometer range or even below is aimed in the present thesis. Ce{sub 0.8}Gd{sub 0.2}O{sub 2-{delta}} (CGO) with fluorite crystal structure and La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF) with perovskite crystal structure were developed as thin film membrane. CGO is expected to be more stable than other potential MIEC membranes in reducing atmospheres and to achieve sufficient oxygen permeation, e.g. in syngas production or petrol chemistry. LSCF is expected to be highly permeable with an acceptable chemical stability in Oxyfuel-combustion. Various porous ceramic substrates were prepared by vacuum-slip-casting and warm-pressing, and then characterized for porosity, gas-permeability and surface roughness. Subsequently, two approaches to fabrication of thin film membranes were investigated, which are wetchemical deposition (WCD) and physical vapor deposition (PVD). For WCD, nano-dispersions and colloidal sols were prepared for membrane top-layer and/or interlayer. When CGO nano-dispersion (NDCGO) was spin-coated as thin film membrane, the gastightness of sintered membranes was increased with decrease in spinning time and increase in concentration of

  20. Gas Separation through Bilayer Silica, the Thinnest Possible Silica Membrane.

    Science.gov (United States)

    Yao, Bowen; Mandrà, Salvatore; Curry, John O; Shaikhutdinov, Shamil; Freund, Hans-Joachim; Schrier, Joshua

    2017-12-13

    Membrane-based gas separation processes can address key challenges in energy and environment, but for many applications the permeance and selectivity of bulk membranes is insufficient for economical use. Theory and experiment indicate that permeance and selectivity can be increased by using two-dimensional materials with subnanometer pores as membranes. Motivated by experiments showing selective permeation of H 2 /CO mixtures through amorphous silica bilayers, here we perform a theoretical study of gas separation through silica bilayers. Using density functional theory calculations, we obtain geometries of crystalline free-standing silica bilayers (comprised of six-membered rings), as well as the seven-, eight-, and nine-membered rings that are observed in glassy silica bilayers, which arise due to Stone-Wales defects and vacancies. We then compute the potential energy barriers for gas passage through these various pore types for He, Ne, Ar, Kr, H 2 , N 2 , CO, and CO 2 gases, and use the data to assess their capability for selective gas separation. Our calculations indicate that crystalline bilayer silica, which is less than a nanometer thick, can be a high-selectivity and high-permeance membrane material for 3 He/ 4 He, He/natural gas, and H 2 /CO separations.

  1. Isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.; Rabinowitz, P.

    1979-01-01

    A method of separating the isotopes of an element is described, which comprises the steps of (i) subjecting molecules of a gaseous compound of the element simultaneously to two infrared radiations of different wavelengths, the first radiation having a wavelength which corresponds to an absorption band of the compound, which in turn corresponds to a mode of molecular motion in which there is participation by atoms of the element, and the second radiation having a power density greater than 10 6 watts per cm 2 , thereby exciting molecules of the compound in an isotopically selective manner, this step being conducted in such manner that the excited molecules either receive a level of energy sufficient to cause them to undergo conversion by unimolecular decomposition or receive a level of energy sufficient to cause them to undergo conversion by reaction with molecules of another gas present for that purpose; and (ii) separating and recovering converted molecules from unconverted molecules. (author)

  2. Laser isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.

    1976-01-01

    The claimed invention is a method of isotope separation based on the unimolecular decomposition of vibrationally excited negative ions which are produced in the reaction of thermal electrons and molecules which have been vibrationally excited in an isotope selective manner. This method is especially applicable to molecules represented by the formula MF 6 wherein M is selected from the group consisting of U, S, W, Se, Te, Mo, Re, and Tc. 9 claims, 1 drawing figure

  3. URANIUM SEPARATION PROCESS

    Science.gov (United States)

    Lyon, W.L.

    1962-04-17

    A method of separating uranium oxides from PuO/sub 2/, ThO/sub 2/, and other actinide oxides is described. The oxide mixture is suspended in a fused salt melt and a chlorinating agent such as chlorine gas or phosgene is sparged through the suspension. Uranium oxides are selectively chlorinated and dissolve in the melt, which may then be filtered to remove the unchlorinated oxides of the other actinides. (AEC)

  4. Membranes for separation of carbon dioxide

    Science.gov (United States)

    Ku, Anthony Yu-Chung [Rexford, NY; Ruud, James Anthony [Delmar, NY; Ramaswamy, Vidya [Niskayuna, NY; Willson, Patrick Daniel [Latham, NY; Gao, Yan [Niskayuna, NY

    2011-03-01

    Methods for separating carbon dioxide from a fluid stream at a temperature higher than about 200.degree. C. with selectivity higher than Knudsen diffusion selectivity include contacting a porous membrane with the fluid stream to preferentially transport carbon dioxide. The porous membrane includes a porous support and a continuous porous separation layer disposed on a surface of the porous support and extending between the fluid stream and the porous support layer. The porous support comprises alumina, silica, zirconia, stabilized zirconia, stainless steel, titanium, nickel-based alloys, aluminum-based alloys, zirconium-based alloys or a combination thereof. Median pore size of the porous separation layer is less than about 10 nm, and the porous separation layer comprises titania, MgO, CaO, SrO, BaO, La.sub.2O.sub.3, CeO.sub.2, HfO.sub.2, Y.sub.2O.sub.3, VO.sub.z, NbO.sub.z, TaO.sub.z, ATiO.sub.3, AZrO.sub.3, AAl.sub.2O.sub.4, A.sup.1FeO.sub.3, A.sup.1MnO.sub.3, A.sup.1CoO.sub.3, A.sup.1NiO.sub.3, A.sup.2HfO.sub.3, A.sup.3 CeO.sub.3, Li.sub.2ZrO.sub.3, Li.sub.2SiO.sub.3, Li.sub.2TiO.sub.3, Li.sub.2HfO.sub.3, A.sup.4N.sup.1.sub.yO.sub.z, Y.sub.xN.sup.1.sub.yO.sub.z, La.sub.xN.sup.1.sub.yO.sub.z, HfN.sup.2.sub.yO.sub.z, or a combination thereof; wherein A is La, Mg, Ca, Sr or Ba; A.sup.1 is La, Ca, Sr or Ba; A.sup.2 is Ca, Sr or Ba; A.sup.3 is Sr or Ba; A.sup.4 is Mg, Ca, Sr, Ba, Ti or Zr; N.sup.1 is V, Nb, Ta, Cr, Mo, W, Mn, Si or Ge; N.sup.2 is V, Mo, W or Si; x is 1 or 2; y ranges from 1 to 3; and z ranges from 2 to 7.

  5. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.; Kaldor, A.

    1977-01-01

    In a method for the separation of isotopes of uranium in UF 6 , the UF 6 is subjected to ir radiation at a predetermined wavelength or set of wavelengths for less than 10 -3 sec in such a manner that at least 0.1% of the 235 UF 6 molecules absorb an energy of more than 2000 cm -1 . The excited UF 6 is then reacted with a gaseous reagent, F 2 , Cl 2 , or Br 2 , to produce a product which is then recovered by means known in the art

  6. Isotope separation process

    International Nuclear Information System (INIS)

    Wexler, Sol; Young, C.E.

    1976-01-01

    Description is given of method for separating a specific isotope from a mixture of isotopes of an actinide element present as MF 6 , wherein M is the actinide element. It comprises: preparing a feed gas mixture of MF 6 in a propellant gas; passing the feed gas mixture under pressure through an expansion nozzle while heating the mixture to about 600 0 C; releasing the heated gas mixture from the nozzle into an exhaust chamber having a reduced pressure, whereby a gas jet of MF 6 molecules, MF 6 molecular clusters and propellant gas molecules is formed, the MF 6 molecules having a translational energy of about 3 eV; converting the MF 6 molecules to MF 6 ions by passing the jet through a cross jet of electron donor atoms so that an electron transfer takes place between the MF 6 - molecules and the electron donor atoms whereby the jet is now quasi-neutral, containing negative MF 6 - ions and positive donor ions; passing the quasi-neutral jet through a radiofrequency mass filter tuned to separate the MF 6 ions containing the specific isotope from the MF 6 - ions of the other isotopes and neutralizing and collecting the MF 6 molecules of the specific isotope [fr

  7. Application of membrane technologies for liquid radioactive waste processing

    International Nuclear Information System (INIS)

    2004-01-01

    Membrane separation processes have made impressive progress since the first synthesis of membranes almost 40 years ago. This progress was driven by strong technological needs and commercial expectations. As a result the range of successful applications of membranes and membrane processes is continuously broadening. In addition, increasing application of membrane processes and technologies lies in the increasing variations of the nature and characteristics of commercial membranes and membrane apparatus. The objective of the report is to review the information on application of membrane technologies in the processing of liquid radioactive waste. The report covers the various types of membranes, equipment design, range of applications, operational experience and the performance characteristics of different membrane processes. The report aims to provide Member States with basic information on the applicability and limitations of membrane separation technologies for processing liquid radioactive waste streams

  8. Smart membranes for monitoring membrane based desalination processes

    KAUST Repository

    Laleg-Kirati, Taous-Meriem; Karam, Ayman M.

    2017-01-01

    Various examples are related to smart membranes for monitoring membrane based process such as, e.g., membrane distillation processes. In one example, a membrane, includes a porous surface and a plurality of sensors (e.g., temperature, flow and

  9. Separation process using microchannel technology

    Science.gov (United States)

    Tonkovich, Anna Lee [Dublin, OH; Perry, Steven T [Galloway, OH; Arora, Ravi [Dublin, OH; Qiu, Dongming [Bothell, WA; Lamont, Michael Jay [Hilliard, OH; Burwell, Deanna [Cleveland Heights, OH; Dritz, Terence Andrew [Worthington, OH; McDaniel, Jeffrey S [Columbus, OH; Rogers, Jr; William, A [Marysville, OH; Silva, Laura J [Dublin, OH; Weidert, Daniel J [Lewis Center, OH; Simmons, Wayne W [Dublin, OH; Chadwell, G Bradley [Reynoldsburg, OH

    2009-03-24

    The disclosed invention relates to a process and apparatus for separating a first fluid from a fluid mixture comprising the first fluid. The process comprises: (A) flowing the fluid mixture into a microchannel separator in contact with a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the first fluid is sorbed by the sorption medium, removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing first fluid from the sorption medium and removing desorbed first fluid from the microchannel separator. The process and apparatus are suitable for separating nitrogen or methane from a fluid mixture comprising nitrogen and methane. The process and apparatus may be used for rejecting nitrogen in the upgrading of sub-quality methane.

  10. Metal-organic frameworks based membranes for liquid separation.

    Science.gov (United States)

    Li, Xin; Liu, Yuxin; Wang, Jing; Gascon, Jorge; Li, Jiansheng; Van der Bruggen, Bart

    2017-11-27

    Metal-organic frameworks (MOFs) represent a fascinating class of solid crystalline materials which can be self-assembled in a straightforward manner by the coordination of metal ions or clusters with organic ligands. Owing to their intrinsic porous characteristics, unique chemical versatility and abundant functionalities, MOFs have received substantial attention for diverse industrial applications, including membrane separation. Exciting research activities ranging from fabrication strategies to separation applications of MOF-based membranes have appeared. Inspired by the marvelous achievements of MOF-based membranes in gas separations, liquid separations are also being explored for the purpose of constructing continuous MOFs membranes or MOF-based mixed matrix membranes. Although these are in an emerging stage of vigorous development, most efforts are directed towards improving the liquid separation efficiency with well-designed MOF-based membranes. Therefore, as an increasing trend in membrane separation, the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes, along with the latest application progress in the area of liquid separations, such as pervaporation, water treatment, and organic solvent nanofiltration. Moreover, some attractive dual-function applications of MOF-based membranes in the removal of micropollutants, degradation, and antibacterial activity are also reviewed. Finally, we define the remaining challenges and future opportunities in this field. This Tutorial Review provides an overview and outlook for MOF-based membranes for liquid separations. Further development of MOF-based membranes for liquid separation must consider the demands of strict separation standards and environmental safety for industrial application.

  11. Metal–organic frameworks based membranes for liquid separation

    KAUST Repository

    Li, Xin

    2017-11-07

    Metal-organic frameworks (MOFs) represent a fascinating class of solid crystalline materials which can be self-assembled in a straightforward manner by the coordination of metal ions or clusters with organic ligands. Owing to their intrinsic porous characteristics, unique chemical versatility and abundant functionalities, MOFs have received substantial attention for diverse industrial applications, including membrane separation. Exciting research activities ranging from fabrication strategies to separation applications of MOF-based membranes have appeared. Inspired by the marvelous achievements of MOF-based membranes in gas separations, liquid separations are also being explored for the purpose of constructing continuous MOFs membranes or MOF-based mixed matrix membranes. Although these are in an emerging stage of vigorous development, most efforts are directed towards improving the liquid separation efficiency with well-designed MOF-based membranes. Therefore, as an increasing trend in membrane separation, the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes, along with the latest application progress in the area of liquid separations, such as pervaporation, water treatment, and organic solvent nanofiltration. Moreover, some attractive dual-function applications of MOF-based membranes in the removal of micropollutants, degradation, and antibacterial activity are also reviewed. Finally, we define the remaining challenges and future opportunities in this field. This Tutorial Review provides an overview and outlook for MOF-based membranes for liquid separations. Further development of MOF-based membranes for liquid separation must consider the demands of strict separation standards and environmental safety for industrial application.

  12. Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes

    Science.gov (United States)

    Baker, Richard W.; Pinnau, Ingo; He, Zhenjie; Da Costa, Andre R.; Daniels, Ramin; Amo, Karl D.; Wijmans, Johannes G.

    2003-06-03

    A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

  13. CO2/CH4 Separation Performance of Ionic-Liquid-Based Epoxy-Amine Ion Gel Membranes under Mixed Feed Conditions Relevant to Biogas Processing.

    Czech Academy of Sciences Publication Activity Database

    Friess, K.; Lanč, M.; Pilnáček, Kryštof; Fíla, V.; Vopička, O.; Sedláková, Zuzana; Cowan, M.G.; McDaniel, W.M.; Noble, R.D.; Gin, D.L.; Izák, Pavel

    2017-01-01

    Roč. 528, APRIL (2017), s. 64-71 ISSN 0376-7388 R&D Projects: GA ČR GA14-12695S; GA MŠk LH14006; GA TA ČR TE01020080 Institutional support: RVO:67985858 Keywords : epoxy-amine-based ion gel membranes * biogas processing * humid mixed-gas permeation Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 6.035, year: 2016

  14. Heavy Water - Industrial Separation Processes

    International Nuclear Information System (INIS)

    Peculea, M.

    1984-01-01

    This monograph devoted to the heavy water production mainly presents the Romanian experience in the field which started in early sixties from the laboratory scale production and reached now the level of large scale industrial production at ROMAG-Drobeta, Romania. The book is structured in eleven chapters entitled: Overview, The main physical properties, Sources, Uses, Separation factor and equilibrium constant, Mathematical modelling of the separation process, Thermodynamical considerations on the isotope separation, Selection criteria for heavy water separation processes, Industrial installations for heavy water production, Prospects, Acknowledgements. 200 Figs., 90 Tabs., 135 Refs

  15. Development of new microporous silica membranes for gas separation

    International Nuclear Information System (INIS)

    Camelia Barboiu; Alejandro Mourgues; Beatrice Sala; Serge de Perthuis; Camelia Barboiu; Alejandro Mourgues; Beatrice Sala; Anne Julbe; Jose Sanchez

    2006-01-01

    This paper presents the synthesis and the application of molecular sieving ceramic membranes to purify hydrogen or helium from various gas mixtures. The membranes prepared in this work consist of an ultra-microporous silica-based separative layer produced via a sol-gel process. Ultra microporous silica containing boron is synthesized by the acid catalyzed hydrolysis and condensation of tetra-ethyl-ortho-silicate in ethanol. The layer is deposited inside a tubular asymmetric alumina support with a meso-porous y alumina inner layer. The thickness of the silica layers after treatment is about 200 nm, estimated from their cross-section SEM micrographs. Ultra-microporous membranes (with pore sizes less than 0.7 nm) are thus required to get high selectivity. Such membranes enable to carry out gas separation up to 500 deg C under a transmembrane pressure lower than 8 bars. He and H 2 permeance values close to 10 -7 mol.m -2 s -1 Pa -1 are obtained, associated with ideal selectivities α(He/CO 2 ) and α(H 2 /CO 2 ) between 10 and 20 at 300 deg C. (authors)

  16. Actinide separations by supported liquid membranes

    International Nuclear Information System (INIS)

    Danesi, P.R.; Horwitz, E.P.; Rickert, P.; Chiarizia, R.

    1984-01-01

    The work has demonstrated that actinide removal from synthetic waste solutions using both flat-sheet and hollow-fiber SLM's is a feasible chemical process at the laboratory scale level. The process is characterized by the typical features of SLM's processes: very small quantities of extractant required; the potential for operations with high feed/strip volume ratios, resulting in a corresponding concentration factor of the actinides; and simplicity of operation. Major obstacles to the implementation of the SLM technology to the decontamination of liquid nuclear wastes are the probable low resistance of polypropylene supports to high radiation fields, which may prevent the application to high-level nuclear wastes; the unknown lifetime of the SLM; and the high Na content of the separated actinide solution

  17. CO2/CH4 Separation via Polymeric Blend Membrane

    Directory of Open Access Journals (Sweden)

    H. Sanaeepur

    2013-01-01

    Full Text Available CO2/CH4 gas separation is a very important applicatable process in upgrading the natural gas and landfil gas recovery. In this work, to investigate the membrane separation process performance, the gas permeation results andCO2/CH4 separation characteristics of different prepared membranes (via blending different molecular weights of polyethylene glycol (PEG as a modifier with acrylonitrile-butadiene-styrene (ABS as a backbone structure have been studied. Furthermore, SEM analysis was carried out for morphological investigations. The effect of PEG content on gas transport properties on the selected sample was also studied. The effect of pressure on CO2 permeation was examined and showed that at the pressure beyond 4 bar, permeability is not affected by pressure. The results showed that more or less in all cases, incorporation of PEG molecules without any significant increase in CH4 permeability increases the CO2/CH4 selectivity. From the view point of gas separation applications the resultant data are within commercial attractive range

  18. Metal–organic frameworks based membranes for liquid separation

    KAUST Repository

    Li, Xin; Liu, Yuxin; Wang, Jing; Gascon, Jorge; Li, Jiansheng; Van der Bruggen, Bart

    2017-01-01

    , the field of MOF-based membranes for liquid separation is highlighted in this review. The criteria for judicious selection of MOFs in fabricating MOF-based membranes are given. Special attention is paid to rational design strategies for MOF-based membranes

  19. Theoretical investigation of gas separation in functionalized nanoporous graphene membranes

    Science.gov (United States)

    Wang, Yong; Yang, Qingyuan; Zhong, Chongli; Li, Jinping

    2017-06-01

    Graphene has enormous potential as a membrane-separation material with ultrahigh permeability and selectivity. The understanding of mass-transport mechanism in graphene membranes is crucial for applications in gas separation field. We computationally investigated the capability and mechanisms of functionalized nanoporous graphene membranes for gas separation. The functionalized graphene membranes with appropriate pore size and geometry possess excellent high selectivity for separating CO2/N2, CO2/CH4 and N2/CH4 gas mixtures with a gas permeance of ∼103-105 GPU, compared with ∼100 GPU for typical polymeric membranes. More important, we found that, for ultrathin graphene membranes, the gas separation performance has a great dependence not only with the energy barrier for gas getting into the pore of the graphene membranes, but also with the energy barrier for gas escaping from the pore to the other side of the membranes. The gas separation performance can be tuned by changing the two energy barriers, which can be realized by varying the chemical functional groups on the pore rim of the graphene. The novel mass-transport mechanism obtained in current study may provide a theoretical foundation for guiding the future design of graphene membranes with outstanding separation performance.

  20. Highly Hydrothermally Stable Microporous Membranes for Hydroge Separation

    NARCIS (Netherlands)

    Wei, Qi; Wang, Fei; Wang, F.; Nie, Zuo-Ren; Song, C.; Wang, Yan-Li; Li, Qun-Yan

    2008-01-01

    Fluorocarbon-modified silica membranes were deposited on γ-Al2O3/α-Al2O3 supports by the sol−gel technique for hydrogen separation. The hydrophobic property, pore structure, gas transport and separation performance, and hydrothermal stability of the modified membranes were investigated. It is

  1. Efficient separations & processing crosscutting program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    The Efficient Separations and Processing Crosscutting Program (ESP) was created in 1991 to identify, develop, and perfect chemical and physical separations technologies and chemical processes which treat wastes and address environmental problems throughout the DOE complex. The ESP funds several multiyear tasks that address high-priority waste remediation problems involving high-level, low-level, transuranic, hazardous, and mixed (radioactive and hazardous) wastes. The ESP supports applied research and development (R & D) leading to the demonstration or use of these separations technologies by other organizations within the Department of Energy (DOE), Office of Environmental Management.

  2. Recent advances in multi-layer composite polymeric membranes for CO2 separation: A review

    Directory of Open Access Journals (Sweden)

    Zhongde Dai

    2016-07-01

    Full Text Available The development of multilayer composite membranes for CO2 separation has gained increasing attention due to the desire for energy efficient technologies. Multilayer composite membranes have many advantages, including the possibility to optimize membrane materials independently by layers according to their different functions and to reduce the overall transport resistance by using ultrathin selective layers, and less limitations on the material mechanical properties and processability. A comprehensive review is required to capture details of the progresses that have already been achieved in developing multilayer composite membranes with improved CO2 separation performance in the past 15–20 years. In this review, various composite membrane preparation methods were compared, advances in composite membranes for CO2/CH4 separation, CO2/N2 and CO2/H2 separation were summarized with detailed data, and challenges facing for the CO2 separation using composite membranes, such as aging, plasticization and long-term stability, were discussed. Finally the perspectives and future research directions for composite membranes were presented. Keywords: Composite membrane, CO2 separation, Membrane fabrication, Membrane aging, Long-term stability

  3. Ion transport restriction in mechanically strained separator membranes

    Science.gov (United States)

    Cannarella, John; Arnold, Craig B.

    2013-03-01

    We use AC impedance methods to investigate the effect of mechanical deformation on ion transport in commercial separator membranes and lithium-ion cells as a whole. A Bruggeman type power law relationship is found to provide an accurate correlation between porosity and tortuosity of deformed separators, which allows the impedance of a separator membrane to be predicted as a function of deformation. By using mechanical compression to vary the porosity of the separator membranes during impedance measurements it is possible to determine both the α and γ parameters from the modified Bruggeman relation for individual separator membranes. From impedance testing of compressed pouch cells it is found that separator deformation accounts for the majority of the transport restrictions arising from compressive stress in a lithium-ion cell. Finally, a charge state dependent increase in the impedance associated with charge transfer is observed with increasing cell compression.

  4. Electro/powder separation process

    International Nuclear Information System (INIS)

    Dunn, J.P.

    1977-01-01

    A report is presented to introduce the ELECTRO/POWDER process to the P/M Industry. The process effectively uses electrostatic forces to convey, sort, meter, and blend fine powders. The major advantages of this separating process consist of the processing of primary particles, low particle energy due to particle velocity control and the pattern of particle movement over the sieve (vertical oscillation of particles above the sieve aperture). The report briefly describes the forces involved in both mechanical and sieving devices, with major emphasis on the operating principles of this process. Sieve separation of particulates is basically the result of two physical separating processes which occur simultaneously or independently; separation (dispersion) of particulates from each other and the size separation by passage through fixed apertures. In order to accomplish this goal, mechanical sieving devices utilize various motions to induce shear forces between the sieve surface and the particulates, and between the particulates themselves. It is noted that the ELECTRO/POWDER process is making steady progress in becoming an industrial tool for sieving and feeding of fine particles. Its potential extends into both the blending and admixing of powders, either by incorporating two opposing feeders, one being charged with the opposite polarity or by modifying the ELECTRO/SIEVE to incorporate more than one input and a solid electrode to replace the sieve electrode

  5. Zeolitic imidazolate framework membranes and methods of making and using same for separation of c2- and c3+ hydrocarbons and separation of propylene and propane mixtures

    KAUST Repository

    Lai, Zhiping

    2012-12-06

    Certain embodiments are directed to processes for fabrication of zeolitic imidazolate framework (ZIF) membranes. These ZIF membranes can be used in separating C2-hydrocarbons from C3+ hydrocarbons and propylene/propane mixtures.

  6. Zeolitic imidazolate framework membranes and methods of making and using same for separation of c2- and c3+ hydrocarbons and separation of propylene and propane mixtures

    KAUST Repository

    Lai, Zhiping; Pan, Yichang

    2012-01-01

    Certain embodiments are directed to processes for fabrication of zeolitic imidazolate framework (ZIF) membranes. These ZIF membranes can be used in separating C2-hydrocarbons from C3+ hydrocarbons and propylene/propane mixtures.

  7. Membranes for Enhanced Emulsification Processes

    NARCIS (Netherlands)

    Güell, Carme; Ferrando, Montse; Schroen, C.G.P.H.

    2016-01-01

    The use of membrane technology for the production of single and double emulsions has been proven feasible for a wide range of systems. The low energy requirements and mild process conditions (shear stress and temperature) of membrane emulsification (ME) compared to conventional processes makes it of

  8. Phase separation and shape deformation of two-phase membranes

    International Nuclear Information System (INIS)

    Jiang, Y.; Lookman, T.; Saxena, A.

    2000-01-01

    Within a coupled-field Ginzburg-Landau model we study analytically phase separation and accompanying shape deformation on a two-phase elastic membrane in simple geometries such as cylinders, spheres, and tori. Using an exact periodic domain wall solution we solve for the shape and phase separating field, and estimate the degree of deformation of the membrane. The results are pertinent to preferential phase separation in regions of differing curvature on a variety of vesicles. (c) 2000 The American Physical Society

  9. Robust membrane systems for actinide separations

    International Nuclear Information System (INIS)

    Jarvinen, Gordon D.; McCleskey, T. Mark; Bluhm, Elizabeth A.; Abney, Kent D.; Ehler, Deborah S.; Bauer, Eve; Le, Quyen T.; Young, Jennifer S.; Ford, Doris K.; Pesiri, David R.; Dye, Robert C.; Robison, Thomas W.; Jorgensen, Betty S.; Redondo, Antonio; Pratt, Lawrence R.; Rempe, Susan L.

    2000-01-01

    Our objective in this project is to develop very stable thin membrane structures containing ionic recognition sites that facilitate the selective transport of target metal ions, especially the actinides

  10. The development of zirconia membrane oxygen separation technology

    International Nuclear Information System (INIS)

    Chiacchi, F.T.; Badwal, S.P.S.; Velizko, V.

    2000-01-01

    The oxygen separation technology based on ceramic membranes constructed from stabilised zirconia is currently under development for applications ranging from oxygen generation or air enrichment for medical use to control of oxygen concentration or oxygen removal from gas streams and enclosures for semiconductor, food packaging and process control instrumentation industries. The technology is based on a rugged tubular design with extensive thermal cycling capability. Several single and three tube devices have been operated for periods up to 5000h. An eight tube module, as a building block for larger scale oxygen production or removal devices, has been constructed and is being evaluated. In this paper, the construction of the device, oxygen generating capacity, life time tests and performance of the ceramic membrane device under development at CSIRO will be discussed. Copyright (2000) The Australian Ceramic Society

  11. Deposition and consolidation of porous ceramic films for membrane separation

    DEFF Research Database (Denmark)

    Elmøe, Tobias Dokkedal; Tricoli, Antonio; Johannessen, Tue

    The deposition of porous ceramic films for membrane separation can be done by several processes such as thermophoresis [1], dip-coating [2] and spray pyrolysis [3]. Here we present a high-speed method, in which ceramic nano-particles form a porous film by filtration on top of a porous ceramic...... substrate [4]. Ceramic nano-particles are generated in a flame, using either a premixed (gas) flame, in which a metal-oxide precursor is evaporated in an N2 stream, which is combusted with methane and air, or using a flame spray pyrolysis, in which a liquid metal-oxide precursor is sprayed through a nozzle...

  12. Adsorption/membrane filtration as a contaminant concentration and separation process for mixed wastes and tank wastes. 1998 annual progress report

    International Nuclear Information System (INIS)

    Benjamin, M.M.; Korshin, G.

    1998-01-01

    'This report describes progress through May, 1998, which is a little past mid-way through the second year of a three-year project. The goal of the research is to develop a treatment system for the separation of contaminants in low-organic Hanford tank wastes into various sub-groups that are relatively easy to treat further to yield products that are amenable to final disposal. The main target contaminants are Sr and Cs, although heavy metals and actinide-group elements are also targets. Effort during the first half-year of the project was devoted primarily to development of experimental and analytical techniques that could be used to test and quantify the treatability of Sr and Cs in the extremely complex matrix of the tank wastes. The treatment technologies to be tested for isolation of Sr from other waste constituents included adsorption of Sr onto various mineral solids and membrane separation of particulate from dissolved Sr. The proposed technology for treating Cs was electrochemically controlled, reversible binding of the Cs to hexacyanoferrates. Results obtained during the remainder of the first year suggested that hematite (a-Fe 2 O 3 ) and iron-oxide-coated sand (IOCS) were the best adsorbents for Sr among the oxides tested, and work during the second project year followed up on that result.'

  13. Chorioamniotic membrane separation and preterm premature rupture of membranes complicating in utero myelomeningocele repair.

    Science.gov (United States)

    Soni, Shelly; Moldenhauer, Julie S; Spinner, Susan S; Rendon, Norma; Khalek, Nahla; Martinez-Poyer, Juan; Johnson, Mark P; Adzick, N Scott

    2016-05-01

    Since the results of the Management of Myelomeningocele Study were published, maternal-fetal surgery for the in utero treatment of spina bifida has become accepted as a standard of care alternative. Despite promise with fetal management of myelomeningocele repair, there are significant complications to consider. Chorioamniotic membrane separation and preterm premature rupture of membranes are known complications of invasive fetal procedures. Despite their relative frequency associated with fetal procedures, few data exist regarding risk factors that may be attributed to their occurrence or the natural history of pregnancies that are affected with chorionic membrane separation or preterm premature rupture of membranes related to the procedure. The objective of this study was to review chorioamniotic membrane separation and preterm premature rupture of membranes in a cohort of patients undergoing fetal management of myelomeningocele repair including identification of risk factors and outcomes. This was a retrospective review of patients undergoing fetal management of myelomeningocele repair and subsequent delivery from January 2011 through December 2013 at 1 institution. Patients were identified through the institutional fetal management of myelomeningocele repair database and chart review was performed. Perioperative factors and outcomes among patients with chorioamniotic membrane separation and preterm premature rupture of membranes were compared to those without. Risk factors associated with the development of chorioamniotic membrane separation and preterm premature rupture of membranes were determined. A total of 88 patients underwent fetal management of myelomeningocele repair and subsequently delivered during the study period. In all, 21 patients (23.9%) were diagnosed with chorioamniotic membrane separation by ultrasound and preterm premature rupture of membranes occurred in 27 (30.7%). Among the chorioamniotic membrane separation patients, 10 (47.6%) were

  14. Use of reverse osmosis membranes for the separation of lemongrass essential oil and supercritical CO2

    Directory of Open Access Journals (Sweden)

    L.A.V. Sarmento

    2004-06-01

    Full Text Available Although it is still used very little by industry, the process of essential oil extraction from vegetable matrices with supercritical CO2 is regarded as a potentially viable technique. The operation of separating the extract from the solvent is carried out by reducing the pressure in the system. Separation by membranes is an alternative that offers lower energy consumption and easier operation than traditional methods of separation. Combining the processes essential oil extraction with supercritical CO2 and separation by membranes permits the separation of solvent and oil without the need for large variations in extraction conditions. This results in a large energy savings in the case of solvent repressurisation and reuse. In this study, the effectiveness of reverse osmosis membranes in separating lemongrass essential oil from mixtures with supercritical CO2 was tested. The effects of feed oil concentration and transmembrane pressure on CO2 permeate flux and oil retention were studied for three membrane models.

  15. Multicomponent Matrimid Membrane for Gas Separation

    KAUST Repository

    Irerua, Olayinka

    2012-07-01

    Matrimid was utilized for the preparation of membranes with asymmetric structures. A combination of well-known solvents for Matrimid which include 1- methyl-2-Pyrrolidone (NMP), tetrahydrofuran (THF), dichloromethane, tetrachloroethane as well as non-solvents n-butanol, xylene, and acetic acid were used. Cast solutions were prepared at room temperature for different combinations and compositions of polymer/solvent/non-solvent systems. PEG and Octa-(amino phenyl) POSS were introduced in some of the cast solutions. The membranes obtained were characterized by permeation test for gas permeabilities and selectivities, Scanning Electron Microscopy (SEM) and Nuclear Magnetic Resonance (NMR) Spectroscopy. The gas permeation test showed that the use of mixture of dichloromethane and tetrachloroethane as solvents with xylene non-solvent and acetic acid as stabilizer gave membranes with very high gas selectivity of 133 for CO2/N2 and 492 for CO2/CH4. Also, cast solutions containing PEG resulted in membranes with slightly enhanced selectivities from 30 to 42 for CO2/N2. Permeation results for CO2, N2 and H2 and the selectivities for gas pairs such as CO2/N2, CO2/CH4, are discussed in relation to the effect of pressure on the membrane permeance, they are also compared with existing results.

  16. Polyether based block copolymer membranes for CO2 separation

    NARCIS (Netherlands)

    Reijerkerk, Sander

    2010-01-01

    The work described in this thesis is dedicated to the development of polymeric membrane materials for the separation of CO2 from light gases, and in particular to the separation of CO2 from nitrogen as required in a post-combustion capture conguration for the separation of CO2 from flue gases. An

  17. Novel Ceramic-Polymer Composite Membranes for the Separation of Hazardous Liquid Waste

    Energy Technology Data Exchange (ETDEWEB)

    Yoram Cohen

    2001-12-01

    The present project was conceived to address the need for robust yet selective membranes suitable for operating in harsh ph, solvent, and temperature environments. An important goal of the project was to develop a membrane chemical modification technology that would allow one to tailor-design membranes for targeted separation tasks. The method developed in the present study is based on the process of surface graft polymerization. Using essentially the same base technology of surface modification the research was aimed at demonstrating that improved membranes can be designed for both pervaporation separation and ultrafiltration. In the case of pervaporation, the present study was the first to demonstrate that pervaporation can be achieved with ceramic support membranes modified with an essentially molecular layer of terminally anchored polymer chains. The main advantage of the above approach, relative to other proposed membranes, is that the separating polymer layer is covalently attached to the ceramic support. Therefore, such membranes have a potential use in organic-organic separations where the polymer can swell significantly yet membrane robustness is maintained due to the chemical linkage of the chains to be inorganic support. The above membrane technology was also useful in developing fouling resistant ultrafiltration membranes. The prototype membrane developed in the project was evaluated for the treatment of oil-in-water microemulsions, demonstrating lack of irreversible fouling common with commercial membranes.

  18. Polymer membranes as separators for supercapacitors

    Science.gov (United States)

    Szubzda, Bronisław; Szmaja, Aleksandra; Ozimek, Mariusz; Mazurkiewicz, Sławomir

    2014-12-01

    The purpose of the studies described was to examine the influence of low-energy plasma modification of polyamide and polypropylene polymer nonwoven fabrics on the usable properties of supercapacitors when using these fabrics as the separator material. To achieve this goal the following investigations were carried out: testing the time required for electrolyte saturation of separators and the conductivity of the electrolyte contained in the separator, as well as electrochemical examinations of supercapacitor models in which the modified fabric separators were used. The tests conducted fully confirm the usability of this modification for cleaning the surface and improving the wettability of separators by the electrolyte, which in turn results in a significant decrease of the internal resistance of the supercapacitor, thus increasing the usable power of the device.

  19. Membranes as separators of dispersed emulsion phases

    NARCIS (Netherlands)

    Lefferts, A.G.

    1997-01-01

    The reuse or discharge of industrial waste waters, containing small fractions of dispersed oil, requires a purification treatment for which membranes can be used. If only little oil is present, removal of the dispersed phase might be preferable to the more commonly applied removal of the

  20. Development of O-18 stable isotope separation technology using membrane

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Woo; Kim, Taek Soo; Choi, Hwa Rim; Park, Sung Hee; Lee, Ki Tae; Chang, Dae Shik

    2006-06-15

    The ultimate goal of this investigation is to develop the separation technology for O-18 oxygen stable isotope used in a cyclotron as a target for production of radioisotope F-18. F-18 is a base material for synthesis of [F-18]FDG radio-pharmaceutical, which is one of the most important tumor diagnostic agent used in PET (Positron Emission Tomography). More specifically, this investigation is focused on three categories as follow, 1) development of the membrane distillation isotope separation process to re-enrich O-18 stable isotope whose isotopic concentration is reduced after used in a cyclotron, 2) development of organic impurity purification technology to remove acetone, methanol, ethanol, and acetonitrile contained in a used cyclotron O-18 enriched target water, and 3) development of a laser absorption spectroscopic system for analyzing oxygen isotopic concentration in water.

  1. Carbon dioxide (hydrogen sulfide) membrane separations and WGS membrane reactor modeling for fuel cells

    Science.gov (United States)

    Huang, Jin

    Acid-gas removal is of great importance in many environmental or energy-related processes. Compared to current commercial technologies, membrane-based CO2 and H2S capture has the advantages of low energy consumption, low weight and space requirement, simplicity of installation/operation, and high process flexibility. However, the large-scale application of the membrane separation technology is limited by the relatively low transport properties. In this study, CO2 (H2S)-selective polymeric membranes with high permeability and high selectivity have been studied based on the facilitated transport mechanism. The membrane showed facilitated effect for both CO2 and H2S. A CO2 permeability of above 2000 Barrers, a CO2/H2 selectivity of greater than 40, and a CO2/N2 selectivity of greater than 200 at 100--150°C were observed. As a result of higher reaction rate and smaller diffusing compound, the H2S permeability and H2S/H2 selectivity were about three times higher than those properties for CO2. The novel CO2-selective membrane has been applied to capture CO 2 from flue gas and natural gas. In the CO2 capture experiments from a gas mixture with N2 and H2, a permeate CO 2 dry concentration of greater than 98% was obtained by using steam as the sweep gas. In CO2/CH4 separation, decent CO 2 transport properties were obtained with a feed pressure up to 500 psia. With the thin-film composite membrane structure, significant increase on the CO2 flux was achieved with the decrease of the selective layer thickness. With the continuous removal of CO2, CO2-selective water-gas-shift (WGS) membrane reactor is a promising approach to enhance CO conversion and increase the purity of H2 at process pressure under relatively low temperature. The simultaneous reaction and transport process in the countercurrent WGS membrane reactor was simulated by using a one-dimensional non-isothermal model. The modeling results show that a CO concentration of less than 10 ppm and a H2 recovery of greater

  2. Improvements in or relating to separation processes

    International Nuclear Information System (INIS)

    Smyth, M.J.; Cumberland, R.F.

    1981-01-01

    This relates to a process for separating a substance from a liquid. Toxic materials (such as mercury, cadmium, lead and other heavy metals) or valuable materials (such as copper) can be removed by this method, also radioactive effluents to remove radioactive substances prior to storage or discharge. The liquid is treated with a chemical reagent to form a colloidal solution containing colloidal particles of radioactive substance and these are then separated from the liquid by use of a semi-permeable membrane or centrifuge. Examples given are for the separation of radiostrontium and/or radiocesium from an aqueous solution containing magnesium nitrate ions, or from an aqueous solution containing non-radioactive sodium ions. The advantage over other methods is that only a comparatively small amount of chemical reagent is required to produce the colloidal solution rather than a precipitate. The quantity of sludge produced is also much reduced. (U.K.)

  3. Intrinsically Microporous Polymer Membranes for High Performance Gas Separation

    KAUST Repository

    Swaidan, Raja

    2014-01-01

    This dissertation addresses the rational design of intrinsically microporous solutionprocessable polyimides and ladder polymers for highly permeable and highly selective gas transport in cornerstone applications of membrane-based gas separation

  4. Effective separation of propylene/propane binary mixtures by ZIF-8 membranes

    KAUST Repository

    Pan, Yichang; Li, Tao; Lestari, Gabriella; Lai, Zhiping

    2012-01-01

    The separation of propylene/propane mixtures is one of the most important but challenging processes in the petrochemical industry. A novel zeolitic imidazole framework (ZIF-8) membrane prepared by a facile hydrothermal seeded growth method showed

  5. Functionalized copolyimide membranes for the separation of gaseous and liquid mixtures

    Directory of Open Access Journals (Sweden)

    Nadine Schmeling

    2010-08-01

    Full Text Available Functionalized copolyimides continue to attract much attention as membrane materials because they can fulfill the demands for industrial applications. Thus not only good separation characteristics but also high temperature stability and chemical resistance are required. Furthermore, it is very important that membrane materials are resistant to plasticization since it has been shown that this phenomenon leads to a significant increase in permeability with a dramatic loss in selectivity. Plasticization effects occur with most polymer membranes at high CO2 concentrations and pressures, respectively. Plasticization effects are also observed with higher hydrocarbons such as propylene, propane, aromatics or sulfur containing aromatics. Unfortunately, these components are present in mixtures of high commercial relevance and can be separated economically by single membrane units or hybrid processes where conventional separation units are combined with membrane-based processes. In this paper the advantages of carboxy group containing 6FDA (4,4′-hexafluoroisopropylidene diphthalic anhydride -copolyimides are discussed based on the experimental results for non cross-linked, ionically and covalently cross-linked membrane materials with respect to the separation of olefins/paraffins, e.g. propylene/propane, aromatic/aliphatic separation e.g. benzene/cyclohexane as well as high pressure gas separations, e.g. CO2/CH4 mixtures. In addition, opportunities for implementing the membrane units in conventional separation processes are discussed.

