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Sample records for gas separation processes

  1. Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

    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.

  2. Gas stripping and recirculation process in heavy water separation plant

    Nazzer, D.B.; Thayer, V.R.

    1976-01-01

    Hydrogen sulfide is stripped from hot effluent, in a heavy water separation plant of the dual temperature isotope separation type, by taking liquid effluent from the hot tower before passage through the humidifier, passing the liquid through one or more throttle devices to flash-off the H 2 S gas content, and feeding the gas into an absorption tower containing incoming feed water, for recycling of the gas through the process

  3. Mathematical Modeling of Nonstationary Separation Processes in Gas Centrifuge Cascade for Separation of Multicomponent Isotope Mixtures

    Orlov Alexey; Ushakov Anton; Sovach Victor

    2016-01-01

    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 casca...

  4. Cooling process in separation devices of krypton gas

    Kimura, S; Sugimoto, K

    1975-06-11

    To prevent entry of impurities into purified gases and to detect leaks of heat exchanger in a separation and recovering device of krypton gas by means of liquefaction and distillation, an intermediate refrigerant having the same or slightly higher boiling point than that of gas to be cooled is used between the gas to be cooled (process gas) and refrigerant (nitrogen), and the pressure of the gas to be cooled is controlled to have a pressure higher than the intermediate refrigerant to cool the gas to be cooled.

  5. Glovebox atmosphere detritiation process using gas separation membranes

    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

  6. Gas separating

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  7. Gas-centrifuge unit and centrifugal process for isotope separation

    Stark, T.M.

    1979-01-01

    An invention involving a process and apparatus for isotope-separation applications such as uranium-isotope enrichment is disclosed which employs cascades of gas centrifuges. A preferred apparatus relates to an isotope-enrichment unit which includes a first group of cascades of gas centrifuges and an auxiliary cascade. Each cascade has an input, a light-fraction output, and a heavy-fraction output for separating a gaseous-mixture feed including a compound of a light nuclear isotope and a compound of a heavy nuclear isotope into light and heavy fractions respectively enriched and depleted in the light isotope. The cascades of the first group have at least one enriching stage and at least one stripping stage. The unit further includes means for introducing a gaseous-mixture feedstock into each input of the first group of cascades, means for withdrawing at least a portion of a product fraction from the light-fraction outputs of the first group of cascades, and means for withdrawing at least a portion of a waste fraction from the heavy-fraction outputs of the first group of cascades. The isotope-enrichment unit also includes a means for conveying a gaseous-mixture from a light-fraction output of a first cascade included in the first group to the input of the auxiliary cascade so that at least a portion of a light gaseous-mixture fraction produced by the first group of cascades is further separated into a light and a heavy fraction by the auxiliary cascade. At least a portion of a product fraction is withdrawn from the light fraction output of the auxiliary cascade. If the light-fraction output of the first cascade and the heavy-fraction output of the auxiliary cascade are reciprocal outputs, the concentraton of the light isotope in the heavy fraction produced by the auxiliary cascade essentially equals the concentration of the light isotope in the gaseous-mixture feedstock

  8. Reliability Omnipotent Analysis For First Stage Separator On The Separation Process Of Gas, Oil And Water

    Sony Tjahyani, D. T.; Ismu W, Puradwi; Asmara Santa, Sigit

    2001-01-01

    Reliability of industry can be evaluated based on two aspects which are risk and economic aspects. From these points, optimation value can be determined optimation value. Risk of the oil refinery process are fire and explosion, so assessment of this system must be done. One system of the oil refinery process is first stage separator which is used to separate gas, oil and water. Evaluation of reliability for first stage separator system has been done with FAMECA and HAZap method. The analysis results, the probability of fire and explosion of 1.1x10 - 2 3 /hour and 1.2x10 - 1 1 /hour, respectively. The reliability value of the system is high because each undesired event is anticipated with safety system or safety component

  9. Mathematical model of nonstationary hydraulic processes in gas centrifuge cascade for separation of multicomponent isotope mixtures

    Orlov, Aleksey Alekseevich; Ushakov, Anton; Sovach, Victor

    2017-01-01

    The article presents results of development of a mathematical model of nonstationary hydraulic processes in gas centrifuge cascade for separation of multicomponent isotope mixtures. This model was used for the calculation parameters of gas centrifuge cascade for separation of silicon isotopes. Comparison of obtained values with results of other authors revealed that developed mathematical model is adequate to describe nonstationary hydraulic processes in gas centrifuge cascades for separation...

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

    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)

  11. Application of gas hydrate formation in separation processes: A review of experimental studies

    Eslamimanesh, Ali; Mohammadi, Amir H.; Richon, Dominique; Naidoo, Paramespri; Ramjugernath, Deresh

    2012-01-01

    Highlights: ► Review of gas hydrate technology applied to separation processes. ► Gas hydrates have potential to be a future sustainable separation technology. ► More theoretical, simulation, and economic studies needed. - Abstract: There has been a dramatic increase in gas hydrate research over the last decade. Interestingly, the research has not focussed on only the inhibition of gas hydrate formation, which is of particular relevance to the petroleum industry, but has evolved into investigations on the promotion of hydrate formation as a potential novel separation technology. Gas hydrate formation as a separation technology shows tremendous potential, both from a physical feasibility (in terms of effecting difficult separations) as well as an envisaged lower energy utilization criterion. It is therefore a technology that should be considered as a future sustainable technology and will find wide application, possibly replacing a number of current commercial separation processes. In this article, we focus on presenting a brief description of the positive applications of clathrate hydrates and a comprehensive survey of experimental studies performed on separation processes using gas hydrate formation technology. Although many investigations have been undertaken on the positive application of gas hydrates to date, there is a need to perform more theoretical, experimental, and economic studies to clarify various aspects of separation processes using clathrate/semi-clathrate hydrate formation phenomena, and to conclusively prove its sustainability.

  12. Investigation of a Gas-Solid Separation Process for Cement Raw Meal

    Maarup, Claus; Hjuler, Klaus; Clement, Karsten

    2015-01-01

    The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation efficienc......The gas/solid heat exchanger (2D-HX), developed to replace the cyclone preheaters in cement plants is presented. This design aims at reducing construction height and operation costs. The separation process in the 2D-HX is experimentally investigated, and the results show that separation...