  6. Gas separation performance of tapered cascade with membrane

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    Membrane gas separation cascades are analyzed at steady state. The method of calculating the flow rate and concentration profiles in the cascade are examined, using formulas expressing the various membrane separation cell characteristics. The method adopted is applicable to relatively high concentrations and separation factors. Considerations are further given on the steady state performance of four theoretical forms of cascade: (a) with common value of cut for all stages, (b) with symmetric separation cells, (c) with no mixing at the junction at each stage, and (d) ideal cascade. The analysis showed that, with membrane cells, the ideal cascade would have a pressure ratio varying from stage to stage. The symmetric separation cascade would provide a separation performance lower than the ideal cascade on account of the mixing at the junctions of streams possessing different concentrations, whereas the cut and separation factor of the no-mixing cascade requiring minimum membrane area exhibits zig-zag curves when plotted against stage number. Both these circumstances contribute to the lower separation performance obtained with these two forms as compared with the ideal cascade, and results in larger total membrane area; but these semi-ideal forms retain the advantage of easy practical treatment with their pressure ratio common to all stages. (auth.)

  7. Biological black water treatment combined with membrane separation

    NARCIS (Netherlands)

    van Voorthuizen, E.M.; Zwijnenburg, A.; van der Meer, Walterus Gijsbertus Joseph; Temmink, Hardy

    2008-01-01

    Separate treatment of black (toilet) water offers the possibility to recover energy and nutrients. In this study three combinations of biological treatment and membrane filtration were compared for their biological and membrane performance and nutrient conservation: a UASB followed by effluent

  8. High selectivity ZIF-93 hollow fiber membranes for gas separation.

    Science.gov (United States)

    Cacho-Bailo, Fernando; Caro, Guillermo; Etxeberría-Benavides, Miren; Karvan, Oğuz; Téllez, Carlos; Coronas, Joaquín

    2015-06-30

    Zeolitic imidazolate framework-93 (ZIF-93) continuous membranes were synthesized on the inner side of P84 co-polyimide hollow fiber supports by microfluidics. MOFs and polymers showed high compatibility and the membrane exhibited H2-CH4 and CO2-CH4 separation selectivities of 97 (100 °C) and 17 (35 °C), respectively.

  9. Mixed-matrix membrane adsorbers for protein separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Borneman, Z.; Wessling, M.

    2003-01-01

    The separation of two similarly sized proteins, bovine serum albumin (BSA) and bovine hemoglobin (Hb) was carried out using a new type of ion-exchange mixed-matrix adsorber membranes. The adsorber membranes were prepared by incorporation of various types of Lewatit ion-exchange resins into an

  10. Novel silica membranes for high temperature gas separations

    KAUST Repository

    Bighane, Neha; Koros, William J.

    2011-01-01

    and pure gas separation performance in the temperature range 35-80°C is presented. It is observed that the membranes exhibit activated transport for small gas penetrants such as He, H 2 and CO 2. The membranes can withstand temperatures up to 350°C in air

  11. Niobia-silica and silica membranes for gas separation

    NARCIS (Netherlands)

    Boffa, V.

    2008-01-01

    This thesis describes the development of ceramic membranes suitable for hydrogen separation and CO2 recovery from gaseous streams. The research work was focused on the three different parts of which gas selective ceramic membranes are composed, i.e., the microporous gas selective silica layer, the

  12. An Integrated Membrane Process for Butenes Production

    Directory of Open Access Journals (Sweden)

    Leonardo Melone

    2016-11-01

    Full Text Available Iso-butene is an important material for the production of chemicals and polymers. It can take part in various chemical reactions, such as hydrogenation, oxidation and other additions owing to the presence of a reactive double bond. It is usually obtained as a by-product of a petroleum refinery, by Fluidized Catalytic Cracking (FCC of naphtha or gas-oil. However, an interesting alternative to iso-butene production is n-butane dehydroisomerization, which allows the direct conversion of n-butane via dehydrogenation and successive isomerization. In this work, a simulation analysis of an integrated membrane system is proposed for the production and recovery of butenes. The dehydroisomerization of n-butane to iso-butene takes place in a membrane reactor where the hydrogen is removed from the reaction side with a Pd/Ag alloys membrane. Afterwards, the retentate and permeate post-processing is performed in membrane separation units for butenes concentration and recovery. Four different process schemes are developed. The performance of each membrane unit is analyzed by appropriately developed performance maps, to identify the operating conditions windows and the membrane permeation properties required to maximize the recovery of the iso-butene produced. An analysis of integrated systems showed a yield of butenes higher than the other reaction products with high butenes recovery in the gas separation section, with values of molar concentration between 75% and 80%.

  13. Membrane systems for energy efficient separation of light gases

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Archuleta, T.; Barbero, R. [Los Alamos National Lab., NM (United States)] [and others

    1997-04-01

    Ethylene and propylene are two of the largest commodity chemicals in the United States and are major building blocks for the petrochemicals industry. These olefins are separated currently by cryogenic distillation which demands extremely low temperatures and high pressures. Over 75 billion pounds of ethylene and propylene are distilled annually in the US at an estimated energy requirement of 400 trillion BTU`s. Non-domestic olefin producers are rapidly constructing state-of-the-art plants. These energy-efficient plants are competing with an aging United States olefins industry in which 75% of the olefins producers are practicing technology that is over twenty years old. New separation opportunities are therefore needed to continually reduce energy consumption and remain competitive. Amoco has been a leader in incorporating new separation technology into its olefins facilities and has been aggressively pursuing non-cryogenic alternatives to light gas separations. The largest area for energy reduction is the cryogenic isolation of the product hydrocarbons from the reaction by-products, methane and hydrogen. This separation requires temperatures as low as {minus}150{degrees}F and pressures exceeding 450 psig. This CRADA will focus on developing a capillary condensation process to separate olefinic mixtures from light gas byproducts at temperatures that approach ambient conditions and at pressures less than 250 psig; this technology breakthrough will result in substantial energy savings. The key technical hurdle in the development of this novel separation concept is the precise control of the pore structure of membrane materials. These materials must contain specially-shaped channels in the 20-40A range to provide the driving force necessary to remove the condensed hydrocarbon products. In this project, Amoco is the technology end-user and provides the commercialization opportunity and engineering support.

  14. Separation performance and interfacial properties of nanocomposite reverse osmosis membranes

    KAUST Repository

    Pendergast, MaryTheresa M.; Ghosh, Asim K.; Hoek, E.M.V.

    2013-01-01

    Four different types of nanocomposite reverse osmosis (RO) membranes were formed by interfacial polymerization of either polyamide (PA) or zeolite A-polyamide nanocomposite (ZA-PA) thin films over either pure polysulfone (PSf) or zeolite A-polysulfone nanocomposite (ZA-PSf) support membranes cast by wet phase inversion. All three nanocomposite membranes exhibited superior separation performance and interfacial properties relative to hand-cast TFC analogs including: (1) smoother, more hydrophilic surfaces (2) higher water permeability and salt rejection, and (3) improved resistance to physical compaction. Less compaction occurred for membranes with nanoparticles embedded in interfacially polymerized coating films, which adds further proof that flux decline associated with physical compaction is influenced by coating film properties in addition to support membrane properties. The new classes of nanocomposite membrane materials continue to offer promise of further improved RO membranes for use in desalination and advanced water purification. © 2011 Elsevier B.V.

  15. Membrane for distillation including nanostructures, methods of making membranes, and methods of desalination and separation

    KAUST Repository

    Lai, Zhiping; Huang, Kuo-Wei; Chen, Wei

    2016-01-01

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure provide membranes, methods of making the membrane, systems including the membrane, methods of separation, methods of desalination, and the like.

  16. Membrane for distillation including nanostructures, methods of making membranes, and methods of desalination and separation

    KAUST Repository

    Lai, Zhiping

    2016-01-21

    In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, embodiments of the present disclosure provide membranes, methods of making the membrane, systems including the membrane, methods of separation, methods of desalination, and the like.

  17. Biomimetic membranes for sensor and separation applications

    DEFF Research Database (Denmark)

    Helix Nielsen, Claus

    2009-01-01

    preventing the passage of others, a property critical for the overall conservation of the cells internal pH and salt concentration. Both ion and water channels are highly efficient membrane pore proteins capable of transporting solutes at very high rates, up to 109 molecules per second. Carrier proteins...... and biomimetic support matrix. Also the stability of the incorporated protein must be addressed and the protein-biomimetic matrix must be encapsulated in order to protect it and make it sufficiently stable in a final application. Here I will review and discuss these challenges and how they are met in some...

  18. An Underwater Superoleophobic Sepiolite Fibrous Membrane (SFM) for Oil­‐in­‐water Emulsion Separation

    KAUST Repository

    Yao, Pinjiang

    2014-01-01

    was fabricated by a facile vacuum filtration process of sepiolite nanofibers and chitosan, and after the cross-linking via glutaraldehyde, a self-standing membrane was obtained. The as-prepared membrane exhibited excellent capability of separating both

  19. Development of natural rubber membranes for separation of methyl tert-butyl ether and methanol

    International Nuclear Information System (INIS)

    Nur Azrini Ramlee; Ghazali Mohd Nawawi; Khairul Zaman Dahlan

    2010-01-01

    As a new commercial process, membrane separation raises significant expectations in the process plant of the future and therefore this research was being initiated to develop and characterize pervaporation membrane based on natural rubber (NR). Natural Rubber SMR-L grade which was supplied by Malaysia Rubber Research Institute (MRRI) was used for the development of the membranes via interpenetrating polymer network (IPN) techniques. Polystyrene (PS) was used to modify the natural rubber to further improve their mechanical and chemical properties. The membranes were prepared with various blend ratios of natural rubber, polystyrene and divinyl benzene as cross linker with constant 1 % of dicumyl peroxide as the initiator. The developed membranes were then characterized to study the functional group presence, membranes morphology, crosslink density, tear strength, adsorption of the membranes and pervaporation separation of Methyl-Tert-Butyl-Ether (MTBE) and Methanol. Pervaporation process was conducted by using varies of MTBE concentration 10, 30, 50 and 70 wt % and at differ operation temperature, 25 degree Celsius and 55 degree Celsius. Separation performance of IPN NR/ PS membranes were based on the presented permeation flux and separation factor. Examination through Fourier Transform Infrared Spectroscopy (FTIR), determined crosslink density and tear strength, 6 series of IPN NR/ PS membranes were successfully developed using natural rubber. Observation from Scanning Electron Microscopy (SEM) showed that the membranes were dense and appropriated for the pervaporation process application. From the pervaporation of MTBE and Methanol, IPN NR/ PS membranes of series D4N30 shown low permeation flux of MTBE but high separation factor while D2N70 membranes was vice versa for both temperature of 25 degree Celsius and 55 degree Celsius. (author)

  20. Stakeholder acceptance analysis: In-well vapor stripping, in-situ bioremediation, gas membrane separation system (membrane separation)

    International Nuclear Information System (INIS)

    Peterson, T.

    1995-12-01

    This document provides stakeholder evaluations on innovative technologies to be used in the remediation of volatile organic compounds from soils and ground water. The technologies evaluated are; in-well vapor stripping, in-situ bioremediation, and gas membrane separation

  1. Causal and causally separable processes

    Science.gov (United States)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-09-01

    outcomes for each party, these correlations form a polytope whose facets define causal inequalities. The case of quantum correlations in this paradigm is captured by the process matrix formalism. We investigate the link between causality and the closely related notion of causal separability of quantum processes, which we here define rigorously in analogy with the link between Bell locality and separability of quantum states. We show that causality and causal separability are not equivalent in general by giving an example of a physically admissible tripartite quantum process that is causal but not causally separable. We also show that there are causally separable quantum processes that become non-causal if extended by supplying the parties with entangled ancillas. This motivates the concepts of extensibly causal and extensibly causally separable (ECS) processes, for which the respective property remains invariant under extension. We characterize the class of ECS quantum processes in the tripartite case via simple conditions on the form of the process matrix. We show that the processes realizable by classically controlled quantum circuits are ECS and conjecture that the reverse also holds.

  2. Causal and causally separable processes

    International Nuclear Information System (INIS)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-01-01

    outcomes for each party, these correlations form a polytope whose facets define causal inequalities. The case of quantum correlations in this paradigm is captured by the process matrix formalism. We investigate the link between causality and the closely related notion of causal separability of quantum processes, which we here define rigorously in analogy with the link between Bell locality and separability of quantum states. We show that causality and causal separability are not equivalent in general by giving an example of a physically admissible tripartite quantum process that is causal but not causally separable. We also show that there are causally separable quantum processes that become non-causal if extended by supplying the parties with entangled ancillas. This motivates the concepts of extensibly causal and extensibly causally separable (ECS) processes, for which the respective property remains invariant under extension. We characterize the class of ECS quantum processes in the tripartite case via simple conditions on the form of the process matrix. We show that the processes realizable by classically controlled quantum circuits are ECS and conjecture that the reverse also holds. (paper)

  3. Metal–organic framework membranes: from synthesis to separation application

    KAUST Repository

    Qiu, Shilun

    2014-06-26

    Metal-organic framework (MOF) materials, which are constructed from metal ions or metal ion clusters and bridging organic linkers, exhibit regular crystalline lattices with relatively well-defined pore structures and interesting properties. As a new class of porous solid materials, MOFs are attractive for a variety of industrial applications including separation membranes-a rapidly developing research area. Many reports have discussed the synthesis and applications of MOFs and MOF thin films, but relatively few have addressed MOF membranes. This critical review provides an overview of the diverse MOF membranes that have been prepared, beginning with a brief introduction to the current techniques for the fabrication of MOF membranes. Gas and liquid separation applications with different MOF membranes are also included (175 references). This journal is © the Partner Organisations 2014.

  4. Surface-Modified Membrane as A Separator for Lithium-Ion Polymer Battery

    Directory of Open Access Journals (Sweden)

    Jun Young Kim

    2010-04-01

    Full Text Available This paper describes the fabrication of novel modified polyethylene (PE membranes using plasma technology to create high-performance and cost-effective separator membranes for practical applications in lithium-ion polymer batteries. The modified PE membrane via plasma modification process plays a critical role in improving wettability and electrolyte retention, interfacial adhesion between separators and electrodes, and cycle performance of lithium-ion polymer batteries. This paper suggests that the performance of lithium-ion polymer batteries can be greatly enhanced by the plasma modification of commercial separators with proper functional materials for targeted application.

  5. Emerging trends in chemical separations with liquid membranes: an overview

    International Nuclear Information System (INIS)

    Shukla, J.P.

    1997-01-01

    It can be concluded that varied configurations of liquid membranes (LMs) will definitely play an important role in metal separations particularly in situations where other conventional chemical separation techniques fail to deliver goods. Potential areas include decontamination of biotoxic/ radioactive wastes, recovery of precious and strategic metals from lean/ extremely dilute solutions, add on to existing units, hydrometallurgy, etc

  6. A review of recent advances in molecular simulation of graphene-derived membranes for gas separation

    Science.gov (United States)

    Fatemi, Seyyed Mahmood; Abbasi, Zeynab; Rajabzadeh, Halimeh; Hashemizadeh, Seyyed Ali; Deldar, Amir Noori

    2017-07-01

    To obtain an ideal membrane for gas separation the following three characteristics should be considered: the membrane should be as thin as possible, be mechanically robust, and have well-defined pore sizes. These features will maximize its solvent flux, preserve it from fracture, and guarantee its selectivity. These attractive properties of graphene-derived membranes introduce them as appropriate candidates for gas separation and gas molecular-sieving processes in nanoscale dimensions. The current effort has focused on two issues, including the review of the most newly progression on drilling holes in single graphene membranes for making ultrathin membranes for gas separation, and studying functionalized nanoporous sheet and graphene-derived membranes, including doped graphene, graphene oxide, fluorographene, and reduced graphene oxide from theoretical perspectives for making functional coatings for nano ultrafiltration for gas separation. We investigated the basic mechanism of separation by membranes derived from graphene and relevant possible applications. Functionalized nanoporous membranes as novel approach are characterized by low energy cost in realizing high throughput molecular-sieving separation.

  7. Polymethylmethacrylate/Polyacrylonitrile Membranes via Centrifugal Spinning as Separator in Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Meltem Yanilmaz

    2015-04-01

    Full Text Available Electrospun nanofiber membranes have been extensively studied as separators in Li-ion batteries due to their large porosity, unique pore structure, and high electrolyte uptake. However, the electrospinning process has some serious drawbacks, such as low spinning rate and high production cost. The centrifugal spinning technique can be used as a fast, cost-effective and safe technique to fabricate high-performance fiber-based separators. In this work, polymethylmethacrylate (PMMA/polyacrylonitrile (PAN membranes with different blend ratios were produced via centrifugal spinning and characterized by using different electrochemical techniques for use as separators in Li-ion batteries. Compared with commercial microporous polyolefin membrane, centrifugally-spun PMMA/PAN membranes had larger ionic conductivity, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. Centrifugally-spun PMMA/PAN membrane separators were assembled into Li/LiFePO4 cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using centrifugally-spun PMMA/PAN membrane separators showed superior C-rate performance compared to those using microporous polypropylene (PP membranes. It is, therefore, demonstrated that centrifugally-spun PMMA/PAN membranes are promising separator candidate for high-performance Li-ion batteries.

  8. Structural Changes of PVDF Membranes by Phase Separation Control

    International Nuclear Information System (INIS)

    Lee, Semin; Kim, Sung Soo

    2016-01-01

    Thermally induced phase separation (TIPS) and nonsolvent induced phase separation (NIPS) were simultaneously induced for the preparation of flat PVDF membranes. N-methyl-2-pyrrolidone (NMP) was used as a solvent and dibutyl-phthlate (DBP) was used as a diluent for PVDF. When PVDF was melt blended with NMP and DBP, crystallization temperature was lowered for TIPS and unstable region was expanded for NIPS. Ratio of solvent to diluent changed the phase separation mechanism to obtain the various membrane structures. Contact mode of dope solution with nonsolvent determined the dominant phase separation behavior. Since heat transfer rate was greater than mass transfer rate, surface structure was formed by NIPS and inner structure was by TIPS. Quenching temperature of dope solution also affected the phase separation mechanism and phase separation rate to result in the variation of structure

  9. Intrinsically Microporous Polymer Membranes for High Performance Gas Separation

    KAUST Repository

    Swaidan, Raja

    2014-11-01

    This dissertation addresses the rational design of intrinsically microporous solutionprocessable polyimides and ladder polymers for highly permeable and highly selective gas transport in cornerstone applications of membrane-based gas separation – that is, air enrichment, hydrogen recovery and natural gas sweetening. By virtue of rigid and contorted chains that pack inefficiently in the solid state, polymers of intrinsic microporosity (PIMs) have the potential to unite the solution-processability, mechanical flexibility and organic tunability of commercially relevant polymers with the microporosity characteristics of porous crystalline materials. The performance enhancements of PIMs over conventional low-free-volume polymers have been primarily permeability-driven, compromising the selectivity essential to commercial viability. An approach to unite high permeability with high selectivity for performance transcending the state-of-the-art in air and hydrogen separations was demonstrated via a fused-ring integration of a three-dimensional, shape persistent triptycene moiety optimally substituted with short, branched isopropyl chains at the 9,10-bridgeheads into a highly inflexible backbone. The resulting polymers exhibited selectivities (i.e., O2/N2, H2/N2, H2/CH4) similar to or higher than commercial materials matched with permeabilities up to three hundred times higher. However, the intra-chain rigidity central to such conventional PIM-design principles was not a singular solution to suppression of CO2-induced plasticization in CO2/CH4 mixedgas separations. Plasticization diminishes the sieving capacity of the membrane, resulting in costly hydrocarbon losses that have significantly limited the commercialization of new polymers. Unexpectedly, the most permeable and selective PIMs designed for air and hydrogen separations strongly plasticized in 50:50 CO2/CH4 mixtures, enduring up to three-fold increases in mixed-gas CH4 permeability by 30 bar and strong drops in

  10. Separation of hydrogen from dilute streams (e.g. using membranes)

    Energy Technology Data Exchange (ETDEWEB)

    Brueschke, H.E.A. [Sulzer Chemtech GmbH Membrantechnik, Neunkirchen (Germany)

    2003-07-01

    As a conclusion it can be stated that the use of membranes in the separation and purification of hydrogen is still limited. In areas where hydrogen at not too high purity can be recovered from otherwise low value gas mixtures, like in the examples given above, the application of membranes has developed into a proven state-of-art technology. Where high purity hydrogen at high pressure is demanded, still fairly large work is ahead for membrane and process developers. (orig.)

  11. MXene molecular sieving membranes for highly efficient gas separation.

    Science.gov (United States)

    Ding, Li; Wei, Yanying; Li, Libo; Zhang, Tao; Wang, Haihui; Xue, Jian; Ding, Liang-Xin; Wang, Suqing; Caro, Jürgen; Gogotsi, Yury

    2018-01-11

    Molecular sieving membranes with sufficient and uniform nanochannels that break the permeability-selectivity trade-off are desirable for energy-efficient gas separation, and the arising two-dimensional (2D) materials provide new routes for membrane development. However, for 2D lamellar membranes, disordered interlayer nanochannels for mass transport are usually formed between randomly stacked neighboring nanosheets, which is obstructive for highly efficient separation. Therefore, manufacturing lamellar membranes with highly ordered nanochannel structures for fast and precise molecular sieving is still challenging. Here, we report on lamellar stacked MXene membranes with aligned and regular subnanometer channels, taking advantage of the abundant surface-terminating groups on the MXene nanosheets, which exhibit excellent gas separation performance with H 2 permeability >2200 Barrer and H 2 /CO 2 selectivity >160, superior to the state-of-the-art membranes. The results of molecular dynamics simulations quantitatively support the experiments, confirming the subnanometer interlayer spacing between the neighboring MXene nanosheets as molecular sieving channels for gas separation.

  12. Nanoporous polymer--clay hybrid membranes for gas separation.

    Science.gov (United States)

    Defontaine, Guillaume; Barichard, Anne; Letaief, Sadok; Feng, Chaoyang; Matsuura, Takeshi; Detellier, Christian

    2010-03-15

    Nanohybrid organo-inorgano clay mineral-polydimethylsiloxane (PDMS) membranes were prepared by the reaction of pure and/or modified natural clay minerals (Sepiolite and montmorillonite) with PDMS in hexane, followed by evaporation of the solvent at 70 degrees C. The membranes were characterized by means of XRD, SEM, ATD-TG and solid state (29)Si magic angle spinning (MAS) and cross-polarization (CP) CP/MAS NMR. The morphology of the membranes depends on the content loading of clay mineral. For low content, the membrane composition is homogeneous, with well dispersed nanoparticles of clay into the polymer matrix, whereas for higher clay content, the membranes are constituted also of a mixture of well dispersed nanoparticles into the polymer, but in the presence of agglomerations of small clay particles. Quantitative (29)Si MAS NMR demonstrated a strong correlation between the clay content of the membrane and the average length of the PDMS chain, indicating that the nanohybrid material is made of clay particles covalently linked to the PDMS structure. This is particularly the case for Sepiolite with has a high density of Q(2) silanol sites. The separation performances of the prepared membranes were tested for CO(2)/CH(4) and O(2)/N(2) mixtures. The observed separation factors showed an increase of the selectivity in the case of CO(2)/CH(4) in comparison with membranes made from PDMS alone under the same conditions. 2009 Elsevier Inc. All rights reserved.

  13. Ceramic membranes applied in separation of hot gases; Membranas Ceramicas para Separacion de Gases en Caliente

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The aim of this project is to develop and evaluate inorganic membranes of a ceramic type, with nanometric pore size, applied in separation of contaminants and fuel enrichment, gas mixture in coal gasification . etc. Using ceramic materials have the advantage of being highly physical and chemical resistance, which makes these membranes more adequate then metal equivalent for these applications. A support manufacture and the development of natricum membranes technology to estimate the potential fields of applications and industrial viability of ceramic membranes are the intermediate goals so that the project could be considered successful one. The project has been carried out jointly by the following entities: TGI, S. A. (Tecnologia y Gestion de la Innovacion, Spain). CIEMAT (Centro de Investigaciones energeticas, Medioambientales y Tecnologicas, Spain) and CSIC-UAM (Centro mixto Consejo Superior de Investigaciones Cientificas-Universidad Autonoma de Madrid. Instituto de Ciencias de Materiales, Spain). The range of activities proposed in this project is to get the sufficient knowledge of preparation and behaviour of separation membranes to be able to procede to the desing and manufacture of an industrial filter. The project phases include; the ameiloration of ceramic support processing methods, the fluid dynamic evaluation, technology for membrane desing and manufacturing, the mounting (setting up) of an experimental installation for testing and evaluation. As a previous step a state of the art review about the following topics was made: high temperature inorganic membranes, technology separation mechanisms, gasifications process and its previous experience applications of membranes and determination of membranes specifications and characteristics of testing conditions. At the end a new inorganic ceramic membrane, with nanometric pore size and useful in several industrial processes (filtration, separation of contaminants, fuel enrichment, purification of gas mixtures

  14. Smart membranes for monitoring membrane based desalination processes

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-10-12

    Various examples are related to smart membranes for monitoring membrane based process such as, e.g., membrane distillation processes. In one example, a membrane, includes a porous surface and a plurality of sensors (e.g., temperature, flow and/or impedance sensors) mounted on the porous surface. In another example, a membrane distillation (MD) process includes the membrane. Processing circuitry can be configured to monitor outputs of the plurality of sensors. The monitored outputs can be used to determine membrane degradation, membrane fouling, or to provide an indication of membrane replacement or cleaning. The sensors can also provide temperatures or temperature differentials across the porous surface, which can be used to improve modeling or control the MD process.

  15. Concentration gradient driven molecular dynamics: a new method for simulations of membrane permeation and separation.

    Science.gov (United States)

    Ozcan, Aydin; Perego, Claudio; Salvalaglio, Matteo; Parrinello, Michele; Yazaydin, Ozgur

    2017-05-01

    In this study, we introduce a new non-equilibrium molecular dynamics simulation method to perform simulations of concentration driven membrane permeation processes. The methodology is based on the application of a non-conservative bias force controlling the concentration of species at the inlet and outlet of a membrane. We demonstrate our method for pure methane, ethane and ethylene permeation and for ethane/ethylene separation through a flexible ZIF-8 membrane. Results show that a stationary concentration gradient is maintained across the membrane, realistically simulating an out-of-equilibrium diffusive process, and the computed permeabilities and selectivity are in good agreement with experimental results.

  16. Recent advances on mixed matrix membranes for CO2 separation

    Institute of Scientific and Technical Information of China (English)

    Ming Wang; Zhi Wang; Song Zhao; Jixiao Wang; Shichang Wang

    2017-01-01

    Recent advances on mixed matrix membrane for CO2 separation are reviewed in this paper. To improve CO2 separation performance of polymer membranes, mixedmatrixmembranes (MMMs) are developed. The concept of MMM is illustrated distinctly. Suitable polymer and inorganic or organic fillers for MMMs are summarized.Possible interface morphologies between polymer and filler, and the effect of interface morphologies on gas transport properties of MMMs are summarized. The methods to improve compatibility between polymer and filler are introduced. There are eightmethods including silane coupling, Grignard treatment, incorporation of additive,grafting, in situ polymerization, polydopamine coating, particle fusion approach and polymer functionalization. To achieve higher productivity for industrial application,mixed matrix composite membranes are developed. The recent development on hollow fiber and flat mixedmatrix composite membrane is reviewed in detail. Last, the future trend of MMM is forecasted.

  17. Simulation Model of Membrane Gas Separator Using Aspen Custom Modeler

    Energy Technology Data Exchange (ETDEWEB)

    Song, Dong-keun [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Shin, Gahui; Yun, Jinwon; Yu, Sangseok [Chungnam Nat’l Univ., Daejeon (Korea, Republic of)

    2016-12-15

    Membranes are used to separate pure gas from gas mixtures. In this study, three different types of mass transport through a membrane were developed in order to investigate the gas separation capabilities of a membrane. The three different models typically used are a lumped model, a multi-cell model, and a discretization model. Despite the multi-cell model producing similar results to a discretization model, the discretization model was selected for this investigation, due to the cell number dependence of a multi-cell model. The mass transport model was then used to investigate the effects of pressure difference, flow rate, total exposed area, and permeability. The results showed that the pressure difference increased with the stage cut, but the selectivity was a trade-off for the increasing pressure difference. Additionally, even though permeability is an important parameter, the selectivity and stage cut of the membrane converged as permeability increased.

  18. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    International Nuclear Information System (INIS)

    Susanto, H.; Roihatin, A.; Aryanti, N.; Anggoro, D.D.; Ulbricht, M.

    2012-01-01

    This paper compares the performance of different hydrophilization methods to prepare low fouling ultrafiltration (UF) membranes. The methods include post-modification with hydrophilic polymer and blending of hydrophilic agent during either conventional or reactive phase separation (PS). The post-modification was done by photograft copolymerization of water-soluble monomer, poly(ethylene glycol) methacrylate (PEGMA), onto a commercial polyethersulfone (PES) UF membrane. Hydrophilization via blend polymer membrane with hydrophilic additive was performed using non-solvent induced phase separation (NIPS). In reactive PS method, the cast membrane was UV-irradiated before coagulation. The resulting membrane characteristic, the performance and hydrophilization stability were systematically compared. The investigated membrane characteristics include surface hydrophilicity (by contact angle /CA/), surface chemistry (by FTIR spectroscopy), and surface morphology (by scanning electron microscopy). The membrane performance was examined by investigation of adsorptive fouling and ultrafiltration using solution of protein or polysaccharide or humic acid. The results suggest that all methods could increase the hydrophilicity of the membrane yielding less fouling. Post-modification decreased CA from 44.8 ± 4.2 o to 37.8 ± 4.2 o to 42.5 ± 4.3 o depending on the degree of grafting (DG). The hydrophilization via polymer blend decreased CA from from 65 deg. to 54 deg. for PEG concentration of 5%. Nevertheless, decreasing hydraulic permeability was observed after post-modification as well as during polymer blend modification. Stability examination showed that there was leaching out of modifier agent from the membrane matrix prepared via conventional PS after 10 days soaking in both water and NaOH. Reactive PS could increase the stability of the modifier agent in membrane matrix. Highlights: ► We compared different methods to prepare low fouling ultrafiltration (UF) membranes.

  19. Effect of membrane hydrophilization on ultrafiltration performance for biomolecules separation

    Energy Technology Data Exchange (ETDEWEB)

    Susanto, H., E-mail: heru.susanto@undip.ac.id [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Roihatin, A.; Aryanti, N.; Anggoro, D.D. [Department of Chemical Engineering, Universitas Diponegoro, Jl. Prof. Sudarto-Tembalang, Semarang (Indonesia); Ulbricht, M. [Lehrstuhl fuer Technische Chemie, Universitaet Duisburg-Essen, Germany, Universitaetstr. 5, Essen (Germany)

    2012-10-01

    This paper compares the performance of different hydrophilization methods to prepare low fouling ultrafiltration (UF) membranes. The methods include post-modification with hydrophilic polymer and blending of hydrophilic agent during either conventional or reactive phase separation (PS). The post-modification was done by photograft copolymerization of water-soluble monomer, poly(ethylene glycol) methacrylate (PEGMA), onto a commercial polyethersulfone (PES) UF membrane. Hydrophilization via blend polymer membrane with hydrophilic additive was performed using non-solvent induced phase separation (NIPS). In reactive PS method, the cast membrane was UV-irradiated before coagulation. The resulting membrane characteristic, the performance and hydrophilization stability were systematically compared. The investigated membrane characteristics include surface hydrophilicity (by contact angle /CA/), surface chemistry (by FTIR spectroscopy), and surface morphology (by scanning electron microscopy). The membrane performance was examined by investigation of adsorptive fouling and ultrafiltration using solution of protein or polysaccharide or humic acid. The results suggest that all methods could increase the hydrophilicity of the membrane yielding less fouling. Post-modification decreased CA from 44.8 {+-} 4.2{sup o} to 37.8 {+-} 4.2{sup o} to 42.5 {+-} 4.3{sup o} depending on the degree of grafting (DG). The hydrophilization via polymer blend decreased CA from from 65 deg. to 54 deg. for PEG concentration of 5%. Nevertheless, decreasing hydraulic permeability was observed after post-modification as well as during polymer blend modification. Stability examination showed that there was leaching out of modifier agent from the membrane matrix prepared via conventional PS after 10 days soaking in both water and NaOH. Reactive PS could increase the stability of the modifier agent in membrane matrix. Highlights: Black-Right-Pointing-Pointer We compared different methods to prepare low

  20. Membrane Separation of 2-Ethyl Hexyl Amine/1-Decene

    KAUST Repository

    Bawareth, Bander

    2012-12-01

    1-Decene is a valuable product in linear alpha olefins plants that is contaminated with 2-EHA (2-ethyl hexyl amine). Using organic solvent nanofiltration membranes for this separation is quite challengeable. A membrane has to be a chemically stable in this environment with reasonable and stable separation factor. This paper shows that Teflon AF 2400 and cellulose acetate produced interesting results in 1-decene/2-EHA separation. The separation factor of Teflon AF 2400 is 3 with a stable permeance of 1.1x10-2 L/(m2·h·bar). Likewise, cellulose acetate gave 2-EHA/1-decene separation factor of 2 with a lower permeance of 3.67x10-3 L/(m2·h·bar). A series of hydrophilic membranes were tested but they did not give any separation due to high degree of swelling of 2-EHA with these polymers. The large swelling causes the membrane to lose its diffusivity selectivity because of an increase in the polymer\\'s chain mobility.

  1. Recent progress in molecular simulation of nanoporous graphene membranes for gas separation

    Science.gov (United States)

    Fatemi, S. Mahmood; Baniasadi, Aminreza; Moradi, Mahrokh

    2017-07-01

    If an ideal membrane for gas separation is to be obtained, the following three characteristics should be considered: the membrane should be as thin as possible, be mechanically robust, and have welldefined pore sizes. These features will maximize its solvent flux, preserve it from fracture, and guarantee its selectivity. Graphene is made up of a hexagonal honeycomb lattice of carbon atoms with sp 2 hybridization state forming a one-atom-thick sheet of graphite. Following conversion of the honeycomb lattices into nanopores with a specific geometry and size, a nanoporous graphene membrane that offers high efficiency as a separation membrane because of the ultrafast molecular permeation rate as a result of its one-atom thickness is obtained. Applications of nanoporous graphene membranes for gas separation have been receiving remarkably increasing attention because nanoporous graphene membranes show promising results in this area. This review focuses on the recent advances in nanoporous graphene membranes for applications in gas separation, with a major emphasis on theoretical works. The attractive properties of nanoporous graphene membranes introduce make them appropriate candidates for gas separation and gas molecular-sieving processes in nanoscale dimensions.

  2. Ordered mesoporous silica (OMS) as an adsorbent and membrane for separation of carbon dioxide (CO2).

    Science.gov (United States)

    Chew, Thiam-Leng; Ahmad, Abdul L; Bhatia, Subhash

    2010-01-15

    Separation of carbon dioxide (CO(2)) from gaseous mixture is an important issue for the removal of CO(2) in natural gas processing and power plants. The ordered mesoporous silicas (OMS) with uniform pore structure and high density of silanol groups, have attracted the interest of researchers for separation of carbon dioxide (CO(2)) using adsorption process. These mesoporous silicas after functionalization with amino groups have been studied for the removal of CO(2). The potential of functionalized ordered mesoporous silica membrane for separation of CO(2) is also recognized. The present paper reviews the synthesis of mesoporous silicas and important issues related to the development of mesoporous silicas. Recent studies on the CO(2) separation using ordered mesoporous silicas (OMS) as adsorbent and membrane are highlighted. The future prospectives of mesoporous silica membrane for CO(2) adsorption and separation are also presented and discussed. Copyright 2009 Elsevier B.V. All rights reserved.

  3. Antioxidants, mechanisms, and recovery by membrane processes.

    Science.gov (United States)

    Bazinet, Laurent; Doyen, Alain

    2017-03-04

    Antioxidants molecules have a great interest for bio-food and nutraceutical industries since they play a vital role for their capacity to reduce oxidative processes. Consequently, these molecules, generally present in complex matrices, have to be fractionated and purified to characterize them and to test their antioxidant activity. However, as natural or synthetics antioxidant molecules differ in terms of structural composition and physico-chemical properties, appropriate separation technologies must be selected. Different fractionation technologies are available but the most commonly used are filtration processes. Indeed, these technologies allow fractionation according to molecular size (pressure-driven processes), charge, or both size and charge (electrically driven processes). In this context, and after summarizing the reaction mechanisms of the different classes and nature of antioxidants as well as membrane fractionation technologies, this manuscript presents the specific applications of these membranes processes for the recovery of antioxidant molecules.

  4. Hydrogen separation membranes annual report for FY 2010.

    Energy Technology Data Exchange (ETDEWEB)

    Balachandran, U.; Dorris, S. E; Emerson, J. E.; Lee, T. H.; Lu, Y.; Park, C. Y.; Picciolo, J. J. (Energy Systems)

    2011-03-14

    The objective of this work is to develop dense ceramic membranes for separating hydrogen from other gaseous components in a nongalvanic mode, i.e., without using an external power supply or electrical circuitry. The goal of this project is to develop dense hydrogen transport membranes (HTMs) that nongalvanically (i.e., without electrodes or external power supply) separate hydrogen from gas mixtures at commercially significant fluxes under industrially relevant operating conditions. These membranes will be used to separate hydrogen from gas mixtures such as the product streams from coal gasification, methane partial oxidation, and water-gas shift reactions. Potential ancillary uses of HTMs include dehydrogenation and olefin production, as well as hydrogen recovery in petroleum refineries and ammonia synthesis plants, the largest current users of deliberately produced hydrogen. This report describes the results from the development and testing of HTM materials during FY 2010.

  5. CO2 separation from biogas with ceramic membranes

    International Nuclear Information System (INIS)

    Fassauer, Burkhardt; Richter, Hannes; Schwarz, Bjoern; Reger-Wagner, Norman; Kaemnitz, Susanne; Lubenau, Udo; Mothes, Raimund

    2015-01-01

    Biogas contains after the production of up to 55% CO 2 . In order to use biogas as a fuel or to feed it into the natural gas network, it must be purified before. Adsorption and scrubbing processes are primarily used technically. Membrane processes offer the advantage of continuous operation and a simple modular and flexible system design, which imply relatively low investment costs and low energy needs. Moreover, membrane systems can be started up and shut down quickly without any problems. Ceramic membranes are characterised by high stability (thermal, chemical, mechanical) and very high flows in comparison to polymeric membranes. [de

  6. Preparation and Characterization of Membranes Formed by Nonsolvent Induced Phase Separation: A Review

    KAUST Repository

    Guillen, Gregory R.

    2011-04-06

    The methods and mechanisms of nonsolvent induced phase separation have been studied for more than fifty years. Today, phase inversion membranes are widely used in numerous chemical industries, biotechnology, and environmental separation processes. The body of knowledge has grown exponentially in the past fifty years, which suggests the need for a critical review of the literature. Here we present a review of nonsolvent induced phase separation membrane preparation and characterization for many commonly used membrane polymers. The key factors in membrane preparation discussed include the solvent type, polymer type and concentration, nonsolvent system type and composition, additives to the polymer solution, and film casting conditions. A brief introduction to membrane characterization is also given, which includes membrane porosity and pore size distribution characterization, membrane physical and chemical properties characterization, and thermodynamic and kinetic evaluation of the phase inversion process. One aim of this review is to lay out the basics for selecting polymer solvent nonsolvent systems with appropriate film casting conditions to produce membranes with the desired performance, morphology, and stability, and to choose the proper way to characterize these properties of nonsolvent induced phase inversion membranes. © 2011 American Chemical Society.

  7. Effective separation of propylene/propane binary mixtures by ZIF-8 membranes

    KAUST Repository

    Pan, Yichang

    2012-02-01

    The separation of propylene/propane mixtures is one of the most important but challenging processes in the petrochemical industry. A novel zeolitic imidazole framework (ZIF-8) membrane prepared by a facile hydrothermal seeded growth method showed excellent separation performances for a wide range of propylene/propane mixtures. The membrane showed a permeability of propylene up to 200. barrers and a propylene to propane separation factor up to 50 at optimal separation conditions, well surpassing the "upper-bound trade-off" lines of existing polymer and carbon membranes. The experimental data also showed that the membranes had excellent reproducibility, long-term stability and thermal stability. © 2011 Elsevier B.V.

  8. Membrane processes in production of functional whey components

    Directory of Open Access Journals (Sweden)

    Lutfiye Yilmaz-Ersan

    2009-12-01

    Full Text Available In recent years, whey has been recognised as a major source of nutritional and functional ingredients for the food industry. Commercial whey products include various powders, whey protein concentrates and isolates, and fractionated proteins, such as a-lactalbumin and b-lactoglobulin. The increased interest in separation and fractionation of whey proteins arises from the differences in their functional, biological and nutritional properties. In response to concerns about environmental aspects, research has been focused on membrane filtration technology, which provides exciting new opportunities for large-scale protein and lactose fractionation. Membrane separation is such technique in which particles are separated according to their molecular size. The types of membrane processing techniques are ultrafiltration, microfiltration, reverse osmosis, pervaporation, electrodialysis and nanofiltration. A higher purification of whey proteins is possible by combining membrane separation with ion-exchange. This paper provides an overview of types and applications of membrane separation techniques

  9. Ceramic membrane technologies for gas separation

    International Nuclear Information System (INIS)

    Badwal, S.P.S.; Ciacchi, F.T.

    2000-01-01

    Solid state electrochemical cells based on oxygen-ion or proton conduction (pure ionic or mixed ionic/electronic conductors) allow selective transport of oxygen (oxygen-ion conducting materials) or hydrogen (for proton conducting materials) in the form of ionic flux at high temperatures. Thus these systems can act as filters for molecular oxygen or hydrogen and can be used for both generation or removal of these gases selectively. The usage of such devices are numerous including control of atmosphere in industrial environments to production of power and chemicals, in petroleum and medical industries, and in combustion processes. In this paper, a brief overview of the technology has been given and various doped materials for construction of such devices, such as zirconia, ceria, bismuth oxides or lanthanum gallates have been briefly reviewed. Copyright (2000) The Australian Ceramic Society

  10. Separation of Gas Mixtures by New Type of Membranes – Dynamic Liquid Membranes.

    Czech Academy of Sciences Publication Activity Database

    Setničková, Kateřina; Šíma, Vladimír; Petričkovič, Roman; Řezníčková Čermáková, Jiřina; Uchytil, Petr

    2016-01-01

    Roč. 160, FEB 29 (2016), s. 132-135 ISSN 1383-5866 Institutional support: RVO:67985858 Keywords : gas separation * liquid membrane * methane Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  11. Les techniques de séparation de gaz par membranes Gas Separation Techniques by Membranes

    Directory of Open Access Journals (Sweden)

    Avrillon R.

    2006-11-01

    high permeability and good mechanical strength. This structure has a thin dense and selective skin (0. 1 to 1 µm thick supported by a thick microporous substructure (50 to 200 µm. Such membranes come either in a flat shape or in the form of hollow fibers with their skin outside. The asymmetric structure is obtained by the so-called phase inversiontechnique, which consists in transforming a homogeneous polymer solution into a two-phase medium made up of a polymer-rich phase and a polymer-poor phase. The continuous rich phase prefigures the pore walls of the substructure. Once the poor phase becomes continuous, it will make up a network of communicating pores. Phase inversion can be caused in several ways: (a solvent departure by evaporation (dry process (b introduction of a nonsolvent (wet process (c dry-wet process (d temperature reduction (thermal process. The dense skin is formed on the side where evaporation takes place or where contact is made with the nonsolvent, or again on the cooled side (with the other side being in contact with the support for a flat membrane and a more or less coagulating liquid with a hollow fiber. A dense skin is formed by the superficial polymer overconcentration resulting from solvent evaporation or from its extraction by the nonsolvent before phase inversion. Figure 6 shows a ternary polymer-solvent-nonsolvent isothermal phase diagram on which arrows indicate how the homogeneous polymer solution (I evolves toward a liquidliquid phase separation (II or toward a gel structure (III. Industrial Development -Industrial permeators have large membrane surface areas in a compact form. These areas can be up to 500 m²/m³ for the flat version and up to 8000 m²/m³ for the hollow-fiber version. This compactness is obtained by the spiral winding of flat membranes or by the grouping of hollow fibers in bundles. Fig. 7 shows both types of permeators. The advantages of gas permeation lie in the small investment required, low energy consumption

  12. Coupling of separation and reaction in zeolite membrane reactor for hydroisomerization of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gora, L.; Maloncy, M.L.; Jansen, J.C. [Ceramic Membrane Centre, The Pore, DelftChemTech, Delft Univ. of Technology (Netherlands)

    2004-07-01

    A zeolite membrane reactor has been developed for the hydroisomerization of hydrocarbons, in which the linear molecules are separated from branch ones on the silicalite-1 membrane prior to conversion of the permeated linear hydrocarbons to equilibrium levels on the catalyst bed. A model studies using C6 components are conduct. Separated n-C6 from 2MP (selectivity 24) is converted for 72% with 36% selectivity towards di-branched isomers (at 393 K). The results indicate that platinum containing chlorinated alumina/silicalite-1 membrane reactor has a potential in upgrading octane values and offers advantages such as higher efficiency, better process control and lower consumption of energy. (orig.)

  13. Estimation of phase separation temperatures for polyethersulfone/solvent/non-solvent systems in RTIPS and membrane properties

    DEFF Research Database (Denmark)

    Liu, Min; Liu, Sheng-Hui; Skov, Anne Ladegaard

    2018-01-01

    was observed. When the membrane-forming temperature was higher than the cloud point, membranes with a bi-continuous structure were acquired and showed a higher pure water permeation flux than that of membranes prepared with the non-solvent induced phase separation (NIPS) process. The pure water permeation flux...... and the mean pore size of membranes prepared with the RTIPS process decreased in line with an increase of PES molecular weight. When the membrane formation mechanism was the RTIPS process, the mechanical properties were better than those of the corresponding membranes prepared with the NIPS process....

  14. An Underwater Superoleophobic Sepiolite Fibrous Membrane (SFM) for Oil­‐in­‐water Emulsion Separation

    KAUST Repository

    Yao, Pinjiang

    2014-12-01

    Separating oil/water emulsions is significant for the ecosystem and the petroleum and processing industry. To this end, we prepared an underwater superoleophobic membrane inspired by unique wettability of the fish scales. This membrane was fabricated by a facile vacuum filtration process of sepiolite nanofibers and chitosan, and after the cross-linking via glutaraldehyde, a self-standing membrane was obtained. The as-prepared membrane exhibited excellent capability of separating both the surfactant-free and surfactant-stabilized oil-in-water emulsions with high efficiency. This sepiolite fibrous membrane offers a convenient, reliable and efficient way for the large-scale de-emulsification process.

  15. One Step Biomass Gas Reforming-Shift Separation Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Michael J. [Gas Technology Institute; Souleimanova, Razima [Gas Technology Institute

    2012-12-28

    GTI developed a plan where efforts were concentrated in 4 major areas: membrane material development, membrane module development, membrane process development, and membrane gasifier scale-up. GTI assembled a team of researchers to work in each area. Task 1.1 Ceramic Membrane Synthesis and Testing was conducted by Arizona State University (ASU), Task 1.2 Metallic Membrane Synthesis and Testing was conducted by the U.S. National Energy Technology Laboratory (NETL), Task 1.3 was conducted by SCHOTT, and GTI was to test all membranes that showed potential. The initial focus of the project was concentrated on membrane material development. Metallic and glass-based membranes were identified as hydrogen selective membranes under the conditions of the biomass gasification, temperatures above 700C and pressures up to 30 atmospheres. Membranes were synthesized by arc-rolling for metallic type membranes and incorporating Pd into a glass matrix for glass membranes. Testing for hydrogen permeability properties were completed and the effects of hydrogen sulfide and carbon monoxide were investigated for perspective membranes. The initial candidate membrane of Pd80Cu20 chosen in 2008 was selected for preliminary reactor design and cost estimates. Although the H2A analysis results indicated a $1.96 cost per gge H2 based on a 5A (micron) thick PdCu membrane, there was not long-term operation at the required flux to satisfy the go/no go decision. Since the future PSA case yielded a $2.00/gge H2, DOE decided that there was insufficient savings compared with the already proven PSA technology to further pursue the membrane reactor design. All ceramic membranes synthesized by ASU during the project showed low hydrogen flux as compared with metallic membranes. The best ceramic membrane showed hydrogen permeation flux of 0.03 SCFH/ft2 at the required process conditions while the metallic membrane, Pd80Cu20 showed a flux of 47.2 SCFH/ft2 (3 orders of magnitude difference). Results from

  16. Mechanistic insights into porous graphene membranes for helium separation and hydrogen purification

    Science.gov (United States)

    Wei, Shuxian; Zhou, Sainan; Wu, Zhonghua; Wang, Maohuai; Wang, Zhaojie; Guo, Wenyue; Lu, Xiaoqing

    2018-05-01

    Porous graphene (PG) and nitrogen-substituted PG monolayers of 3N-PG and 6N-PG were designed as effective membranes for the separation of He and H2 over Ne, Ar, N2, CO, and CH4 by using density functional theory. Results showed that PG and 3N-PG exhibited suitable pore sizes and relatively high stabilities for He and H2 separation. PG and 3N-PG membranes also presented excellent He and H2 selectivities over Ne, Ar, N2, CO and CH4 at a wide temperature range. 6N-PG membrane exerted unexceptionable permeances of the studied gases, especially He and H2, which could remarkably improve the separation efficiency of He and H2. Analyses on the most stable adsorption configurations and maximum adsorption energies indicated weak Van der Waals interactions between the gases and the three PG-based membranes. Microscopic permeation process analyses based on the minimum energy pathway, energy profiles, and electron density isosurfaces elucidated the remarkable selectivities of He over Ne/CO/N2/Ar/CH4 and H2 over CO/N2/CH4 and the high permeances of He and H2 passing through the three PG-based membranes. This work not only highlighted the potential use of the three PG-based membranes for He separation and H2 purification but also provided a superior alternative strategy to design and screen membrane materials for gas separation.

  17. Investigation of separation factors of neptunium and plutonium in the process of mass transfer through liquid impregnated membranes with di-2-ethylhexylphosphoric acid

    International Nuclear Information System (INIS)

    Novikov, A.P.; Mikheeva, M.N.; Myasoedov, B.F.

    1990-01-01

    Kinetics of joint transfer of neptunium(6) and plutonium(4) through liquid membranes with di-2-ethylhexylphosphoric acid, depending on the concentration of the carrier, nature of reextracting agent and ratio of metal concentrations, was investigated. The optimal conditions for selective isolation of microimpurity of one of the elements from solutions of the other were determined. Solution of ammonium carbonate with carrier concentration of 0.1-0.2 mol/l can be expediently utilized as reextracting phase for neptunium impurity removal

  18. Selective separation of oil and water with special wettability mesh membranes

    KAUST Repository

    Liu, Defei

    2017-02-24

    Due to the different interfacial effects of oil and water, utilizing the special wettability of solid surfaces to design an oil and water separation process has been demonstrated to be an effective approach for oil/water separation. In this report, a simple process has been developed to fabricate special surface wettability mesh membranes. The carbon nanoparticles with diameters of 10 nm were first coated onto the surface of steel wires based on a candle soot coating process. These templates of carbon nanoparticles were then coated with a more stable layer of silica (SiO2) particles via a facile chemical vapor deposition route. After being modified by two separate methods, a superhydrophobic/superoleophilic membrane was obtained by the use of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTS) and a oleophobic/superhydrophilic membrane was obtained by using poly(diallyldimethylammonium-perfluorooctanoate) (PDDA–PFO). Separation experiments show that these superhydrophobic/superoleophilic or oleophobic/superhydrophilic mesh membranes can be used to selectively separate oil/water with a high flux of more than 930 L m−2 h−1 and a collecting efficiency of over 97%. Furthermore, the repetitions of the separation experiments demonstrate that these superhydrophobic/superoleophilic or oleophobic/superhydrophilic mesh membranes are durable, stable and reusable, making them encouraging candidates for practical oil-polluted water treatment.

  19. Substituted polynorbornenes as promising materials for gas separation membranes

    International Nuclear Information System (INIS)

    Finkelshtein, Evgenii Sh; Bermeshev, Maksim V; Gringolts, Mariya L; Starannikova, L E; Yampolskii, Yu P

    2011-01-01

    Published results concerning the synthesis and study of the transport characteristics of polynorbornenes are considered and analyzed. Conclusions are drawn regarding the effect of the backbone rigidity and the nature of side groups on the gas permeability level. The prospects of using addition organosilicon polynorbornenes as gas separating membrane materials are discussed.

  20. Gas separation properties of new polyoxadiazole and polytriazole membranes

    NARCIS (Netherlands)

    Hensema, E.R.; Hensema, E.R.; Borges-Sena, M.E.R.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.

    1994-01-01

    The gas separation properties of new aromatic poly-1,2,4-triazole and poly-1,3,4-oxadiazole membranes have been systematically investigated. Various functional groups were incorporated as pendent groups onto the polymer backbone of poly-1,2,4-triazoles. A wide permeability/selectivity spectrum was

  1. Evaluation of the permeability of microporous membranes polyamide 6 / clay bentonite for water-oil separation

    International Nuclear Information System (INIS)

    Medeiros, P.S.S.; Medeiros, K.M.; Araujo, E.M.; Lira, H.L.

    2014-01-01

    The petroleum refining industries have faced major problems in relation to the treatment of their effluents before disposal into the environment. Among the conventional technologies treatment of these effluents, the process of oil-water separation by means of membranes has been extensively used, for having enormous potentiality. Therefore, in this study, hybrid membranes of polyamide 6/ bentonite clay were produced by the technique of phase inversion and by precipitation of the solution from the nanocomposites obtained by melt intercalation. The clay was organically modified with the quaternary ammonium salt (Cetremide®). The nanocomposites were obtained from (PA6) with untreated (AST) and treated clay (ACT), which were subsequently characterized by X-ray diffraction (XRD). Already membranes were characterized by XRD, scanning electron microscopy (SEM) and flow measurements. From the XRD results, it was observed an exfoliated and/or partially exfoliated structure for the nanocomposites and for the membranes. From SEM images it was observed that the presence of AST and ACT clays in the polymeric matrix caused changes in membrane morphology and pore formation. The flow with distilled water in the membranes showed a decrease initially and then followed by stability. All membranes tested in the process of separating emulsions of oil in water, particularly those of nanocomposites obtained a significant reduction of oil concentration in the permeate, thus showing that these membranes have a great potential to be applied to the water-oil separation. (author)

  2. Highly hydrothermally stable microporous silica membranes for hydrogen separation.

    Science.gov (United States)

    Wei, Qi; Wang, Fei; Nie, Zuo-Ren; Song, Chun-Lin; Wang, Yan-Li; Li, Qun-Yan

    2008-08-07

    Fluorocarbon-modified silica membranes were deposited on gamma-Al2O3/alpha-Al2O3 supports by the sol-gel technique for hydrogen separation. The hydrophobic property, pore structure, gas transport and separation performance, and hydrothermal stability of the modified membranes were investigated. It is observed that the water contact angle increases from 27.2+/-1.5 degrees for the pure silica membranes to 115.0+/-1.2 degrees for the modified ones with a (trifluoropropyl)triethoxysilane (TFPTES)/tetraethyl orthosilicate (TEOS) molar ratio of 0.6. The modified membranes preserve a microporous structure with a micropore volume of 0.14 cm3/g and a pore size of approximately 0.5 nm. A single gas permeation of H2 and CO2 through the modified membranes presents small positive apparent thermal activation energies, indicating a dominant microporous membrane transport. At 200 degrees C, a single H2 permeance of 3.1x10(-6) mol m(-2) s(-1) Pa(-1) and a H2/CO2 permselectivity of 15.2 were obtained after proper correction for the support resistance and the contribution from the defects. In the gas mixture measurement, the H2 permeance and the H2/CO2 separation factor almost remain constant at 200 degrees C with a water vapor pressure of 1.2x10(4) Pa for at least 220 h, indicating that the modified membranes are hydrothermally stable, benefiting from the integrity of the microporous structure due to the fluorocarbon modification.

  3. Study of a dense metal membrane reactor for hydrogen separation from hydroiodic acid decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Tosti, Silvano; Borelli, Rodolfo; Borgognoni, Fabio [ENEA, Dipartimento FPN, C.R. ENEA Frascati, Via E. Fermi 45, Frascati, Roma I-00044 (Italy); Favuzza, Paolo; Tarquini, Pietro [ENEA, Dipartimento TER, C.R. ENEA Casaccia, Via Anguillarese 301, Roma (Italy); Rizzello, Claudio [Tesi Sas, Via Bolzano 28, Roma (Italy)

    2008-10-15

    A membrane reactor has been studied for separating the hydrogen produced by the dissociation of hydroiodic acid in the thermochemical-sulfur iodine process. A dense metal membrane tube of wall thickness 0.250 mm has been considered in this analysis for hosting a fixed-bed catalyst: the selective separation of hydrogen from an azeotropic H{sub 2}O-HI mixture has been studied in the temperature range of 700-800 K. The materials being considered for the construction of the membrane tube are niobium and tantalum; as a matter of fact, the most commonly used Pd-Ag membranes cannot withstand the corrosive environment generated by the hydroiodic acid. The Damkohler-Peclet analysis has been used for designing the membrane reactor, while a finite element method has simulated its behaviour: the effect of the temperature and pressure on the HI conversion and hydrogen yield has been evaluated. (author)

  4. Process for separating radioactive gases

    International Nuclear Information System (INIS)

    Kimura, Shigeru; Awada, Yoshihisa.

    1976-01-01

    Object: To efficiently and safely separate and recover raw gases such as krypton which requires radioactive attenuation by a long term storage. Structure: A mixture of krypton and xenon is separated by liquefaction from raw gases at a first distillation column, using latent heat of liquid nitrogen. The krypton and xenon mixture separated by liquefaction at the first distillation column is separated into krypton and xenon, by controlling operation pressure of a second distillation column at about 3 - 5 atm., using sensible heat of low temperature nitrogen gas discharged from a top of the first distillation column and a condenser. (Aizawa, K.)

  5. Surface patterning of polymeric separation membranes and its influence on the filtration performance

    Science.gov (United States)

    Maruf, Sajjad

    Polymeric membrane based separation technologies are crucial for addressing the global issues such as water purification. However, continuous operations of these processes are often hindered by fouling which increases mass transport resistance of the membrane to permeation and thus the energy cost, and eventually replacement of the membrane in the system. In comparison to other anti-fouling strategies, the use of controlled surface topography to mitigate fouling has not been realized mainly due to the lack of methods to create targeted topography on the porous membrane surface. This thesis aims to develop a new methodology to create surface-patterned polymeric separation membrane to improve their anti-fouling characteristics during filtration. First, successful fabrication of sub-micron surface patterns directly on a commercial ultrafiltration (UF) membrane surface using nanoimprint lithographic (NIL) technique was demonstrated. Comprehensive filtration studies revealed that the presence of these sub-micron surface patterns mitigates not only the onset of colloidal particle deposition, but also lowers the rate of growth of cake layer after initial deposition, in comparison with un-patterned membranes. The anti-fouling effects were also observed for model protein solutions. Staged filtration experiments, with backwash cleaning, revealed that the permeate flux of the patterned membrane after protein fouling was considerably higher than that of the pristine or un-patterned membrane. In addition to the surface-patterning of UF membranes, successful fabrication of a surface-patterned thin film composite (TFC) membrane was shown for the first time. A two-step fabrication process was carried out by (1) nanoimprinting a polyethersulfone (PES) support using NIL, and (2) forming a thin dense film atop the PES support via interfacial polymerization (IP). Fouling experiments suggest that the surface patterns alter the hydrodynamics at the membrane-feed interface, which is

  6. Membrane-based ethylene/ethane separation: The upper bound and beyond

    KAUST Repository

    Rungta, Meha; Zhang, Chen; Koros, William J.; Xu, Liren

    2013-01-01

    Ethylene/ethane separation via cryogenic distillation is extremely energy-intensive, and membrane separation may provide an attractive alternative. In this paper, ethylene/ethane separation performance using polymeric membranes is summarized

  7. RADIATION STABILITY OF NAFION MEMBRANES USED FOR ISOTOPE SEPARATION BY PROTON EXCHANGE MEMBRANE ELECTROLYSIS

    International Nuclear Information System (INIS)

    Fox, E.

    2009-01-01

    Proton Exchange Membrane Electrolyzers have potential interest for use for hydrogen isotope separation from water. In order for PEME to be fully utilized, more information is needed on the stability of Nafion when exposed to radiation. This work examines Nafion 117 under varying exposure conditions, including dose rate, total dosage and atmospheric condition. Analytical tools, such as FT-IR, ion exchange capacity, DMA and TIC-TOC were used to characterize the exposed membranes. Analysis of the water from saturated membranes can provide important data on the stability of the membranes during radiation exposure. It was found that the dose rate of exposure plays an important role in membrane degradation. Potential mechanisms for membrane degradation include peroxide formation by free radicals

  8. RADIATION STABILITY OF NAFION MEMBRANES USED FOR ISOTOPE SEPARATION BY PROTON EXCHANGE MEMBRANE ELECTROLYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Fox, E

    2009-05-15

    Proton Exchange Membrane Electrolyzers have potential interest for use for hydrogen isotope separation from water. In order for PEME to be fully utilized, more information is needed on the stability of Nafion when exposed to radiation. This work examines Nafion 117 under varying exposure conditions, including dose rate, total dosage and atmospheric condition. Analytical tools, such as FT-IR, ion exchange capacity, DMA and TIC-TOC were used to characterize the exposed membranes. Analysis of the water from saturated membranes can provide important data on the stability of the membranes during radiation exposure. It was found that the dose rate of exposure plays an important role in membrane degradation. Potential mechanisms for membrane degradation include peroxide formation by free radicals.

  9. Preparation and characterization of new zeolite membranes. Application to gaseous separation; Preparation et caracterisation de nouvelles membranes de zeolithe application a la separation gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Anstett, M.

    1996-11-25

    Zeolites are interesting for the preparation of inorganic membranes which could be used for the continuous separation of gas and liquids by gas permeation and pervaporation. Zeolites membranes are obtained by hydrothermal synthesis and are characterized by XRD, SEM, TDA, IR, chemical analysis, EPMA, NMR, MAS NMR and gas permeation. After some tests of preparation of zeolite CHA and MFI self supporting membranes, the work is turned towards the preparation of zeolite MFI membranes supported by porous disks or {alpha} alumina, glass and tubes of carbon covered with a thin layer or zirconium dioxide. It is shown that the characteristics of the support (reactivity, pores dimensions, ...) strongly influence the quality of the prepared membrane. Two originals preparation processes are finalized. For the alumina disks, a gel precursor of zeolite is firs formed at the surface of the support by immersing successively that support in two non miscible liquids before the crystallisation. The gel is then converted into the zeolite by contact with water vapor. The zeolite layer obtained is localized at the surface of the support and present not only at the outside but also at the inside of the support. The characteristics of the zeolite layer can be controlled and the method can be adapted to various porous supports. The membrane obtained is interesting for hydrocarbons separations, for example the separation of methane and isobutane. In the case of Vycor glass disks, the reactivity of the support is first enhanced by contact with saturated water vapour. The temperature of the synthesis is then chosen relatively low in order to limit the attack of the support. With that method, a basic solution can be used without degradation of the support.The basicity leads to the formation of little crystals whose assembling is compact and homogeneous. The membrane obtained is interesting for example for the separation of normal butane and isobutane. (author) 71 refs.

  10. Separation of gases through gas enrichment membrane composites

    Science.gov (United States)

    Swedo, Raymond J.; Kurek, Paul R.

    1988-01-01

    Thin film composite membranes having as a permselective layer a film of a homopolymer of certain vinyl alkyl ethers are useful in the separation of various gases. Such homopolymers have a molecular weight of greater than 30,000 and the alkyl group of the vinyl alkyl monomer has from 4 to 20 carbon atoms with branching within the alkyl moiety at least at the carbon atom bonded to the ether oxygen or at the next adjacent carbon atom. These membranes show excellent hydrolytic stability, especially in the presence of acidic or basic gaseous components.

  11. Gas separation by composite solvent-swollen membranes

    Science.gov (United States)

    Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

    1989-01-01

    There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

  12. Gas separation by composite solvent-swollen membranes

    Science.gov (United States)

    Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

    1989-04-25

    There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

  13. Membrane processes in biotechnology: an overview.

    Science.gov (United States)

    Charcosset, Catherine

    2006-01-01

    Membrane processes are increasingly reported for various applications in both upstream and downstream technology, such as the established ultrafiltration and microfiltration, and emerging processes as membrane bioreactors, membrane chromatography, and membrane contactors for the preparation of emulsions and particles. Membrane systems exploit the inherent properties of high selectivity, high surface-area-per-unit-volume, and their potential for controlling the level of contact and/or mixing between two phases. This review presents these various membrane processes by focusing more precisely on membrane materials, module design, operating parameters and the large range of possible applications.

  14. Separation of some metal ions using coupled transport supported liquid membranes

    International Nuclear Information System (INIS)

    Chaudhary, M.A.

    1993-01-01

    Liquid membrane extraction processes has become very popular due to their superiority in many ways over other separation techniques. In coupled transport membranes the metal ions can be transported across the membrane against their concentration gradient under the influence of chemical potential difference. Liquid membranes consisting of a carrier-cum-diluent, supported in microporous polymeric hydrophobic films have been studied for transport of metal ions like U(VI), Cr(VI), Be(II), V(V), Ti(IV), Zn(II), Cd(II), Hf(IV), W(VI), and Co(II). The present paper presents basic data with respect to flux and permeabilities of these metal ions across membranes based on experimental results and theoretical equations, using different carriers and diluents and provides a brief reference to possibility of such membranes for large scale applications. (author)

  15. Software for the simulation of gases separation instalations with zeolite membranes

    OpenAIRE

    Yoenia M. Martínez Díaz; Dr. Carlos R. González González; MSc. Osmar Leyet Fernández; Dr. Omar J. Ochoa Rodríguez

    2013-01-01

    The simulation of gases separation processes is a very important field of the scientific work; it affects directly the chemical technologies related to petroleum refining, petrochemical, fine chemistry, gaseous fuels (methane, synthetic gas and hydrogen) and biotechnology, among other economic activities. This paper, presents an important tool for the simulation of gas separation processes using zeolite membranes in several configurations. The tool is based on a mathematic...

  16. [Study on essential oil separation from Forsythia suspensa oil-bearing water body based on vapor permeation membrane separation technology].

    Science.gov (United States)

    Zhang, Qian; Zhu, Hua-Xu; Tang, Zhi-Shu; Pan, Yong-Lan; Li, Bo; Fu, Ting-Ming; Yao, Wei-Wei; Liu, Hong-Bo; Pan, Lin-Mei

    2018-04-01

    To investigate the feasibility of vapor permeation membrane technology in separating essential oil from oil-water extract by taking the Forsythia suspensa as an example. The polydimethylsiloxane/polyvinylidene fluoride (PDMS/PVDF) composite flat membrane and a polyvinylidene fluoride (PVDF) flat membrane was collected as the membrane material respectively. Two kinds of membrane osmotic liquids were collected by self-made vapor permeation device. The yield of essential oil separated and enriched from two kinds of membrane materials was calculated, and the microscopic changes of membrane materials were analyzed and compared. Meanwhile, gas chromatography-mass spectrometry (GC-MS) was used to compare and analyze the differences in chemical compositions of essential oil between traditional steam distillation, PVDF membrane enriched method and PDMS/PVDF membrane enriched method. The results showed that the yield of essential oil enriched by PVDF membrane was significantly higher than that of PDMS/PVDF membrane, and the GC-MS spectrum showed that the content of main compositions was higher than that of PDMS/PVDF membrane; The GC-MS spectra showed that the components of essential oil enriched by PVDF membrane were basically the same as those obtained by traditional steam distillation. The above results showed that vapor permeation membrane separation technology shall be feasible for the separation of Forsythia essential oil-bearing water body, and PVDF membrane was more suitable for separation and enrichment of Forsythia essential oil than PDMS/PVDF membrane. Copyright© by the Chinese Pharmaceutical Association.

  17. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo; Car, Anja; Peinemann, Klaus-Viktor

    2010-01-01

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  18. Nanostructured membrane material designed for carbon dioxide separation

    KAUST Repository

    Yave, Wilfredo

    2010-03-15

    In this work carbon dioxide selective membrane materials from a commercially available poly(amide-b-ethylene oxide) (Pebax (R), Arkema) blended with polyethylene glycol ethers are presented. The preferred PEG-ether was PEG-dimethylether (PEG-DME). PEG-DME is well known as a physical solvent for acid gas absorption. It is used under the trade name Genosorb (R) in the Selexol (R) process (UOP) for acid gas removal from natural gas and synthesis gas. The combination of the liquid absorbent with the multiblock copolymer resulted in mechanically stable films with superior CO(2) separation properties. The addition of 50 wt.% PEG-DME to the copolymer resulted in a 8-fold increase of the carbon dioxide permeability; the CO(2)/H(2)-selectivity increased simultaneously from 9.1 to 14.9. It is shown that diffusivity as well as solubility of carbon dioxide is strongly increased by the blending of the copolymer with PEG-ethers. (c) 2009 Elsevier B.V. All rights reserved.

  19. Separations using biological carriers immobilized in porous polymeric and sol-gel template synthesized nanotubular membranes

    Science.gov (United States)

    Lakshmi, Brinda B.

    1998-12-01

    The overall goal of the dissertation was to use immobilized biological carriers in membranes to separate compounds as challenging as enantiomers. The membranes were prepared by a process called 'template synthesis'. Template synthesis has been used to synthesize semiconductor nanostructures and also membranes which do the enantioseparation by a process called facilitated transport. The immobilized proteins act as carriers facilitating the transport of the substrate molecules through the membrane. The apoenzymes are enzymes devoid of cofactor. Apoenzymes will possess the molecular recognition site for the substrate but will not catalyze the reaction. Apoenzymes immobilized in the pores of porous polycarbonate membrane was used as a carrier. The ends of the pores were closed with porous polypyrrole. Compounds as interesting as enantiomers were separated with these membranes. Template synthesis has been extended to the synthesis of many important semiconductor oxide naostructures like TiO2, SiO2, ZnO, Co3O4 and MnO2. These structures were made by dipping the alumina template membrane in the sol and heating. Ti0 2 tubules and fibers were obtained by this method. The fibers were used to study photocatalysis reaction of organic compounds in sunlight. Proteins were immobilized within the inner surface of the tubules using Sn chemistry. Bovine serum albumn (BSA) immobilized within the different diameter tubules showed varying degree of facilitation with phenylalanine. The membranes also show interesting switching of selectivity from L to D depending on the tube size and feed concentration.

  20. Carbon Nano tubes Based Mixed Matrix Membrane for Gas Separation

    International Nuclear Information System (INIS)

    Sanip, S.M.; Ismail, A.F.; Goh, P.S.; Norrdin, M.N.A.; Soga, T.; Tanemura, M.; Yasuhiko, H.

    2011-01-01

    Carbon nano tubes based mixed matrix membrane (MMM) was prepared by the solution casting method in which the functionalized multi walled carbon nano tubes (f-MWNTs) were embedded into the polyimide membrane and the resulting membranes were characterized. The effect of nominal MWNTs content between 0.5 and 1.0 wt % on the gas separation properties were looked into. The morphologies of the MMM also indicated that at 0.7 % loading of f- MWNTs, the structures of the MMM showed uniform finger-like structures which have facilitated the fast gas transport through the polymer matrix. It may also be concluded that addition of open ended and shortened MWNTs to the polymer matrix can improve its permeability by increasing diffusivity through the MWNTs smooth cavity. (author)

  1. Supported liquid inorganic membranes for nuclear waste separation

    Science.gov (United States)

    Bhave, Ramesh R; DeBusk, Melanie M; DelCul, Guillermo D; Delmau, Laetitia H; Narula, Chaitanya K

    2015-04-07

    A system and method for the extraction of americium from radioactive waste solutions. The method includes the transfer of highly oxidized americium from an acidic aqueous feed solution through an immobilized liquid membrane to an organic receiving solvent, for example tributyl phosphate. The immobilized liquid membrane includes porous support and separating layers loaded with tributyl phosphate. The extracted solution is subsequently stripped of americium and recycled at the immobilized liquid membrane as neat tributyl phosphate for the continuous extraction of americium. The sequestered americium can be used as a nuclear fuel, a nuclear fuel component or a radiation source, and the remaining constituent elements in the aqueous feed solution can be stored in glassified waste forms substantially free of americium.

  2. Advanced Palladium Membrane Scale-up for Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Emerson, Sean; Magdefrau, Neal; She, Ying; Thibaud-Erkey, Catherine

    2012-10-31

    The main objective of this project was to construct, test, and demonstrate a Pd-Cu metallic tubular membrane micro-channel separator capable of producing 2 lb day{sup -1} H{sub 2} at 95% recovery when operating downstream of an actual coal gasifier. A key milestone for the project was to complete a pilot-scale gasifier test by 1 September 2011 and demonstrate the separation of 2 lb day{sup -1} H{sub 2} to verify progress toward the DOE's goals prior to down-selection for larger-scale (100 lb day{sup -1}) hydrogen separator development. Three different pilot-scale (1.5 ft{sup 2}) separators were evaluated downstream of coal gasifiers during four different tests and the key project milestone was achieved in August 2011, ahead of schedule. During three of those tests, all of the separators demonstrated or exceeded the targeted separation rate of 2 lb day{sup -1} H{sub 2}. The separator design was proved to be leak tight and durable in the presence of gasifier exhaust contaminants at temperatures and pressures up to 500 °C and 500 psia. The contaminants in the coal gasifier syngas for the most part had negligible impact on separator performance, with H{sub 2} partial pressure being the greatest determinant of membrane performance. Carbon monoxide and low levels of H{sub 2}S (<39 ppmv) had no effect on H{sub 2} permeability, in agreement with laboratory experiments. However, higher levels of H{sub 2}S (>100 ppmv) were shown to significantly reduce H{sub 2} separation performance. The presence of trace metals, including mercury and arsenic, appeared to have no effect based on the experimental data. Subscale Pd-Cu coupon tests further quantified the impact of H{sub 2}S on irreversible sulfide formation in the UTRC separators. Conditions that have a thermodynamic driving force to form coke were found to reduce the performance of the separators, presumably by blockage of effective separation area with carbon deposits. However, it was demonstrated that both in situ

  3. Foam films as thin liquid gas separation membranes.

    Science.gov (United States)

    Ramanathan, Muruganathan; Müller, Hans Joachim; Möhwald, Helmuth; Krastev, Rumen

    2011-03-01

    In this letter, we testify the feasibility of using freestanding foam films as a thin liquid gas separation membrane. Diminishing bubble method was used as a tool to measure the permeability of pure gases like argon, nitrogen, and oxygen in addition to atmospheric air. All components of the foam film including the nature of the tail (fluorocarbon vs hydrocarbon), charge on the headgroup (anionic, cationic, and nonionic) and the thickness of the water core (Newton black film vs Common black film) were systematically varied to understand the permeation phenomena of pure gases. Overall results indicate that the permeability values for different gases are in accordance with magnitude of their molecular diameter. A smaller gaseous molecule permeates faster than the larger ones, indicating a new realm of application for foam films as size selective separation membranes.

  4. DEVELOPMENT OF MESOPOROUS MEMBRANE MATERIALS FOR CO2 SEPARATION; SEMIANNUAL

    International Nuclear Information System (INIS)

    Wei-Heng Shih; Qiang Zhao; Tejas Patil

    2002-01-01

    The authors propose to use microporous silica as a suitable candidate for CO(sub 2)/N(sub 2) separation because the pore size is less than 10(angstrom). If a CO(sub 2)adsorbent is added to the microporous silica, the adsorption of CO(sub 2) can block the passage of N(sub 2) and an effective CO(sub 2)/N(sub 2) separator will be found. It was first demonstrated that microporous silica could be synthesized. The microporous silica was then impregnated with Ba(OH)(sub 2). The results of GC study showed that at temperatures between 50 C and 90 C, Ba-doped microporous silica can separate CO(sub 2) from N(sub 2) and the idea of a microporous membrane for CO(sub 2)/N(sub 2) separation is feasible. The new result gives strong support to the proposed research that was outlined in the Phase II proposal. They hope to be able to continue the research and build an effective CO(sub 2)/N(sub 2) membrane separator in the Phase II of this project

  5. High-Flux Carbon Molecular Sieve Membranes for Gas Separation.

    Science.gov (United States)

    Richter, Hannes; Voss, Hartwig; Kaltenborn, Nadine; Kämnitz, Susanne; Wollbrink, Alexander; Feldhoff, Armin; Caro, Jürgen; Roitsch, Stefan; Voigt, Ingolf

    2017-06-26

    Carbon membranes have great potential for highly selective and cost-efficient gas separation. Carbon is chemically stable and it is relative cheap. The controlled carbonization of a polymer coating on a porous ceramic support provides a 3D carbon material with molecular sieving permeation performance. The carbonization of the polymer blend gives turbostratic carbon domains of randomly stacked together sp 2 hybridized carbon sheets as well as sp 3 hybridized amorphous carbon. In the evaluation of the carbon molecular sieve membrane, hydrogen could be separated from propane with a selectivity of 10 000 with a hydrogen permeance of 5 m 3 (STP)/(m 2 hbar). Furthermore, by a post-synthesis oxidative treatment, the permeation fluxes are increased by widening the pores, and the molecular sieve carbon membrane is transformed from a molecular sieve carbon into a selective surface flow carbon membrane with adsorption controlled performance and becomes selective for carbon dioxide. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ionic Liquid Membranes for Carbon Dioxide-Methane Separation

    Czech Academy of Sciences Publication Activity Database

    Uchytil, Petr; Schauer, Jan; Petričkovič, Roman; Setničková, Kateřina; Suen, S.Y.

    2011-01-01

    Roč. 383, 1-2 (2011), s. 262-271 ISSN 0376-7388 R&D Projects: GA ČR GA104/09/1165; GA ČR GCP106/10/J038; GA MŠk ME 889 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40500505 Keywords : ionic liquid membrane * gas separation * gas transport Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.850, year: 2011

  7. Nanoporous Membrane Technologies for Pathogen Collection, Separation, and Detection

    National Research Council Canada - National Science Library

    Lee, Sang W; Shang, Hao; Lee, Gil U; Griffin, Matthew T; Fulton, Jack

    2003-01-01

    Partial contents: Nanoporous Membranes, Membrane Chemistries, Characterization of Membrane Chemistries,Protein Fouling, Collector,Gas and Liquid Permeabilities, Membrane Permeabilities in the Presence of Water...

  8. Size enlargement of radioactive and hazardous species and their separation by microfiltration and ultrafiltration membranes

    International Nuclear Information System (INIS)

    Vijayan, S.; Wong, C.F.; Buckley, L.P.

    1993-01-01

    Separation and volume reduction of aqueous solutions involving membranes is evolving into an expanding and diversified field. Numerous commercially successful membranes and their applications are now available. Among different driving forces used in membrane separation, pressure-driven separation has gained wide application. Depending on the size of the dissolved species in solution to be separated, the pressure needed to achieve the desired separation varies. The microfiltration and ultrafiltration membrane systems are low-pressure processes that generally operate below 350 kPa. To exploit these membranes in applications involving the removal of dissolved contaminants from solutions, it is essential to create a suitable size for the dissolved contaminants, so that the membranes can effectively retain them while producing a filtrate stream essentially free of contaminants. Size enlargement of the dissolved contaminants can be achieved through solution conditioning with the addition of one or a combination of chemical reagents and powdered materials. Examples of typical additives include: pH chemicals, polyelectrolytes, microorganisms and powdered adsorption/ion-exchange materials. In many situations, adequate control and optimization of the system chemistry and hydraulic conditions provide high selectivity and efficiency for contaminant removal. This paper summarizes removal efficiency data for cadmium, lead, mercury, uranium, arsenic, strontium-90/85, cesium-137 and iron. These data resulted from various initiatives on membrane technology undertaken during the past five years by the Waste Processing Technology group at Chalk River Laboratories. The technology involves size enlargement of contaminants present in waste solution, and their separation using either microfiltration or ultrafiltration. The data support remedial applications involving treatment of contaminated groundwater and soils

  9. Separation processes, I: Azeotropic rectification

    Directory of Open Access Journals (Sweden)

    Milojević Svetomir

    2005-01-01

    Full Text Available In a series of two articles, the problems of azeotrope separation (part I and the design of separation units (part II were analyzed. The basic definition and equations of vapour-liquid equilibria for ideal and non-ideal systems, the importance of the activity coefficient calculation necessary for the analysis of non-ideal equilibrium systems, as well as theoretical aspects of azeotrope rectification and the determination of the optimal third component (modifier or azeotrope agent are presented in the first part.

  10. Separation process for boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rockwood, S D

    1975-06-12

    The method according to the invention is characterized by the steps of preparing a gaseous mixture of BCl/sub 3/ containing the isotopes of boron and oxygen as the extractor, irradiating that mixture in the tube of the separator device by means of P- or R-lines of a CO/sub 2/ laser for exciting the molecules containing a given isotope of boron, simultaneously irradiating the mixture with UV for photodissociating the excited BCl/sub 3/ molecules and separating BCl/sub 3/ from the reaction products of photodissociation and from oxygen. Such method is suitable for preparing boron used in nuclear reactors.