  13. Energy consumption estimation for greenhouse gas separation processes by clathrate hydrate formation

    Tajima, Hideo; Yamasaki, Akihiro; Kiyono, Fumio

    2004-01-01

    The process energy consumption was estimated for gas separation processes by the formation of clathrate hydrates. The separation process is based on the equilibrium partition of the components between the gaseous phase and the hydrate phase. The separation and capturing processes of greenhouse gases were examined in this study. The target components were hydrofluorocarbon (HFC-134a) from air, sulfur hexafluoride (SF 6 ) from nitrogen, and CO 2 from flue gas. Since these greenhouse gases would form hydrates under much lower pressure and higher temperature conditions than the accompanying components, the effective capturing of the greenhouse gases could be achieved by using hydrate formation. A model separation process for each gaseous mixture was designed from the basis of thermodynamics, and the process energy consumption was estimated. The obtained results were then compared with those for conventional separation processes such as liquefaction separation processes. For the recovery of SF 6 , the hydrate process is preferable to liquefaction process in terms of energy consumption. On the other hand, the liquefaction process consumes less energy than the hydrate process for the recovery of HFC-134a. The capturing of CO 2 by the hydrate process from a flue gas will consume a considerable amount of energy; mainly due to the extremely high pressure conditions required for hydrate formation. The influences of the operation conditions on the heat of hydrate formation were elucidated by sensitivity analysis. The hydrate processes for separating these greenhouse gases were evaluated in terms of reduction of global warming potential (GWP)

  14. Gas separation membrane module assembly

    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.

  15. Gas separation membranes

    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.

  16. Centrifugal gas separator

    Sakurai, M

    1970-03-27

    A centrifugal gas separator of a highly endurable construction and with improved gas sealing qualities utilizes a cylincrical elastic bellows or similar system in cooperation with a system of dynamic pressure operable gas seals as means for removing separated gases from the interior of the rotor drum, collecting the separated gases in their respective separated gas chambers defined by the corresponding bellows and their supporting stationary wall members, gas seals and rotor end caps, and means for discharging to the exterior of the surrounding cylindrical wall member the gaseous components from their respective separated gas chambers. In the vicinity of the rotary drum motor is a mixed gas chamber and means for providing the gas mixture along a co-axial passage into the rotary drum chamber. Orifices are bored into the end caps of the rotary drum to direct the separated gases into the aforementioned separated gas chambers which, through the action of the gas seals, freely slide upon the rotating drum to collect and thereafter discharge the thus separated gases. Therefore, according to the present invention, helium gas used to prevent separated gas remixture is unnecessary and, furthermore, the gas seals and elastic bellows means provide an air-tight seal superior to that of the contact sealing system of the former art.

  17. Centrifugal gas separator

    Sakurai, Mitsuo.

    1970-01-01

    A centrifugal gas separator of a highly endurable construction and with improved gas sealing qualities utilizes a cylincrical elastic bellows or similar system in cooperation with a system of dynamic pressure operable gas seals as means for removing separated gases from the interior of the rotor drum, collecting the separated gases in their respective separated gas chambers defined by the corresponding bellows and their supporting stationary wall members, gas seals and rotor end caps, and means for discharging to the exterior of the surrounding cylindrical wall member the gaseous components from their respective separated gas chambers. In the vicinity of the rotary drum motor is a mixed gas chamber and means for providing the gas mixture along a co-axial passage into the rotary drum chamber. Orifices are bored into the end caps of the rotary drum to direct the separated gases into the aforementioned separated gas chambers which, through the action of the gas seals, freely slide upon the rotating drum to collect and thereafter discharge the thus separated gases. Therefore, according to the present invention, helium gas used to prevent separated gas remixture is unnecessary and, furthermore, the gas seals and elastic bellows means provide an air-tight seal superior to that of the contact sealing system of the former art. (K.J. Owens)

  18. Gas separation with membranes

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

    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.

  20. Effect of inlet and outlet flow conditions on natural gas parameters in supersonic separation process.

    Yan Yang

    Full Text Available A supersonic separator has been introduced to remove water vapour from natural gas. The mechanisms of the upstream and downstream influences are not well understood for various flow conditions from the wellhead and the back pipelines. We used a computational model to investigate the effect of the inlet and outlet flow conditions on the supersonic separation process. We found that the shock wave was sensitive to the inlet or back pressure compared to the inlet temperature. The shock position shifted forward with a higher inlet or back pressure. It indicated that an increasing inlet pressure declined the pressure recovery capacity. Furthermore, the shock wave moved out of the diffuser when the ratio of the back pressure to the inlet one was greater than 0.75, in which the state of the low pressure and temperature was destroyed, resulting in the re-evaporation of the condensed liquids. Natural gas would be the subsonic flows in the whole supersonic separator, if the mass flow rate was less than the design value, and it could not reach the low pressure and temperature for the condensation and separation of the water vapor. These results suggested a guidance mechanism for natural gas supersonic separation in various flow conditions.

  1. Finite Element Modeling of Adsorption Processes for Gas Separation and Purification

    Humble, Paul H.; Williams, Richard M.; Hayes, James C.

    2009-01-01

    Pacific Northwest National Laboratory (PNNL) has expertise in the design and fabrication of automated radioxenon collection systems for nuclear explosion monitoring. In developing new systems there is an ever present need to reduce size, power consumption and complexity. Most of these systems have used adsorption based techniques for gas collection and/or concentration and purification. These processes include pressure swing adsorption, vacuum swing adsorption, temperature swing adsorption, gas chromatography and hybrid processes that combine elements of these techniques. To better understand these processes, and help with the development of improved hardware, a finite element software package (COMSOL Multiphysics) has been used to develop complex models of these adsorption based operations. The partial differential equations used include a mass balance for each gas species and adsorbed species along with a convection conduction energy balance equation. These equations in conjunction with multicomponent temperature dependent isotherm models are capable of simulating separation processes ranging from complex multibed PSA processes, and multicomponent temperature programmed gas chromatography, to simple two component temperature swing adsorption. These numerical simulations have been a valuable tool for assessing the capability of proposed processes and optimizing hardware and process parameters.

  2. Radioactive krypton gas separation

    Martin, J.R.

    1976-01-01

    Radioactive krypton is separated from a gas mixture comprising nitrogen and traces of carbon dioxide and radioactive krypton by selective adsorption and then cryogenic distillation of the prepurified gas against nitrogen liquid to produce krypton bottoms concentrate liquid, using the nitrogen gas from the distillation for two step purging of the adsorbent. 16 Claims, 8 Drawing Figures

  3. Centrifugal gas separator

    Kanagawa, A; Fujii, O; Nakamoto, H

    1970-03-09

    Counter currents in the rotary drum of a centrifugal gas separator are produced by providing, at either end of the drum in the vicinity of the circumferential and central positions, respectively, outflow and inflow holes with a communicating passage external to the drum there between whereby gaseous counter currents are caused to flow within the drum and travel through the passage which is provided with gas flow adjustment means. Furthermore, the space defined by the stationary portion of the passage and the rotor drum is additionally provided with a screw pump or throttling device at either its stationary side or drum side or both in order to produce a radially directed gas flow therewithin. A gas mixture is axially admitted into the drum while centrifugal force and a cooling element provided therebelow cause an increase in gas pressure along and a gaseous flow toward the wall member, whereupon the comparatively high pressured circumferentially distributed gas is extracted from the outlet holes, flows through the external gas passage and back into the lower pressured drum core through the inlet holes, thus producing the desired counter currents. The gases thus separated are withdrawn along axially provided discharge pipes. Accordingly, this invention permits heating elements which were formerly used to produce thermal convection currents to be disposed of and allows the length of the rotor drum to be more efficiently utilized to enhance separation efficiency.

  4. Relaxation phenomena in dense gas separation membranes

    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. Polymide gas separation membranes

    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.

  6. Detection of outliers by neural network on the gas centrifuge experimental data of isotopic separation process

    Andrade, Monica de Carvalho Vasconcelos

    2004-01-01

    This work presents and discusses the neural network technique aiming at the detection of outliers on a set of gas centrifuge isotope separation experimental data. In order to evaluate the application of this new technique, the result obtained of the detection is compared to the result of the statistical analysis combined with the cluster analysis. This method for the detection of outliers presents a considerable potential in the field of data analysis and it is at the same time easier and faster to use and requests very less knowledge of the physics involved in the process. This work established a procedure for detecting experiments which are suspect to contain gross errors inside a data set where the usual techniques for identification of these errors cannot be applied or its use/demands an excessively long work. (author)

  7. Separation parameters of gas centrifuges

    May, W.G.

    1977-01-01

    Early work on development of the gas centrifuge for separation of uranium isotopes has recently been reviewed. Several configurations were investigated. The preferred configuration eventually turned out to be a countercurrent centrifuge. In this form, an internal circulation is set up, and as a consequence, light isotope concentrates at one end of the centrifuge, heavy isotope at the other. In many ways the effect resembles the separation obtained in packed columns in the chemical and petroleum industries. It is the purpose of this paper to develop this analogy between countercurrent gas centrifuges and packed towers and to illustrate its usefulness in understanding the separation process in the centrifuge. 8 figures

  8. Some interesting developments relating to gas dynamics in the application of the UCOR process for isotope separation

    Alant, T.G.; Schumann, W.A.

    1980-01-01

    The separating element employed in the UCOR process for uranium enrichment has a very small cut, i.e. is highly asymmetrical with respect to the UF 6 flow in the enriched and depleted streams. For the commercial exploitation of the process, the so-called helikon technique of cascading was developed. The process is dependent on the transmission of parallel streams of diffferent isotopic composition through an axial compressor without significant mixing between them. A light gas (H 2 ), which is present in large molar excess, increases the flow velocity of the process gas (UF 6 ) and hence adds to improved separation performance. The separating element not only separates isotopes but also causes appreciable separation between the process gas and the light carrier gas. The paper consists of a brief description of the helikon cascading technique followed by a comprehensive assessment of the various aspects of gas mixing in an axial compressor. Phenomena of mole mass and pressure transients which occur in the module during run-up of the compressors are also discussed. The operating characteristics of axial compressors and of the separating element produce a driving force which tends to cause mole mass and associated pressure gradients to occur circumferentially in a helikon module under static conditions. The paper includes 5 references and 10 figures

  9. Method of gas separation

    Weltner, W.W.

    1980-01-01

    In order to separate a mixture of gases having widely different partial pressures at a given temperature, a chamber is employed. A batch of gas mixture is passed into the chamber. The walls of the chamber are cooled by a refrigerant which passes through coils in heat exchange relationship with the walls. By this means the temperature of the chamber is cooled to a temperature (and held at such temperature until equilibrium is reached) at which all the components of the gas mixture have changed state, at least one being solidified and at least one liquefied. The liquid constituents are removed first. Then the chamber is warmed to facilitate removal of the previously solidified constituents. In an example, the gas mixture comprises nitrogen, argon, krypton and xenon, and the walls of the chamber are cooled by liquid nitrogen, the argon and nitrogen being liquefied and the xenon and krypton being solidified. (author)

  10. Process and device for the adsorptive separation of krypton from a krypton/nitrogen gas mixture

    Ringel, H.; Messler, M.

    1985-01-01

    The gas mixture flows through an adsorption column, which is filled with a means of adsorbing Krypton and nitrogen. The adsorption column is desorbed after adsorption of the gas components by a gaseous flushing material, which flows through the adsorption column in the same direction as the gas mixture. In order to achieve a high degree of separation, the adsorption material is loaded with nitrogen and Krypton from the gas inlet, where Krypton is only absorbed over part of the length of the whole column by the adsorption material. The part of the length is such that on desorption of the adsorption column with the flushing material at first only nitrogen and later only Krypton is obtained at the outlet of the adsorption column. (Waste gas system of a reprocession plant). (orig./HP) [de

  11. Integration of biohydrogen fermentation and gas separation processes to recover and enrich hydrogen

    Bélafi-Bakó, K.; Búcsú, D.; Pientka, Zbyněk; Bálint, B.; Herbel, Z.; Kovács, K. L.; Wessling, M.

    2006-01-01

    Roč. 31, č. 11 (2006), s. 1490-1495 ISSN 0360-3199 R&D Projects: GA ČR GA203/06/1207 Institutional research plan: CEZ:AV0Z40500505 Keywords : integrated system * gas separation * polymer membranes Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.612, year: 2006

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

    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

    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. Isotope separation process

    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

  15. Isotope separation process

    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

  16. STUDY OF GAS SEPARATION PROCESS BY DYNAMIC ADSORPTION IN FIXED BED

    Ioan Solomon

    2010-10-01

    Full Text Available An experimental study of mass transfer at gas separation by dynamic adsorption in fixed bed of impregnated silica gel is presented in this work. By means of a mathematical model based on constants and coefficient easy to evaluate, the distributions of adsorbate concentration in gas and solid phases were determined as a function of time and throughout the height of the fixed bed, under isothermal conditions.With this aim, water vapors from air were adsorbed in a fixed bed of impregnated silica gel. The values of the volumetric mass transfer coefficient, Kv, were determined experimentally at several values of air superficial velocity, an air relative humidity of 69�20at 38 °C. The influence of the gas flow velocity and initial water concentration in adsorbent on the distribution of water concentration in both phases was established as a function of time and throughout the height of the fixed bed. The results obtained allow one to determination of the local adsorption rate.