  11. Hydrothermally stable molecular separation membranes from organically linked silica

    Energy Technology Data Exchange (ETDEWEB)

    Castricum, H.L.; Sah, A; Blank, D.H.A.; Ten Elshof, J.E. [Inorganic Materials Science, MESA Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Kreiter, R.; Vente, J.F. [ECN Energy Efficiency in the Industry, Petten (Netherlands)

    2008-06-15

    A highly hydrothermally stable microporous network material has been developed that can be applied in energy-efficient molecular sieving. The material was synthesized by employing organically bridged monomers in acid-catalysed sol-gel hydrolysis and condensation, and is composed of covalently bonded organic and inorganic moieties. Due to its hybrid nature, it withstands higher temperatures than organic polymers and exhibits high solvolytical and acid stability. A thin film membrane that was prepared with the hybrid material was found to be stable in the dehydration of n-butanol at 150C for almost two years. This membrane is the first that combines a high resistance against water at elevated temperatures with a high separation factor and permeance. It therefore has high potential for energy-efficient molecular separation under industrial conditions, including the dehydration of organic solvents. The organically bridged monomers induce increased toughness in the thin film layer. This suppresses hydrolysis of Si-O-Si network bonds and results in a high resistance towards stress-induced cracking. The large non-hydrolysable units thus remain well incorporated in the surrounding matrix such that the material combines high (pore) structural and mechanical stability. The sol mean particle size was found to be a viable parameter to tune the thickness of the membrane layer and thus optimize the separation performance. We anticipate that other hybrid organosilicas can be made in a similar fashion, to yield a whole new class of materials with superior molecular sieving properties and high hydrothermal stability.

  12. Dual Phase Membrane for High Temperature CO2 Separation

    Energy Technology Data Exchange (ETDEWEB)

    Jerry Lin

    2007-06-30

    This project aimed at synthesis of a new inorganic dual-phase carbonate membrane for high temperature CO{sub 2} separation. Metal-carbonate dual-phase membranes were prepared by the direct infiltration method and the synthesis conditions were optimized. Permeation tests for CO{sub 2} and N{sub 2} from 450-750 C showed very low permeances of those two gases through the dual-phase membrane, which was expected due to the lack of ionization of those two particular gases. Permeance of the CO{sub 2} and O{sub 2} mixture was much higher, indicating that the gases do form an ionic species, CO{sub 3}{sup 2-}, enhancing transport through the membrane. However, at temperatures in excess of 650 C, the permeance of CO{sub 3}{sup 2-} decreased rapidly, while predictions showed that permeance should have continued to increase with temperature. XRD data obtained from used membrane indicated that lithium iron oxides formed on the support surface. This lithium iron oxide layer has a very low conductivity, which drastically reduces the flow of electrons to the CO{sub 2}/O{sub 2} gas mixture; thus limiting the formation of the ionic species required for transport through the membrane. These results indicated that the use of stainless steel supports in a high temperature oxidative environment can lead to decreased performance of the membranes. This revelation created the need for an oxidation resistant support, which could be gained by the use of a ceramic-type membrane. Work was extended to synthesize a new inorganic dual-phase carbonate membrane for high temperature CO{sub 2} separation. Helium permeance of the support before and after infiltration of molten carbonate are on the order of 10{sup -6} and 10{sup -10} moles/m{sup 2} {center_dot} Pa {center_dot} s respectively, indicating that the molten carbonate is able to sufficiently infiltrate the membrane. It was found that La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (LSCF) was a suitable candidate for the support

  13. Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

    KAUST Repository

    Alshehri, Ali

    2014-12-01

    As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions that need to be answered. This report aims to use process simulations to find: (1) at what conditions a single-stage membrane process can meet the separation task that is defined by product purity and recovery ratio and (2) what are the most important parameters that determine the energy consumption. To perform a certain separation task, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is defined only by product purity and recovery ratio. The membrane/distillation hybrid system was used to study the energy consumption. A shortcut method was developed to calculate the minimum practical separation energy (MPSE) of the membrane process and the distillation process. It was found that the MPSE of the hybrid system is only determined by the membrane selectivity and the applied transmembrane pressure ratio in three stages. At the first stage when selectivity is low, the membrane process is not competitive to the distillation process. Adding a membrane unit to a distillation tower will not help in reducing energy. At the second medium selectivity stage, the membrane/distillation hybrid system can help reduce the energy consumption, and the higher the membrane selectivity, the lower is the energy. The energy conservation is further improved as pressure ratio increases. At the third stage when both selectivity and pressure ratio are high, the hybrid system will change to a single-stage membrane unit and this change will cause significant reduction in energy consumption. The energy at this stage keeps decreasing with selectivity at slow rate, but slightly increases with pressure ratio. Overall, the higher the membrane selectivity, the more the energy is saved. Therefore, the two

  14. Digital holographic microscopy of phase separation in multicomponent lipid membranes

    Science.gov (United States)

    Farzam Rad, Vahideh; Moradi, Ali-Reza; Darudi, Ahmad; Tayebi, Lobat

    2016-12-01

    Lateral in-homogeneities in lipid compositions cause microdomains formation and change in the physical properties of biological membranes. With the presence of cholesterol and mixed species of lipids, phospholipid membranes segregate into lateral domains of liquid-ordered and liquid-disordered phases. Coupling of two-dimensional intralayer phase separations and interlayer liquid-crystalline ordering in multicomponent membranes has been previously demonstrated. By the use of digital holographic microscopy (DHMicroscopy), we quantitatively analyzed the volumetric dynamical behavior of such membranes. The specimens are lipid mixtures composed of sphingomyelin, cholesterol, and unsaturated phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine. DHMicroscopy in a transmission mode is an effective tool for quantitative visualization of phase objects. By deriving the associated phase changes, three-dimensional information on the morphology variation of lipid stacks at arbitrary time scales is obtained. Moreover, the thickness distribution of the object at demanded axial planes can be obtained by numerical focusing. Our results show that the volume evolution of lipid domains follows approximately the same universal growth law of previously reported area evolution. However, the thickness of the domains does not alter significantly by time; therefore, the volume evolution is mostly attributed to the changes in area dynamics. These results might be useful in the field of membrane-based functional materials.

  15. Novel nanocomposite Kevlar fabric membranes: Fabrication characterization, and performance in oil/water separation

    Science.gov (United States)

    Karimnezhad, Hanieh; Rajabi, Laleh; Salehi, Ehsan; Derakhshan, Ali Ashraf; Azimi, Sara

    2014-02-01

    Nanocomposite membranes with hydrophilic surface were fabricated for separation of oil (n-hexane) from oil/water emulsion. Three different nanomaterials namely, para-aminobenzoate alumoxane (PAB-A), boehmite-epoxide and polycitrate alumoxane (PC-A) were coated on the Kevlar fabric (support), according to a three-step dip-coating protocol. FTIR, SEM, TEM, UV/vis spectrophotometer, and wettability analyses were used to characterize the composite membranes. The three coating layers interacted chemically with one another and also physically with the Kevlar fabric. Water uptake measurements indicated that the membrane is a hydrophilic one. SEM and TEM analyses showed the smooth surface of the composite membrane and three-dimensional dendrimeric hyper-branched structure of (PC-A), respectively. A dead-end filtration setup was applied to test the membranes performance under natural gravity force. Effect of pH as an important variable affecting separation process was investigated with the neutral pH provided the optimum condition for the separation. Oil rejection and permeate fluxes were also monitored. The optimum flux and rejection obtained, were 7392 (Lm-2 h-1) and 89.06% at pH 7, respectively. Fouling occurred as a gel layer on the membrane surface. The deposited oil droplets on the surface of the membrane were successfully washed away with satisfactory permeate flux recovery (FRR = 88.88% at neutral pH), using hot distilled water and acidic solution as eluents.

  16. Electrochemically etched nanoporous silicon membrane for separation of biological molecules in mixture

    Science.gov (United States)

    Burham, Norhafizah; Azlan Hamzah, Azrul; Yunas, Jumril; Yeop Majlis, Burhanuddin

    2017-07-01

    This paper presents a technique for separating biological molecules in mixture using nanoporous silicon membrane. Nanopores were formed using electrochemical etching process (ECE) by etching a prefabricated silicon membrane in hydrofluoric acid (HF) and ethanol, and then directly bonding it with PDMS to form a complete filtration system for separating biological molecules. Tygon S3™ tubings were used as fluid interconnection between PDMS molds and silicon membrane during testing. Electrochemical etching parameters were manipulated to control pore structure and size. In this work, nanopores with sizes of less than 50 nm, embedded on top of columnar structures have been fabricated using high current densities and variable HF concentrations. Zinc oxide was diluted with deionized (DI) water and mixed with biological molecules and non-biological particles, namely protein standard, serum albumin and sodium chloride. Zinc oxide particles were trapped on the nanoporous silicon surface, while biological molecules of sizes up to 12 nm penetrated the nanoporous silicon membrane. The filtered particles were inspected using a Zetasizer Nano SP for particle size measurement and count. The Zetasizer Nano SP results revealed that more than 95% of the biological molecules in the mixture were filtered out by the nanoporous silicon membrane. The nanoporous silicon membrane fabricated in this work is integratable into bio-MEMS and Lab-on-Chip components to separate two or more types of biomolecules at once. The membrane is especially useful for the development of artificial kidney.

  17. Novel Membranes and Processes for Oxygen Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Haiqing

    2011-11-15

    The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions

  18. Membranes for Food and Bioproduct Processing

    Science.gov (United States)

    Avram, Alexandru M.

    Modified membranes for process intensification in biomass hydrolysis: Production of biofuels and chemicals from lignocellulosic biomass is one of the leading candidates for replacement of petroleum based fuels and chemicals. However, conversion of lignocellulosic biomass into fuels and chemicals is not cost effective compared to the production of fuels and chemicals from crude oil reserves. Some novel and economically feasible approaches involve the use of ionic liquids as solvents or co-solvents, since these show improved solvation capability of cellulose over simple aqueous systems. Membranes offer unique opportunities for process intensification which involves fractionation of the resulting biomass hydrolysate leading to a more efficient and cheaper operation. This research attempts to develop membranes that would usher the economics of the biochemical conversion of lignocellulosic biomass into fuels and chemicals by recycling the expensive ionic liquid. The overall aim of this work is the development of novel membranes with unique surface properties that enable the selective separation of non-reacted cellulose and hydrolysis sugars from ionic liquids. Nanofiltration separation for application in food product engineering: With the advent of the modern, well-informed consumer who has high expectations from the nutritional value of consumed food products, novel approaches are being developed to produce nutrient-enhanced foods and drinks. As a response to the consumer needs, different techniques to recover, concentrate and retain as much as possible of bioactive compounds are being investigated. Membrane technology has the advantage of selective fractionation of food products (e.g. salt removal, removal of bitter-tasting compounds or removal of sugar for sweet taste adjustment), volume reduction, and product recovery at mild conditions. In this work, we use nanofiltration in dead-end and crossflow mode to concentrate polyphenols from blueberry pomace. Blueberry

  19. The impact of chemical cleaning on separation efficiency and properties of reverse osmosis membrane

    KAUST Repository

    Baatiyyah, Hani

    2018-04-01

    One of most major concerns from both cost-effective and technical point of view in membrane process industry is membrane cleaning. The aim of the project was to investigate the variations in membrane surface properties and separation efficiency of reverse osmosis membrane. Compativtive analysis have to be performed on four RO membrane before and after exposing the virgin membrane into chemical cleaning to identify and analysis the impact of the chemical cleaning on the performance of RO membrane. Commerical chemical cleaning used in this project were caustic and acidic cleaning agent. The project’s aim is the investigation of simulation software’s precision for the four membranes performance projection at different conditions of the feed water. The assessment of the membranes performance was done in the Innovation Cluster at pilot plant that was industrial in size. The main commercial elements used were the thin-film composite membranes with a spiral-wound of 8-inch polyamide. Ultrafiltration (UF) and seawater RO membrane pretreatment process was done for the red sea sourced feed water. A pressure vessel dimensioned at 8-inch was operated in conjunction with an individual element at 8 -20 m3/hr feed flow rate, with an 8 to 12 % recovery and an average 35,000-42,000 mg/L of total dissolved solids (TDS) composition for the feed water. To achieve the project’s aim in assessing the membranes, three phase experimental stages were completed. The membranes performance was assessed in terms of their water flux, salt rejection, boron rejection, bicarbonate rejection and permeate quality. In addition, the membrane surfaces were characterized after exposing the fresh membranes with a chemical cleaning reagent. The experimental results showed an increase in both permeate flow and salt passage for all studied elements. The changes in the membranes performance were systematically explained based on the changes in the charge density and chemical structure of the membranes

  20. Preparation of Novel Thin-Film Composite Nanofiltration Membranes for Separation of Amoxicillin

    Directory of Open Access Journals (Sweden)

    A. Akbari

    2014-04-01

    Full Text Available Several novel composite membranes were prepared to separate and recycle amoxicillin from pharmaceutical wastewater via nanofiltration process. The synthesis of these membranes included three stages: 1- preparation of polysulfone ultrafiltration membranes as a support via phase separation process, 2- modification of its surface by interfacial polymerization as a selective layer (polyamide, and 3- self-assembly of TiO2 nanoparticles on the selective layer as an anti-fouling agent. The rejection of all nanofiltration membranes was more than 99% and only its flux was changed proportional to different conditions. In the presence and absence of TiO2 nanoparticles, the pure water flux of polyamide thin-film membrane also obtained 44.4 and 38.4 L/h.m2 at 4 bar pressure, respectively. These were equal to 34 L/h.m2 for amoxicillin solutions. The results showed that TiO2 nanoparticles increased hydrophilicity of polyamide selective layer and therefore, nanoparticles decreased the fouling level. SEM images illustrated the excellent establishment of polyamide layer and distribution of TiO2 nanoparticles on the selective layer. The properties of membrane surface were taken into consideration by using AFM, indicating the increment of surface roughness with interfacial polymerization and TiO2 nanoparticles self-assembly. The pore size of membranes was in the nanoscale (2.653 and 2.604 nm without and with TiO2 nanoparticles self-assembly, respectively

  1. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    Science.gov (United States)

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step,...

  2. Cross-linked polymeric membranes for carbon dioxide separation

    Science.gov (United States)

    Hong, Tao; Chatterjee, Sabornie; Mahurin, Shannon Mark; Long, Brian Keith; Jiang, De-en; Mays, Jimmy Wayne; Sokolov, Alexei P.; Saito, Tomonori

    2018-01-23

    A membrane useful in gas separation, the membrane comprising a cross-linked polysiloxane structure having a cross-link density of about 0.1.times.10.sup.-5 mol/cm.sup.3 to about 6.times.10.sup.-5 mol/cm.sup.3, where, in particular embodiments, the cross-linked polysiloxane structure has the following general structure: ##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently selected from hydrocarbon groups having at least 1 and up to 6 carbon atoms; A.sup.1 and A.sup.2 are independently selected from cyclic hydrocarbon groups; L.sup.1 and L.sup.2 are linking groups or covalent bonds; n is an integer of at least 1; r and s are independently selected from integers of at least 1; and p is an integer of at least 10. The invention also includes methods for making and using the above-described membranes for gas separation.

  3. Membrane Separation of Gas Mixtures under the Influence of Resonance Radiation.

    Czech Academy of Sciences Publication Activity Database

    Levdansky, Valerij Vladimirovič; Izák, Pavel

    2017-01-01

    Roč. 173, FEB (2017), s. 93-98 ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S Institutional support: RVO:67985858 Keywords : membranes * gas mixture * separation Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 3.359, year: 2016

  4. Separation of gaseous air pollutants using membrane contactors

    Science.gov (United States)

    Sverak, T.; Bulejko, P.; Ostrezi, J.; Kristof, O.; Kalivoda, J.; Kejik, P.; Mayerova, K.; Adamcik, M.

    2017-10-01

    This work deals with the separation of CO2 gaseous pollutant from gas mixtures to a water solution using the laboratory contactor. The laboratory set process parameters showed the rate of carbon dioxide transition through the interface in a so promising level the contactor separators can be considered as a very promising pathway to reduce the content of this greenhouse gas from the air.

  5. Membrane Materials and Technology for Xylene Isomers Separation and Isomerization via Pervaporation

    KAUST Repository

    Bilaus, Rakan

    2014-01-01

    technology’s high energy intensity has become a growing concern. Membrane separation technology is a potential low-energy alternative. Polymeric membranes were investigated in a pervaporation experiment to separate xylene isomers. Polymers of intrinsic

  6. Volatile organic carbon/air separation test using gas membranes

    International Nuclear Information System (INIS)

    King, C.V.; Kaschemekat, J.

    1993-08-01

    An estimated 900 metric tons of carbon tetrachloride were discharged to soil columns during the Plutonium Finishing Plant Operations at the Hanford Site. The largest percentage of this volatile organic compound was found in the vadose region of the 200 West Area. Using a Vacuum Extraction System, the volatile organic compound was drawn from the soil in an air mixture at a concentration of about 1,000 parts per million. The volatile organic compounds were absorbed from the air stream using granulated activated carbon canisters. A gas membrane separation system, developed by Membrane Technology and Research, Inc., was tested at the Vacuum Extraction System site to determine if the volatile organic compound load on the granulated activated carbon could be reduced. The Vacuum Extraction System condensed most of the volatile organic compound into liquid carbon tetrachloride and vented the residual gas stream into the granulated activated carbon. This system reduced the cost of operation about $5/kilogram of volatile organic compound removed

  7. Fabrication of Separator Demonstration Facility process vessel

    International Nuclear Information System (INIS)

    Oberst, E.F.

    1985-01-01

    The process vessel system is the central element in the Separator Development Facility (SDF). It houses the two major process components, i.e., the laser-beam folding optics and the separators pods. This major subsystem is the critical-path procurement for the SDF project. Details of the vaious parts of the process vessel are given

  8. Tuning of Preparational Factors Affecting the Morphological Structure and Gas Separation Property of Asymmetric Polysulfone Membranes

    Science.gov (United States)

    Yuenyao, C.; Ruangdit, S.; Chittrakarn, T.

    2017-09-01

    The aim of this work was to study the effect of preparational factors such as solvent type, evaporation time (ET) and non-solvent additive, on the morphological structure, physical and gas separation properties of the prepared membrane samples by tuning of these parameters. Flat sheet asymmetric polysulfone (PSF) membranes were prepared by the dry/wet phase inversion process combined with the double coagulation bath method. The alteration of the prepared membranes were analyzed through scientific techniques such as Scanning Electron Microscope (SEM) and Dynamic Mechanical Thermal Analysis (DMTA). Furthermore, gas separation performance of membrane samples was measured in term of gas permeation and ideal selectivity of CO2/CH4. Experimental results showed that the change of preparational factors affected to the gas permeation of asymmetric PSF membranes. For example, the selective layer thickness increased with increasing of ET. This lead to increase significantly of ideal selectivity of CO2/CH4. The CO2/CH4 ideal selectivity was also increased with increase of ethanol (non-solvent additive) concentration in casting solution. In summary, the tuning of preparational factors affected to morphological structure, physical and gas separation properties of PSF membranes.

  9. Mesoporous Silica Thin Membranes with Large Vertical Mesochannels for Nanosize-Based Separation.

    Science.gov (United States)

    Liu, Yupu; Shen, Dengke; Chen, Gang; Elzatahry, Ahmed A; Pal, Manas; Zhu, Hongwei; Wu, Longlong; Lin, Jianjian; Al-Dahyan, Daifallah; Li, Wei; Zhao, Dongyuan

    2017-09-01

    Membrane separation technologies are of great interest in industrial processes such as water purification, gas separation, and materials synthesis. However, commercial filtration membranes have broad pore size distributions, leading to poor size cutoff properties. In this work, mesoporous silica thin membranes with uniform and large vertical mesochannels are synthesized via a simple biphase stratification growth method, which possess an intact structure over centimeter size, ultrathin thickness (≤50 nm), high surface areas (up to 1420 m 2 g -1 ), and tunable pore sizes from ≈2.8 to 11.8 nm by adjusting the micelle parameters. The nanofilter devices based on the free-standing mesoporous silica thin membranes show excellent performances in separating differently sized gold nanoparticles (>91.8%) and proteins (>93.1%) due to the uniform pore channels. This work paves a promising way to develop new membranes with well-defined pore diameters for highly efficient nanosize-based separation at the macroscale. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Dense film polyimide membranes for aggressive sour gas feed separations

    KAUST Repository

    Kraftschik, Brian

    2013-02-01

    Dense film membranes of the copolyimide 6FDA-DAM:DABA (3:2) are studied for simultaneous removal of CO2 and H2S from sour natural gas streams. Pure and mixed gas permeation as well as pure gas sorption data are reported at 35°C and pressures up to 62bar. The H2S partial pressures used are representative of highly aggressive field operations. Penetrant-induced plasticization effects are evident at feed pressures below 1bar in pure H2S feeds; sub-Tg thermal annealing is used to effectively mitigate this effect, and these annealed films are used throughout the study. Surprisingly, H2S/CH4 selectivity nearly doubles for mixed gas testing in comparison to the pure component ideal selectivity values and approaches the level of a state-of-the-art glassy polymer, cellulose acetate (CA), at H2S partial pressures above 2bar. Furthermore, permeation experiments using a 9.95% H2S, 19.9% CO2, 70.15% CH4 mixture at low feed pressures give CO2/CH4 selectivity of up to 49-over 30% greater than the pure component selectivity for 6FDA-DAM:DABA (3:2). The overall sour gas separation performance of this polyimide is comparable to high-performance rubbery polymer membranes, which have been reported for only moderate H2S partial pressure feeds, and is superior to that for CA based on a practical combined acid gas separation efficiency metric that we introduce. Finally, methods for continued development of the current polyimide membrane material for aggressive sour gas separations are presented. © 2012 Elsevier B.V.

  11. Dense film polyimide membranes for aggressive sour gas feed separations

    KAUST Repository

    Kraftschik, Brian; Koros, William J.; Johnson, J.R.; Karvan, Oguz

    2013-01-01

    Dense film membranes of the copolyimide 6FDA-DAM:DABA (3:2) are studied for simultaneous removal of CO2 and H2S from sour natural gas streams. Pure and mixed gas permeation as well as pure gas sorption data are reported at 35°C and pressures up to 62bar. The H2S partial pressures used are representative of highly aggressive field operations. Penetrant-induced plasticization effects are evident at feed pressures below 1bar in pure H2S feeds; sub-Tg thermal annealing is used to effectively mitigate this effect, and these annealed films are used throughout the study. Surprisingly, H2S/CH4 selectivity nearly doubles for mixed gas testing in comparison to the pure component ideal selectivity values and approaches the level of a state-of-the-art glassy polymer, cellulose acetate (CA), at H2S partial pressures above 2bar. Furthermore, permeation experiments using a 9.95% H2S, 19.9% CO2, 70.15% CH4 mixture at low feed pressures give CO2/CH4 selectivity of up to 49-over 30% greater than the pure component selectivity for 6FDA-DAM:DABA (3:2). The overall sour gas separation performance of this polyimide is comparable to high-performance rubbery polymer membranes, which have been reported for only moderate H2S partial pressure feeds, and is superior to that for CA based on a practical combined acid gas separation efficiency metric that we introduce. Finally, methods for continued development of the current polyimide membrane material for aggressive sour gas separations are presented. © 2012 Elsevier B.V.

  12. Analysis of Gas Separated for Silica Membrane in Hydrogen Gas Production by Using Nuclear Reactor Thermal

    International Nuclear Information System (INIS)

    Pandiangan, Tumpal

    2007-01-01

    One of the hydrogen production method that have been developed is a thermo-chemical method. This method is permissible to increase thermal efficiency up to 70 % and to decrease of operational temperature from 800℃ down to 450 ℃. One of several factor that can increase of the hydrogen production thermal efficiency at the above method is to apply a separated membrane that have a relative good for permeansce and selectivity performance. It had been carried out for analyzing of time and temperature CVD (Chemical Vapouration Deposition) that is affected to permeansce and power selecting performance of the membrane. The layering membrane silica process was carried out by means of the CVD method at atmosphere pressure. The membrane silica layering that was observed was developed by a CVD method in atmospheric pressure. The silica membrane was formed at the out side surface of the alumina gamma cylinder that had been coated by alumina gamma which it has average porosity about of 0.01 mic.meter. A permeansce and separation power performance of the membrane silica that was carried out by means of CVD method at 600 ℃ on H 2 , He and N 2 are : 2 x 10 -10 , 9 x 10 -9 and 4 x 10 -7 mol Pa/m 2 s and the selected power of H 2 /N 2 = 45. The permeansce of that membrane is relative good but the selected power is relative not so good. (author)

  13. Polymeric membrane systems of potential use for battery separators

    Science.gov (United States)

    Philipp, W. H.

    1977-01-01

    Two membrane systems were investigated that may have potential use as alkaline battery separators. One system comprises two miscible polymers: a support polymer (e.g., polyvinyl formal) and an ion conductor such as polyacrylic acid. The other system involves a film composed of two immiscible polymers: a conducting polymer (e.g., calcium polyacrylate) suspended in an inert polymer support matrix, polyphenylene oxide. Resistivities in 45-percent potassium hydroxide and qualitative mechanical properties are presented for films comprising various proportions of conducting and support polymers. In terms of these parameters, the results are encouraging for optimum ratios of conducting to support polymers.

  14. Application of reverse osmosis membrane for separation of toxic metal in water

    International Nuclear Information System (INIS)

    Syahril Ahmad

    2010-01-01

    Experimental separation of toxic metal in water has been done using reverse osmosis membrane made from composite material. Experiment was done by simulation in which metals that will be observed solved with water in different concentration and then used as feed solution in reverse osmosis process. Metals observed were Cr"6"+, Mn"2"+ and Pb"2"+ and reverse osmosis process was done at pressure of 40 Bar for all metals. Experiment result showed that value of feed solution concentration would affect flux and coefficient rejection of membrane. Composite membrane with polyacrylamide as active layer of membrane can reject metals observed with value of rejection coefficient more than 90%, except for Mn"2"+metal that have concentration 250 ppm and 500 ppm. (author)

  15. Study of ion separation through solid-supported liquid membrane

    International Nuclear Information System (INIS)

    Kang, Young Ho; Kim, Jung Do; Kim, Kyoung Ho

    1990-01-01

    The membranes used in this study consist of a microporous polymeric support with the solvent contraining alamine 336, Tri-N-Octyl phosphine oxide, Tri-N-butyl phosphate, Di-(2-ethylhexyl) phosphoric acid as a carrier within the pores by the capillary forces. When this liquid membrane is interposed between aqueous feed and product solutions, the carrier serving as a complexing agent, can pick up the uranium ions on the feed side of the membrane and carry them across the membrane by diffusion. In this study, the uranium flux through the solid-supported liquid membrane was analyzed as a function of carrier concentration and acidity of the feed solution for the carrier species. Also, the Gel-liquid extraction of uranium ions from aqueous solution was performed. The adsorbents were prepared by casting the polymer solution composed of polyvinyl chloride, TOPO, and additions. The extraction of uranyl nitrate ions has been investigated as a function of TOPO/PVC ratio, evaporation time, and the stability. The results show that is maybe possible to develop an alternative uranium purification process. (author)

  16. Tunable hydrogen separation in porous graphene membrane: first-principle and molecular dynamic simulation.

    Science.gov (United States)

    Tao, Yehan; Xue, Qingzhong; Liu, Zilong; Shan, Meixia; Ling, Cuicui; Wu, Tiantian; Li, Xiaofang

    2014-06-11

    First-principle density functional theory (DFT) calculation and molecular dynamic (MD) simulation are employed to investigate the hydrogen purification performance of two-dimensional porous graphene material (PG-ESX). First, the pore size of PG-ES1 (3.2775 Å) is expected to show high selectivity of H2 by DFT calculation. Then MD simulations demonstrate the hydrogen purification process of the PG-ESX membrane. The results indicate that the selectivity of H2 over several other gas molecules that often accompany H2 in industrial steam methane reforming or dehydrogenation of alkanes (such as N2, CO, and CH4) is sensitive to the pore size of the membrane. PG-ES and PG-ES1 membranes both exhibit high selectivity for H2 over other gases, but the permeability of the PG-ES membrane is much lower than the PG-ES1 membrane because of the smaller pore size. The PG-ES2 membrane with bigger pores demonstrates low selectivity for H2 over other gases. Energy barrier and electron density have been used to explain the difference of selectivity and permeability of PG-ESX membranes by DFT calculations. The energy barrier for gas molecules passing through the membrane generally increase with the decreasing of pore sizes or increasing of molecule kinetic diameter, due to the different electron overlap between gas and a membrane. The PG-ES1 membrane is far superior to other carbon membranes and has great potential applications in hydrogen purification, energy clean combustion, and making new concept membrane for gas separation.

  17. Bioinspired Diatomite Membrane with Selective Superwettability for Oil/Water Separation.

    Science.gov (United States)

    Lo, Yu-Hsiang; Yang, Ching-Yu; Chang, Haw-Kai; Hung, Wei-Chen; Chen, Po-Yu

    2017-05-03

    Membranes with selective superwettability for oil/water separation have received significant attention during the past decades. Hierarchical structures and surface roughness are believed to improve the oil repellency and the stability of Cassie-Baxter state. Diatoms, unicellular photosynthetic algae, possess sophisticated skeletal shells (called frustules) which are made of hydrated silica. Motivated by the hierarchical micro- and nanoscale features of diatom, we fabricate a hierarchical diatomite membrane which consists of aligned micro-sized channels by the freeze casting process. The fine nano-porous structures of frustules are well preserved after the post sintering process. The bioinspired diatomite membrane performs both underwater superoleophobicity and superhydrophobicity under various oils. Additionally, we demonstrate the highly efficient oil/water separation capabililty of the membranes in various harsh environments. The water flux can be further adjusted by tuning the cooling rates. The eco-friendly and robust bioinspired membranes produced by the simple, cost-effective freeze casting method can be potentially applied for large scale and efficient oil/water separation.

  18. Hybrid membrane--PSA system for separating oxygen from air

    Science.gov (United States)

    Staiger, Chad L [Albuquerque, NM; Vaughn, Mark R [Albuquerque, NM; Miller, A Keith [Albuquerque, NM; Cornelius, Christopher J [Blackburg, VA

    2011-01-25

    A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

  19. Electrospun polyacrylonitrile nanofibrous membranes with varied fiber diameters and different membrane porosities as lithium-ion battery separators

    International Nuclear Information System (INIS)

    Ma, Xiaojing; Kolla, Praveen; Yang, Ruidong; Wang, Zhao; Zhao, Yong; Smirnova, Alevtina L.; Fong, Hao

    2017-01-01

    Highlights: • Nine types of electrospun polyacrylonitrile nanofibrous membranes were prepared. • These membranes had varied fiber diameters and different membrane porosities. • The membranes were explored as innovative Li-ion battery (LIB) separators. • The hot-pressed membrane with thin fibers had superior performance as LIB separator. - Abstract: In this study, nine types of polyacrylonitrile (PAN) nanofibrous membranes with varied fiber diameters and different membrane porosities are prepared by electrospinning followed by hot-pressing. Subsequently, these membranes are explored as Li-ion battery (LIB) separators. The impacts of fiber diameter and membrane porosity on electrolyte uptake, Li"+ ion transport through the membrane, electrochemical oxidation potential, and membrane performance as LIB separator (during charge/discharge cycling and rate capability tests of a cathodic half-cell) have been investigated. When compared to commercial Celgard PP separator, hot-pressed electrospun PAN nanofibrous membranes exhibit larger electrolyte uptake, higher thermal stability, wider electrochemical potential window, higher Li"+ ion permeability, and better electrochemical performance in LiMn_2O_4/separator/Li half-cell. The results also indicate that the PAN-based membrane/separator with small fiber diameters of 200–300 nm and hot-pressed under high pressure of 20 MPa surpasses all other membranes/separators and demonstrates the best performance, leading to the highest discharge capacity (89.5 mA h g"−"1 at C/2 rate) and cycle life (with capacity retention ratio being 97.7%) of the half-cell. In summary, this study has revealed that the hot-pressed electrospun PAN nanofibrous membranes (particularly those consisting of thin nanofibers) are promising as high-performance LIB separators.

  20. Tunable Nanocomposite Membranes for Water Remediation and Separations

    Science.gov (United States)

    Sierra, Sebastian Hernandez

    Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes. Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these responsive materials prevent the loss of nanomaterials to the environment and improve reactivity due to their larger surface areas, expanding their range of applications. The present work describes different techniques used to create nanocomposites based on poly(vinylidene fluoride) (PVDF) hollow fiber and flat sheet membranes, both thick sponge-like and thin. Due to their hydrophobicity, hollow fiber membranes were hydrophilized by a water-based green process of cross-linking polyvinylpyrrolidone (PVP) onto their surface. Commercial hydrophilic and hydrophilized lab-prepared membranes were subsequently functionalized with a poly(acrylic acid) (PAA) hydrogel through free radical polymerizations. This work advanced membrane functionalization, specifically flat sheet membranes, from lab-scale to full-scale by modifications of the polymerization procedures. The hydrogel functionalized membranes by redox polymerization showed an expected responsive behavior, represented by permeability variation at various pH values (4.0 ≤ pH ≤ 9.0), from 53.9 to 3.4 L/(m2EhEbar) and a change in effective pore size from 222 to 111 nm, being 3800 L/(m 2EhEbar) and 650 nm the former permeability and pore size values of the

  1. Efficient ethanol recovery from yeast fermentation broth with integrated distillation-membrane process

    Science.gov (United States)

    A hybrid process integrating vapor stripping with vapor compression and vapor permeation membrane separation, termed Membrane Assisted Vapor Stripping (MAVS), was evaluated for recovery and dehydration of ethanol from aqueous solution as an alternative to conventional distillatio...

  2. Selective separation of oil and water with mesh membranes by capillarity

    KAUST Repository

    Yu, Yuanlie; Chen, Hua; Liu, Yun; Craig, Vincent S.J.; Lai, Zhiping

    2016-01-01

    The separation of oil and water from wastewater generated in the oil-production industries, as well as in frequent oil spillage events, is important in mitigating severe environmental and ecological damage. Additionally, a wide arrange of industrial processes require oils or fats to be removed from aqueous systems. The immiscibility of oil and water allows for the wettability of solid surfaces to be engineered to achieve the separation of oil and water through capillarity. Mesh membranes with extreme, selective wettability can efficiently remove oil or water from oil/water mixtures through a simple filtration process using gravity. A wide range of different types of mesh membranes have been successfully rendered with extreme wettability and applied to oil/water separation in the laboratory. These mesh materials have typically shown good durability, stability as well as reusability, which makes them promising candidates for an ever widening range of practical applications. © 2016 Elsevier B.V.

  3. Selective separation of oil and water with mesh membranes by capillarity

    KAUST Repository

    Yu, Yuanlie

    2016-05-29

    The separation of oil and water from wastewater generated in the oil-production industries, as well as in frequent oil spillage events, is important in mitigating severe environmental and ecological damage. Additionally, a wide arrange of industrial processes require oils or fats to be removed from aqueous systems. The immiscibility of oil and water allows for the wettability of solid surfaces to be engineered to achieve the separation of oil and water through capillarity. Mesh membranes with extreme, selective wettability can efficiently remove oil or water from oil/water mixtures through a simple filtration process using gravity. A wide range of different types of mesh membranes have been successfully rendered with extreme wettability and applied to oil/water separation in the laboratory. These mesh materials have typically shown good durability, stability as well as reusability, which makes them promising candidates for an ever widening range of practical applications. © 2016 Elsevier B.V.

  4. Recent developments on ion-exchange membranes and electro-membrane processes.

    Science.gov (United States)

    Nagarale, R K; Gohil, G S; Shahi, Vinod K

    2006-02-28

    Rapid growth of chemical and biotechnology in diversified areas fuels the demand for the need of reliable green technologies for the down stream processes, which include separation, purification and isolation of the molecules. Ion-exchange membrane technologies are non-hazardous in nature and being widely used not only for separation and purification but their application also extended towards energy conversion devices, storage batteries and sensors etc. Now there is a quite demand for the ion-exchange membrane with better selectivities, less electrical resistance, high chemical, mechanical and thermal stability as well as good durability. A lot of work has been done for the development of these types of ion-exchange membranes during the past twenty-five years. Herein we have reviewed the preparation of various types of ion-exchange membranes, their characterization and applications for different electro-membrane processes. Primary attention has been given to the chemical route used for the membrane preparation. Several general reactions used for the preparation of ion-exchange membranes were described. Methodologies used for the characterization of these membranes and their applications were also reviewed for the benefit of readers, so that they can get all information about the ion-exchange membranes at one platform. Although there are large number of reports available regarding preparations and applications of ion-exchange membranes more emphasis were predicted for the usefulness of these membranes or processes for solving certain type of industrial or social problems. More efforts are needed to bring many products or processes to pilot scale and extent their applications.

  5. Membrane contactor/separator for an advanced ozone membrane reactor for treatment of recalcitrant organic pollutants in water

    International Nuclear Information System (INIS)

    Chan, Wai Kit; Jouët, Justine; Heng, Samuel; Yeung, King Lun; Schrotter, Jean-Christophe

    2012-01-01

    An advanced ozone membrane reactor that synergistically combines membrane distributor for ozone gas, membrane contactor for pollutant adsorption and reaction, and membrane separator for clean water production is described. The membrane reactor represents an order of magnitude improvement over traditional semibatch reactor design and is capable of complete conversion of recalcitrant endocrine disrupting compounds (EDCs) in water at less than three minutes residence time. Coating the membrane contactor with alumina and hydrotalcite (Mg/Al=3) adsorbs and traps the organics in the reaction zone resulting in 30% increase of total organic carbon (TOC) removal. Large surface area coating that diffuses surface charges from adsorbed polar organic molecules is preferred as it reduces membrane polarization that is detrimental to separation. - Graphical abstract: Advanced ozone membrane reactor synergistically combines membrane distributor for ozone, membrane contactor for sorption and reaction and membrane separator for clean water production to achieve an order of magnitude enhancement in treatment performance compared to traditional ozone reactor. Highlights: ► Novel reactor using membranes for ozone distributor, reaction contactor and water separator. ► Designed to achieve an order of magnitude enhancement over traditional reactor. ► Al 2 O 3 and hydrotalcite coatings capture and trap pollutants giving additional 30% TOC removal. ► High surface area coating prevents polarization and improves membrane separation and life.

  6. Systems and methods for using a boehmite bond-coat with polyimide membranes for gas separation

    Science.gov (United States)

    Polishchuk, Kimberly Ann

    2013-03-05

    The subject matter disclosed herein relates to gas separation membranes and, more specifically, to polyimide gas separation membranes. In an embodiment, a gas separation membrane includes a porous substrate, a substantially continuous polyimide membrane layer, and one or more layers of boehmite nanoparticles disposed between the porous substrate and the polyimide membrane layer to form a bond-coat layer. The bond-coat layer is configured to improve the adhesion of the polyimide membrane layer to the porous substrate, and the polyimide membrane layer has a thickness approximately 100 nm or less.

  7. Novel studies of molecular orientation in synthetic polymeric membranes for gas separation

    International Nuclear Information System (INIS)

    Ismail, Ahmad Fauzi

    1998-01-01

    The main objective of this investigation was to produce a super-selective asymmetric membrane for gas separation. To achieve this, molecular orientation induced by rheological conditions during membrane fabrication was investigated and related to the gas separation performance of flat sheet and hollow fiber membranes. Infrared dichroism, a spectroscopic technique, was developed in the first phase of the research to directly measure molecular orientation in flat sheet membranes. The degree of molecular orientation was found to increase with increasing shear during fabrication which enhanced both pressure-normalised flux and selectivity of the coated membranes. The rheology of polymer solutions and the mechanism of molecular orientation have been treated in detail for membrane production. This is a novel approach since previous fundamental work has focused on the phase inversion process. The current study showed that rheological conditions during membrane fabrication have the utmost importance in enhancing membrane selectivity. The effects of molecular orientation at greater shear, as experienced by hollow fiber membranes during extrusion through the spinneret channel, were investigated in the second phase of this research. In order to produce a good quality fiber, a unique tube-in-orifice spinneret and a modified hollow fiber spinning rig were designed and fabricated. Thus the combined effects of reduced water activity in the bore coagulant during hollow fiber spinning and rheologically induced molecular orientation were investigated. The selectivity of the coated high shear hollow fiber membranes was heightened and even surpassed the recognised intrinsic selectivity of the polymer. Pressure-normalised flux also increased with increasing shear rate. In the third phase of this research phase inversion conditions were further optimised to give a superior skin layer and thus provide an even better platform for the advantageous effects of molecular orientation. These

  8. Radioactive rare gas separation using a separation cell with two kinds of membrane differing in gas permeability tendency

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Ozaki, Osamu; Sato, Hajime; Kimura, Shoji; Miyauchi, Terukatsu.

    1977-01-01

    A separation cell embodying two kinds of membrane-porous and nonporous, i.e. differing in gas permeability - has a separation factor higher than possible with a conventional separation cell with a single kind of membrane. The performance of such separation cells and of cascades constituted thereof are analyzed theoretically and measured experimentally for different conditions of operation, to determine the applicability of the concept to the separation of rare gases from gaseous waste out of nuclear plants. Theoretical considerations indicate that, in a cascade composed of symmetric separation cells, the separation performance can be improved by recycling part of the effluent from a cell back through the same cell (recycling cascade). It is shown that its performance is better than with the arrangement of diverting another effluent several stages upstream. With the recycling cascade, the symmetric separation recycling rate is determined by the depletion separation and enrichment separation factors relevant to the respective membranes. The separation performance of a 9-stage recycling cascade composed of separation cells with silicone rubber tubular membranes and cellulose acetate tubular membranes is derived for a case of Kr separation from N 2 -Kr mixture. The experimental data coincide well with the analytical results. From both the experimental and the analytical results, it is found that the attainable separation coefficient per stage of the cascade comes to average approximately 0.97. (auth.)

  9. Study on CO2/ N2 separation: the effect of rubbery polymer coating on PVDF membrane

    Science.gov (United States)

    Zuwairi, M. Z.; Rahman, S. A.