  17. Isotope separation process

    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

  18. Isotope separation process

    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

  19. Mars Atmospheric Capture and Gas Separation

    Muscatello, Anthony; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

    2011-01-01

    The Mars atmospheric capture and gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure C02 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as welL To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from un-reacted carbon oxides (C02- CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3) carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include freezers, selective membranes, selective solvents, polymeric sorbents, zeolites, and new technologies. This paper and presentation will summarize the results of an extensive literature review and laboratory evaluations of candidate technologies for the capture and separation of C02 and other relevant gases.

  20. Gas separation membranes current status

    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

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

    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.

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

    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

  3. Separation of water through gas hydrate formation

    Boch Andersen, Torben; Thomsen, Kaj

    2009-01-01

    Gas hydrate is normally recognized as a troublemaker in the oil and gas industry. However, gas hydrate has some interesting possibilities when used in connection with separation of water. Nordic Sugar has investigated the possibility of using gas hydrates for concentration of sugar juice. The goal...... of the project was to formulate an alternative separation concept, which can replace the traditional water evaporation process in the sugar production. Work with the separation concept showed that gas hydrates can be used for water separation. The process is not suitable for sugar production because of large...... volumes and the needs for high pressure. The process could be interesting for concentration of heat sensitive, high value products...

  4. Separation of gas mixtures

    1981-01-01

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  5. Process for isotope separation

    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

  6. Isotope separation process

    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

  7. Process for separation of inert fission gases for waste gas of a reprocessing plant for nuclear fuel

    Schnez, H.

    1980-01-01

    The inert fission gases Kr and Xe released in the resolver and other waste gases are taken to an acid regeneration plant. Part of the inert fission gases is separated by compression, cooling and filtering and deposited. The other part flows back to the resolver as flushing gas so that a flushing gas circuit is formed, which prevents explosive gas mixtures occurring. (DG) [de

  8. Electrochemically Modulated Gas/Liquid Separation Technology for In Situ Resource Utilization Process Streams, Phase I

    National Aeronautics and Space Administration — In this phase I program MicroCell Technologies, LLC (MCT) proposes to demonstrate the feasibility of an electrochemically modulated phase separator for in situ...

  9. Hydrogen separation process

    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.

  10. Isotope separation process

    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

  11. Four-port gas separation membrane module assembly

    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.

  12. Energy Efficient Hybrid Gas Separation with Ionic Liquids

    Liu, Xinyan; Liang, Xiaodong; Gani, Rafiqul

    2017-01-01

    Shale gas, like natural gas, contains H2, CO2, CH4 and that light hydrocarbon gases needs processing to separate the gases for conversion to higher value products. Currently, distillation based separation is employed, which is energy intensive. Hybrid gas separation processes, combining absorption...... systems is established for process design-analysis. A strategy for hybrid gas separation process synthesis where distillation and IL-based absorption are employed for energy efficient gas processing is developed and its application is highlighted for a model shale gas processing case study....

  13. Tailoring MCM-41 mesoporous silica particles through modified sol-gel process for gas separation

    Sang, Wong Yean; Ching, Oh Pei

    2017-10-01

    Mobil Composition of Matter-41 (MCM-41) is recognized as a potential filler to enhance permeability of mixed matrix membrane (MMM). However, the required loading for available micron-sized MCM-41 was considerably high in order to achieve desired separation performance. In this work, reduced-size MCM-41 was synthesized to minimize filler loading, improve surface modification and enhance polymer-filler compatibility during membrane fabrication. The effect of reaction condition, stirring rate and type of post-synthesis washing solution used on particle diameter of resultant MCM-41 were investigated. It was found that MCM-41 produced at room temperature condition yield particles with smaller diameter, higher specific surface area and enhanced mesopore structure. Increase of stirring rate up to 500 rpm during synthesis also reduced the particle diameter. In addition, replacing water with methanol as the post-synthesis washing solution to remove bromide ions from the precipitate was able to further reduce the particle size by inhibiting polycondensation reaction.

  14. Phosphazene membranes for gas separations

    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.

  15. Gas separation using porous cement membrane.

    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.

  16. URANIUM SEPARATION PROCESS

    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)

  17. AKUT: a process for the separation of aerosols, krypton, and tritium from burner off-gas in HTR-fuel reprocessing

    Laser, M.; Barnert-Wiemer, H.; Beaujean, H.; Merz, E.; Vygen, H.

    1975-01-01

    The AKUT process consists of the following process steps: (1) aerosol retention by an electrostatic separator followed by HEPA filters, (2) oxidation of CO with O 2 or reaction of excess O 2 with CO, respectively, (3) compression, (4) scrubbing and/or liquefaction, (5) separation of krypton by distillation, and (6) separation of tritiated water and iodine by adsorption or chemical reaction. Liquefied off-gas with low permanent gas content resulting from graphite burning with oxygen may be distilled at ambient temperature. Off-gas with higher permanent gas content from burning with oxygen enriched air must be processed at lower temperature. The ambient temperature flow sheet is preferable from an economic as well as safety point of view. (U.S.)

  18. Isotope separation process

    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

  19. Industrial separation processes : fundamentals

    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,

  20. Isotope separation process

    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

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

    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.

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

    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.

  3. Isotope separation process

    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)

  4. Separation of uranium isotopes by gas centrifugation

    Jordan, I.

    1980-05-01

    The uranium isotope enrichment is studied by means of the countercurrent gas centrifuge driven by thermal convection. A description is given of (a) the transfer and purification of the uranium hexafluoride used as process gas in the present investigation; (b) the countercurrent centrifuge ZG3; (c) the system designed for the introduction and extraction of the process gas from the centrifuge; (d) the measurement of the process gas flow rate through the centrifuge; (e) the determination of the uranium isotopic abundance by mass spectrometry; (f) the operation and mechanical behavior of the centrifuge and (g) the isotope separation experiments, performed, respectively, at total reflux and with production of enriched material. The results from the separation experiments at total reflux are discussed in terms of the enrichment factor variation with the magnitude and flow profile of the countercurrent given by the temperature difference between the rotor covers. As far as the separation experiments with production are concerned, the discussion of their results is presented through the variation of the enrichment factor as a function of the flow rate, the observed asymmetry of the process and the calculated separative power of the centrifuge. (Author) [pt

  5. Noble gas separation methods for radioactivity retention in nuclear facilities

    Lehmer, W.; Schiller, H.