    2017-06-01

    The emission of harmful gases such as carbon dioxide (CO2) via gas processing plant and daily human activities gave negative impacts to the environment and global inhabitant. Flat sheet asymmetric membranes were produced from homogenous solution of Poly(vinylideneflouride) (PVDF) via phase inversion method using N-methyl-2-pyrrolidone (NMP) as the solvent. While the poly ether b-amide (PEBAX) was dissolve by using of (70 ethanol and 30 water) as a solvent and and lithium chloride as a additives. The morphology and cross section of the produced membranes were observed by Scanning Electron Microscope (SEM). Then, the membranes were tested for chemical analysis to define the presence of PEBAX in the membrane by using Fourier Transform Infrared (FTIR) spectroscopy. The permeation performances of the membranes were evaluated in terms of permeability and selectivity of the membranes by using gas permeation test. Increasing the PEBAX content significantly increased the selectivity of the PVDF membrane to separate the CO2/N2 gases but decreased the amount of the gases that passed through the membrane.

  10. Use of a Ceramic Membrane to Improve the Performance of Two-Separate-Phase Biocatalytic Membrane Reactor

    OpenAIRE

    Ranieri, G; Mazzei, R; Wu, Z; Li, K; Giorno, L

    2016-01-01

    Biocatalytic membrane reactors (BMR) combining reaction and separation within the same unit have many advantages over conventional reactor designs. Ceramic membranes are an attractive alternative to polymeric membranes in membrane biotechnology due to their high chemical, thermal and mechanical resistance. Another important use is their potential application in a biphasic membrane system, where support solvent resistance is highly needed. In this work, the preparation of asymmetric ceramic ho...

  11. Coupling of separation and reaction in zeolite membrane reactor for hydroisomerization of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Gora, L.; Jansen, J.C. [Ceramic Membrane Centre, The Pore, DelftChemTech, Delft Univ. of Technology, Delft (Netherlands)

    2005-03-01

    A zeolite membrane reactor has been developed for the hydroisomerization of hydrocarbons, in which the linear molecules are separated from branched ones on the silicalite-1 membrane prior to conversion of the permeated linear hydrocarbons to equilibrium levels on the catalyst bed. Model studies using C{sub 6} components are conducted. n-C{sub 6} separated from 2MP (selectivity 24) is converted for 72% with 36% selectivity towards di-branched isomers (at 393 K). The results indicate that platinum containing chlorinated alumina/silicalite-1 membrane reactor has a potential in upgrading octane values and offers advantages such as higher efficiency, better process control and lower consumption of energy. (orig.)

  12. Membrane gas separation. January 1970-September 1989 (Citations from the NTIS data base). Report for January 1970-September 1989

    International Nuclear Information System (INIS)

    1989-09-01

    This bibliography contains citations concerning the research and development of gas separation and purification utilizing plastic and metal membranes. Among the topics included are isotope separation, osmotic techniques, reverse osmosis, and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties as well as molecular structure. The selectivity of polymeric films for a variety of gases is also included. (This updated bibliography contains 100 citations, 18 of which are new entries to the previous edition.)

  13. Membrane gas separation. January 1970-September 1988 (Citations from the NTIS data base). Report for January 1970-September 1988

    International Nuclear Information System (INIS)

    1988-09-01

    This bibliography contains citations concerning the research and development of gas separation and purification utilizing plastic and metal membranes. Among the topics included are isotope separation, osmotic techniques, reverse osmosis, and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties as well as molecular structure. The selectivity of polymeric films for a variety of gases is also included. (This updated bibliography contains 150 citations, 27 of which are new entries to the previous edition.)

  14. RECENT PROGRESS OF OXYGEN/NITROGEN SEPARATION USING MEMBRANE TECHNOLOGY

    OpenAIRE

    K. C. CHONG; S. O. LAI; H. S. THIAM; H. C. TEOH; S. L. HENG

    2016-01-01

    The oxygen-enriched air is highly demanded for various industrial applications such as medical, chemical and enhanced combustion processes. The conventional oxygen/nitrogen production is either cryogenic distillation or pressure swing adsorption (PSA). Both of these techniques possess the production capability of 20 to 300 tonnes of oxygen per day and oxygen purity of more than 95%. However, these techniques are energy intensive. Alternatively, membrane technology is an emerging technology...

  15. The Efficient Separations and Processing Integrated Program

    International Nuclear Information System (INIS)

    Kuhn, W.L.; Gephart, J.M.

    1994-08-01

    The Efficient Separations and Processing Integrated Program (ESPIP) was created in 1991 to identify, develop, and perfect separations technologies and processes to treat wastes and address environmental problems throughout the US Department of Energy (DOE) complex. The ESPIP funds several multiyear tasks that address high-priority waste remediation problems involving high-level, low-level, transuranic, hazardous, and mixed (radioactive and hazardous) wastes. The ESPIP supports applied R ampersand D leading to demonstration or use of these separations technologies by other organizations within DOE's Office of Environmental Restoration and Waste Management. Examples of current ESPIP-funded separations technologies are described here

  16. Tunable integration of absorption-membrane-adsorption for efficiently separating low boiling gas mixtures near normal temperature

    Science.gov (United States)

    Liu, Huang; Pan, Yong; Liu, Bei; Sun, Changyu; Guo, Ping; Gao, Xueteng; Yang, Lanying; Ma, Qinglan; Chen, Guangjin

    2016-01-01

    Separation of low boiling gas mixtures is widely concerned in process industries. Now their separations heavily rely upon energy-intensive cryogenic processes. Here, we report a pseudo-absorption process for separating low boiling gas mixtures near normal temperature. In this process, absorption-membrane-adsorption is integrated by suspending suitable porous ZIF material in suitable solvent and forming selectively permeable liquid membrane around ZIF particles. Green solvents like water and glycol were used to form ZIF-8 slurry and tune the permeability of liquid membrane surrounding ZIF-8 particles. We found glycol molecules form tighter membrane while water molecules form looser membrane because of the hydrophobicity of ZIF-8. When using mixing solvents composed of glycol and water, the permeability of liquid membrane becomes tunable. It is shown that ZIF-8/water slurry always manifests remarkable higher separation selectivity than solid ZIF-8 and it could be tuned to further enhance the capture of light hydrocarbons by adding suitable quantity of glycol to water. Because of its lower viscosity and higher sorption/desorption rate, tunable ZIF-8/water-glycol slurry could be readily used as liquid absorbent to separate different kinds of low boiling gas mixtures by applying a multistage separation process in one traditional absorption tower, especially for the capture of light hydrocarbons. PMID:26892255

  17. Effect of solvent concentration on performance of polysulfone membrane for filtration and separation

    Science.gov (United States)

    Syafiq Mohamad Sofian, Muhamad; Zaini Yunos, Muhamad; Ahmad, Azlinnorazia; Harun, Zawati; Akhair, Siti Hajar Mohd; Adibah Raja Ahmad, Raja; Hafeez Azhar, Faiz; Rashid, Abdul Qaiyyum Abd; Ismail, Al Emran

    2017-08-01

    This study was conducted to investigate the effect of solvent concentration on the performance of polysulfone membrane via airbrush spray method. The solvent concentration was varied from 73% to 80% in dope solution. The study also investigated airbrush processing parameter such as spray time and distance at different solvent concentration. The prepared membrane was characterized in respect to its morphology and the performance of the membrane were evaluated via gas permeability performance. This study found that the membrane fiber size was reduced as solvent concentration increases. When time increased the diameter of fiber also increased. The distance also affected the fiber size, when the distance increased the diameter of fiber became smaller. 80% of solvent concentration has better filtration and separation ability compared to other solvent due to its porosity and morphology. From the gas permeability cell testing it shows that the permeability is increasing as the solvent concentration decrease.

  18. Separation and Extraction of Some Heavy and Toxic Metal Ions from Their Wastes by Ionic Membranes

    International Nuclear Information System (INIS)

    El-Sayed Hegazy, A.; Kamal, H.; Mahmoud, Gh. A.; Khalifa, N.A.

    1999-01-01

    Preparation and characterisation of a series of ion-exchange membranes for the purpose of separation and extraction of some heavy and toxic metal ions from their wastes have been studied. Such ion exchange membranes prepared by γ-radiation grafting of acrylonitrile (AN) and vinyl acetate (VAc) in a binary monomers mixture onto low density polyethylene (LDPE) using direct technique of grafting. The reaction conditions at which grafting process proceeds successfully have been determined. Many modification treatments have been attempted for the prepared membranes to improve their ion-exchange properties. The possibility of their practical use in waste water treatment from some heavy and toxic metal ions such as Pb 2+ , Cd 2+ ,Cu 2+ ,Fe 3+ ,Sr 2+ and Li + have been investigated. These grafted membranes showed great promise for its use in the field of extraction and removal of some heavy and toxic metals from their wastes

  19. New processes for uranium isotope separation

    International Nuclear Information System (INIS)

    Vanstrum, P.R.; Levin, S.A.

    1977-01-01

    An overview of the status and prospects for processes other than gaseous diffusion, gas centrifuge, and separation nozzle for uranium isotope separation is presented. The incentive for the development of these processes is the increasing requirements for enriched uranium as fuel for nuclear power plants and the potential for reducing the high costs of enrichment. The latest nuclear power projections are converted to uranium enrichment requirements. The size and timing of the market for new enrichment processes are then determined by subtracting the existing and planned uranium enrichment capacities. It is estimated that to supply this market would require the construction of a large new enrichment plant of 9,000,000 SWU per year capacity, costing about $3 billion each (in 1976 dollars) about every year till the year 2000. A very comprehensive review of uranium isotope separation processes was made in 1971 by the Uranium Isotope Separation Review Ad Hoc Committee of the USAEC. Many of the processes discussed in that review are of little current interest. However, because of new approaches or remaining uncertainties about potential, there is considerable effort or continuing interest in a number of alternative processes. The status and prospects for attaining the requirements for competitive economics are presented for these processes, which include laser, chemical exchange, aerodynamic other than separation nozzle, and plasma processes. A qualitative summary comparison of these processes is made with the gaseous diffusion, gas centrifuge, and separation nozzle processes. In order to complete the overview of new processes for uranium isotope separation, a generic program schedule of typical steps beyond the basic process determination which are required, such as subsystem, module, pilot plant, and finally plant construction, before large-scale production can be attained is presented. Also the present value savings through the year 2000 is shown for various

  20. Robust and Elastic Polymer Membranes with Tunable Properties for Gas Separation.

    Science.gov (United States)

    Cao, Peng-Fei; Li, Bingrui; Hong, Tao; Xing, Kunyue; Voylov, Dmitry N; Cheng, Shiwang; Yin, Panchao; Kisliuk, Alexander; Mahurin, Shannon M; Sokolov, Alexei P; Saito, Tomonori

    2017-08-09

    Polymer membranes with the capability to process a massive volume of gas are especially attractive for practical applications of gas separation. Although much effort has been devoted to develop novel polymer membranes with increased selectivity, the overall gas-separation performance and lifetime of membrane are still negatively affected by the weak mechanical performance, low plasticization resistance and poor physical aging tolerance. Recently, elastic polymer membranes with tunable mechanical properties have been attracting significant attentions due to their tremendous potential applications. Herein, we report a series of urethane-rich PDMS-based polymer networks (U-PDMS-NW) with improved mechanical performance for gas separation. The cross-link density of U-PDMS-NWs is tailored by varying the molecular weight (M n ) of PDMS. The U-PDMS-NWs show up to 400% elongation and tunable Young's modulus (1.3-122.2 MPa), ultimate tensile strength (1.1-14.3 MPa), and toughness (0.7-24.9 MJ/m 3 ). All of the U-PDMS-NWs exhibit salient gas-separation performance with excellent thermal resistance and aging tolerance, high gas permeability (>100 Barrer), and tunable gas selectivity (up to α[P CO 2 /P N 2 ] ≈ 41 and α[P CO 2 /P CH 4 ] ≈ 16). With well-controlled mechanical properties and gas-separation performance, these U-PDMS-NW can be used as a polymer-membrane platform not only for gas separation but also for other applications such as microfluidic channels and stretchable electronic devices.

  1. Matrimid® derived carbon molecular sieve hollow fiber membranes for ethylene/ethane separation

    KAUST Repository

    Xu, Liren; Rungta, Meha; Koros, William J.

    2011-01-01

    materials in realistic gas separations. The very challenging ethylene/ethane separation is the primary target of this work. Matrimid® derived CMS hollow fiber membranes have been investigated in this work. Resultant CMS fiber showed interesting separation

  2. Tröger’s Base Ladder Polymer for Membrane-Based Hydrocarbon Separation

    KAUST Repository

    Alhazmi, Abdulrahman

    2017-01-01

    The use of polymeric membranes for natural gas separation has rapidly increased during the past three decades, particularly for carbon dioxide separation from natural gas. Another valuable application is the separation of heavy hydrocarbons from

  3. Membrane preparation and process development for radioactive waste treatment

    International Nuclear Information System (INIS)

    Lee, K. W.; Kim, G. W.; Kim, S. K.

    2012-01-01

    The membrane manufacturing technology with hydrophilic function that can minimize fouling when it applies to the radioactive liquid waste treatment process was developed. Thermodynamic and rheological analysis for polysulfone casting solution containing polyvinylpyrrolidone was performed. On the basis of the results of preparation of the hydrophilic polymer membrane solution, the hollow fiber membrane for radioactive liquid waste treatment was manufactured and its performance analysis was carried out. As a results, it turns out the hydrophilic hollow fiber membrane has more 90 % of flux increment effect and also more 2.5 times fouling reducing effect than one prepared with only polysulfone. In addition, as investigating the separation property of radioactive liquid waste for the electrofilteration membrane process, a proper range for application of radioactive liquid wastes was established through the thorough electrofiltration analysis of various wastes containing metal salt, surfactants and oil

  4. Membrane preparation and process development for radioactive waste treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. W.; Kim, G. W.; Kim, S. K. [KAERI, Daejeon (Korea, Republic of); and others

    2012-01-15

    The membrane manufacturing technology with hydrophilic function that can minimize fouling when it applies to the radioactive liquid waste treatment process was developed. Thermodynamic and rheological analysis for polysulfone casting solution containing polyvinylpyrrolidone was performed. On the basis of the results of preparation of the hydrophilic polymer membrane solution, the hollow fiber membrane for radioactive liquid waste treatment was manufactured and its performance analysis was carried out. As a results, it turns out the hydrophilic hollow fiber membrane has more 90 % of flux increment effect and also more 2.5 times fouling reducing effect than one prepared with only polysulfone. In addition, as investigating the separation property of radioactive liquid waste for the electrofilteration membrane process, a proper range for application of radioactive liquid wastes was established through the thorough electrofiltration analysis of various wastes containing metal salt, surfactants and oil.

  5. Aerodynamic isotope separation processes for uranium enrichment: process requirements

    International Nuclear Information System (INIS)

    Malling, G.F.; Von Halle, E.

    1976-01-01

    The pressing need for enriched uranium to fuel nuclear power reactors, requiring that as many as ten large uranium isotope separation plants be built during the next twenty years, has inspired an increase of interest in isotope separation processes for uranium enrichment. Aerodynamic isotope separation processes have been prominently mentioned along with the gas centrifuge process and the laser isotope separation methods as alternatives to the gaseous diffusion process, currently in use, for these future plants. Commonly included in the category of aerodynamic isotope separation processes are: (a) the separation nozzle process; (b) opposed gas jets; (c) the gas vortex; (d) the separation probes; (e) interacting molecular beams; (f) jet penetration processes; and (g) time of flight separation processes. A number of these aerodynamic isotope separation processes depend, as does the gas centrifuge process, on pressure diffusion associated with curved streamlines for the basic separation effect. Much can be deduced about the process characteristics and the economic potential of such processes from a simple and elementary process model. In particular, the benefit to be gained from a light carrier gas added to the uranium feed is clearly demonstrated. The model also illustrates the importance of transient effects in this class of processes

  6. Ceramic membranes for gas processing in coal gasification

    Energy Technology Data Exchange (ETDEWEB)

    Smart, S.; Lin, C.X.C.; Ding, L.; Thambimuthu, K.; da Costa, J.C.D. [University of Queensland, Brisbane, Qld. (Australia)

    2010-07-01

    Pre-combustion options via coal gasification, especially integrated gasification combined cycle (IGCC) processes, are attracting the attention of governments, industry and the research community as an attractive alternative to conventional power generation. It is possible to build an IGCC plant with CCS with conventional technologies however; these processes are energy intensive and likely to reduce power plant efficiencies. Novel ceramic membrane technologies, in particular molecular sieving silica (MSS) and pervoskite membranes, offer the opportunity to reduce efficiency losses by separating gases at high temperatures and pressures. MSS membranes can be made preferentially selective for H{sub 2}, enabling both enhanced production, via a water-gas shift membrane reactor, and recovery of H{sub 2} from the syngas stream at high temperatures. They also allow CO{sub 2} to be concentrated at high pressures, reducing the compression loads for transportation and enabling simple integration with CO{sub 2} storage or sequestration operations. Perovskite membranes provide a viable alternative to cryogenic distillation for air separation by delivering the tonnage of oxygen required for coal gasification at a reduced cost. In this review we examine ceramic membrane technologies for high temperature gas separation and discuss the operational, mechanical, design and process considerations necessary for their successful integration into IGCC with CCS systems.

  7. Osmotically driven flows in microchannels separated by a semipermeable membrane

    DEFF Research Database (Denmark)

    Jensen, Kåre Hartvig; Lee, J.; Bohr, Tomas

    2009-01-01

    We have fabricated lab-on-a-chip systems with microchannels separated by integrated membranes allowing for osmotically driven microflows. We have investigated these flows experimentally by studying the dynamics and structure of the front of a sugar solution travelling in 200 mu m wide and 50-200 mu...... m deep microchannels. We find that the sugar front travels at a constant speed, and that this speed is proportional to the concentration of the sugar solution and inversely proportional to the depth of the channel. We propose a theoretical model, which, in the limit of low axial flow resistance......, predicts that the sugar front should indeed travel with a constant velocity. The model also predicts an inverse relationship between the depth of the channel and the speed, and a linear relation between the sugar concentration and the speed. We thus find good qualitative agreement between the experimental...

  8. Mixed protonic-electronic conductors for hydrogen separation membranes

    Science.gov (United States)

    Song, Sun-Ju

    2003-10-01

    The chemical functionality of mixed protonic-electronic conductors arises out of the nature of the defect structure controlled by thermodynamic defect equilibria of the materials, and results in the ability to transport charged species. This dissertation is to develop a fundamental understanding of defect chemistry and transport properties of mixed protonic-electronic conducting perovskites for hydrogen separation membranes. Furthermore, it was aimed to develop the algorithm to predict how these properties affect the permeability in chemical potential gradients. From this objective, first of all, the appropriate equations governing proton incorporation into perovskite oxides were suggested and the computer simulation of defect concentrations across a membrane oxide under various conditions were performed. Electrical properties of p-type electronic defects at oxidizing conditions and n-type electrical properties of SrCe 0.95Eu0.05O3-delta at reducing atmospheres were studied. Defect equilibrium diagrams as a function of PO2 , PH2O ) produced from the Brouwer method were verified by computational simulation and electrical conductivity measurements. The chemical diffusion of hydrogen through oxide membranes was described within the framework of Wagner's chemical diffusion theory and it was solved without any simplifying assumptions on functional dependence of partial conductivity due to the successful numerical modeling of partial conductivities as a function of both hydrogen and oxygen partial pressures. Finally the hydrogen permeability of Eu and Sm doped SrCeO3-delta was studied as a function of temperature, hydrogen partial pressure gradient, and water vapor pressure gradient. The dopant dependence of hydrogen permeability was explained in terms of the difference in ionization energy and ionic radius of dopant.

  9. Ion-Exchange Membrane Chromatography as an Alternative Method of Separation of Potato y Virus

    Directory of Open Access Journals (Sweden)

    Treder Krzysztof

    2015-12-01

    Full Text Available Procedures of separation of virus particles from a plant material are multistage. Furthermore often they are difficult in terms of methodology and require use of expensive, highly specialist equipment and yield of separation is often low. The antigen obtained is often degraded and contains admixtures of other proteins. Therefore, generation of high quality and specificity antibodies based on such antigen is very difficult and quality of the antibodies has impact on reliability, sensitivity and unambiguity of results of immunodiagnostic tests (e.g. ELISA that are currently conventionally used to detect vegetable viruses. In this study three conventionally-performed methods of separation of potato virus Y (PVY were compared and a method of separation based on membrane chromatography, as an alternative separation technique, has been presented. It has been demonstrated that in proper process conditions good quality virus preparation can be obtained.

  10. Synthesis of a composite inorganic membrane for the separation of nitrogen, tetrafluoromethane and hexafluoropropylene

    Directory of Open Access Journals (Sweden)

    Hertzog Bissett

    2011-09-01

    Full Text Available Composite inorganic membranes were synthesised for gas component separation of N2, CF4 and C3F6. Selectivities lower than Knudsen selectivities were obtained due to membrane defects. A composite ceramic membrane consisting of a ceramic support structure, a MFI intermediate zeolite layer and a Teflon top layer, was developed to improve separation.

  11. Zinc-substituted ZIF-67 nanocrystals and polycrystalline membranes for propylene/propane separation

    KAUST Repository

    Wang, Chongqing

    2016-09-09

    Continuous ZIF-67 polycrystalline membranes with effective propylene/propane separation performances were successfully fabricated through the incorporation of zinc ions into the ZIF-67 framework. The separation factor increases from 1.4 for the pure ZIF-67 membrane to 50.5 for the 90% zinc-substituted ZIF-67 membrane.

  12. A ''master key'' to chemical separation processes

    International Nuclear Information System (INIS)

    Madic, Ch.; Hill, C.

    2002-01-01

    One of the keys to sorting nuclear waste is extracting minor actinides - the most troublesome long-lived elements - from the flow of waste by separating them from lanthanides, which have very similar chemical properties to actinides, for possible transmutation into shorter-lived elements. Thanks to a European initiative coordinated by CEA, this key is now available: its name is Sanex. There now remains to develop tough, straightforward industrial processes to integrate it into a new nuclear waste management approach by 2005. Sanex joins the Diamex process, used for the combined separation of lanthanides and minor actinides from fission products. A third process, Sesame, designed to separate americium, completes the list of available separation processes. (authors)

  13. The development of membrane based high purity oily water separators for use in Arctic waters

    Energy Technology Data Exchange (ETDEWEB)

    Peng, H.; Tremblay, A.Y. [Ottawa Univ., ON (Canada). Dept. of Chemical Engineering, Industrial Membrane Centre; Veinot, D.E. [Defence Research and Development Canada, Halifax, NS (Canada)

    2005-07-01

    With increased exploration and industrial activity in the Canadian Arctic, interest in the Northwest Passage as a shipping route has also increased. The oily wastewater produced by ships must be treated prior to discharge, particularly in the sensitive Arctic environment where biodegradation of organics is very slow due to cold climatic conditions and low sunlight. As such, safe techniques are needed for the treatment of oily wastewater released from ships. However, bilge water is difficult to treat because it contains seawater, particulates, used oils and detergents. Membrane based oily water separators (OWS) are considered to be a key technology for the treatment of bilge water onboard ships. The issues that must be taken into account in the ship-born use of membrane based OWS include the proper treatment of the oily brine before discharge; the substantial reduction in volume that is required; the complexity of the technology; labour associated with the operation of the system due to filter changes and cleaning; and, system automation to simplify its operation. In this study, a membrane-based process for treating bilge water was developed to meet stringent discharge regulations for discharge in Arctic waters. Currently, this discharge limit is set at 0 ppm. A pilot scale membrane cascade system was designed and evaluated. Multilumen ceramic membranes were used in the first stage and Sepa{sup R} test cells were used in the second stage. Optimal membrane pore size was determined. The study investigated the separation of oil and grease using different molecular weight cut-off (MWCO) membranes. The study revealed that through proper membrane design, it is possible to remove oil and grease from bilge water to a level permitting its discharge to Arctic waters. However, it was recommended that low level aromatic diesel fuels be used in ships operating in Arctic waters since the presence of soluble aromatics in diesel fuel increases the technical difficulty of reaching

  14. Separation of BSA through FAU-type zeolite ceramic composite membrane formed on tubular ceramic support: Optimization of process parameters by hybrid response surface methodology and biobjective genetic algorithm.

    Science.gov (United States)

    Vinoth Kumar, R; Ganesh Moorthy, I; Pugazhenthi, G

    2017-08-09

    In this study, Faujasite (FAU) zeolite was coated on low-cost tubular ceramic support as a separating layer through hydrothermal route. The mixture of silicate and aluminate solutions was used to create a zeolitic separation layer on the support. The prepared zeolite ceramic composite membrane was characterized using X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), particle size distribution (PSD), field emission scanning electron microscopy (FESEM), and zeta potential measurements. The porosity of ceramic support (53%) was reduced by the deposition of FAU (43%) zeolite layer. The pore size and water permeability of the membrane were evaluated as 0.179 µm and 1.62 × 10 -7  m 3 /m 2  s kPa, respectively, which are lower than that of the support (pore size of 0.309 µm and water permeability of 5.93 × 10 -7  m 3 /m 2  s kPa). The permeate flux and rejection potential of the prepared membrane were evaluated by microfiltration of bovine serum albumin (BSA). To study the influences of three independent variables such as operating pressure (68.94-275.79 kPa), concentration of BSA (100-500 ppm), and solution pH (2-4) on permeate flux and percentage of rejection, the response surface methodology (RSM) was used. The predicted models for permeate flux and rejection were further subjected to biobjective genetic algorithm (GA). The hybrid RSM-GA approach resulted in a maximum permeate flux of 2.66 × 10 -5  m 3 /m 2  s and BSA rejection of 88.02%, at which the optimum conditions were attained as 100 ppm BSA concentration, 2 pH solution, and 275.79 kPa applied pressure. In addition, the separation efficiency was compared with other membranes applied for BSA separation to know the potential of the fabricated FAU zeolite ceramic composite membrane.

  15. Computational simulation of the blood separation process.

    Science.gov (United States)

    De Gruttola, Sandro; Boomsma, Kevin; Poulikakos, Dimos; Ventikos, Yiannis

    2005-08-01

    The aim of this work is to construct a computational fluid dynamics model capable of simulating the quasitransient process of apheresis. To this end a Lagrangian-Eulerian model has been developed which tracks the blood particles within a delineated two-dimensional flow domain. Within the Eulerian method, the fluid flow conservation equations within the separator are solved. Taking the calculated values of the flow field and using a Lagrangian method, the displacement of the blood particles is calculated. Thus, the local blood density within the separator at a given time step is known. Subsequently, the flow field in the separator is recalculated. This process continues until a quasisteady behavior is reached. The simulations show good agreement with experimental results. They shows a complete separation of plasma and red blood cells, as well as nearly complete separation of red blood cells and platelets. The white blood cells build clusters in the low concentrate cell bed.

  16. Separation of Olefin/Paraffin Mixtures with Carrier Facilitated Membrane Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, T.C.; Blanc, R.; Zeid, J.; Suwarlim, A.; Firat, B.; Wijmans, H.; Asaro, M. (SRI); Greene, M.(Lummus)

    2007-03-12

    This document describes the results of a DOE funded joint effort of Membrane Technology and Research Inc. (MTR), SRI International (SRI), and ABB Lummus (ABB) to develop facilitated transport membranes for olefin/paraffin separations. Currently, olefin/paraffin separation is done by distillation—an extremely energy-intensive process because of the low relative volatilities of olefins and paraffins. If facilitated transport membranes could be successfully commercialized, the potential energy savings achievable with this membrane technology are estimated to be 48 trillion Btu per year by the year 2020. We discovered in this work that silver salt-based facilitated transport membranes are not stable even in the presence of ideal olefin/paraffin mixtures. This decline in membrane performance appears to be caused by a previously unrecognized phenomenon that we have named olefin conditioning. As the name implies, this mechanism of performance degradation becomes operative once a membrane starts permeating olefins. This project is the first study to identify olefin conditioning as a significant factor impacting the performance of facilitated olefin transport membranes. To date, we have not identified an effective strategy to mitigate the impact of olefin conditioning. other than running at low temperatures or with low olefin feed pressures. In our opinion, this issue must be addressed before further development of facilitated olefin transport membranes can proceed. In addition to olefin conditioning, traditional carrier poisoning challenges must also be overcome. Light, hydrogen, hydrogen sulfide, and acetylene exposure adversely affect membrane performance through unwanted reaction with silver ions. Harsh poisoning tests with these species showed useful membrane lifetimes of only one week. These tests demonstrate a need to improve the stability of the olefin complexing agent to develop membranes with lifetimes satisfactory for commercial application. A successful effort

  17. Fabrication of perforated isoporous membranes via a transfer-free strategy: enabling high-resolution separation of cells.

    Science.gov (United States)

    Ou, Yang; Lv, Chang-Jiang; Yu, Wei; Mao, Zheng-Wei; Wan, Ling-Shu; Xu, Zhi-Kang

    2014-12-24

    Thin perforated membranes with ordered pores are ideal barriers for high-resolution and high-efficiency selective transport and separation of biological species. However, for self-assembled thin membranes with a thickness less than several micrometers, an additional step of transferring the membranes onto porous supports is generally required. In this article, we present a facile transfer-free strategy for fabrication of robust perforated composite membranes via the breath figure process, and for the first time, demonstrate the application of the membranes in high-resolution cell separation of yeasts and lactobacilli without external pressure, achieving almost 100% rejection of yeasts and more than 70% recovery of lactobacilli with excellent viability. The avoidance of the transfer step simplifies the fabrication procedure of composite membranes and greatly improves the membrane homogeneity. Moreover, the introduction of an elastic triblock copolymer increases the interfacial strength between the membrane and the support, and allows the preservation of composite membranes in a dry state. Such perforated ordered membranes can also be applied in other size-based separation systems, enabling new opportunities in bioseparation and biosensors.

  18. Porous membrane modifier as a new trend for deoiling process

    Directory of Open Access Journals (Sweden)

    Nermen H. Mohamed

    2017-09-01

    Full Text Available Porous membranes are prepared through micro phase separation of immiscible polymers consisting of hydrophobic polymer (polystyrene and hydrophilic polymer (poly(2-vinylpyridine. The greatest difficulties during petrolatum deoiling are related to the filtration stage for obtaining microcrystalline wax. The present study deals with the addition of porous membrane as modifier for the crystal structure of solid hydrocarbons, which will be the cornerstone in rearrangement and reformulation of new hard crystals in deoiling process. XRD and SEM photographs were used to evaluate the crystallinity and crystal sizes of the separated hard waxes.

  19. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying

    2012-05-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  20. Enhanced Gas Separation through Nanoconfined Ionic Liquid in Laminated MoS2 Membrane.

    Science.gov (United States)

    Chen, Danke; Ying, Wen; Guo, Yi; Ying, Yulong; Peng, Xinsheng

    2017-12-20

    Two-dimensional (2D) materials-based membranes show great potential for gas separation. Herein an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]), was confined in the 2D channels of MoS 2 -laminated membranes via an infiltration process. Compared with the corresponding bulk [BMIM][BF 4 ], nanoconfined [BMIM][BF 4 ] shows an obvious incremental increase in freezing point and a shift of vibration bands. The resulting MoS 2 -supported ionic liquid membrane (MoS 2 SILM) exhibits excellent CO 2 separation performance with high CO 2 permeance (47.88 GPU) and superb selectivity for CO 2 /N 2 (131.42), CO 2 /CH 4 (43.52), and CO 2 /H 2 (14.95), which is much better than that of neat [BMIM][BF 4 ] and [BMIM][BF 4 ]-based membranes. The outstanding performance of MoS 2 SILMs is attributed to the nanoconfined [BMIM][BF 4 ], which enables fast transport of CO 2 . Long-term operation also reveals the durability and stability of the prepared MoS 2 SILMs. The method of confining ILs in the 2D nanochannels of 2D materials may pave a new way for CO 2 capture and separation.

  1. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying; Johnson, J.R.; Karvan, Oğuz; Sholl, David S.; Koros, W.J.

    2012-01-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  2. NOVEL CERAMIC MEMBRANE FOR HIGH TEMPERATURE CARBON DIOXIDE SEPARATION

    International Nuclear Information System (INIS)

    Ida, Jun-ichi; Yang, Zhaohui; Lin, Jerry Y.S.

    2002-01-01

    A new CO 2 semi-permeable dense inorganic membrane consisting of a porous metal phase and molten carbonate was proposed. A simple direct infiltration method was used to synthesize the metal-carbonate dual-phase membrane. Hermetic (gas-tight) dual phase membrane was successfully obtained. Permeation data showed that nitrogen or helium is not permeable through the membrane (only CO 2 , with O 2 can permeate through the membrane based on transport mechanism)

  3. Fouling distribution in forward osmosis membrane process.

    Science.gov (United States)

    Lee, Junseok; Kim, Bongchul; Hong, Seungkwan

    2014-06-01

    Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis (FO) membrane process. The flux distribution model developed in this study showed a good agreement with experimental results, validating the robustness of the model. This model demonstrated, as expected, that the permeate flux decreased along the membrane channel due to decreasing osmotic pressure differential across the FO membrane. A series of fouling experiments were conducted under the draw and feed solutions at various recoveries simulated by the model. The simulated fouling experiments revealed that higher organic (alginate) fouling and thus more flux decline were observed at the last section of a membrane channel, as foulants in feed solution became more concentrated. Furthermore, the water flux in FO process declined more severely as the recovery increased due to more foulants transported to membrane surface with elevated solute concentrations at higher recovery, which created favorable solution environments for organic adsorption. The fouling reversibility also decreased at the last section of the membrane channel, suggesting that fouling distribution on FO membrane along the module should be carefully examined to improve overall cleaning efficiency. Lastly, it was found that such fouling distribution observed with co-current flow operation became less pronounced in counter-current flow operation of FO membrane process. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  4. Membrane-based, sedimentation-assisted plasma separator for point-of-care applications.

    Science.gov (United States)

    Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D; Edelstein, Paul H; Collman, Ronald G; Bau, Haim H

    2013-11-05

    Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 μL of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification.

  5. High mass isotope separation process and arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1978-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically identical but isotopically different molecules by either photon-induced pure rovibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically reactive agent to form a chemical compound containing primarily the atoms of isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically identical but isotopically different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope

  6. Effects of dope extrusion rate on the morphology and gas separation performance of asymmetric polysulfone hollow fiber membranes for O2/N2 separation

    Directory of Open Access Journals (Sweden)

    Ahmad Fausi Ismail

    2002-11-01

    Full Text Available The objective of this study was to investigate the influence of dope extrusion rates on morphology and gas separation performance of asymmetric polysulfone hollow fiber membranes. Asymmetric polysulfone hollow fiber membranes for gas separation were prepared from a solution consisting of 26.0 wt. % of polysulfone, 30.4 wt. % of N, N-dimethylacetamide, 30.4 wt. % of tetrahydrofuran and 13.2 wt. % ethanol. The dry/wet phase separation process was applied to a dry/wet spinning process. Fibers were spun at various dope extrusion rates (DER ranging from 1.5 - 3.0 cm3/min and hence at different levels of shear. The results suggest that as the dope extrusion rate is increased, the selectivity will increase until a critical level of shear is reached, beyond which the membrane performance deteriorates. Pressure-normalized-fluxes and selectivities were evaluated by using pure oxygen and nitrogen as test gases.

  7. Sustainable development of gree solvent separation process

    OpenAIRE

    Lisickov, Kiril; Fidancevska, Emilija; Grujic, Radoslav; Srebrenkoska, Vineta; Kuvendziev, Stefan

    2011-01-01

    Solvents defi ne a major part of the environmental performance of processes in the chemical industry and impact on cost, safety and health issues. The idea of green solvents expresses the goal to minimize the environmental impact resulting from the use of solvents in chemical production. In spite of conventional separation methods, precise process green technologies are based on the application of modern processes and process equipment as well as control and management...

  8. Cellulose acetate-based molecularly imprinted polymeric membrane for separation of vanillin and o-vanillin

    OpenAIRE

    Zhang,Chunjing; Zhong,Shian; Yang,Zhengpeng

    2008-01-01

    Cellulose acetate-based molecularly imprinted polymeric membranes were prepared using vanillin as template molecule. The microscopic structure of the resultant polymeric membranes was characterized by SEM and FTIR spectroscopy, and the selective binding properties and separation capacity of the membranes for vanillin and o-vanillin were tested with binding experiments and separate experiments, respectively. The results showed that the vanillin-imprinted polymeric membranes displayed higher bi...

  9. A simulation model for transient response of a gas separation module using a hollow fiber membrane

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Takahiko, E-mail: t-sugiyama@nucl.nagoya-u.ac.jp [Nagoya University, Fro-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Miyahara, Naoya [Nagoya University, Fro-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Tanaka, Masahiro [National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292 (Japan); Munakata, Kenzo [Akita University, Tegata Gakuen-cho 1-1, Akita-shi, Akita 010-8502 (Japan); Yamamoto, Ichiro [Nagoya University, Fro-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2011-10-15

    A simulation model has been developed for transient response of a gas separation module using a hollow fiber membrane for the removal of tritium from the atmosphere of the confinement space. The mass transfer process such as sorption and desorption of gases at the surface of the dense layer and the porous support layer, diffusive transfer in the both layers are treated in the model. Sorption isotherm, mass transfer rate and permeance are estimated through step-wise transient response experiments. The present model represents well not only separation factors and recovery ratio at the steady state but also responses to the multi-step wise change in the sweep gas rate.

  10. Effect of Evaporation Time on Separation Performance of Polysulfone/Cellulose Acetate (PSF/CA) Membrane

    Science.gov (United States)

    Syahbanu, Intan; Piluharto, Bambang; Khairi, Syahrul; Sudarko

    2018-01-01

    Polysulfone and cellulose acetate are common material in separation. In this research, polysulfone/cellulose actetate (PSF/CA) blend membrane was prepared. The aim of this research was to study effect of evaporation time in casting of PSF/CA membrane and its performance in filtration. CA was obtained by acetylation process of bacterial cellulose (BC) from fermentation of coconut water. Fourier Transform Infra Red (FTIR) Spectroscopy was used to examine functional groups of BC, CA and commercial cellulose acetate. Subtitution of acetyl groups determined by titration method. Blend membranes were prepared through phase inversion technique in which composition of PSF/PEG/CA/NMP(%w) was 15/5/5/75. Polyethyleneglycol (PEG) and N-methyl-2-pyrrolidone (NMP) were act as pore forming agent and solvent, respectively. Variation of evaporation times were used as parameter to examine water uptake, flux, and morphology of PSF/CA blend membranes. FTIR spectra of CA show characteristic peak of acetyl group at 1220 cm-1 indicated that BC was acetylated succesfully. Degree of subtitution of BCA was found at 2.62. Highest water flux was performed at 2 bar obtained at 106.31 L.m-2.h-1 at 0 minute variation, and decrease as increasing evaporation time. Morphology of PSF/BCA blend membranes were investigated by Scanning Electron Microscopy (SEM) showed that porous asymetric membrane were formed.

  11. Dehydration processes using membranes with hydrophobic coating

    Science.gov (United States)

    Huang, Yu; Baker, Richard W; Aldajani, Tiem; Ly, Jennifer

    2013-07-30

    Processes for removing water from organic compounds, especially polar compounds such as alcohols. The processes include a membrane-based dehydration step, using a membrane that has a dioxole-based polymer selective layer or the like and a hydrophilic selective layer, and can operate even when the stream to be treated has a high water content, such as 10 wt % or more. The processes are particularly useful for dehydrating ethanol.

  12. Computer aided design, analysis and experimental investigation of membrane assisted batch reaction-separation systems

    DEFF Research Database (Denmark)

    Mitkowski, Piotr Tomasz; Buchaly, Carsten; Kreis, Peter

    2009-01-01

    Membrane assisted batch reaction operation offers an interesting option for equilibrium limited reaction systems in chemical and biochemical manufacturing by selective removal of one of the products and thereby increasing the product yield. The design of such hybrid systems need to take into acco......Membrane assisted batch reaction operation offers an interesting option for equilibrium limited reaction systems in chemical and biochemical manufacturing by selective removal of one of the products and thereby increasing the product yield. The design of such hybrid systems need to take...... into account the performance of each constituent element and the optimisation of the design must take into consideration their interdependency. In this paper use of a membrane, to assist in the synthesis of propyl-propionate is investigated through the use of a hybrid process design framework, which consists...... and separation functionalities and to design/analyse the hybrid scheme. The generated hybrid scheme has been validated through experiments involving an esterification reaction....

  13. Complexation-Induced Phase Separation: Preparation of Metal-Rich Polymeric Membranes

    KAUST Repository

    Villalobos Vazquez de la Parra, Luis Francisco

    2017-08-01

    The majority of state-of-the-art polymeric membranes for industrial or medical applications are fabricated by phase inversion. Complexation induced phase separation (CIPS)—a surprising variation of this well-known process—allows direct fabrication of hybrid membranes in existing facilities. In the CIPS process, a first step forms the thin metal-rich selective layer of the membrane, and a succeeding step the porous support. Precipitation of the selective layer takes place in the same solvent used to dissolve the polymer and is induced by a small concentration of metal ions. These ions form metal-coordination-based crosslinks leading to the formation of a solid skin floating on top of the liquid polymer film. A subsequent precipitation in a nonsolvent bath leads to the formation of the porous support structure. Forming the dense layer and porous support by different mechanisms while maintaining the simplicity of a phase inversion process, results in unprecedented control over the final structure of the membrane. The thickness and morphology of the dense layer as well as the porosity of the support can be controlled over a wide range by manipulating simple process parameters. CIPS facilitates control over (i) the thickness of the dense layer throughout several orders of magnitude—from less than 15 nm to more than 6 μm, (ii) the type and amount of metal ions loaded in the dense layer, (iii) the morphology of the membrane surface, and (iv) the porosity and structure of the support. The nature of the CIPS process facilitates a precise loading of a high concentration of metal ions that are located in only the top layer of the membrane. Moreover, these metal ions can be converted—during the membrane fabrication process—to nanoparticles or crystals. This simple method opens up fascinating possibilities for the fabrication of metal-rich polymeric membranes with a new set of properties. This dissertation describes the process in depth and explores promising

  14. Use of a Ceramic Membrane to Improve the Performance of Two-Separate-Phase Biocatalytic Membrane Reactor.

    Science.gov (United States)

    Ranieri, Giuseppe; Mazzei, Rosalinda; Wu, Zhentao; Li, Kang; Giorno, Lidietta

    2016-03-14

    Biocatalytic membrane reactors (BMR) combining reaction and separation within the same unit have many advantages over conventional reactor designs. Ceramic membranes are an attractive alternative to polymeric membranes in membrane biotechnology due to their high chemical, thermal and mechanical resistance. Another important use is their potential application in a biphasic membrane system, where support solvent resistance is highly needed. In this work, the preparation of asymmetric ceramic hollow fibre membranes and their use in a two-separate-phase biocatalytic membrane reactor will be described. The asymmetric ceramic hollow fibre membranes were prepared using a combined phase inversion and sintering technique. The prepared fibres were then used as support for lipase covalent immobilization in order to develop a two-separate-phase biocatalytic membrane reactor. A functionalization method was proposed in order to increase the density of the reactive hydroxyl groups on the surface of ceramic membranes, which were then amino-activated and treated with a crosslinker. The performance and the stability of the immobilized lipase were investigated as a function of the amount of the immobilized biocatalytst. Results showed that it is possible to immobilize lipase on a ceramic membrane without altering its catalytic performance (initial residual specific activity 93%), which remains constant after 6 reaction cycles.

  15. Use of a Ceramic Membrane to Improve the Performance of Two-Separate-Phase Biocatalytic Membrane Reactor

    Directory of Open Access Journals (Sweden)

    Giuseppe Ranieri

    2016-03-01

    Full Text Available Biocatalytic membrane reactors (BMR combining reaction and separation within the same unit have many advantages over conventional reactor designs. Ceramic membranes are an attractive alternative to polymeric membranes in membrane biotechnology due to their high chemical, thermal and mechanical resistance. Another important use is their potential application in a biphasic membrane system, where support solvent resistance is highly needed. In this work, the preparation of asymmetric ceramic hollow fibre membranes and their use in a two-separate-phase biocatalytic membrane reactor will be described. The asymmetric ceramic hollow fibre membranes were prepared using a combined phase inversion and sintering technique. The prepared fibres were then used as support for lipase covalent immobilization in order to develop a two-separate-phase biocatalytic membrane reactor. A functionalization method was proposed in order to increase the density of the reactive hydroxyl groups on the surface of ceramic membranes, which were then amino-activated and treated with a crosslinker. The performance and the stability of the immobilized lipase were investigated as a function of the amount of the immobilized biocatalytst. Results showed that it is possible to immobilize lipase on a ceramic membrane without altering its catalytic performance (initial residual specific activity 93%, which remains constant after 6 reaction cycles.

  16. Synthesis of a composite inorganic membrane for the separation of nitrogen, tetrafluoromethane and hexafluoropropylene

    Directory of Open Access Journals (Sweden)

    Hertzog Bissett

    2013-09-01

    Full Text Available The advanced use of inorganic membranes, such as zeolites, in large-scale industrial processes is hindered by the inability to manufacture continuous and defect-free membranes. We therefore aimed to construct such a defect-free membrane. Various zeolites were synthesised on the inner surface of ?-alumina support tubes by a hydrothermal process. Gas permeation properties were investigated at 298 K for single component systems of N2, CF4 and C3F6. Ideal selectivities lower than Knudsen selectivities were obtained as a result of defects from intercrystalline slits and crack formation during synthesis and template removal. A composite ceramic membrane consisting of a ceramic support structure, a mordenite framework inverted intermediate zeolite layer and a Teflon AF 2400 top layer was developed to improve separation. The Teflon layer sealed possible defects present in the separation layer forcing the gas molecules to follow the path through the zeolite pores. Ideal selectivities of 88 and 71 were obtained for N2/CF4 and N2/C3F6 respectively. Adsorption experiments performed on materials present in the membrane structure suggested that although adsorption of C3F6 onto Teflon AF 2400 compared to CF4 results in a considerable contribution to permeation for the composite ceramic membrane, the sealing effect of the zeolite layer by the Teflon layer is the reason for the large N2/CF4 and N2/C3F6 selectivities obtained. The Teflon layer effectively sealed intercrystalline areas in-between zeolite crystals, which resulted in high ideal selectivies for N2/CF4 and N2/C3F6.

  17. Separation of Peptides with Forward Osmosis Biomimetic Membranes

    OpenAIRE

    Bajraktari, Niada; Madsen, Henrik T.; Gruber, Mathias F.; Truelsen, Sigurd; Jensen, Elzbieta L.; Jensen, Henrik; H?lix-Nielsen, Claus

    2016-01-01

    Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of...

  18. Separation process of zirconium and hafnium

    International Nuclear Information System (INIS)

    Hure, J.; Saint-James, R.

    1955-01-01

    About the separation different processes of zirconium-hafnium, the extraction by solvent in cross-current is the most easily the process usable on an industrial scale. It uses tributyl phosphate as solvent, diluted with white spirit to facilitate the decanting. Some exploratory tests showed that nitric environment seemed the most favorable for extraction; but a lot of other factors intervene in the separation process. We studied the influence of the acidity successively, the NO 3 - ions concentration, the role of the cation coming with NO 3 - , as well as the influence of the concentration of zirconium in the solution on the separation coefficient β = α Zr / α Hf . (M.B.) [fr

  19. Separation of Peptides with Forward Osmosis Biomimetic Membranes

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Madsen, Henrik T; Gruber, Mathias Felix

    2016-01-01

    Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions...

  20. Process for separating nitrogen from methane using microchannel process technology

    Science.gov (United States)

    Tonkovich, Anna Lee [Marysville, OH; Qiu, Dongming [Dublin, OH; Dritz, Terence Andrew [Worthington, OH; Neagle, Paul [Westerville, OH; Litt, Robert Dwayne [Westerville, OH; Arora, Ravi [Dublin, OH; Lamont, Michael Jay [Hilliard, OH; Pagnotto, Kristina M [Cincinnati, OH

    2007-07-31

    The disclosed invention relates to a process for separating methane or nitrogen from a fluid mixture comprising methane and nitrogen, the process comprising: (A) flowing the fluid mixture into a microchannel separator, the microchannel separator comprising a plurality of process microchannels containing a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the methane or nitrogen is sorbed by the sorption medium, and removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing the methane or nitrogen from the sorption medium and removing the desorbed methane or nitrogen from the microchannel separator. The process is suitable for upgrading methane from coal mines, landfills, and other sub-quality sources.

  1. Process for producing a porous diffusion membrane

    International Nuclear Information System (INIS)

    Kabayama, Shisho; Ikeda, Hirosaka.

    1969-01-01

    A diffusion membrane having a sandwich construction, the pore diameter of which is 1,000A or less, is provided for the separation and enrichment of, for example, U-235F from U-238F. Flexibility, corrosion resistance and separation efficiency of the barrier are improved by a process which comprises the steps of filling powders of metallic or inorganic materials into a mesh or grid-like support, superimposing onto the filled support a fluorine resin sheet consisting of a fluorine resin and a liquid foaming agent so that the outermost layers are the fluorine resin sheets, adhering them by applying a pressure of 30 to 30,000kg/cm 2 , and removing the foaming agent. Particle size of the powders may be 0.3 microns or less, but preferably 0.1 microns or less. Gold, silver, copper, platinum, nickel, monel metal, stainless steel, alumina and the like can be used with or without fluorine treatment. The powders are filled in the support by slip casting, rolling or electrophoresis. In one example, 100 parts by weight of polytetrafluoroethylene mixed with 50 parts of perfluoroalkane were compressed in a metallic die under a pressure of 25kg/cm 3 and were rolled to a thickness of 0.05m. A 250 mesh nickel wire filled with alumina particles having a diameter of 0.05 microns were compressed under 10 tons/cm 2 . The above sheets were laminated onto the nickel support on opposite surfaces, and thereafter pressed under a pressure of 100kg/cm 2 . The perfluoroalkane was removed. Argon isotope permeability of the product was 1.60 x 10 -5 mol/cm 2 .min.cmHg. The separation efficiency was 78%. (Iwakiri, K.)

  2. Analysis of hydrogen separation methods in low pressure industrial processes

    International Nuclear Information System (INIS)

    Milidoni, M.; Somoza, J.; Borzone, E.M.; Blanco, M.V.; Cestau, D.; Baruj, A.; Meyer, G.

    2012-01-01

    In this work we present strategies for removing part of the hydrogen contained in a tank of 500 1 at a total pressure of 95 kPa. Hydrogen is mixed with other gases in a relation 95:5. The gas is generated as an end product during the production of radioisotopes. Main impurities are N 2 , humidity and activated gases. Two separation methods are proposed: one of them based on the use of a commercial Pd/Cu membrane, while the other involves the use of materials capable of forming metal hydrides (HFM). Characterization of hydrogen separation properties using a Pd/Cu membrane from pure H 2 and H 2 /Ar mixture were performed in the laboratory. We present simulations of a device containing HFM of the LaNi 5 -xSnx (0.x.0,5), using the properties of reaction with hydrogen measured in our laboratory. The performance of the different options was evaluated. Results were compared using as evaluation criteria the value of the pressure in the tank after 3 h of separation process and the time needed to separate the same amount of hydrogen generated during a batch of the process (author)

  3. Organosilica Membrane with Ionic Liquid Properties for Separation of Toluene/H₂ Mixture.

    Science.gov (United States)

    Hirota, Yuichiro; Maeda, Yohei; Yamamoto, Yusuke; Miyamoto, Manabu; Nishiyama, Norikazu

    2017-08-03

    In this study, we present a new concept in chemically stabilized ionic liquid membranes: an ionic liquid organosilica (ILOS) membrane, which is an organosilica membrane with ionic liquid-like properties. A silylated ionic liquid was used as a precursor for synthesis. The permselectivity, permeation mechanism, and stability of the membrane in the H₂/toluene binary system were then compared with a supported ionic liquid membrane. The membrane showed a superior separation factor of toluene/H₂ (>17,000) in a binary mixture system based on a solution-diffusion mechanism with improved durability over the supported ionic liquid membrane.

  4. A Mechanistic Study of Chemically Modified Inorganic Membranes for Gas and Liquid Separations

    Energy Technology Data Exchange (ETDEWEB)

    Way, J. Douglas [Colorado School of Mines, Golden, CO (United States). Dept. of Chemical Engineering

    2011-01-21

    This final report will summarize the progress made during the period August 1, 1993 - October 31, 2010 with support from DOE grant number DE-FG03-93ER14363. The objectives of the research have been to investigate the transport mechanisms in micro- and mesoporous, metal oxide membranes and to examine the relationship between the microstructure of the membrane, the membrane surface chemistry, and the separation performance of the membrane. Examples of the membrane materials under investigation are the microporous silica hollow fiber membrane manufactured by PPG Industries, chemically modified mesoporous oxide membranes, and polymer membranes containing microporous oxides (mixed matrix membranes). Analytical techniques such as NMR, FTIR and Raman spectroscopy, thermal analysis, and gas adsorption were used to investigate membrane microstructure and to probe the chemical interactions occurring at the gas-membrane interface.

  5. Carbon molecular sieve membranes derived from Matrimid® polyimide for nitrogen/methane separation

    KAUST Repository

    Ning, Xue; Koros, William J.

    2014-01-01

    A commercial polyimide, Matrimid® 5218, was pyrolyzed under an inert argon atmosphere to produce carbon molecular sieve (CMS) dense film membranes for nitrogen/methane separation. The resulting CMS dense film separation performance was evaluated

  6. Process synthesis and intensification of hybrid separations

    DEFF Research Database (Denmark)

    Errico, Massimiliano

    2017-01-01

    Hybrid flowsheets are defined, in the context of process intensification, as alternatives suitable for replacing energy-intensive separation methods through the combination of more than one unit operation. Distillation is one of the first options considered for achieving a required separation...... and commented on. The corresponding distillation-based processes are considered for comparison. Synthesis of the possible hybrid flowsheets appears to be important, especially when multicomponent mixtures are considered. This aspect is discussed for the combination of liquid-liquid extraction and distillation...... as applied to the separation of biobutanol from its fermentation broth. The synthesis of alternative hybrid flowsheets is reported, showing that one configuration can realize a 43% reduction in the total annual cost. Bioalcohol production by fermentation perfectly represents the casewhere distillation alone...

  7. Restoring solvent for nuclear separation processes

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    Solvent extraction separation processes are used to recover usable nuclear materials from spent fuels. These processes involve the use of an extractant/diluent (solvent) for separation of the reusable actinides from unwanted fission products. The most widely used processes employ tributyl phosphate as an extractant diluted with a normal-paraffin hydrocarbon. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. In most processes, the solvent is recycled after cleaning. Solvent cleaning generally involves scrubbing with a sodium carbonate solution. Studies at the Savannah River Laboratory have shown that carbonate washing, although removing residual solvent activity, does not remove more solvent-soluble binding ligands (formed by solvent degradation), which hold fission products in the solvent. Treatment of the solvent with a solid adsorbent after carbonate washing removes binding ligands and significantly improves recycled solvent performance. Laboratory work to establish the advantage of adsorbent cleaning and the development of a full-scale adsorption process is described. The application of this process for cleaning the first cycle solvent of a Savannah River Plant production process is discussed

  8. Ultrathin self-assembled anionic polymer membranes for superfast size-selective separation

    Science.gov (United States)

    Deng, Chao; Zhang, Qiu Gen; Han, Guang Lu; Gong, Yi; Zhu, Ai Mei; Liu, Qing Lin

    2013-10-01

    Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than commercial membranes, and can highly efficiently separate 5 and 15 nm gold nanoparticles from their mixtures. The newly developed nanoporous membranes have a wide application in separation and purification of biomacromolecules and nanoparticles.Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than

  9. Hypercrosslinked Additives for Ageless Gas-Separation Membranes.

    Science.gov (United States)

    Lau, Cher Hon; Mulet, Xavier; Konstas, Kristina; Doherty, Cara M; Sani, Marc-Antoine; Separovic, Frances; Hill, Matthew R; Wood, Colin D

    2016-02-05

    The loss of internal pores, a process known as physical aging, inhibits the long-term use of the most promising gas-separation polymers. Previously we reported that a porous aromatic framework (PAF-1) could form a remarkable nanocomposite with gas-separation polymers to stop aging. However, PAF-1 synthesis is very onerous both from a reagent and reaction-condition perspective, making it difficult to scale-up. We now reveal a highly dispersible and scalable additive based on α,α'-dichloro-p-xylene (p-DCX), that inhibits aging more effectively, and crucially almost doubles gas-transport selectivity. These synergistic effects are related to the intimately mixed nanocomposite that is formed though the high dispersibility of p-DCX in the gas-separation polymer. This reduces particle-size effects and the internal free volume is almost unchanged over time. This study shows this inexpensive and scalable polymer additive delivers exceptional gas-transport performance and selectivity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Production of Biodiesel Using a Membrane Reactor to Minimize Separation Cost

    Science.gov (United States)

    Olagunju, O. A.; Musonge, P.

    2017-07-01

    This study investigates the performance of a packed bed membrane reactor in the transesterification process of triglycerides to methyl ester using soyabean oil as feedstock. A TiO2/Al2O3 ceramic microporous membrane was selected due to its chemical inert nature and thermal stability to selectively remove the product from the reaction medium. CaO impregnated on the surface of activated carbon was packed into the membrane and acted as catalyst. The synthesized catalyst had a total loading of 40.50 % and was characterized by XRD and temperature-programmed desorption of CO2 (CO2-TPD). The crude biodiesel produced was micro-filtered by the ceramic membrane with a pore size of 0.02 μm to retain the unreacted oil and free glycerol, at the transmembrane pressure of 100 KPa. The best condition was achieved with a temperature of 65 °C, methanol/oil molar ratio of 6:1 for 150 minutes, which resulted in the highest FAME yield of 94 %. Methyl ester produced met the ASTM D6751 and SANS 1935 specifications. The product obtained was mainly composed of methyl esters. Glycerol was not detected in the product stream due to the ability of the membrane to retain the glycerol and the unreacted oil in the medium, which solved the issue of glycerol separation from biodiesel.

  11. Enhanced Performance of Polyurethane Hybrid Membranes for CO2 Separation by Incorporating Graphene Oxide: The Relationship between Membrane Performance and Morphology of Graphene Oxide.

    Science.gov (United States)

    Wang, Ting; Zhao, Li; Shen, Jiang-nan; Wu, Li-guang; Van der Bruggen, Bart

    2015-07-07

    Polyurethane hybrid membranes containing graphene oxide (GO) with different morphologies were prepared by in situ polymerization. The separation of CO2/N2 gas mixtures was studied using these novel membranes. The results from the morphology characterization of GO samples indicated that the oxidation process in the improved Hummers method introduced oxygenated functional groups into graphite, making graphite powder exfoliate into GO nanosheets. The surface defects on the GO sheets increased when oxidation increased due to the introduction of more oxygenated functional groups. Both the increase in oxygenated functional groups on the GO surface and the decrease in the number of GO layers leads to a better distribution of GO in the polymer matrix, increasing thermal stability and gas separation performance of membranes. The addition of excess oxidant destroyed the structure of GO sheets and forms structural defects, which depressed the separation performance of membranes. The hybrid membranes containing well-distributed GO showed higher permeability and permeability selectivity for the CO2. The formation of GO aggregates in the hybrid membranes depressed the membrane performance at a high content of GO.

  12. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    International Nuclear Information System (INIS)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi

    2015-01-01

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity

  13. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    Energy Technology Data Exchange (ETDEWEB)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2015-04-15

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity.

  14. Role of functional nanoparticles to enhance the polymeric membrane performance for mixture gas separation

    NARCIS (Netherlands)

    Ingole, Pravin G.; Baig, Muhammad Irshad; Choi, Wook; An, Xinghai; Choi, Won Kil; Lee, Hyung Keun

    2017-01-01

    To improve the water vapor/gas separation the hydroxylated TiO2(OH-TiO2) nanopartilces have been synthesized and surface of polysulfone (PSf) hollow fiber membrane (HFM) has been coated as thin film nanocomposite (TFN) membranes. To remove the water vapor from mixture gas, hollow fiber membrane has

  15. Synthesis and separation properties of an α-alumina-supported high-silica MEL membrane

    NARCIS (Netherlands)

    Kosinov, N.; Hensen, E.J.M.

    2013-01-01

    A thin high-silica MEL membrane was synthesized on a porous a-alumina hollow fiber support by a secondary growth approach. The membrane quality was evaluated by permporometry, single-gas permeation and butane isomer separation. Comparison of the pervaporation performance of MEL membranes with a MFI

  16. Separation of tritiated water from water using composite membranes

    International Nuclear Information System (INIS)

    Duncan, J.; Nelson, D.

    1996-01-01

    Polymeric composite membranes are being developed to remove tritium from contaminated water at DOE sites. Industrial membrane systems are being developed that have proven to be energy efficient, and membrane technologies such as reverse-osmosis have been well developed for desalination and other industrial/municipal applications. Aromatic polyphosphazene membranes are being investigated because they have excellent radiological, thermal, and chemical stability. The FY 1996 effort is directed toward delineating a potential mechanism, providing a statistical approach to data acquisition, refining a mass balance, and designing a staged array module

  17. Process for separating liquid hydrocarbons from waxes

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, F J

    1948-03-08

    A process is described for the separation of liquid hydrocarbons from waxes comprising adding to a mixture of liquid hydrocarbons and waxes a sufficient quantity of an organo-silicon compound to cause the separation of the hydrocarbon and wax. The organo-silicon compounds are selected from the class of organic silicanes and their hydrolysis products and polymers. The silicanes have the formula R/sub y/SiX/sub z/, in which R is a saturated or unsaturated hydrocarbon radical, X is a halogen or another hydrocarbon radical or an -OR group, y has a value 1, 2, or 3 and z has a value 1, 2, or 3.

  18. Electrochemical membrane reactor: In situ separation and recovery of chromic acid and metal ions

    International Nuclear Information System (INIS)

    Khan, Jeeshan; Tripathi, Bijay P.; Saxena, Arunima; Shahi, Vinod K.

    2007-01-01

    An electrochemical membrane reactor with three compartments (anolyte, catholyte and central compartment) based on in-house-prepared cation- and anion-exchange membrane was developed to achieve in situ separation and recovery of chromic acid and metal ions. The physicochemical and electrochemical properties of the ion-exchange membrane under standard operating conditions reveal its suitability for the proposed reactor. Experiments using synthetic solutions of chromate and dichromate of different concentrations were carried out to study the feasibility of the process. Electrochemical reactions occurring at the cathode and anode under operating conditions are proposed. It was observed that metal ion migrated through the cation-exchange membrane from central compartment to catholyte and OH - formation at the cathode leads to the formation of metal hydroxide. Simultaneously, chromate ion migrated through the anion-exchange membrane from central compartment to the anolyte and formed chromic acid by combining H + produced their by oxidative water splitting. Thus a continuous decay in the concentration of chromate and metal ion was observed in the central compartment, which was recovered separately in the anolyte and catholyte, respectively, from their mixed solution. This process was completely optimized in terms of operating conditions such as initial concentration of chromate and metal ions in the central compartment, the applied cell voltage, chromate and metal ion flux, recovery percentage, energy consumption, and current efficiency. It was concluded that chromic acid and metal ions can be recovered efficiently from their mixed solution leaving behind the uncharged organics and can be reused as their corresponding acid and base apart from the purifying water for further applications

  19. Synthesis and characterization of microporous inorganic membranes for propylene/propane separation

    Science.gov (United States)

    Ma, Xiaoli

    Membrane-based gas separation is promising for efficient propylene/propane (C3H6/C3H8) separation with low energy consumption and minimum environment impact. Two microporous inorganic membrane candidates, MFI-type zeolite membrane and carbon molecular sieve membrane (CMS) have demonstrated excellent thermal and chemical stability. Application of these membranes into C3H6/C3H 8 separation has not been well investigated. This dissertation presents fundamental studies on membrane synthesis, characterization and C3H 6/C3H8 separation properties of MFI zeolite membrane and CMS membrane. MFI zeolite membranes were synthesized on α-alumina supports by secondary growth method. Novel positron annihilation spectroscopy (PAS) techniques were used to non-destructively characterize the pore structure of these membranes. PAS reveals a bimodal pore structure consisting of intracrystalline zeolitic micropores of ~0.6 nm in diameter and irregular intercrystalline micropores of 1.4 to 1.8 nm in size for the membranes. The template-free synthesized membrane exhibited a high permeance but a low selectivity in C3H 6/C3H8 mixture separation. CMS membranes were synthesized by coating/pyrolysis method on mesoporous gamma-alumina support. Such supports allow coating of thin, high-quality polymer films and subsequent CMS membranes with no infiltration into support pores. The CMS membranes show strong molecular sieving effect, offering a high C3H 6/C3H8 mixture selectivity of ~30. Reduction in membrane thickness from 500 nm to 300 nm causes an increase in C3H8 permeance and He/N2 selectivity, but a decrease in the permeance of He, N 2 and C3H6 and C3H6/C 3H8 selectivity. This can be explained by the thickness dependent chain mobility of the polymer film resulting in final carbon membrane of reduced pore size with different effects on transport of gas of different sizes, including possible closure of C3H6-accessible micropores. CMS membranes demonstrate excellent C3H6/C 3H8 separation

  20. Use of exhaust gas as sweep flow to enhance air separation membrane performance

    Science.gov (United States)

    Dutart, Charles H.; Choi, Cathy Y.

    2003-01-01

    An intake air separation system for an internal combustion engine is provided with purge gas or sweep flow on the permeate side of separation membranes in the air separation device. Exhaust gas from the engine is used as a purge gas flow, to increase oxygen flux in the separation device without increasing the nitrogen flux.

  1. Ionic liquid-based materials: a platform to design engineered CO2 separation membranes.

    Science.gov (United States)

    Tomé, Liliana C; Marrucho, Isabel M

    2016-05-21

    During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided.

  2. Surface-Enhanced Separation of Water from Hydrocarbons: Potential Dewatering Membranes for the Catalytic Fast Pyrolysis of Pine Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Engtrakul, Chaiwat; Hu, Michael Z.; Bischoff, Brian L.; Jang, Gyoung G.

    2016-10-20

    The impact of surface-selective coatings on water permeation through a membrane when exposed to catalytic fast pyrolysis (CFP) vapor products was studied by tailoring the surface properties of the membrane coating from superhydrophilic to superhydrophobic. Our approach used high-performance architectured surface-selective (HiPAS) membranes that were inserted after a CFP reactor. At this insertion point, the inner wall surface of a tubular membrane was exposed to a mixture of water and upgraded product vapors, including light gases and deoxygenated hydrocarbons. Under proper membrane operating conditions, a high selectivity for water over one-ring upgraded biomass pyrolysis hydrocarbons was observed as a result of a surface-enhanced capillary condensation process. Owing to this surface-enhanced effect, HiPAS membranes have the potential to enable high flux separations, suggesting that water can be selectively removed from the CFP product vapors.

  3. Hydrogen separation from high temperature CO-containing syn-gas flow using molecular ceramic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Soudarev, A.; Konakov, G.; Souryaninov, A.; Molchanov, A. [Boyko Research Engineering Ceramic Heat Engines Center Ltd., St. Petersburg (Russian Federation); Lelait, L.; Stevens, P.H. [European Inst. for Power Studies, Karlsruhe (Germany)

    2006-07-01

    Poisoning of the platinum (Pt) metals used as catalysts for proton exchange membrane fuel cells (PEMFCs) can negatively impact on PEMFC operation efficiency. In order to address this issue, a supply of hydrogen with a carbon monoxide (CO) admixtures is required. This paper provided details of a new type of molecular ceramic membrane (MCM) that allows the separation of hydrogen (H{sub 2}) from the hydrocarbon fuel reforming products that contain CO and has higher temperature and pressure capacity than other membranes. After various tests, alumo-magnesium spinel (AMS) was selected as the most promising porous material for the ceramic multi-layer membrane. The crystalline structure of the AMS showed good thermo-dynamic stability during tests that ranged between 20 and 1400 degrees C, as well as a chemical resistance relative to the effects of the aggressive fuel cell environment, and no exposure to the oxidation-recovery processes in the CO and H{sub 2} flow. The macroporous substrate of the AMS and the membrane selection layers have the same composition. The formation of the carrier was conducted by a semi-dry molding on a hydraulic press. Formation of the nano-porous structure in the carrier macro-pores by the polysilicon acid sol solution treatment allowed the synthesis of the amorphous silica and crystobalite crystals with a developed surface and nano-dimension subporosity. Test results have shown that the MCM has optimum penetrability and selectivity values as well as admissible thermo-mechanical properties. H{sub 2} flow through the membrane was 1.5-1.7 times greater than the CO flow. It was concluded that the AMS-based membrane devices will increase the efficiency of the PEMFC power plants and reduce their degradation capacity. 2 refs., 1 tab., 1 fig.

  4. Separating uranium by laser: the atomic process

    Energy Technology Data Exchange (ETDEWEB)

    Destro, Marcelo G.; Damiao, Alvaro J.; Neri, Jose W.; Schwab, Carlos; Rodrigues, Nicolau A.S.; Riva, Rudimar [Centro Tecnico Aeroespacial (CTA-IEAv), Sao Jose dos Campos, SP (Brazil). Inst. de Estudos Avancados

    1996-07-01

    Among the countries around the world that utilizes nuclear energy, several ones are investing significantly in the development of laser techniques applied to isotope separation. In Brazil these studies are concentrated in one research institute, the IEAv (Institute for Advanced Studies), and aim at demonstrating the viability of this process using, as much as possible, resources available in the country. In this paper we briefly describe the laser methods for isotope separation, giving an overview of the present research and development status in this area. We also show some results obtained our laboratories. We focused this report on the atomic route for laser isotope separation, mainly in the areas of laser development and spectroscopy. (author)

  5. Separating uranium by laser: the atomic process

    International Nuclear Information System (INIS)

    Destro, Marcelo G.; Damiao, Alvaro J.; Neri, Jose W.; Schwab, Carlos; Rodrigues, Nicolau A.S.; Riva, Rudimar

    1996-01-01

    Among the countries around the world that utilizes nuclear energy, several ones are investing significantly in the development of laser techniques applied to isotope separation. In Brazil these studies are concentrated in one research institute, the IEAv (Institute for Advanced Studies), and aim at demonstrating the viability of this process using, as much as possible, resources available in the country. In this paper we briefly describe the laser methods for isotope separation, giving an overview of the present research and development status in this area. We also show some results obtained our laboratories. We focused this report on the atomic route for laser isotope separation, mainly in the areas of laser development and spectroscopy. (author)

  6. Tubular membrane bioreactors for biotechnological processes.

    Science.gov (United States)

    Wolff, Christoph; Beutel, Sascha; Scheper, Thomas

    2013-02-01

    This article is an overview of bioreactors using tubular membranes such as hollow fibers or ceramic capillaries for cultivation processes. This diverse group of bioreactor is described here in regard to the membrane materials used, operational modes, and configurations. The typical advantages of this kind of system such as environments with low shear stress together with high cell densities and also disadvantages like poor oxygen supply are summed up. As the usage of tubular membrane bioreactors is not restricted to a certain organism, a brief overview of various applications covering nearly all types of cells from prokaryotic to eukaryotic cells is also given here.

  7. Robust, high temperature-ceramic membranes for gas separation

    Science.gov (United States)

    Berchtold, Kathryn A.; Young, Jennifer S.

    2014-07-29

    A method of making ceramic membranes, and the ceramic membranes so formed, comprising combining a ceramic precursor with an organic or inorganic comonomer, forming the combination as a thin film on a substrate, photopolymerizing the thin film, and pyrolyzing the photopolymerized thin film.

  8. Graphene oxide – molybdenum disulfide hybrid membranes for hydrogen separation

    KAUST Repository

    Ostwal, Mayur

    2017-12-24

    Graphene oxide – molybdenum disulfide hybrid membranes were prepared using vacuum filtration technique. The thickness and the MoS2 content in the membranes were varied and their H2 permeance and H2/CO2 selectivity are reported. A 60nm hybrid membrane containing ~75% by weight of MoS2 exhibited the highest H2 permeance of 804×10−9mol/m2·s·Pa with corresponding H2/CO2 selectivity of 26.7; while a 150nm hybrid membrane with ~29% MoS2 showed the highest H2/CO2 selectivity of 44.2 with corresponding H2 permeance of 287×10−9mol/m2·s·Pa. The hybrid membranes exhibited much higher H2 permeance compared to graphene oxide membranes and higher selectivity compared to MoS2 membranes, which fully demonstrated the synergistic effect of both nanomaterials. The membranes also displayed excellent operational long-term stability.

  9. Graphene oxide – molybdenum disulfide hybrid membranes for hydrogen separation

    KAUST Repository

    Ostwal, Mayur; Shinde, Digambar B.; Wang, Xinbo; Gadwal, Ikhlas; Lai, Zhiping

    2017-01-01

    Graphene oxide – molybdenum disulfide hybrid membranes were prepared using vacuum filtration technique. The thickness and the MoS2 content in the membranes were varied and their H2 permeance and H2/CO2 selectivity are reported. A 60nm hybrid membrane containing ~75% by weight of MoS2 exhibited the highest H2 permeance of 804×10−9mol/m2·s·Pa with corresponding H2/CO2 selectivity of 26.7; while a 150nm hybrid membrane with ~29% MoS2 showed the highest H2/CO2 selectivity of 44.2 with corresponding H2 permeance of 287×10−9mol/m2·s·Pa. The hybrid membranes exhibited much higher H2 permeance compared to graphene oxide membranes and higher selectivity compared to MoS2 membranes, which fully demonstrated the synergistic effect of both nanomaterials. The membranes also displayed excellent operational long-term stability.

  10. Basic characteristics of hollow-filament polyimide membrane in gas separation and application to tritium monitors

    International Nuclear Information System (INIS)

    Sasaki, Sh.; Suzuki, T.; Kondo, K.; Tega, E.; Shimada, A.; Akahori, S.; Okuno, K.

    2003-01-01

    The separation efficiency of hollow-filament polyimide membranes for 3 H and 41 Ar is preliminarily examined for a potential application to continuous gas monitoring systems for analysis of stack emission from accelerator facilities. The basic gas separation characteristics of the membranes are experimentally investigated, and a preliminary gas monitor design is proposed. The membranes are capable of selectively enriching hydrogen by more than 25 times, with negligible variation with respect to the species of isotope. (author)

  11. Industrial Membrane Filtration and Short-bed Fractal Separation Systems for Separating Monomers from Heterogeneous Plant Material

    Energy Technology Data Exchange (ETDEWEB)

    Kearney, M; Kochergin, V; Hess, R; Foust, T; Herbst, R; Mann, N

    2005-03-31

    Large-scale displacement of petroleum will come from low-cost cellulosic feedstocks such as straw and corn stover crop residues. This project has taken a step toward making this projection a reality by reducing capital and energy costs, the two largest cost factors associated with converting cellulosic biomass to chemicals and fuels. The technology exists for using acid or enzyme hydrolysis processes to convert biomass feedstock (i.e., waste cellulose such as straw, corn stover, and wood) into their base monomeric sugar building blocks, which can, in turn, be processed into chemicals and fuels using a number of innovative fermentation technologies. However, while these processes are technically possible, practical and economic barriers make these processes only marginally feasible or not feasible at all. These barriers are due in part to the complexity and large fixed and recurring capital costs of unit operations including filtration, chromatographic separation, and ion exchange. This project was designed to help remove these barriers by developing and implementing new purification and separation technologies that will reduce the capital costs of the purification and chromatographic separation units by 50% to 70%. The technologies fundamental to these improvements are: (a) highly efficient clarification and purification systems that use screening and membrane filtration to eliminate suspended solids and colloidal material from feed streams and (b) fractal technology based chromatographic separation and ion exchange systems that can substitute for conventional systems but at much smaller size and cost. A non-hazardous ''raw sugar beet juice'' stream (75 to 100 gal/min) was used for prototype testing of these technologies. This raw beet juice stream from the Amalgamated Sugar LLC plant in Twin Falls, Idaho contained abrasive materials and membrane foulants. Its characteristics were representative of an industrial-scale heterogeneous plant extract

  12. Nanoporous, Metal Carbide, Surface Diffusion Membranes for High Temperature Hydrogen Separations

    Energy Technology Data Exchange (ETDEWEB)

    Way, J. Douglas [Colorado School of Mines, Golden, CO (United States). Dept. of Chemical and Biological Engineering; Wolden, Colin A. [Colorado School of Mines, Golden, CO (United States)

    2013-09-30

    Colorado School of Mines (CSM) developed high temperature, hydrogen permeable membranes that contain no platinum group metals with the goal of separating hydrogen from gas mixtures representative of gasification of carbon feedstocks such as coal or biomass in order to meet DOE NETL 2015 hydrogen membrane performance targets. We employed a dual synthesis strategy centered on transition metal carbides. In the first approach, novel, high temperature, surface diffusion membranes based on nanoporous Mo2C were fabricated on ceramic supports. These were produced in a two step process that consisted of molybdenum oxide deposition followed by thermal carburization. Our best Mo2C surface diffusion membrane achieved a pure hydrogen flux of 367 SCFH/ft2 at a feed pressure of only 20 psig. The highest H2/N2 selectivity obtained with this approach was 4.9. A transport model using “dusty gas” theory was derived to describe the hydrogen transport in the Mo2C coated, surface diffusion membranes. The second class of membranes developed were dense metal foils of BCC metals such as vanadium coated with thin (< 60 nm) Mo2C catalyst layers. We have fabricated a Mo2C/V composite membrane that in pure gas testing delivered a H2 flux of 238 SCFH/ft2 at 600 °C and 100 psig, with no detectable He permeance. This exceeds the 2010 DOE Target flux. This flux is 2.8 times that of pure Pd at the same membrane thickness and test conditions and over 79% of the 2015 flux target. In mixed gas testing we achieved a permeate purity of ≥99.99%, satisfying the permeate purity milestone, but the hydrogen permeance was low, ~0.2 SCFH/ft2.psi. However, during testing of a Mo2C coated Pd alloy membrane with DOE 1 feed gas mixture a hydrogen permeance of >2 SCFH/ft2.psi was obtained which was stable during the entire test, meeting the permeance associated with

  13. Separation of Peptides with Forward Osmosis Biomimetic Membranes

    Science.gov (United States)

    Bajraktari, Niada; Madsen, Henrik T.; Gruber, Mathias F.; Truelsen, Sigurd; Jensen, Elzbieta L.; Jensen, Henrik; Hélix-Nielsen, Claus

    2016-01-01

    Forward osmosis (FO) membranes have gained interest in several disciplines for the rejection and concentration of various molecules. One application area for FO membranes that is becoming increasingly popular is the use of the membranes to concentrate or dilute high value compound solutions such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of larger biomolecules with often flexible conformations. In this study, transport of two chemically similar peptides with molecular weight (Mw) of 375 and 692 Da across a thin film composite Aquaporin Inside™ Membrane (AIM) FO membrane was investigated. Despite the relative large size, both peptides were able to permeate the dense active layer of the AIM membrane and the transport mechanism was determined to be diffusion-based. Interestingly, the membrane permeability increased 3.65 times for the 692 Da peptide (1.39 × 10−12 m2·s−1) compared to the 375 Da peptide (0.38 × 10−12 m2·s−1). This increase thus occurs for an 85% increase in Mw but only for a 34% increase in peptide radius of gyration (Rg) as determined from molecular dynamics (MD) simulations. This suggests that Rg is a strong influencing factor for membrane permeability. Thus, an increased Rg reflects the larger peptide chains ability to sample a larger conformational space when interacting with the nanostructured active layer increasing the likelihood for permeation. PMID:27854275

  14. An energetic analysis of CO2 capture on a gas turbine combining flue gas recirculation and membrane separation

    International Nuclear Information System (INIS)

    Belaissaoui, Bouchra; Cabot, Gilles; Cabot, Marie-Sophie; Willson, David; Favre, Eric

    2012-01-01

    Post-combustion Carbon Capture and Storage (CCS) is currently intensively investigated as a key issue for the mitigation of greenhouse gases emissions. A very large number of studies is dedicated to coal power plants. In this paper, the possibility to achieve carbon capture on a gas turbine, based on a combination of flue gas recycle and membrane separation is reported. Membrane processes are effectively known to offer attractive performances in terms of energy efficiency, as soon as concentrated and/or pressure mixtures have to be treated. Two different flow schemes have been simulated and compared: flue gas recycle with air combustion and flue gas recycle with an oxygen enriched feed mixture. The energy requirement of the different processes, expressed in GJ (thermal basis) per ton of recovered CO 2 , and the size of the membrane capture process (expressed in m 2 of membrane area) have been systematically estimated for different membrane separation performances. It is shown that an overall energy requirement down to 2.6 GJ per ton can possibly be achieved when optimal operating conditions, based on oxygen enriched air (OEA) combustion together with a highly selective membrane (CO 2 /N 2 selectivity of 200) are combined. Additional possibilities in order to minimise the energy penalty of the process are discussed. -- Highlights: ► A carbon capture process for gas turbine has been investigated for the first time, with membrane separation unit. ► Air combustion systematically induces CO 2 capture specific energy requirement far above alternative capture processes. ► Remarkably, a very low energy requirement can be achieved (down to 2.6 GJ/ton) with Oxygen Enriched Air combustion. ► Target membrane selectivities and optimal oxygen content for combustion have been identified.

  15. Design study of fuel circulating system using Pd-alloy membrane isotope separation method

    International Nuclear Information System (INIS)

    Naito, T.; Yamada, T.; Yamanaka, T.; Aizawa, T.; Kasahara, T.; Nishikawa, M.; Asami, N.

    1980-01-01

    Design study on the fuel circulating system (FCS) for a tokamak experimental fusion reactor (JXFR) has been carried out to establish the system concept, to plan the development program, and to evaluate the feasibility of diffusion system. The FCS consists of main vacuum system, fuel gas refiners, isotope separators, fuel feeders, and auxiliary systems. In the system design, Pd-alloy membrane permeation method is adopted for fuel refining and isotope separating. All impurities are effectively removed and hydrogen isotopes are sufficiently separated by Pd-alloy membrane. The isotope separation system consists of 1st (47 separators) and 2nd (46 separators) cascades for removing protium and separating deuterium, respectively. In the FCS, while cryogenic distillation method appears to be practicable, Pd-alloy membrane diffusion method is attractive for isotope separation and refining of fuel gas. The choice will have to be based on reliability, economic, and safety analyses

  16. Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ting; Feng, Xuhui; Elsaidi, Sameh K.; Thallapally, Praveen K.; Carreon, Moises A.