    1976-01-01

    The possibilities of applying process techniques in order to reduce gas-borne activity by means of different gas separation processes are looked at and their effectiveness are critically compared. (HP/LN) [de

  6. Process and apparatus for separating and recovering krypton-85 from exhaust gas of nuclear reactor or the like

    Yusa, H.; Kamiya, K.; Murata, T.; Yamaki, H.; Hisatomi, S.

    1975-01-01

    An apparatus is described for separating and recovering radioactive krypton-85 contained in an exhaust gas of a nuclear reactor or the like, which comprises a plurality of adsorption beds connected in parallel with respect to a passageway for the exhaust gas, each being packed with activated carbon, wherein adsorption and desorption of krypton-85 in each of the beds are alternatively and repeatedly performed by operating valves disposed between each of the beds and means for reducing pressure in the beds to be desorbed in accordance with a predetermined time schedule. The adsorption and concentration efficiencies are markedly increased by combining the above adsorption apparatus and a distillation apparatus

  7. Experimental study of multi-component separation by gas centrifuge

    Zhou, M.S.; Liang, X.W.; Chen, W.N.; Yin, Y.T.

    2006-01-01

    Stable isotopes are applied in many areas and most stable isotopes are multi-component, This paper presents experimental results of several stable isotopes separation conducted in Tsinghua University by using ultra-speed gas centrifuges. Xe, WF 6 , TeF 6 , SiHCl 3 , SiF 4 were chosen as the process gases. By adjusting some of the centrifuge's parameters, the suitable centrifuge parameters for different process gas separations were found and the overall unit separation factors γ 0 were obtained by means of single gas centrifuge separation. The experimental results show that with appropriate process gases, stable isotope separation by gas centrifuge was effective. (authors)

  8. Process for isotope separation

    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

  9. Anisotropic membranes for gas separation

    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.

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

    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

  11. Latest development on the membrane formation for gas separation

    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. Adsorption Model for Off-Gas Separation

    Veronica J. Rutledge

    2011-03-01

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed in gPROMS software. Inputs include gas stream constituents, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. It models dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions for a multiple component gas stream. The simulation outputs component concentrations along the column length as a function of time from which the breakthrough data is obtained. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data will be input into the adsorption model to develop a model specific for iodine adsorption on silver mordenite as well as model(s) specific for krypton and xenon adsorption. The model will be validated with experimental breakthrough curves. Another future off-gas modeling goal is to develop a model for the unit operation absorption. The off-gas models will be made available via the server or web for evaluation by customers.

  13. Zirconium isotope separation process

    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

  14. Radioactive gas processing device

    Kita, Kaoru; Minemoto, Masaki; Takezawa, Kazuaki; Okazaki, Akira; Kumagaya, Koji.

    1982-01-01

    Purpose: To simplify the structure of a gas processing system which has hitherto been much complicated by the recyclic use of molecular sieve regeneration gas, by enabling to release the regeneration gas to outside in a once-through manner. Constitution: The system comprises a cooler for receiving and cooling gases to be processed containing radioactive rare gases, moisture-removing pipelines each connected in parallel to the exit of the cooler and having switching valves and a moisture removing column disposed between the valves and a charcoal absorber in communication with the moisture removing pipelines. Pipelines for flowing regeneration heating gases are separately connected to the moisture removing columns, and molecular sieve is charged in the moisture removing column by the amount depending on the types of the radioactive rare gases. (Aizawa, K.)

  15. Reduction of emission when applying thermal separation processes in the dismantling of nuclear facilities - oxy-fuel gas and plasma arc cutting

    Stoiber, H.; Hammer, G.; Schultz, H.

    1995-01-01

    Plasma arc cutting and laser beam cutting was used for the studies with the goal of significantly reducing material emission by changing the operating and equipment parameters. Some separations using the oxy-fuel gas cutting process served the purpose of providing a guide for determining which factors can most effectively reduce emission. The separation experiments were carried out with specimens of R-St 37-2, 10 mm thick, as well as of X 6 CrNi 18 10 steel 5, 10, 15 and 20 mm thick. In all cases, lowering speed and the amount of gas proved at first to be effective measures to check material emission. It was also possible to achieve adherence of molten mass and slag on the flank of the joint with excessive icicling. When the plasma separates the CrNi steel, it is possible to increase emission reduction additionally by using an argon/hydrogen mixture instead of nitrogen as a cutting gas. (orig./DG) [de

  16. Polymeric Gas-Separation Membranes for Petroleum Refining

    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.

  17. Laser isotope separation process

    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

  18. Gas separation techniques in nuclear facilities

    Hioki, Hideaki; Morisue, Tetsuo; Ohno, Masayoshi

    1983-01-01

    The literatures concerning the gas separation techniques which are applied to the waste gases generated from nuclear power plants and nuclear fuel reprocessing plants, uranium enrichment and the instrumentation of nuclear facilities are reviewed. The gas permeability and gas separation performance of membranes are discussed in terms of rare gas separation. The investigation into the change of the gas permeability and mechanical properties of membranes with exposure to radiation is reported. The theoretical investigation of the separating cells used for the separation of rare gas and the development of various separating cells are described, and the theoretical and experimental investigations concerning rare gas separation using cascades are described. The application of membrane method to nuclear facilities is explained showing the examples of uranium enrichment, the treatment of waste gases from nuclear reactor buildings and nuclear fuel reprocessing plants, the monitoring of low level β-emitters in stacks, the detection of failed fuels and the detection of water leak in fast breeder reactors. (Yoshitake, I.)

  19. Novel silica membranes for high temperature gas separations

    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.

  20. Process for separating radioactive gases

    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.)

  1. Isotope separation process

    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

  2. Analysis of an integrated cryogenic air separation unit, oxy-combustion carbon dioxide power cycle and liquefied natural gas regasification process by exergoeconomic method

    Mehrpooya, Mehdi; Zonouz, Masood Jalali

    2017-01-01

    Highlights: • Exergoeconomic analyses is done on an integrated cryogenic air separation unit. • Liquefied natural gas cold energy is used in the process. • The main multi stream heat exchanger is the worst device based on the results. - Abstract: Exergoeconomic and sensitivity analyses are performed on the integrated cryogenic air separation unit, oxy-combustion Carbon dioxide power cycle and liquefied natural gas regasification process. Exergy destruction, exergy efficiency, cost rate of exergy destruction, cost rate of capital investment and operating and maintenance, exergoeconomic factor and relative cost difference have been calculated for the major components of the process. The exergy efficiency of the process is around 67.1% and after mixers, tees, tank and expansion valves the multi-stream heat exchanger H-3 have the best exergy efficiency among all process components. Total exergy destruction rate of the process is 1.93 × 10"7 kW. Results of exergoeconomic analysis demonstrates that maximum exergy destruction and capital investment operating and maintenance cost rate are related to the multi-stream heat exchanger H-1 and pump P-1 with the values of 335,144 ($/h) and 12,838 ($/h), respectively. In the sensitivity analysis section the effects of the varying economic parameters, such as interest rate and plant life time are investigated on the trend of the capital investment operating and maintenance cost rate of the major components of the process and in another cases the effect of the gas turbine isentropic efficiency on the exergy and exergoeconomic parameters are studied.

  3. New processes for uranium isotope separation

    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

  4. Method for improved gas-solids separation

    Kusik, C.L.; He, B.X.

    1990-11-13

    Methods are disclosed for the removal of particulate solids from a gas stream at high separation efficiency, including the removal of submicron size particles. The apparatus includes a cyclone separator type of device which contains an axially mounted perforated cylindrical hollow rotor. The rotor is rotated at high velocity in the same direction as the flow of an input particle-laden gas stream to thereby cause enhanced separation of particulate matter from the gas stream in the cylindrical annular space between the rotor and the sidewall of the cyclone vessel. Substantially particle-free gas passes through the perforated surface of the spinning rotor and into the hollow rotor, from where it is discharged out of the top of the apparatus. Separated particulates are removed from the bottom of the vessel. 4 figs.

  5. A Sensitive Method Approach for Chromatographic Analysis of Gas Streams in Separation Processes Based on Columns Packed with an Adsorbent Material

    I. A. A. C. Esteves

    2016-01-01

    Full Text Available A sensitive method was developed and experimentally validated for the in-line analysis and quantification of gaseous feed and product streams of separation processes under research and development based on column chromatography. The analysis uses a specific mass spectrometry method coupled to engineering processes, such as Pressure Swing Adsorption (PSA and Simulated Moving Bed (SMB, which are examples of popular continuous separation technologies that can be used in applications such as natural gas and biogas purifications or carbon dioxide sequestration. These processes employ column adsorption equilibria on adsorbent materials, thus requiring real-time gas stream composition quantification. For this assay, an internal standard is assumed and a single-point calibration is used in a simple mixture-specific algorithm. The accuracy of the method was found to be between 0.01% and 0.25% (-mol for mixtures of CO2, CH4, and N2, tested as case-studies. This makes the method feasible for streams with quality control levels that can be used as a standard monitoring and analyzing procedure.

  6. Separation process using microchannel technology

    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.

  7. Method of separation of gas mixtures

    Berlin, M.A.; Potapov, V.F.; Potapova, M.S.

    1980-04-05

    Gas mixtures are separated in a rectification tower by repeated counterflow contact of the heated gas flow and cool condensate as the pressure drops in each stage of separation (StR) and when condensate is added from StR with lower pressure to the StR with higher pressure. In order to reduce energy consumption noncondensing gas in amounts of 5-15 percent by weight of the amount of incoming gases are added. Hydrocarbon or carbon dioxide gas can be used as the latter. Example. To separate natural gas of the Shatlyk deposit of composition, percent by mo1: C1 -- 94.960; C2 -- 4.260; C3 -- 0.200; C4 -- 0.08; C4+B -- 0.51. It is enriched with carbon dioxide gas in an amount of 10 percent by weight. Upon rectification of the enriched hydrocarbon mixture separation is achieved at lower pressures of the gas mixture and less cold. This leads to reduction of energy consumption by 10-12 percent.

  8. A general model for membrane-based separation processes

    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...

  9. Heavy Water - Industrial Separation Processes

    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

  10. Exhaust gas processing facility

    Terada, Shin-ichi.

    1995-01-01

    The facility of the present invention comprises a radioactive liquid storage vessel, an exhaust gas dehumidifying device for dehumidifying gases exhausted from the vessel and an exhaust gas processing device for reducing radioactive materials in the exhaust gases. A purified gas line is disposed to the radioactive liquid storage vessel for purging exhaust gases generated from the radioactive liquid, then dehumidified and condensed liquid is recovered, and exhaust gases are discharged through an exhaust gas pipe disposed downstream of the exhaust gas processing device. With such procedures, the scale of the exhaust gas processing facility can be reduced and exhaust gases can be processed efficiently. (T.M.)

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

    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

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

    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

  13. Efficient separations & processing crosscutting program

    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.

  14. Evaluation of Mars CO2 Capture and Gas Separation Technologies

    Muscatello, Anthony C.; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

    2011-01-01

    Recent national policy statements have established that the ultimate destination of NASA's human exploration program is Mars. In Situ Resource Utilization (ISRU) is a key technology required to ,enable such missions and it is appropriate to review progress in this area and continue to advance the systems required to produce rocket propellant, oxygen, and other consumables on Mars using the carbon dioxide atmosphere and other potential resources. The Mars Atmospheric Capture and Gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure CO2 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as well. To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from unreacted carbon oxides (C02-CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3)/carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include' freezers, selective membranes, selective solvents, polymeric sorbents

  15. Noble gas separation with the use of inorganic adsorbents

    Pence, D.T.; Chou, C.C.; Christian, J.D.; Paplawsky, W.J.

    1979-01-01

    A noble gas separation process is proposed for application to airborne nuclear fuel reprocessing plant effluents. The process involves the use of inorganic adsorbents for the removal of contaminant gases and noble gas separation through selective adsorption. Water and carbon dioxide are removed with selected zeolites that do not appreciably adsorb the noble gases. Xenon is essentially quantitatively removed with a specially developed adsorbent using conventional adsorption-desorption techniques. Oxygen is removed to low ppM levels by the use of a rapid cycle adsorption technique on a special adsorbent leaving a krypton-nitrogen mixture. Krypton is separated from nitrogen with a special adsorbent operated at about -80 0 C. Because the separation process does not require high pressures and oxygen is readily removed to sufficiently limit ozone formation to insignificant levels, appreciable capital and operating cost savings with this process are possible compared with other proposed processes. In addition, the proposed process is safer to operate

  16. Metal oxide membranes for gas separation

    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.