    2017-01-30

    Herein, we demonstrate that a prototypical type of metal organic framework, zeolitic imidazolate framework-8 (ZIF-8), in membrane form, can effectively separate Kr/Xe gas mixtures at industrially relevant compositions. The best membranes separated Kr/Xe mixtures with average Kr permeances as high as 1.5 × 10-8 ± 0.2 mol/m2 s Pa and average separation selectivities of 14.2 ± 1.9 for molar feed compositions corresponding to Kr/Xe ratio encountered typically in air. Molecular sieving, competitive adsorption, and differences in diffusivities were identified as the prevailing separation mechanisms. These membranes potentially represent a less-energy-intensive alternative to cryogenic distillation, which is the benchmark technology used to separate this challenging gas mixture. To our best knowledge, this is the first example of any metal organic membrane composition displaying separation ability for Kr/Xe gas mixtures.

  17. Molecular simulations of MOF membranes for separation of ethane/ethene and ethane/methane mixtures.

    Science.gov (United States)

    Altintas, Cigdem; Keskin, Seda

    2017-11-11

    Metal organic framework (MOF) membranes have been widely investigated for gas separation applications. Several MOFs have been recently examined for selective separation of C 2 H 6 . Considering the large number of available MOFs, it is not possible to fabricate and test the C 2 H 6 separation performance of every single MOF membrane using purely experimental methods. In this study, we used molecular simulations to assess the membrane-based C 2 H 6 /C 2 H 4 and C 2 H 6 /CH 4 separation performances of 175 different MOF structures. This is the largest number of MOF membranes studied to date for C 2 H 6 separation. We computed adsorption selectivity, diffusion selectivity, membrane selectivity and gas permeability of MOFs for C 2 H 6 /C 2 H 4 and C 2 H 6 /CH 4 mixtures. Our results show that a significant number of MOF membranes are C 2 H 6 selective for C 2 H 6 /C 2 H 4 separation in contrast to traditional nanoporous materials. Selectivity and permeability of MOF membranes were compared with other membrane materials, such as polymers, zeolites, and carbon molecular sieves. Several MOFs were identified to exceed the upper bound established for polymeric membranes and many MOF membranes exhibited higher gas permeabilities than zeolites and carbon molecular sieves. Examining the structure-performance relations of MOF membranes revealed that MOFs with cavity diameters between 6 and 9 Å, porosities lower than 0.50, and surface areas between 500-1000 m 2 g -1 have high C 2 H 6 selectivities. The results of this study will be useful to guide the experiments to the most promising MOF membranes for efficient separation of C 2 H 6 and to accelerate the development of new MOFs with high C 2 H 6 selectivities.

  18. Cesium separation using integrated electro-membrane technique

    International Nuclear Information System (INIS)

    Fors, Patrik; Lillfors-Pintér, Christina; Widestrand, Henrik; Velin, Anna; Bengtsson, Bernt

    2014-01-01

    Conventional separation technologies such as ion exchange, electro-deionisation and cross flow filtration are not always effective to eliminate nuclides, which are weekly ionised, complexed or hydrated in effluents. Specific nuclide selective absorbers perform well for the treatment of active and contaminated wastewaters but most absorbers generate additional waste while treating high volumes of contaminated water and often show limitations in operating at high flow rates. Electrochemical Ion Exchange (EIX) and EIX in combination with absorbers may offer an alternative solution that overcomes those limitations. This paper reports on the optimization and performance of the integrated technique EIX, for the treatment of low activity effluents that contain cesium and other nuclides. The three-compartment EIX system, which operates with authentic reactor coolant with enhanced nuclide content, indicates high, over 90%, elimination of cesium in a single pass operation mode. With the in-situ and instant ion exchange regeneration, the system successfully reduces the activity from an initial range of 400-2600 Bq/kg to close to detection limit at a velocity of 10-15 cm/min. The applied current density varies between 50-200 mA/cm 2 and the mass balance is close to 100%. During the process, the eliminated cesium and other nuclides are concentrated up to the limits where reverse migration from the concentrated chamber occurs. The concentrate could then be treated with specific absorbents at low flow rates. EIX in combination with cesium-selective ion exchanger CsTreat ® separates the cesium-137 efficiently, but up to now the process does not perform according to EIX principles for the treatment of low grade radioactive wastewaters it rather performs as an irreversible adsorber. The aim with the outcome of the presently ongoing long-term tests is to further support the Best Available Technique Minimizing All Nuclide (BATMAN) projects of Vattenfall NPPs. (author)

  19. Design of Separation Processes with Ionic Liquids

    DEFF Research Database (Denmark)

    Peng-noo, Worawit; Kulajanpeng, Kusuma; Gani, Rafiqul

    2015-01-01

    A systematic methodology for screening and designing of Ionic Liquid (IL)-based separation processes is proposed and demonstrated using several case studies of both aqueous and non-aqueous systems, for instance, ethanol + water, ethanol + hexane, benzene + hexane, and toluene + methylcyclohexane....... The best four ILs of each mixture are [mmim][dmp], [emim][bti], [emim][etso4] and [hmim][tcb], respectively. All of them were used as entrainers in the extractive distillation. A process simulation of each system was carried out and showed a lower both energy requirement and solvent usage as compared...

  20. Membrane Separation of 2-Ethyl Hexyl Amine/1-Decene

    KAUST Repository

    Bawareth, Bander

    2012-01-01

    in this environment with reasonable and stable separation factor. This paper shows that Teflon AF 2400 and cellulose acetate produced interesting results in 1-decene/2-EHA separation. The separation factor of Teflon AF 2400 is 3 with a stable permeance of 1.1x10-2 L

  1. pH-sensitive membranes for lithium separation

    International Nuclear Information System (INIS)

    Smolinska, Katarzyna; Bryjak, Marek; Wolska, Joanna; Kujawski, Wojciech

    2014-01-01

    Dielectric barrier discharge plasma was used to modify track etched poly(ethylene terephthalate) membranes followed by grafting of poly(acrylic acid) and copolymers of acrylic acid and di(ethylene glycol)methyl ether methacrylate. The evaluation by IR and XPS spectroscopies showed that both polymers were successfully grafted to the porous membranes. Determination of permeate fluxes pointed the membranes to have excellent responses to pH changes when grafting yield was not so high. When grafting exceeded 0.1 mg cm −2 stimuli response gel-filled membranes were formed that could be used for transport of alkaline ions. The best permselectivity was observed for poly(ethylene terephthalate) membranes grafted with 1:2 copolymer of acrylic acid and di(ethylene glycol)methyl ether methacrylate. The dialysis was more effectively facilitated for lithium than for potassium or sodium salts at solution of pH = 5.5. - Highlights: • Preparation of pore-filled stimuli response membranes that facilitate transport of alkaline salts. • pH controlled transport of alkaline salts. • Facilitation of lithium transport over sodium and potassium

  2. Improved separation and antifouling properties of thin-film composite nanofiltration membrane by the incorporation of cGO

    Science.gov (United States)

    Li, Hongbin; Shi, Wenying; Du, Qiyun; Zhou, Rong; Zhang, Haixia; Qin, Xiaohong

    2017-06-01

    Poly(piperazine amide) composite nanofiltration (NF) membranes were modified through the incorporation of carboxylated graphene oxide (cGO) in the polyamide layer during the interfacial polymerization (IP) process on the polysulfone (PSF)/nonwoven fabric (NWF) ultrafiltration (UF) substrate membrane surface. The composition and morphology of the prepared NF membrane surface were determined by means of ATR-FTIR, SEM-EDX and AFM. The effects of cGO contents on membrane hydrophilicity, separation performance and antifouling properties were investigated through Water Contact Angle (WCA) analysis, the permeance and three-cycle fouling measurements. The growth model of cGO-incorporated polyamide thin-film was proposed. Compared to the original NF membranes, the surface hydrophilicity, water permeability, salt rejection and antifouling properties of the cGO-incorporated NF membrane had all improved. When cGO content was 100 ppm, the MgSO4 rejection of composite NF membrane reached a maximum value of 99.2% meanwhile membrane obtained an obvious enhanced water flux (81.6 L m-2 h-1, at 0.7 MPa) which was nearly three times compared to the virginal NF membrane. The cGO-incorporated NF membrane showed an excellent selectivity of MgSO4 and NaCl with the rejection ratio of MgSO4/NaCl of approximately 8.0.

  3. Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures

    Directory of Open Access Journals (Sweden)

    F. Falbo

    2014-12-01

    Full Text Available Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2 and with a mixture (30% CO2 and 70% N2 in dry and wet conditions at 25 ºC, 50 ºC, 60 ºC and 75 ºC and up to 600 kPa. Interesting values of single gas selectivity up to 60 ºC (between 31 and 28 for CO2/N2 and between 33 and 30 for CO2/CH4 in dry condition were obtained. The separation factor measured for the mixture was 20% lower compared to the single gas selectivity, in the whole temperature range analyzed. In saturation conditions the data showed that water influences the performance of the membranes, inducing a reduction of the permeance of all gases. Moreover, the presence of water caused a decrease of single gas selectivity and separation factor, although not so significant, highlighting the very high water resistance of hollow fiber membrane modules.

  4. PEBAX®/PAN Hollow Fiber Membranes for CO2/CH4 Separation

    Czech Academy of Sciences Publication Activity Database

    Esposito, E.; Clarizia, G.; Bernardo, P.; Jansen, J. C.; Sedláková, Zuzana; Izák, Pavel; Curcio, S.; de Cindio, B.; Tasselli, F.

    2015-01-01

    Roč. 94, SI (2015), s. 53-61 ISSN 0255-2701. [International Congress of Chemical and Process Engineering CHISA 2014 /21./ and Conference PRES 2014 /17./. Prague, 23.08.2014-27.08.2014] R&D Projects: GA ČR GA14-12695S Grant - others:INRP(IT) MicroPERLA:PON01_01840 Institutional support: RVO:67985858 Keywords : composite membrane * hollow fibers * CO2/CH4 separation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.154, year: 2015

  5. A cost-effective device for the rapid transfer of gel-separated proteins onto membranes.

    Science.gov (United States)

    Tam, Hann W; Huang, Yu-Chen; Tam, Ming F

    2009-03-01

    We describe here the fabrication of a cost-effective semi-dry blotting apparatus for the transfer of proteins onto membranes. Graphite sheets were used as electrodes. Protein mixtures were separated on NuPAGE 4% to 12% polyacrylamide gradient gels. With a Tris-bicine buffer, we demonstrated that close to 80% of the proteins with apparent molecular mass of 80kDa or less were removed from the gels after 8min of blotting. The process is much faster than the techniques reported previously in the literature.

  6. Study of Separation and Fouling of Reverse Osmosis Membranes during Model Hydrolysate Solution Filtration.

    Science.gov (United States)

    Ajao, Olumoye; Rahni, Mohamed; Marinova, Mariya; Chadjaa, Hassan; Savadogo, Oumarou

    2017-12-15

    Prehydrolysate, a dilute solution consisting mainly of pentoses, hexoses, and lesser quantities of organic acids, furfural and phenolics, is generated in the Kraft dissolving pulp process. An obstacle facing the valorization of the solution in hemicellulose biorefineries, by conversion of the sugars into bioproducts such as furfural, is the low sugar concentration. Membrane filtration is typically proposed in several hemicellulose based biorefineries for concentrating the solution, although they are usually generated using different wood species, pretreatment methods, and operating conditions. However, the chemical composition of the solutions is generally not considered. Also, the combined effect of composition and operating conditions is rarely investigated for biorefinery applications. The purpose of this work was to determine the impact of the prehydrolysate composition and operating parameters on the component separation and permeate flux during membrane filtration. Using model prehydrolysate solutions, two commercial reverse osmosis (RO) membranes were screened, and one was selected for use, based on its higher sugar and acetic acid retention. A Taguchi L18 experimental design array was then applied to determine the dominant parameters and limiting factors. Results showed that the feed pressure and temperature have the highest impact on permeate flux, but the least effect on sugar retention. Further experiments to quantify flux decline, due to fouling and osmotic pressure, showed that furfural has the highest membrane fouling tendency, and can limit the lifetime of the membrane. Regeneration of the membrane by cleaning with a sodium hydroxide solution is also effective for reversing fouling. It has been demonstrated that RO can efficiently and sustainably concentrate wood prehydrolysate.

  7. Study of Separation and Fouling of Reverse Osmosis Membranes during Model Hydrolysate Solution Filtration

    Directory of Open Access Journals (Sweden)

    Olumoye Ajao

    2017-12-01

    Full Text Available Prehydrolysate, a dilute solution consisting mainly of pentoses, hexoses, and lesser quantities of organic acids, furfural and phenolics, is generated in the Kraft dissolving pulp process. An obstacle facing the valorization of the solution in hemicellulose biorefineries, by conversion of the sugars into bioproducts such as furfural, is the low sugar concentration. Membrane filtration is typically proposed in several hemicellulose based biorefineries for concentrating the solution, although they are usually generated using different wood species, pretreatment methods, and operating conditions. However, the chemical composition of the solutions is generally not considered. Also, the combined effect of composition and operating conditions is rarely investigated for biorefinery applications. The purpose of this work was to determine the impact of the prehydrolysate composition and operating parameters on the component separation and permeate flux during membrane filtration. Using model prehydrolysate solutions, two commercial reverse osmosis (RO membranes were screened, and one was selected for use, based on its higher sugar and acetic acid retention. A Taguchi L18 experimental design array was then applied to determine the dominant parameters and limiting factors. Results showed that the feed pressure and temperature have the highest impact on permeate flux, but the least effect on sugar retention. Further experiments to quantify flux decline, due to fouling and osmotic pressure, showed that furfural has the highest membrane fouling tendency, and can limit the lifetime of the membrane. Regeneration of the membrane by cleaning with a sodium hydroxide solution is also effective for reversing fouling. It has been demonstrated that RO can efficiently and sustainably concentrate wood prehydrolysate.

  8. Rapid One-Pot Microwave Synthesis of Mixed-Linker Hybrid Zeolitic-Imidazolate Framework Membranes for Tunable Gas Separations.

    Science.gov (United States)

    Hillman, Febrian; Brito, Jordan; Jeong, Hae-Kwon

    2018-02-14

    The relatively slow and complex fabrication processes of polycrystalline metal-organic framework (MOF) membranes often times restrict their way to commercialization, despite their potential for molecular separation applications. Herein, we report a rapid one-pot microwave synthesis of mixed-linker hybrid zeolitic-imidazolate framework (ZIF) membranes consisting of 2-methylimidazolate (ZIF-8 linker) and benzimidazolate (ZIF-7 linker) linkers, termed ZIF-7-8 membranes. The fast-volumetric microwave heating in conjunction with a unique counter diffusion of metal and linker solutions enabled unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes in ∼90 s, the fastest MOF membrane preparation up to date. Furthermore, we were able to tune the molecular sieving properties of the ZIF-7-8 membranes by varying the benzimidazole-to-2-methylimidazole (bIm-to-mIm) linker ratio in the hybrid frameworks. The tuning of their molecular sieving properties led to the systematic change in the permeance and selectivity of various small gases. The unprecedented rapid synthesis of well-intergrown ZIF-7-8 membranes with tunable molecular sieving properties is an important step forward for the commercial gas separation applications of ZIF membranes.

  9. A Membrane Process for Recycling Die Lube from Wastewater Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Eric S. Peterson; Jessica Trudeau; Bill Cleary; Michael Hackett; William A. Greene

    2003-04-01

    An active-surface membrane technology was used to separate a die lube manufacturing wastewater stream consisting of various oils, hydrocarbons, heavy metals, and silicones. The ultrafiltration membranes reduced organics from initial oil and grease contents by 20–25X, carbon oxygen demand (COD) by 1.5 to 2X, and total organic carbon (TOC) by 0.6, while the biological oxygen demand (BOD) remained constant. The active-surface membranes were not fouled as badly as non-active-surface systems and the active-surface membrane flux levels were consistently higher and more stable than those of the non-active-surface membranes tested. Field testing demonstrated that the rotary microfilter can concentrate the die lube, i.e. remove the glycerin component, and produce a die lube suitable for recycling. The recycling system operated for six weeks with only seven cleaning cycles and no mechanical or electrical failures. Test data and quality records indicate that the die casting scrap was reduced from 8.4 to 7.8%. There is no doubt that this test yielded tremendous results. This separation process presents significant opportunities that can be evaluated further.

  10. A Membrane Process for Recycling Die Lube from Wastewater Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, E. S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Trudeau, J. [Metaldyne, Inc., Twinsburg, OH (United States); Cleary, B. [Metaldyne, Inc., Twinsburg, OH (United States); Hackett, M. [Metaldyne, Inc., Twinsburg, OH (United States); Greene, W. A. [SpinTek FIltrations, LLC, Los Alamitos, CA (United States)

    2003-04-30

    An active-surface membrane technology was used to separate a die lube manufacturing wastewater stream consisting of various oils, hydrocarbons, heavy metals, and silicones. The ultrafiltration membranes reduced organics from initial oil and grease contents by 20-25X, carbon oxygen demand (COD) by 1.5 to 2X, and total organic carbon (TOC) by 0.6, while the biological oxygen demand (BOD) remained constant. The active-surface membranes were not fouled as badly as non-active-surface systems and the active-surface membrane flux levels were consistently higher and more stable than those of the non-active-surface membranes tested. Field testing demonstrated that the rotary microfilter can concentrate the die lube, i.e. remove the glycerin component, and produce a die lube suitable for recycling. The recycling system operated for six weeks with only seven cleaning cycles and no mechanical or electrical failures. Test data and quality records indicate that the die casting scrap was reduced from 8.4 to 7.8%. There is no doubt that this test yielded tremendous results. This separation process presents significant opportunities that can be evaluated further.

  11. Carbon Dioxide Separation with Supported Ionic Liquid Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Luebke, D.R.; Ilconich, J.B.; Myers, C.R.; Pennline, H.W.

    2007-04-01

    Supported liquid membranes are a class of materials that allow the researcher to utilize the wealth of knowledge available on liquid properties as a direct guide in the development of a capture technology. These membranes also have the advantage of liquid phase diffusivities higher than those observed in polymeric membranes which grant proportionally greater permeabilities. The primary shortcoming of the supported liquid membranes demonstrated in past research has been the lack of stability caused by volatilization of the transport liquid. Ionic liquids, which possess high carbon dioxide solubility relative to light gases such as hydrogen, are an excellent candidate for this type of membrane since they have negligible vapor pressure and are not susceptible to evaporation. A study has been conducted evaluating the use of several ionic liquids, including 1-hexyl-3-methyl-imidazolium bis(trifuoromethylsulfonyl)imide, 1-butyl-3-methyl-imidazolium nitrate, and 1-ethyl-3-methyl-imidazolium sulfate in supported ionic liquid membranes for the capture of carbon dioxide from streams containing hydrogen. In a joint project, researchers at the University of Notre Dame lent expertise in ionic liquid synthesis and characterization, and researchers at the National Energy Technology Laboratory incorporated candidate ionic liquids into supports and evaluated the resulting materials for membrane performance. Initial results have been very promising with carbon dioxide permeabilities as high as 950 barrers and significant improvements in carbon dioxide/hydrogen selectivity over conventional polymers at 37C and at elevated temperatures. Results include a comparison of the performance of several ionic liquids and a number of supports as well as a discussion of innovative fabrication techniques currently under development.

  12. Separation of actinides and lanthanides from acidic nuclear wastes by supported liquid membranes

    International Nuclear Information System (INIS)

    Danesi, P.R.; Chiarizia, R.; Rickert, P.; Horwitz, E.P.

    1985-01-01

    Supported liquid membranes, SLM, consisting of a solution of 0.25 M octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and 0.75 M tributylphosphate (TBP) in decalin absorbed on thin microporous polypropylene supports, have been studied for their ability to perform selective separations and concentrations of actinide and lanthanide ions from synthetic acidic nuclear wastes. The permeability coefficients of selected actinides (Am, Pu, U, Np) and of some of the other major components of the wastes have been measured using SLMs in flat-sheet and hollow-fiber configurations. The results have shown that with the thin (25 μm) flat-sheet SLMs, using Celgard 2500 as support, the membrane permeation process is mainly controlled by the rate of diffusion through the aqueous boundary layers. With the thicker (430 μm) hollow-fiber SLMs, using Accurel hollow-fibers as support, the membrane permeation process is controlled by the rate of diffusion through both the SLM and the aqueous boundary layers. Hollow-fibers SLMs exhibited lower permeability coefficients and longer life-times. The experiments have shown that the actinides can be very efficiently removed from the synthetic waste solutions to the point that the resulting solution could be considered a non-transuranic waste (less than 100 mCi/g of disposed form). The work has demonstrated that actinide removal from synthetic waste solutions is a feasible chemical process at the laboratory scale level

  13. PALLADIUM/COPPER ALLOY COMPOSITE MEMBRANES FOR HIGH TEMPERATURE HYDROGEN SEPARATION FROM COAL-DERIVED GAS STREAMS; F

    International Nuclear Information System (INIS)

    J. Douglas Way; Robert L. McCormick

    2001-01-01

    Recent advances have shown that Pd-Cu composite membranes are not susceptible to the mechanical, embrittlement, and poisoning problems that have prevented widespread industrial use of Pd for high temperature H(sub 2) separation. These membranes consist of a thin ((approx)10(micro)m) film of metal deposited on the inner surface of a porous metal or ceramic tube. Based on preliminary results, thin Pd(sub 60)Cu(sub 40) films are expected to exhibit hydrogen flux up to ten times larger than commercial polymer membranes for H(sub 2) separation, and resist poisoning by H(sub 2)S and other sulfur compounds typical of coal gas. Similar Pd-membranes have been operated at temperatures as high as 750 C. The overall objective of the proposed project is to demonstrate the feasibility of using sequential electroless plating to fabricate Pd(sub 60)Cu(sub 40) alloy membranes on porous supports for H(sub 2) separation. These following advantages of these membranes for processing of coal-derived gas will be demonstrated: High H(sub 2) flux; Sulfur tolerant, even at very high total sulfur levels (1000 ppm); Operation at temperatures well above 500 C; and Resistance to embrittlement and degradation by thermal cycling. The proposed research plan is designed to providing a fundamental understanding of: Factors important in membrane fabrication; Optimization of membrane structure and composition; Effect of temperature, pressure, and gas composition on H(sub 2) flux and membrane selectivity; and How this membrane technology can be integrated in coal gasification-fuel cell systems

  14. Ethanol fermentation integrated with PDMS composite membrane: An effective process.

    Science.gov (United States)

    Fu, Chaohui; Cai, Di; Hu, Song; Miao, Qi; Wang, Yong; Qin, Peiyong; Wang, Zheng; Tan, Tianwei

    2016-01-01

    The polydimethylsiloxane (PDMS) membrane, prepared in water phase, was investigated in separation ethanol from model ethanol/water mixture and fermentation-pervaporation integrated process. Results showed that the PDMS membrane could effectively separate ethanol from model solution. When integrated with batch ethanol fermentation, the ethanol productivity was enhanced compared with conventional process. Fed-batch and continuous ethanol fermentation with pervaporation were also performed and studied. 396.2-663.7g/m(2)h and 332.4-548.1g/m(2)h of total flux with separation factor of 8.6-11.7 and 8-11.6, were generated in the fed-batch and continuous fermentation with pervaporation scenario, respectively. At the same time, high titre ethanol production of ∼417.2g/L and ∼446.3g/L were also achieved on the permeate side of membrane in the two scenarios, respectively. The integrated process was environmental friendly and energy saving, and has a promising perspective in long-terms operation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Nanostructured Membranes Functionalized with Gold Nanoparticles for Separation and Recovery of Monoclonal Antibodies

    KAUST Repository

    Soldan, Giada

    2017-11-01

    The need of purified biomolecules, such as proteins or antibodies, has required the biopharmaceutical industries to look for new recovering solutions to reduce time and costs of bioseparations. In the last decade, the emergent field of membrane chromatography has gained attention as possible substituent of the common used protein A affinity chromatography for bioseparations. In this scenario, gold nanoparticles can be used as means for offering affinity, mainly because of their biocompatible and reversible binding behavior, together with their high surface area-to-volume ratio, which offers a large number of binding sites. This work introduces a new procedure for purification of monoclonal antibodies based on polymeric membranes functionalized with gold nanoparticles. This novel approach shortens the process of purification by promoting selective binding of antibodies, while separating a mixture of biomolecules during a filtration process. The effects of gold nanoparticles and the surrounding ligand on the proteins adsorption and filtration are investigated. The results confirm that the functionalization helps in inducing a selective binding, preventing the non-selective one, and it also improves the selectivity of the separation process.

  16. Data supporting the validation of a simulation model for multi-component gas separation in polymeric membranes.

    Science.gov (United States)

    Giordano, Lorena; Roizard, Denis; Bounaceur, Roda; Favre, Eric

    2016-12-01

    The article describes data concerning the separation performances of polymeric hollow-fiber membranes. The data were obtained using a model for simulating gas separation, described in the research article entitled "Interplay of inlet temperature and humidity on energy penalty for CO 2 post-combustion capture: rigorous analysis and simulation of a single stage gas permeation process" (L. Giordano, D. Roizard, R. Bounaceur, E. Favre, 2016) [1]. The data were used to validate the model by comparison with literature results. Considering a membrane system based on feed compression only, data from the model proposed and that from literature were compared with respect to the molar composition of permeate stream, the membrane area and specific energy requirement, varying the feed pressure and the CO 2 separation degree.

  17. High-flux membrane separation using fluid skimming dominated convective fluid flow

    NARCIS (Netherlands)

    Dinther, van A.M.C.; Schroën, C.G.P.H.; Boom, R.M.

    2011-01-01

    We here report on the separation of yeast cells, with micro-engineered membranes having pores that are typically five times larger than the cells. The separation is due to neither shear-induced diffusion, nor initial lift, but to an effect similar to fluid skimming. The separation performance is

  18. The uranium separation from Ru using Tbp solvent by membrane emulsion method

    International Nuclear Information System (INIS)

    Bintarti, A. N.; Bambang, EHB. J.; Pramono, J.

    1998-01-01

    An extraction process for uranium (U) separation from ruthenium (Ru) by tributyl phosphate (Tbp) as a solvent with kerosene as a diluent and surfactant the Span-80 as emulator has been performed. A sodium carbonate solution having ph 10-11 was used as the internal phase. the feed contained U and Ru in HNO 3 solution, while butanol was used as the membrane sp liter. the membrane used for extraction had a composition of 5% vol surfactant, 10% vol Tbp, 35% vol kerosene and 50% vol Na 2 CO 3 solution. The mixing time and speed were varied in value, so were the acidity levels, ranging from 0.5 M, 0.75 M up to 1 M. The result of the experimental separation of a mixture containing 5000 ppm U and 325 ppm Ru showed that a molarity of 0.5 M HNO 3 in the feed, 15 minutes mixing time, and 800 rpm mixing speed were found to be the best conditions for the extraction. Such condition had resulted in achieving the value of stripping distribution coefficient K d for U= 0.5660 with 49.73% U recovery efficiency and a practically zero separation factor from Ru

  19. [Computer modeling the hydrostatic pressure characteristics of the membrane potential for polymeric membrane, separated non-homogeneous electrolyte solutions].

    Science.gov (United States)

    Slezak, Izabella H; Jasik-Slezak, Jolanta; Rogal, Mirosława; Slezak, Andrzej

    2006-01-01

    On the basis of model equation depending the membrane potential deltapsis, on mechanical pressure difference (deltaP), concentration polarization coefficient (zetas), concentration Rayleigh number (RC) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics deltapsis = f(deltaP)zetas,RC,Ch/Cl for steady values of zetas, RC and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, RC and zetas.

  20. Preparation and characterization of poly (methyl methacrylate) and sulfonated poly (ether ether ketone) blend ultrafiltration membranes for protein separation applications

    International Nuclear Information System (INIS)

    Arthanareeswaran, G.; Thanikaivelan, P.; Raajenthiren, M.

    2009-01-01

    Poly (methyl methacrylate) (PMMA) and poly (methyl methacrylate)/sulfonated poly (ether ether ketone) (SPEEK) blend membranes were prepared by phase inversion technique in various composition using N,N'-dimethylformamide as solvent. The prepared membranes were characterized in terms of pure water flux, water content, porosity and thermal stability. The addition of SPEEK to the casting solution resulted in membranes with high pure water flux, water content, porosity and slightly low thermal stability. The cross sectional views of the blend membranes under electron microscope confirm the porosity and water flux results. The effect of the addition of SPEEK into the PMMA matrix on the extent of bovine serum albumin (BSA) separation was studied. It was found that the permeate flux increased significantly while the rejection of BSA from aqueous solution reduced moderately during ultrafiltration (UF) process. The effect was attributed to the increase in porosity and charge of the membrane due to the addition of SPEEK into the PMMA blend solution

  1. A robust and stretchable superhydrophobic PDMS/PVDF@KNFs membrane for oil/water separation and flame retardancy.

    Science.gov (United States)

    Li, Deke; Gou, Xuelian; Wu, Daheng; Guo, Zhiguang

    2018-04-05

    The wide application of superhydrophobic membranes has been limited due to their complicated preparation technology and weak durability. Inspired by the mechanical flexibility of nanofibrous biomaterials, nanofibrils have been successfully generated from Kevlar, which is one of the strongest synthetic fibers, by appropriate hydrothermal treatment. In this study, a robust superhydrophobic PDMS/PVDF@KNFs membrane is prepared via a simple one-step process and subsequent curing without combination with inorganic fillers. The as-prepared PDMS/PVDF@KNFs membrane not only shows efficient oil/water separation ability and oil absorption capacity but also has excellent superhydrophobicity stability after deformation. The resultant membrane shows stretchability, flexibility and flame retardance because of the reinforcing effect and the excellent flame retardancy of Kevlar. We believe that this simple fabrication of PDMS/PVDF@KNFs has promising applications in filtering membranes and wearable devices.

  2. Recent progress in developments of membrane materials and modification techniques for high performance helium separation and recovery : a review

    NARCIS (Netherlands)

    Soleimany, A.; Hosseini, S.S.; Gallucci, F.

    2017-01-01

    Helium is a valuable gas with unique properties and applications and still the prominent industrial source of helium is natural gas. Because of several advantages of membrane-based separation processes over conventional methods as well as the lack of a comprehensive scientific report, the present

  3. Novel ceramic-polymer composite membranes for the separation of liquid waste. Annual progress report, September 15, 1996 - September 14, 1997

    International Nuclear Information System (INIS)

    Cohen, Y.

    1997-01-01

    'The project on ceramic-supported polymer membranes focuses on the development of a novel class of membranes for the separation of organics from both organic-aqueous and organic-organic mixtures, Theses membranes are fabricated by a graft polymerization process where polymer chains are grown onto the surface of a ceramic support membrane. The surface graft polymerization process, developed at UCLA, results in the formation of a thin polymer layer covalently bonded to the membrane pore surface as a layer of terminally anchored polymeric chains. Through the selection of the polymer most appropriate for the desired separation task, the graft polymerized surface layer can be synthesized to impart specific separation properties to the membrane. It is expected that this project will lead to the demonstration of a new technology for the tailor design of a new class of selective and robust ceramic-supported polymer membranes. This new approach will allow the rapid deployment of task-specific membranes for the separation of waste constituents for subsequent recovery, treatment or disposal. Progress to date includes the preparation of successful silica-polyvinylpyrrolidone (PVP) membrane for the treatment of oil-in-water emulsions and a silica-polyvinylacetate (PVAc) pervaporation membrane for the separation of organics from water. Current work is ongoing to study the performance of the pervaporation membrane for the removal of chlorinated organics from water and to develop a pervaporation membrane for organic-organic separation. In another aspect of the study, the authors are studying the hydrophilic PVP CSP membrane for oil-in-water emulsion treatment with the goal of determining the optimal membrane polymer surface structure as a function of various operating conditions (e.g., tube-side Reynolds number and transmembrane pressure), Work is also in progress to characterize the polymer layer by AFM and internal reflection FTIR, and to model the conformation of the polymer

  4. Microfluidic devices for investigation of biomimetic membranes for sensor and separation applications

    DEFF Research Database (Denmark)

    Pszon-Bartosz, Kamila Justyna

    to microfluidic designs involving protein delivery to biomimetic membranes developed for sensor and separation applications. Finally, an OMP functionality modulation with β-cyclodextrin (β-CD) was shown and revealed the protein potential application as a sensor. Moreover, the β-CD blocker may be used to prevent...... for industrial applications. Among them are the inherent fragility of lipid membranes, the challenge of up-scaling the effective membrane area and the quantification of the protein delivery to the lipid membrane which may determined the biomimetic membrane application. This PhD thesis addresses the above...

  5. Specific oriented metal-organic framework membranes and their facet-tuned separation performance.

    Science.gov (United States)

    Mao, Yiyin; Su, Binbin; Cao, Wei; Li, Junwei; Ying, Yulong; Ying, Wen; Hou, Yajun; Sun, Luwei; Peng, Xinsheng

    2014-09-24

    Modulating the crystal morphology, or the exposed crystal facets, of metal-organic frameworks (MOFs) expands their potential applications in catalysis, adsorption, and separation. In this article, by immobilizing the citrate modulators on Au nanoparticles and subsequently being fixed on solid copper hydroxide nanostrands, a well-intergrown and oriented HKUST-1 cube crystal membrane was formed at room temperature. In contrast, in the absence of Au nanoparticles, well-intergrown and oriented cuboctahedron and octahedron membranes were formed in water/ethanol and ethanol, respectively. The gas separation performances of these HKUST-1 membranes were tuned via their exposed facets with defined pore sizes. The HKUST-1 cube membrane with exposed {001} facets demonstrated the highest permeance but lowest gas binary separation factors, while the octahedron membrane with exposed {111} facets presented the highest separation factors but lowest permeance, since the window size of {111} facets is 0.46 nm which is smaller than 0.9 nm of {001} facets. Separation of 0.38 nm CO2 from 0.55 nm SF6 was realized by the HKUST-1 octahedron membrane. As a proof of concept, this will open a new way to design MOF-related separation membranes by facet controlling.

  6. Ethanol-water separation by pervaporation using silicone and polyvinyl alcohol membranes

    Directory of Open Access Journals (Sweden)

    Chinchiw, S.

    2006-09-01

    Full Text Available In this research, experiments were carried out to investigate the effects of operating parameters onthe pervaporation performance for the separation of ethanol-water solutions. Composite silicone membranessupported on polysulfone prepared with varied silicone contents and commercial polyvinyl alcohol (Pervap®2211, Sulzer membranes were used. The results showed that the composite silicone/polysulfone membranescoated with 3 wt% of silicone exhibited highest permeation flux with slightly lower separation factor forethanol. Furthermore, it was found that the composite silicone/polysulfone membranes were suitable for theseparation of ethanol from a dilute ethanol solutions. Both the separation factor and permeation flux of the composite membranes increased with increasing temperature and feed concentration. A membrane coated with a 7 wt% silicone gave highest separation factor of 7.32 and permeation flux of 0.44 kg/m2h at 5 wt% ethanol feed concentration and feed temperature of 70ºC. For polyvinyl alcohol membranes, the results showed that the membranes were suitable for the dehydration of concentrated ethanol solutions. The permeation flux increased and the separation factor for water decreased with increasing water feed concentration and temperature. The membrane gave highest separation factor of 248 and permeation flux of 0.02 kg/m2h at 5 wt% water feed concentration and feed temperature of 30ºC.

  7. Separation of Peptides with Forward Osmosis Biomimetic Membranes

    DEFF Research Database (Denmark)

    Bajraktari, Niada; Madsen, Henrik T; Gruber, Mathias Felix

    2016-01-01

    such as pharmaceuticals. It is crucial in such settings to control the transport over the membrane to avoid losses of valuable compounds, but little is known about the rejection and transport mechanisms of larger biomolecules with often flexible conformations. In this study, transport of two chemically similar peptides...

  8. A Membrane Gas Separation Experiment for the Undergraduate Laboratory.

    Science.gov (United States)

    Davis, Richard A.; Sandall, Orville C.

    1991-01-01

    Described is a membrane experiment that provides students with experience in fundamental engineering skills such as mass balances, modeling, and using the computer as a research tool. Included are the experimental design, theory, method of solution, sample calculations, and conclusions. (KR)

  9. CO2 sorption of a ceramic separation membrane

    NARCIS (Netherlands)

    Wormeester, Herbert; Benes, Nieck Edwin; Spijksma, G.I.; Verweij, H.; Poelsema, Bene

    2004-01-01

    The ellipsometric characterization of the CO2 sorption of a silica membrane provides a fast and accurate technique for the characterization of maximum sorption and the heat of adsorption. Both parameters are evaluated for the 73 nm thick silica layer as well as the 1650 nm thick supporting γ-layer.

  10. Modelling of biohydrogen production and recovery by membrane gas separation

    Czech Academy of Sciences Publication Activity Database

    Búcsú, D.; Nemestóthy, N.; Pientka, Zbyněk; Gubicza, L.; Bélafi-Bakó, K.

    2009-01-01

    Roč. 240, 1-3 (2009), s. 306-310 ISSN 0011-9164 R&D Projects: GA ČR GA203/06/1207 Institutional research plan: CEZ:AV0Z40500505 Keywords : integrated system * Escherichia coli * PES-PI membrane Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.034, year: 2009

  11. Separation of Azeotropic Mixture Acetone + Hexane by Using Polydimethylsiloxane Membrane.

    Czech Academy of Sciences Publication Activity Database

    Randová, A.; Bartovská, L.; Kačírková, Marie; Ledesma, Oscar Iván Hernández; Červenková Šťastná, Lucie; Izák, Pavel; Žitková, Andrea; Friess, K.

    2016-01-01

    Roč. 170, OCT 1 (2016), s. 256-263 ISSN 1383-5866 R&D Projects: GA MŠk(CZ) LD14094 Institutional support: RVO:67985858 Keywords : azeotropic mixture * PDMS membrane * pervaporation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  12. Analysis of hollow fibre membrane systems for multicomponent gas separation

    KAUST Repository

    Khalilpour, Rajab

    2013-02-01

    This paper analysed the performance of a membrane system over key design/operation parameters. A computation methodology is developed to solve the model of hollow fibre membrane systems for multicomponent gas feeds. The model represented by a nonlinear differential algebraic equation system is solved via a combination of backward differentiation and Gauss-Seidel methods. Natural gas sweetening problem is investigated as a case study. Model parametric analyses of variables, namely feed gas quality, pressure, area, selectivity and permeance, resulted in better understanding of operating and design optima. Particularly, high selectivities and/or permeabilities are shown not to be necessary targets for optimal operation. Rather, a medium selectivity (<60 in the given example) combined with medium permeance (∼300-500×10-10mol/sm2Pa in the given case study) is more advantageous. This model-based membrane systems engineering approach is proposed for the synthesis of efficient and cost-effective multi-stage membrane networks. © 2012 The Institution of Chemical Engineers.

  13. Corrugated Membrane Nonlinear Deformation Process Calculation

    Directory of Open Access Journals (Sweden)

    A. S. Nikolaeva

    2015-01-01

    Full Text Available Elastic elements are widely used in instrumentation. They are used to create a particular interference between the parts, for accumulating mechanical energy, as the motion transmission elements, elastic supports, and sensing elements of measuring devices. Device reliability and quality depend on the calculation accuracy of the elastic elements. A corrugated membrane is rather common embodiment of the elastic element.The corrugated membrane properties depend largely on its profile i.e. a generatrix of the meridian surface.Unlike other types of pressure elastic members (bellows, tube spring, the elastic characteristics of which are close to linear, an elastic characteristic of the corrugated membrane (typical movement versus external load is nonlinear. Therefore, the corrugated membranes can be used to measure quantities, nonlinearly related to the pressure (e.g., aircraft air speed, its altitude, pipeline fluid or gas flow rate. Another feature of the corrugated membrane is that significant movements are possible within the elastic material state. However, a significant non-linearity of membrane characteristics leads to severe complicated calculation.This article is aimed at calculating the corrugated membrane to obtain the elastic characteristics and the deformed shape of the membrane meridian, as well as at investigating the processes of buckling. As the calculation model, a thin-walled axisymmetric shell rotation is assumed. The material properties are linearly elastic. We consider a corrugated membrane of sinusoidal profile. The membrane load is a uniform pressure.The algorithm for calculating the mathematical model of an axisymmetric corrugated membrane of constant thickness, based on the Reissner’s theory of elastic thin shells, was realized as the author's program in C language. To solve the nonlinear problem were used a method of changing the subspace of control parameters, developed by S.S., Gavriushin, and a parameter marching method

  14. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    KAUST Repository

    Hammami, Mohamed Amen

    2017-01-01

    Mixed Matrix Membranes (MMMs) have received worldwide attention during the last decades. This is due to the fact that the resulting materials can combine the good processability and low cost of polymer membranes with the diverse functionality, high

  15. Origins and Evolution of Inorganic-Based and MOF-Based Mixed-Matrix Membranes for Gas Separations

    Directory of Open Access Journals (Sweden)

    Edson V. Perez

    2016-09-01

    Full Text Available Gas separation for industrial, energy, and environmental applications requires low energy consumption and small footprint technology to minimize operating and capital costs for the processing of large volumes of gases. Among the separation methods currently being used, like distillation, amine scrubbing, and pressure and temperature swing adsorption, membrane-based gas separation has the potential to meet these demands. The key component, the membrane, must then be engineered to allow for high gas flux, high selectivity, and chemical and mechanical stability at the operating conditions of feed composition, pressure, and temperature. Among the new type of membranes studied that show promising results are the inorganic-based and the metal-organic framework-based mixed-matrix membranes (MOF-MMMs. A MOF is a unique material that offers the possibility of tuning the porosity of a membrane by introducing diffusional channels and forming a compatible interface with the polymer. This review details the origins of these membranes and their evolution since the first inorganic/polymer and MOF/polymer MMMs were reported in the open literature. The most significant advancements made in terms of materials, properties, and testing conditions are described in a chronological fashion.