  17. Electro/powder separation process

    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

  18. INS gas-filled recoil isotope separator

    Miyatake, M.; Nomura, T.; Kawakami, H.

    1986-09-01

    The characteristics and performance of a small sized gas-filled recoil isotope separator recently made at INS are described. The total efficiency and the ΔBρ/Bρ values have been measured using low velocity 16 O, 40 Ar and 68 As ions and found to be 10 and 5 %, respectively. The Z-dependence of the mean charge is discussed. (author)

  19. Pump Propels Liquid And Gas Separately

    Harvey, Andrew; Demler, Roger

    1993-01-01

    Design for pump that handles mixtures of liquid and gas efficiently. Containing only one rotor, pump is combination of centrifuge, pitot pump, and blower. Applications include turbomachinery in powerplants and superchargers in automobile engines. Efficiencies lower than those achieved in separate components. Nevertheless, design is practical and results in low consumption of power.

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

    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)

  1. Tangential inlet supersonic separators: a novel apparatus for gas purification

    Wen, Chuang; Walther, Jens Honore; Yang, Yan

    2016-01-01

    A novel supersonic separator with a tangential inlet is designed to remove the condensable components from gas mixtures. The dynamic parameters of natural gas in the supersonic separation process are numerically calculated using the Reynolds stress turbulence model with the Peng-Robinson real gas...... be generated by the tangential inlet, and it increases to the maximum of 200 m/s at the nozzle throat due to decrease of the nozzle area of the converging part. The tangential velocity can maintain the value of about 160 m/s at the nozzle exit, and correspondingly generates the centrifugal acceleration of 3...

  2. Preparation of hollow fiber membranes for gas separation

    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

  3. Method of separating radioactive krypton gas

    Kimura, Shigeru; Awada, Yoshihisa.

    1975-01-01

    Object: To effectively and safely separate and recover Kr-85, which requires a long storage period for attenuating radioactivity, from a mixture gas consisting of Kr-85 and Xe by a liquefaction distillation method. Structure: A mixture gas consisting of Kr and Xe is subjected to heat exchange in a cooler with Freon gas from a plurality of distillation towers for its temperature reduction from normal temperature to a lower temperature, and then it is supplied to a distillation tower. The distillation tower is held at a pressure above 15 ata, preferably around 20 ata, and a condenser provided at the top of the distillation tower is furnished with Freon as cooling medium. The rare mixture gas is distilled by liquefaction within a distillation tower, and Kr-85 is obtained from a top duct while obtaining Xe from a bottom duct. Xe after separation by liquefaction is returned to a rare mixture gas supply inlet of a liquefaction distillation means for repeated refinement in the distillation tower. (Kamimura, M.)

  4. FFTF gas processing systems

    Halverson, T.G.

    1977-01-01

    The design and operation of the two radioactive gas processing systems at the Fast Flux Test Facility (FFTF) exemplifies the concept that will be used in the first generation of Liquid Metal Fast Breeder Reactors (LMFBR's). The two systems, the Radioactive Argon Processing System (RAPS) and the Cell Atmosphere Processing System (CAPS), process the argon and nitrogen used in the FFTF for cover gas on liquid metal systems and as inert atmospheres in steel lined cells housing sodium equipment. The RAPS specifically processes the argon cover gas from the reactor coolant system, providing for decontamination and eventual reuse. The CAPS processes radioactive gasses from inerted cells and other liquid metal cover gas systems, providing for decontamination and ultimate discharge to the atmosphere. The cryogenic processing of waste gas by both systems is described

  5. Polymeric molecular sieve membranes for gas separation

    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.

  6. Optimization of the gas chromatographic separations

    Gasco Sanchez, L.

    1973-01-01

    A review and a critical study on the optimization of the gas chromatographic separations are made. After dealing with the fundamental gas chromatographic equations, some methods of expressing column performances are discussed: performance indices, performance parameters, resolution and effective plate number per unit time. This is completed with a comparative study on performances of various types of columns. Moreover, optimization methods for operating chromatographic conditions are extensively dealt with: as resolution optimization, separation time, and normalization techniques for the time of analysis in order to achieve the maximum resolution at constant time. Finally, some others non operating parameters such as: selectivity of stationary phases, column preparation and optimization methods by means of computers are studied. (Author) 68 refs

  7. Gas processing device

    Kobayashi, Yoshihiro; Seki, Eiji.

    1991-01-01

    State of electric discharge is detected based on a gas pressure in a sealed container and a discharging current flowing between both of electrodes. When electric arc discharges occur, introduction of gases to be processed is stopped and a voltage applied to both of the electrodes is interrupted. Then, when the gas pressure in the sealed container is lowered to a predetermined value, a power source voltage is applied again to both of the electrodes to recover glow discharges, and the introduction of the gas to be processed is started. With such steps, even if electric arc discharges occur, they are eliminated automatically and, accordingly, normal glow discharges can be recovered, to prevent failures of the device due to electric arc discharges. The glow discharges are recovered automatically without stopping the operation of the gas processing device, and gas injection and solidification processing can be conducted continuously and stably. (T.M.)

  8. TBP degradation products. Separation and gas-chromatographic determination

    Kuada, T.A.; Alem, C.M.; Matsuda, H.T.; Araujo, B.F. de; Araujo, J.A de.

    1991-11-01

    A separation method for di butylphosphate, mono butylphosphate and phosphoric acid as degradation products in organic and aqueous streams of the process containing variable amounts of actinides and fission products is described. The products were separated by extraction and after methylation the final determination was carried out by gas chromatography. TPP was used as internal standard and 5 to 500 mg/L concentration range was determined with 1 to 10% deviation depending on the concentration of organo phosphates. (author)

  9. Causal and causally separable processes

    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.

  10. Causal and causally separable processes

    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)

  11. Gas recovery process

    Schmidt, W.B.; Lewis, W.W.; Edmiston, A.; Klauser, G.