  16. High-Flux Zeolitic Imidazolate Framework Membranes for Propylene/Propane Separation by Postsynthetic Linker Exchange.

    Science.gov (United States)

    Lee, Moon Joo; Kwon, Hyuk Taek; Jeong, Hae-Kwon

    2018-01-02

    While zeolitic imidazolate framework, ZIF-8, membranes show impressive propylene/propane separation, their throughput needs to be greatly improved for practical applications. A method is described that drastically reduces the effective thickness of ZIF-8 membranes, thereby substantially improving their propylene permeance (that is, flux). The new strategy is based on a controlled single-crystal to single-crystal linker exchange of 2-methylimidazole in ZIF-8 membrane grains with 2-imidazolecarboxaldehyde (ZIF-90 linker), thereby enlarging the effective aperture size of ZIF-8. The linker-exchanged ZIF-8 membranes showed a drastic increase in propylene permeance by about four times, with a negligible loss in propylene/propane separation factor when compared to as-prepared membranes. The linker-exchange effect depends on the membrane synthesis method. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Investigation of humidity control via membrane separation for advanced Extravehicular Mobility Unit (EMU) application

    Science.gov (United States)

    Newbold, D. D.; Ray, R. J.; Pledger, W. A.; Mccray, S. B.; Brown, M. F.

    1989-01-01

    This paper describes the development of a membrane-based process for dehumidifying the Extravehicular Mobility Unit (EMU). The membrane process promises to be smaller, lighter, and more energy efficient than the other technologies for dehumidification. The dehydration membranes were tested for 90 days at conditions expected to be present in the EMU. The results of these tests indicate that membrane-based technology can effectively control humidity in the EMU.

  18. Preparation and Characterization of Membranes Formed by Nonsolvent Induced Phase Separation: A Review

    KAUST Repository

    Guillen, Gregory R.; Pan, Yinjin; Li, Minghua; Hoek, Eric M. V.

    2011-01-01

    . The body of knowledge has grown exponentially in the past fifty years, which suggests the need for a critical review of the literature. Here we present a review of nonsolvent induced phase separation membrane preparation and characterization for many

  19. Complexation-Induced Phase Separation: Preparation of Metal-Rich Polymeric Membranes

    KAUST Repository

    Villalobos, Luis Francisco

    2017-01-01

    The majority of state-of-the-art polymeric membranes for industrial or medical applications are fabricated by phase inversion. Complexation induced phase separation (CIPS)—a surprising variation of this well-known process—allows direct fabrication

  20. Electrodialytic separation of alkali-element ions with the aid of ion-exchange membranes

    International Nuclear Information System (INIS)

    Gurskii, V.S.; Moskvin, L.N.

    1988-01-01

    Electrodialytic separation of ions bearing charges of the same sign with the aid of ion-exchange membranes has been examined in the literature in relation to the so-called ideal membranes, which do not exhibit selectivity with respect to one ion type in ion exchange. It has been shown that separation on such membranes is effective only for counterions differing in size of charge. A matter of greater importance from the practical standpoint is the possibility of using electrodialysis for separating ions bearing like charges and having similar properties, including ionic forms of isotopes of the same element. In this paper they report a comparative study of ion separation, with reference to the Cs-Na pair, by electrodialysis through various types of cation-exchange membranes. Changes of the solution concentration in the cathode compartment were monitored by measurement of 22 Na and 137 Cs activities

  1. Production of xylooligosaccharides from forest waste by membrane separation and Paenibacillus xylanase hydrolysis

    Directory of Open Access Journals (Sweden)

    Chun-Han Ko

    2013-02-01

    Full Text Available Xylooligosaccharides (XO, derived from the alkaline (NaOH extractant of Mikania micrantha, were produced using multiple staged membrane separation and enzymatic xylanolysis. Staged nanofiltration (NMX, ultrafiltration (EUMX, and centrifugation (EMX processes for the ethanol precipitates were conducted. NMX recovered 97.26% of total xylose and removed 73.18% of sodium ions. Concentrations of total xylose were raised from 10.98 to 51.85 mg/mL by the NMX process. Recovered xylan-containing solids were hydrolyzed by the recombinant Paenibacillus xylanase. 68% XO conversions from total xylose of NMX was achieved in 24 hours. Xylopentaose (DP 5 was the major product from NMX and EMX hydrolysis. Xylohexaose (DP 6 was the major product from EUMX hydrolysis. Results of the present study suggest the applicability for XO production by nanofiltration, as NMX gave higher XO yields compared to those from a conventional ethanol-related lignocellulosic waste conversion process.

  2. The practical use of resistance modelling to interpret the gas separation properties of hollow fiber membranes

    International Nuclear Information System (INIS)

    Ahmad Fauzi Ismail; Shilton, S.J.

    2000-01-01

    A simple resistance modelling methodology is presented for gas transport through asymmetric polymeric membranes. The methodology allows fine structural properties such as active layer thickness and surface porosity, to be determined from experimental gas permeation data. This paper, which could be regarded as a practical guide, shows that resistance modeling, if accompanied by realistic working assumptions, need not be difficult and can provide a valuable insight into the relationships between the membrane fabrication conditions and performance of gas separation membranes. (Author)

  3. Inorganic membranes for separative techniques: from uranium isotope separation to non-nuclear fields

    International Nuclear Information System (INIS)

    Charpin, J.; Rigny, P.

    1989-01-01

    Uranium enrichment leads to the development of inorganic porous barriers - either ceramic or metallic. A wide range of these products had considerable potential for the improvement of filtration techniques in liquid media (ultrafiltration and microfiltration). This is how a new generation of inorganic membranes was created reputed for their performance and especially for their lifetime and their behaviour (mechanical and temperature stability, corrosion resistance). These membranes now have a respectable position in applications in the agro-food biotechnology industries, to give only two examples. Before the non-nuclear applications of inorganic membranes are presented, their success in the nuclear power industry are pointed out

  4. Gas separation membranes for zero-emission fossil power plants: MEM-BRAIN

    NARCIS (Netherlands)

    Czyperek, M.; Zapp, P.; Bouwmeester, Henricus J.M.; Modigell, M.; Ebert, K.; Voigt, I.; Meulenberg, W.A.; Singheiser, L.; Stöver, D.

    2010-01-01

    The objective of the “MEM-BRAIN” project is the development and integration of ceramic and polymeric gas separation membranes for zero-emission fossil power plants. This will be achieved using membranes with a high permeability and selectivity for either CO2, O2 or H2, for the three CO2 capture

  5. Thin film composite membranes of glossy polymers for gas separation : preparation and characterization

    NARCIS (Netherlands)

    Ebert, Katrin

    1995-01-01

    The application of polymeric composite membranes can be very interesting in the field of gas separation. The two main parameters which determine the applicability of membranes are the selectivity and the permeability. Good selectivities can be achieved by developing proper materials, high permeation

  6. Formation of defect-free 6FDA-DAM asymmetric hollow fiber membranes for gas separations

    KAUST Repository

    Xu, Liren; Zhang, Chen; Rungta, Meha; Qiu, Wulin; Liu, Junqiang; Koros, William J.

    2014-01-01

    This paper reports the formation of defect-free 6FDA-DAM asymmetric hollow fiber membranes. 6FDA-polyimides are of great interest for advanced gas separation membranes, and 6FDA-DAM polyimide is a representative polymer in this family

  7. Ionizable polyethers as specific metal ion carriers in liquid-liquid extraction and liquid membrane separations

    International Nuclear Information System (INIS)

    Walkowiak, W.; Charewicz, W.A.; Bartsch, R.A.; Ndip, G.M.

    1988-01-01

    Consideration is given to results of investigations into competitive extraction and penetration through a liquid membrane of alkali and alkaline earth cations from aqueous solutions by a series of lipophilic and ionizable acyclic polyethers of various molecular structure. It is shown that specificity and selectiviy of cation carriers in liquid-liquid extraction and liquid membrane separation depend on molecular structure of acyclic polyethers

  8. Membrane-based ethylene/ethane separation: The upper bound and beyond

    KAUST Repository

    Rungta, Meha

    2013-08-02

    Ethylene/ethane separation via cryogenic distillation is extremely energy-intensive, and membrane separation may provide an attractive alternative. In this paper, ethylene/ethane separation performance using polymeric membranes is summarized, and an experimental ethylene/ethane polymeric upper bound based on literature data is presented. A theoretical prediction of the ethylene/ethane upper bound is also presented, and shows good agreement with the experimental upper bound. Further, two ways to overcome the ethylene/ethane upper bound, based on increasing the sorption or diffusion selectivity, is also discussed, and a review on advanced membrane types such as facilitated transport membranes, zeolite and metal organic framework based membranes, and carbon molecular sieve membranes is presented. Of these, carbon membranes have shown the potential to surpass the polymeric ethylene/ethane upper bound performance. Furthermore, a convenient, potentially scalable method for tailoring the performance of carbon membranes for ethylene/ethane separation based on tuning the pyrolysis conditions has also been demonstrated. © 2013 American Institute of Chemical Engineers.

  9. Continuous Hydrolysis and Liquid–Liquid Phase Separation of an Active Pharmaceutical Ingredient Intermediate Using a Miniscale Hydrophobic Membrane Separator

    DEFF Research Database (Denmark)

    Cervera Padrell, Albert Emili; Morthensen, Sofie Thage; Lewandowski, Daniel Jacob

    2012-01-01

    Continuous hydrolysis of an active pharmaceutical ingredient intermediate, and subsequent liquid–liquid (L-L) separation of the resulting organic and aqueous phases, have been achieved using a simple PTFE tube reactor connected to a miniscale hydrophobic membrane separator. An alkoxide product......, obtained in continuous mode by a Grignard reaction in THF, reacted with acidic water to produce partially miscible organic and aqueous phases containing Mg salts. Despite the partial THF–water miscibility, the two phases could be separated at total flow rates up to 40 mL/min at different flow ratios, using...

  10. Adsorbent filled membranes for gas separation. Part 1. Improvement of the gas separation properties of polymeric membranes by incorporation of microporous adsorbents

    NARCIS (Netherlands)

    Duval, J.M.; Duval, J.-M.; Folkers, Albertje; Mulder, M.H.V.; Desgrandchamps, G.; Smolders, C.A.; Smolders, C.A.

    1993-01-01

    The effect of the introduction of specific adsorbents on the gas separation properties of polymeric membranes has been studied. For this purpose both carbon molecular sieves and zeolites are considered. The results show that zeolites such as silicate-1, 13X and KY improve to a large extent the

  11. Synthesis of asymmetric polyetherimide membrane for CO2/N2 separation

    Science.gov (United States)

    Ahmad, A. L.; Salaudeen, Y. O.; Jawad, Z. A.

    2017-06-01

    Large emission of carbon dioxide (CO2) to the environment requires mitigation to avoid unbearable consequences on global climate change. The CO2 emissions generated by fossil fuel combustion within the power and industrial sectors need to be quickly curbed. The gas emission can be abated using membrane technology; this is one of the most promising approaches for selective separation of CO2/N2. The purpose of the study is to synthesis an asymmetric polyetherimide (PEI) membrane and to establish its morphological characteristics for CO2/N2 separation. The PEI flat-sheet asymmetric membrane was fabricated using phase inversion with N-methyl-2-pyrrolidone (NMP) as solvent and water-isopropanol as a coagulant. Particularly, polymer concentration of 20, 25, and 30 wt. % were studied. In addition, the structure and morphology of the produced membrane were observed using scanning electron microscopy (SEM). Importantly, results showed that the membrane with high PEI concentration of 30 wt. % yield an optimal selectivity of 10.7 for CO2/Nitrogen (N2) separation at 1 bar and 25 ºC for pure gas, aided by the membrane surface morphology. The dense skin present was as a result of non-solvent (water) while isopropanol generates a porous sponge structure. This appreciable separation performance makes the PEI asymmetric membrane an attractive alternative for CO2/N2 separation.

  12. Steric Pressure among Membrane-Bound Polymers Opposes Lipid Phase Separation.

    Science.gov (United States)

    Imam, Zachary I; Kenyon, Laura E; Carrillo, Adelita; Espinoza, Isai; Nagib, Fatema; Stachowiak, Jeanne C

    2016-04-19

    Lipid rafts are thought to be key organizers of membrane-protein complexes in cells. Many proteins that interact with rafts have bulky polymeric components such as intrinsically disordered protein domains and polysaccharide chains. Therefore, understanding the interaction between membrane domains and membrane-bound polymers provides insights into the roles rafts play in cells. Multiple studies have demonstrated that high concentrations of membrane-bound polymeric domains create significant lateral steric pressure at membrane surfaces. Furthermore, our recent work has shown that lateral steric pressure at membrane surfaces opposes the assembly of membrane domains. Building on these findings, here we report that membrane-bound polymers are potent suppressors of membrane phase separation, which can destabilize lipid domains with substantially greater efficiency than globular domains such as membrane-bound proteins. Specifically, we created giant vesicles with a ternary lipid composition, which separated into coexisting liquid ordered and disordered phases. Lipids with saturated tails and poly(ethylene glycol) (PEG) chains conjugated to their head groups were included at increasing molar concentrations. When these lipids were sparse on the membrane surface they partitioned to the liquid ordered phase. However, as they became more concentrated, the fraction of GUVs that were phase-separated decreased dramatically, ultimately yielding a population of homogeneous membrane vesicles. Experiments and physical modeling using compositions of increasing PEG molecular weight and lipid miscibility phase transition temperature demonstrate that longer polymers are the most efficient suppressors of membrane phase separation when the energetic barrier to lipid mixing is low. In contrast, as the miscibility transition temperature increases, longer polymers are more readily driven out of domains by the increased steric pressure. Therefore, the concentration of shorter polymers required

  13. Plutonium Chemistry in the UREX+ Separation Processes

    Energy Technology Data Exchange (ETDEWEB)

    ALena Paulenova; George F. Vandegrift, III; Kenneth R. Czerwinski

    2009-10-01

    The project "Plutonium Chemistry in the UREX+ Separation Processes” is led by Dr. Alena Paulenova of Oregon State University under collaboration with Dr. George Vandegrift of ANL and Dr. Ken Czerwinski of the University of Nevada at Las Vegas. The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

  14. Separation of argon isotopes by porous membrane method, (2)

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Fujine, Sachio; Saito, Keiichiro; Ouchi, Misao; Naruse, Yuji

    1979-08-01

    Separation characteristics of an engineering-scale cascade equipment, which is composed of five stages using Al 2 O 3 barriers, were examined under different operating conditions. This report describes the results of the separation experiment of argon isotopes by the square cascade operated under total reflux. The results are as follows: (1) Mean pore diameter and tortuosity of the barriers were estimated to be 400A and 13-15, respectively. (2) Flow mechanism through the barriers was proved to be ideal Knudsen flow by measurement of the permeability. (3) The cascade was equilibriated in 30-40 minutes, depending on stage gas inventory. (4) The effect of an operating pressure on the separation factor could be estimated by Knudsen's and Present-deBethune's theories. (5) The stage separation factor could be estimated by the conventional theoretical equations by introducing a correction factor as a function of Reynolds number of the permeating flow through the barriers. (6) An experimental equation to estimate the flow effect on the separation factor was obtained considering velocity and physical properties of the gas in the vicinity of the barrier surface. (author)

  15. Extraction separation of toluene/cyclohexane with hollow fiber supported ionic liquid membrane

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Fan; Sun, Wei; Liu, Junteng; Zhang, Weidong; Ren, Zhongqi [Beijing University of Chemical Technology, Beijing (China)

    2014-06-15

    A supported liquid membrane with ionic liquid was used for the separation of toluene/cyclohexane. The interactions of ionic liquid with toluene and cyclohexane were calculated and experimentally studied by quantum chemical calculation and liquid-liquid extraction process. The results showed [BPy][BF{sub 4}] have stronger interaction with toluene than that with cyclohexane. The selectivity of SILM processes was larger than 10 at the temperature of 323 K and the flow rate of 13.5 mL·min{sup -1} on both shell side and lumen side. Due to the higher viscosity of IL, SILM process had good long-term stability. As the effects of mass transfer driving force of SILM process, the flux and removal efficiency increased with increase of initial toluene concentration, while the selectivity decreased because of the competitive transport. Base on the resistance in-series model and experimental results, the mass transfer resistance was mainly lay liquid membrane phase. The influence of flow rates on both sides was slight. The higher temperature could enhance the mass transfer performance significantly. The removal efficiency increased from 28.2% to 45.1% with the increasing of operation temperature from 298 K to 323 K.

  16. Plutonium Chemistry in the UREX Separation Processes

    International Nuclear Information System (INIS)

    Paulenova, Alena; Vandegrift, George F. III; Czerwinski, Kenneth R.

    2009-01-01

    The objective of the project is to examine the chemical speciation of plutonium in UREX+ (uranium/tributylphosphate) extraction processes for advanced fuel technology. Researchers will analyze the change in speciation using existing thermodynamics and kinetic computer codes to examine the speciation of plutonium in aqueous and organic phases. They will examine the different oxidation states of plutonium to find the relative distribution between the aqueous and organic phases under various conditions such as different concentrations of nitric acid, total nitrates, or actinide ions. They will also utilize techniques such as X-ray absorbance spectroscopy and small-angle neutron scattering for determining plutonium and uranium speciation in all separation stages. The project started in April 2005 and is scheduled for completion in March 2008.

  17. Cascade theory in isotopic separation processes

    International Nuclear Information System (INIS)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs

  18. Separation of isotopes by cyclical processes

    International Nuclear Information System (INIS)

    Hamrin, C.E. Jr.; Weaver, K.

    1976-01-01

    Various isotopes of hydrogen are separated by a cyclic sorption process in which a gas stream containing the isotopes is periodically passed through a high pressure column containing a palladium sorbent. A portion of the product from the high pressure column is passed through a second column at lower pressure to act as a purge. Before the sorbent in the high pressure column becomes saturated, the sequence is reversed with the stream flowing through the former low-pressure column now at high pressure, and a portion of the product purging the former high pressure column now at low pressure. The sequence is continued in cyclic manner with the product being enriched in a particular isotope

  19. Effect of template on chiral separation of phenylalanine using molecularly imprinted membrane in aqueous medium

    International Nuclear Information System (INIS)

    Haq, N.U.

    2014-01-01

    Wet phase inversion method was used to prepare L-Phenylalanine (L-Phe) and D-Phenylalanine (D-Phe) imprinted poly ((acrylonitrile)-co-(acrylic acid)) membranes for chiral separation. Ultrafiltration experiments were conducted to evaluate the chiral separation ability of the prepared membrane towards racemate aqueous solution of Phenylalanine. The continuous permselectivity was observed by novel membrane. The chiral resolution ability of L-Phe imprinted membrane was much better than that of D-Phe. It was observed that both membranes simultaneously, selectively reject, selectively adsorbed and selectively permeate solute. The achieved adsorption selectivities of L-Phe imprinted membrane (AlphaAds)L and D-Phe imprinted membrane (AlphaAds)D were 2.6 and 2.40 respectively. Permselectivity of L-Phe imprinted membrane (AlphaPerm)L was 2.56 while D-Phe imprinted membrane permselectivity (AlphaPerm)D was 2.03. The rejection selectivities of L-Phe and D-Phe imprinted membranes were (AlphaRej)L=0.32 and (AlphaRej)D =0.28 respectively. (author)

  20. Membrane separation using nano-pores; Nano poa wo riyoshita makubunri

    Energy Technology Data Exchange (ETDEWEB)

    Manabe, S. [Fukuoka Women`s Univ., Fukuoka (Japan)

    1995-08-01

    The membrane constituted by nano-pore only (NF membrane) is sold on the market recently as the membranes used for the matter separations in addition to the reverse osmosis membrane for changing seawater into fresh water, dialysis membrane used for artificial kidney, ultrafiltration membrane used for the separation and condensation of protein and the micro-filter used for removing microbe. It is possible for the membrane constituted by nano-pore to remove the virus with the size being from 20 to 300 nm. In this paper, the pore structure of NF membrane is explained, and then its application as the membrane for removing virus is described. Especially, it is possible for NF membrane to remove the virus with smallest size (parvovirus, etc.), prion albumen (bovine serum pathogen, etc.) and the special gene such as cancer, and it is further applied to the condensation and refining of virus and genes. The broader application of nano-pore to the control of the transportation of micro-particles in the future is expected. 3 refs., 2 figs.

  1. Cross-flow-assembled ultrathin and robust graphene oxide membranes for efficient molecule separation

    Science.gov (United States)

    Ying, Yulong; Ying, Wen; Guo, Yi; Peng, Xinsheng

    2018-04-01

    A graphene oxide (GO) membrane is promising for molecule separation. However, it is still a big challenge to achieve highly stable pristine GO membranes, especially in water. In this work, an ultrathin and robust GO membrane is assembled via the cross-flow method. The as-prepared 12 nm thick GO membrane (GOCF membrane) presents high stability with water permeance of 1505 ± 65 litres per hour per square meter per bar (LHM bar-1) and Evans Blue (EB) rejection of 98.7 ± 0.4%, 21-fold enhancement in water permeance compared with that of a pristine GO membrane (50-70 LHM bar-1) and 100 times higher than that of commercial ultrafiltration membranes (15 LHM.bar-1, GE2540F30, MWCO 1000, GE Co., Ltd) with similar rejection. Attributed to the surface cross-flow, the GO nanosheets will be refolded, crumpled, or wrinkled, resulting in a very strong inter-locking structure among the GO membrane, which significantly enhances the stability and facilitates their separation performance. This cross-flow assembling technique is also easily extended to assemble GO membranes onto other various backing filter supports. Based on the Donnan effect and size sieving mechanism, selective membrane separation of dyes with a similar molecular structure from their mixture (such as Rhodamine B (RhB) and Rose Bengal, and RhB and EB) are achieved with a selectivity of 133 ± 10 and 227 ± 15, respectively. Assembly of this ultrathin GO membrane with high stability and separation performance, via a simple cross-flow method, shows great potential for water purification.

  2. Atmospheric-pressure plasma activation and surface characterization on polyethylene membrane separator

    Science.gov (United States)

    Tseng, Yu-Chien; Li, Hsiao-Ling; Huang, Chun

    2017-01-01

    The surface hydrophilic activation of a polyethylene membrane separator was achieved using an atmospheric-pressure plasma jet. The surface of the atmospheric-pressure-plasma-treated membrane separator was found to be highly hydrophilic realized by adjusting the plasma power input. The variations in membrane separator chemical structure were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Chemical analysis showed newly formed carbonyl-containing groups and high surface concentrations of oxygen-containing species on the atmospheric-pressure-plasma-treated polymeric separator surface. It also showed that surface hydrophilicity primarily increased from the polar component after atmospheric-pressure plasma treatment. The surface and pore structures of the polyethylene membrane separator were examined by scanning electron microscopy, revealing a slight alteration in the pore structure. As a result of the incorporation of polar functionalities by atmospheric-pressure plasma activation, the electrolyte uptake and electrochemical impedance of the atmospheric-pressure-plasma-treated membrane separator improved. The investigational results show that the separator surface can be controlled by atmospheric-pressure plasma surface treatment to tailor the hydrophilicity and enhance the electrochemical performance of lithium ion batteries.

  3. Reverse osmosis performance of cellulose acetate membranes in the separation of uranium from dilute solutions

    International Nuclear Information System (INIS)

    Sastri, V.S.; Ashbrook, A.W.

    1976-01-01

    Batch 316-type cellulose acetate membranes were characterized in terms of pure water permeability constant, solute transport parameter, and mass transfer coefficient with a reference system of aqueous sodium chloride solution. These membranes were used in the determination of reverse osmosis characteristics such as product rate and solute separation in the case of uranium sulfate solutions of different concentrations (100 to 8000 ppM) in the feed solutions. A long-term test extending over a week has been carried out with dilute uranium solutions. Reverse osmosis treatment of synthetic mine water sample showed satisfactory performance of the membranes in the separation of metal ions

  4. Separation of metallic cations by means of coupled filtration on a ceramic membrane. Use of a complexing heteropolyanion

    International Nuclear Information System (INIS)

    Brun, Stephane

    1999-01-01

    In the field of the high level nuclear waste reprocessing, the Nuclear French Agency is currently carrying out studies on several processes (including the SESAME process) which aim at separating radioactive elements in order to dispose them specifically or to transmute them. One of these processes concerns the selective extraction of americium at an upper oxidation state than Ill. This work deals with the separation of Am(IV) from Ln(Ill) by means of complexation-coupled tangential filtration on alumina-titanium ceramic membranes. The chosen selective complexing agent is a lacunar heteropolyanion from the tungstophosphate family α_2P_2W_1_7O_6_1"1"0"-, which synthesis and various properties in solution have been studied. The polyanion stability in 0.5 M nitric solution strongly depends on the quality of the synthesised product. Two analytical techniques were developed to check the quality of the synthesised sets: "3"1P NMR and arsenazo-lanthanum complexometric titration. The separation studies on the cerium (IV)-neodymium (Ill) system were carried out to simulate americium(IV)/lanthanides(Ill) system. For the two alumina-titanium membranes studied (ultrafiltration and nano-filtration), the solvent flow can be described through a capillary mechanism which is characteristic of porous membranes. The ion transfer through the membranes, mainly governed by electrostatic interactions, strongly depends on the ionic strength at the membrane-solution interface. The best separation results, using nano-filtration, still remain below the expected performances, with a Ce(IV)/Nd(Ill) separation factor of 35 on a single stage in 0,5 M nitric medium. (author) [fr

  5. Achieving high permeability and enhanced selectivity for Angstrom-scale separations using artificial water channel membranes.

    Science.gov (United States)

    Shen, Yue-Xiao; Song, Woochul C; Barden, D Ryan; Ren, Tingwei; Lang, Chao; Feroz, Hasin; Henderson, Codey B; Saboe, Patrick O; Tsai, Daniel; Yan, Hengjing; Butler, Peter J; Bazan, Guillermo C; Phillip, William A; Hickey, Robert J; Cremer, Paul S; Vashisth, Harish; Kumar, Manish

    2018-06-12

    Synthetic polymer membranes, critical to diverse energy-efficient separations, are subject to permeability-selectivity trade-offs that decrease their overall efficacy. These trade-offs are due to structural variations (e.g., broad pore size distributions) in both nonporous membranes used for Angstrom-scale separations and porous membranes used for nano to micron-scale separations. Biological membranes utilize well-defined Angstrom-scale pores to provide exceptional transport properties and can be used as inspiration to overcome this trade-off. Here, we present a comprehensive demonstration of such a bioinspired approach based on pillar[5]arene artificial water channels, resulting in artificial water channel-based block copolymer membranes. These membranes have a sharp selectivity profile with a molecular weight cutoff of ~ 500 Da, a size range challenging to achieve with current membranes, while achieving a large improvement in permeability (~65 L m -2  h -1  bar -1  compared with 4-7 L m -2  h -1  bar -1 ) over similarly rated commercial membranes.

  6. Ionic Liquid Confined in Mesoporous Polymer Membrane with Improved Stability for CO2/N2 Separation

    Directory of Open Access Journals (Sweden)

    Ming Tan

    2017-09-01

    Full Text Available Supported ionic liquid membranes (SILMs have a promising prospect of application in flue gas separation, owing to its high permeability and selectivity of CO2. However, existing SILMs have the disadvantage of poor stability due to the loss of ionic liquid from the large pores of the macroporous support. In this study, a novel SILM with high stability was developed by confining ionic liquid in a mesoporous polymer membrane. First, a mesoporous polymer membrane derived from a soluble, low-molecular-weight phenolic resin precursor was deposited on a porous Al2O3 support, and then 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4] was immobilized inside mesopores of phenolic resin, forming the SILM under vacuum. Effects of trans-membrane pressure difference on the SILM separation performance were investigated by measuring the permeances of CO2 and N2. The SILM exhibits a high ideal CO2/N2 selectivity of 40, and an actual selectivity of approximately 25 in a mixed gas (50% CO2 and 50% N2 at a trans-membrane pressure difference of 2.5 bar. Compared to [emim][BF4] supported by polyethersulfone membrane with a pore size of around 0.45 μm, the [emim][BF4] confined in a mesoporous polymer membrane exhibits an improved stability, and its separation performance remained stable for 40 h under a trans-membrane pressure difference of 1.5 bar in a mixed gas before the measurement was intentionally stopped.

  7. Template-mediated synthesis of periodic membranes for improved liquid-phase separations

    International Nuclear Information System (INIS)

    Groger, H.

    1997-01-01

    Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis

  8. Template-mediated synthesis of periodic membranes for improved liquid-phase separations

    Energy Technology Data Exchange (ETDEWEB)

    Groger, H. [American Research Corp. of Virginia, Radford, VA (United States)

    1997-10-01

    Solid/liquid separations of particulates in waste streams will benefit from design and development of ultrafiltration (UF) membranes with uniform, tailorable pore size and chemical, thermal, and mechanical stability. Such membranes will perform solid/liquid separations with high selectivity, permeance, lifetime, and low operating costs. Existing organic and inorganic membrane materials do not adequately meet all these requirements. An innovative solution to the need for improved inorganic membranes is the application of mesoporous ceramics with narrow pore-size distributions and tailorable pore size (1.5 to 10 nm) that have recently been shown to form with the use of organic surfactant molecules and surfactant assemblies as removable templates. This series of porous ceramics, designated MCM-41, consists of silica or aluminosilicates distinguished by periodic arrays of uniform channels. In this Phase I Small Business Innovation Research program, American Research Corporation of Virginia will demonstrate the use of supported MCM-41 thin films deposited by a proprietary technique, as UF membranes. Technical objectives include deposition in thin, defect-free periodic mesoporous MCM-41 membranes on porous supports; measurement of membrane separation factors, permeance, and fouling; and measurement of membrane lifetime as part of an engineering and economic analysis.

  9. Liquid membrane process for uranium recovery

    International Nuclear Information System (INIS)

    Valint, P.L. Jr.

    1982-01-01

    An improved liquid membrane emulsion extraction process for recovering uranium from a WPPA feed solution containing uranyl cations wherein said feed is contacted with a water-in-oil emulsion which extracts and captures the uranium in the interior aqueous phase thereof, wherein the improvement comprises the presence of an alkane diphosphonic acid uranium complexing agent in the interior phase of the emulsion. This improvement results in greater extraction efficiency

  10. FABRICATION AND CHARACTERIZATION OF POLYIMIDE/POLYETHERSULFONE-FUMED SILICA MIXED MATRIX MEMBRANE FOR GAS SEPARATION

    Directory of Open Access Journals (Sweden)

    A. F. Ismail

    2012-01-01

    Full Text Available This study is performed primarily to investigate the feasibility of fumed silica as inorganic material towards gas separation performance of mixed matrix membrane. In this study, polyimide/polyethersulfone (PES-fumed silica mixed matrix membranes were casted using dry/wet technique. The results from the FESEM, DSC and FTIR analysis confirmed that the structure and physical properties of membrane is influenced by inorganic filler. FESEM’s cross-section view indicated good compatibility between polymer and fumed silica for all of range fumed silica used in this study. The gas separation performance of the mixed matrix membranes with fumed silica were relatively higher compared to that of the neat PI/PES membrane. PI/PES-fumed silica 5 wt% yielded significant selectivity enhancement of 7.21 and 40.47 for O2/N2, and CO2/CH4, respectively.

  11. A novel low cost polyvinyl alcohol-Nafion-borosilicate membrane separator for microbial fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, B.R. [Department of Civil Engineering, Indian Institute of Technology, Kharagpur, 721302 (India); Noori, Md.T. [Department of Agriculture and Food Engineering, Indian Institute of Technology, Kharagpur, 721302 (India); Ghangrekar, M.M., E-mail: ghangrekar@civil.iitkgp.ernet.in [Department of Civil Engineering, Indian Institute of Technology, Kharagpur, 721302 (India)

    2016-10-01

    Composite membranes were developed from PVA-borosilicate (MP) and PVA-Nafion-borosilicate (MPN) for application in microbial fuel cells (MFCs). The membranes were characterized in terms of water uptake, PBS uptake, oxygen diffusion and proton conductivity. Proton conductivity for MPN (0.07 Scm{sup −1}) was found to be higher as compared to that of MP (0.03 Scm{sup −1}). Oxygen diffusion coefficient for MPN was 1.47 fold lower than that for MP. As a result, MFC with PVA-Nafion-borosilicate membrane exhibited maximum power density of 6.8 Wm{sup −3}, which was 151% higher than the power produced by MFC having PVA-borosilicate membrane and it was comparable with MFC using Nafion 117 (7.1 Wm{sup −3}) membrane separator. This study demonstrates that borosilicate glass membrane incorporated with PVA-Nafion matrix can be a suitable alternative to costly polymeric membrane to increase power output of MFC. Using such membranes MFC can be fabricated at around 11 fold reduced cost as compared to Nafion 117. - Highlights: • Novel membranes using PVA and borosilicate composite were fabricated. • Proton diffusion for MPN was comparable with Nafion117. • MFC-PN produced power density comparable to MFC with Nafion 117 membrane. • MPN was fabricated at almost 11 times reduced cost than Nafion 117 membranes.

  12. Modelling carbon membranes for gas and isotope separation.

    Science.gov (United States)

    Jiao, Yan; Du, Aijun; Hankel, Marlies; Smith, Sean C

    2013-04-14

    Molecular modelling has become a useful and widely applied tool to investigate separation and diffusion behavior of gas molecules through nano-porous low dimensional carbon materials, including quasi-1D carbon nanotubes and 2D graphene-like carbon allotropes. These simulations provide detailed, molecular level information about the carbon framework structure as well as dynamics and mechanistic insights, i.e. size sieving, quantum sieving, and chemical affinity sieving. In this perspective, we revisit recent advances in this field and summarize separation mechanisms for multicomponent systems from kinetic and equilibrium molecular simulations, elucidating also anomalous diffusion effects induced by the confining pore structure and outlining perspectives for future directions in this field.

  13. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    KAUST Repository

    Hammami, Mohamed Amen

    2017-11-01

    Mixed Matrix Membranes (MMMs) have received worldwide attention during the last decades. This is due to the fact that the resulting materials can combine the good processability and low cost of polymer membranes with the diverse functionality, high performance and thermal properties of the fillers. This work explores the fabrication and application of MMMs. We focused on the design and fabrication of nanofillers to impart target functionality to the membrane for water treatment, protective coating and gas separation. This thesis is divided into three sections according to the application including: I- Water Treatment: This part is divided into three chapters, two related to the membrane distillation (MD) and one related to the oil spill. Three different nanofillers have been used: Periodic mesoporous organosilica (PMO), graphene and carbon nanotube (CNT). Those nanofillers were homogeneously incorporated into polyetherimide (PEI) electrospun nanofiber membranes. The doped nanoparticle not only improved the mechanical properties and thermal stability of the pristine fiber but also enhanced the MD and oil spill performance due to the functionality of those nanofillers. II- Protective coating: This part includes two chapters describing the design and the fabrication of a smart antibacterial and anti-corrosion coating. In the first project, we fabricated colloidal lysozyme-templated gold nanoclusters gating antimicrobial-loaded silica nanoparticles (MSN-AuNCs@lys) as nano-fillers in poly(ethylene oxide)/poly(butylene terephthalate) polymer matrix. MSN-AuNCs@lys dispersed homogeneously within the polymer matrix with zero NPs leaching. The system was coated on a common radiographic dental imaging device that is prone to oral bacteria contamination. This coating can successfully sense and inhibit bacterial contamination via a controlled release mechanism that is only triggered by bacteria. In the second project, the coaxial electrospinning approach has been applied to

  14. SEPARATION OF HAZARDOUS ORGANICS BY LOW PRESSURE REVERSE OSMOSIS MEMBRANES - PHASE II FINAL REPORT

    Science.gov (United States)

    Extensive experimental studies showed that thin-film, composite membranes can be used effectively for the separation of selected hazardous organic compounds. This waste treatment technique offers definite advantages in terms of high solute separations at low pressures (<2MPa) and...

  15. Hydrogen enrichment and separation from synthesis gas by the use of a membrane reactor

    International Nuclear Information System (INIS)

    Sanchez, J.M.; Barreiro, M.M.; Marono, M.

    2011-01-01

    One of the objectives of the CHRISGAS project was to study innovative gas separation and gas upgrading systems that have not been developed sufficiently yet to be tested at a demonstration scale within the time frame of the project, but which show some attractive merits and features for further development. In this framework CIEMAT studied, at bench scale, hydrogen enrichment and separation from syngas by the use of membranes and membrane catalytic reactors. In this paper results about hydrogen separation from synthesis gas by means of selective membranes are presented. Studies dealt with the evaluation of permeation and selectivity to hydrogen of prepared and pre-commercial Pd-based membranes. Whereas prepared membranes turned out to be non-selective, due to discontinuities of the palladium layer, studies conducted with the pre-commercial membrane showed that by means of a membrane reactor it is possible to completely separate hydrogen from the other gas components and produce pure hydrogen as a permeate stream, even in the case of complex reaction system (H 2 /CO/CO 2 /H 2 O) under WGS conditions gas mixtures. The advantages of using a water-gas shift membrane reactor (MR) over a traditional fixed bed reactor (TR) have also been studied. The experimental device included the pre-commercial Pd-based membrane and a commercial high temperature Fe-Cr-based, WGS catalyst, which was packed in the annulus between the membrane and the reactor outer shell. Results show that in the MR concept, removal of H 2 from the reaction side has a positive effect on WGS reaction, reaching higher CO conversion than in a traditional packed bed reactor at a given temperature. On increasing pressure on the reaction side permeation is enhanced and hence carbon monoxide conversion increases. -- Highlights: → H 2 enrichment and separation using a bench-scale membrane reactor MR is studied. → Permeation and selectivity to H 2 of Pd-based membranes was determined. → Complete separation

  16. Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

    Directory of Open Access Journals (Sweden)

    Byung-Sik Lee

    2015-12-01

    Full Text Available The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

  17. Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Sik [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

    2015-12-15

    The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst-Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

  18. Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

    Directory of Open Access Journals (Sweden)

    Orlov Alexey

    2016-01-01

    Full Text Available This article presents results of development of the mathematical model of nonstationary separation processes occurring in gas centrifuge cascades for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of germanium isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary separation processes in gas centrifuge cascades for separation of multicomponent isotope mixtures.

  19. Development of membrane moisture separator for BWR off-gas system

    International Nuclear Information System (INIS)

    Ogata, H.; Kawamura, S.; Kumasaka, M.; Nishikubo, M.

    2001-01-01

    In BWR plant off-gas treatment systems, dehumidifiers are used to maintain noble gas adsorption efficiency in the first half of the charcoal hold-up units. From the perspective of simplifying and reducing the cost of such a dehumidification system, Japanese BWR utilities and plant fabricators have been developing a dehumidification system employing moisture separation membrane of the type already proven in fields such as medical instrumentation and precision measuring apparatus. The first part of this development involved laboratory testing to simulate the conditions found in an actual off-gas system, the results of which demonstrated satisfactory results in terms of moisture separation capability and membrane durability, and suggested favorable prospects for application in actual off-gas systems. Further, in-plant testing to verify moisture separation capability and membrane durability in the presence of actual gases is currently underway, with results so far suggesting that the system is capable of obtaining good moisture separation capability. (author)

  20. Palladium alloy membrane process for the treatment of hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hongsuk; Paek, Seungwoo; Lee, Minsoo; Kim, Kwangrag; Yim, Sungpaal; Ahn, Dohee [KAERI, Daejeon (Korea, Republic of); Shim, Myunghwa [Univ. of Science and Technology, Daejeon (Korea, Republic of)

    2005-11-15

    Tritium is a radioactive isotope of hydrogen and it has a half-life of 12.3 years; it decays to He-3 by emitting a low energy beta radiation with an average energy of 5.7 keV and a maximum energy of 18.6 keV. Transfer of environmentally tritiated water to humans takes place via an inhalation, diffusion through the skin and ingestion. Radioactive waste containing tritium is continuously generated by the nuclear industry in, for example, nuclear reactor operations and a radioisotope production, as well as in medical research. Methods for removing tritium from liquid waste provide an alternative to the control of tritium emissions and a personnel exposure. A combined electrolysis and catalytic exchange process is a very effective method to remove small quantities of tritium from light or heavy waste water streams. The process consists of three main steps: (a) A front end step that exchanges the tritium to a less toxic hydrogen phase. This can be performed either through a chemical exchange in the presence of a platinum supported catalyst or through the decomposition of water. (b) A back end process that purifies the tritiated hydrogen gas which evolved from the electrolysis. This can be performed through a palladium alloy membrane separator. (c) A means of storing the concentrated gas safely. Uranium is used if the storage is temporary; titanium is usually employed for long term storage. To gain a better understanding of the tritiated hydrogen gas purification process, a mathematical model of the palladium alloy membrane has been used. This model is described herein, and the representative results of the model calculations are presented. The authors selected the palladium alloy membrane for the hydrogen purification process by considering the membrane properties, such as a chemical resistance, mechanical stability, thermal stability, high permeability, and a stable operation. The solution-diffusion model can be a useful tool for designing a membrane permeator. The