    1980-01-01

    In order to decontaminate a gas stream containing radioactive krypton, a preliminary step of removing oxygen and oxides of nitrogen by catalytic reaction with hydrogen is performed. The gas stream is then passed serially through a drier, a carbon dioxide adsorber and a xenon adsorber to remove sequentially water, CO 2 and xenon therefrom. The gas exiting the xenon adsorber is passed to a krypton recovery plant wherein krypton is concentrated to a first level in a primary distillation column by contact with a reflux liquid in a packed section of the column. The liquid and vapour collecting at the bottom of the column is passed to a separator in which the liquid is separated from the vapour. The liquid is partially evaporated in a vessel to increase concentration thereof and is brought to a concentration of approximately 90 mole % or greater in a second distillation column thereby enabling efficient storage of a radioactive krypton product. (author)

  12. Gas storage and separation by electric field swing adsorption

    Currier, Robert P; Obrey, Stephen J; Devlin, David J; Sansinena, Jose Maria

    2013-05-28

    Gases are stored, separated, and/or concentrated. An electric field is applied across a porous dielectric adsorbent material. A gas component from a gas mixture may be selectively separated inside the energized dielectric. Gas is stored in the energized dielectric for as long as the dielectric is energized. The energized dielectric selectively separates, or concentrates, a gas component of the gas mixture. When the potential is removed, gas from inside the dielectric is released.

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

    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

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

    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.)

  15. Gas separation by pressure swing adsorption

    Martin, J.R.; Gottzman, C.F.; Notaro, F.; Stewart, H.A.

    1986-01-01

    Over the past twenty years separation processes based upon pressure swing adsorption have replaced cryogenic processes in a number of selected applications such as air separation for production of moderate quantities of nitrogen and oxygen and recovery of hydrogen from refinery and chemical plant gases. Key events contributing to the emergence of PSA as an important process option have been the development of synthetic zeolite molecular sieves by Union Carbide Corporation in the USA and of carbon molecular sieves by Bergbau-Forschung in Germany. Today PSA processes enjoy significant commercial use producing oxygen from 0.1 Nm 3 /h for medical application to 1500 Nm 3 /h for steel mill use, for making nitrogen up to 1000 Nm 3 /h for inerting and in purifying hydrogen streams of up to 100,000 Nm 3 /h for refinery use. In this paper some of the principles of adsorptive separations are reviewed. The history of the technology is traced briefly with emphasis on key material, process and application events. The major commercial processes in the application of adsorption to bulk separation of air and hydrogen purification are reviewed in more detail with comparisons made to cryogenic alternatives in terms of specific characteristics, advantages and disadvantages where appropriate. Information on performance, reliability and comparative economics are discussed where available

  16. Stabilized ultrathin liquid membranes for gas separations

    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

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

    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

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

    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.

  19. Multiple-isotope separation in gas centrifuge

    Wood, Houston G.; Mason, T.C.; Soubbaramayer

    1996-01-01

    In previous works, the Onsager's pancake equation was used to provide solution to the internal counter-current flow field, which is necessary to calculate solutions to the isotope transport equation. The diffusion coefficient was assumed to be constant which is a good approximation for gases with large molecular weights, and small differences in the molecular weights of the various isotopes. A new optimization strategy was presented for determining the operating parameters of a gas centrifuge to be used for multiple-component isotope separation. Scoop drag, linear wall temperature gradient, the feed rate ant the cut have been chosen as operating parameters for the optimization. The investigation was restricted to a single centrifuge, and the problem of cascading for multiple-isotope separation was not addressed. The model describing the flow and separation phenomena in centrifuge includes a set of equations describing the fluid dynamics of the counter-current flow and the diffusion equations written for each isotope of the mixture. In this paper, an optimization algorithm is described and applied to an example for the re enrichment of spent reactor uranium

  20. Flue Gas Desulphurization Processes

    Aly, A.I.M.; Halhouli, K.A.; Abu-Ashur, B.M.

    1999-01-01

    Flue gas desulphurization process are discussed. These processes can be grouped into non-regenerable systems and regenerable systems. The non-regenerable systems produce a product which is either disposed of as waste or sold as a by-product e.g. lime/limestone process. While in the regenerable systems, e.g. Wellman-Lord process, the SO 2 is regenerated from the sorbent(sodium sulphite), which is returned to absorb more SO 2 . Also a newer technology for flue gas desulphurization is discussed. The Ispra process uses bromine as oxidant, producing HBr, from which bromine is regenerated by electrolysis. The only by-products of this process are sulphuric acid and hydrogen, which are both valuable products, and no waste products are produced. Suggested modifications on the process are made based on experimental investigations to improve the efficiency of the process and to reduce its costs

  1. Separation of krypton from dissolver off-gas of a reprocessing plant using preparative gas chromatography

    Matoni, M.

    1984-02-01

    Kr-85 can be separated from the pre-purified purge air in the final processing step of the purification phase for dissolver off-gases of a reprocessing plant with the aid of preparative gas chromatography. Activated carbon adsorbers in combination with helium as carrier gas permits maximum gas mixture through-flow. A separation temperature of 30 0 C is considered optimal. An adsorbent volume of 40 dm 3 is necessary for processing the residual gas flow of 2.5 Nm 3 /h; the adsorbent is divided between 2 columns linked in series each of which are 2 m long with an internal diameter of 100 mm. The helium flow required is five times greater than the off-gas flow. The degree of purity for krypton is greater than 90% for a decontamination factor of greater than 1000. (orig./HP) [de

  2. Separative performance transients in a gas centrifuge

    Olander, D.R.

    1979-01-01

    A general method has been developed to calculate the behavior of the exit compositions from a gas centrifuge under unsteady conditions. The method utilizes the basic enrichment gradient equations derived by Cohen, which, in this case, contain time derivatives of the partial 235 U inventories. These partial differential equations are converted to ordinary differential equations by a linear approximation to the axial concentration distribution for use in the inventory terms only. With this simplification, analytical solution is possible for the feed concentration transient. The transient driven by a change in the feed flow rate, however, requires numerical solution. For analysis of ideal cascades in the unsteady state, the transient flow and separation characteristics of the centrifuge must be combined with total uranium and 235 U material balances on each stage

  3. Immobilized fluid membranes for gas separation

    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. Hypercrosslinked Additives for Ageless Gas-Separation Membranes.

    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.

  5. Separation of a light additive gas by separation nozzle cascades

    Becker, E.; Bley, P.; Ehrfeld, W.; Fritz, W.; Steinhaus, H.

    1984-01-01

    Double-turn separation nozzles, in comparison with single-turn separation nozzles, offer much greater advantages in the separation of UF6 and H2 than in the separation of the U isotopes, for which the double-turn separation nozzles were conceived. By using a double-turn separation-nozzle stage as a preseparation stage in combination with a low-temperature separator, one can reduce the ratio of the buffer input stream to the product stream, in contrast with the solution used up to this time, with only a slight increase in cost of about an order of magnitude. The control program in the case of return feeding of the UF6 from the buffer and the danger of production losses connected with it are thereby correspondingly diminished. An example is given of the enrichment of 235U using the title facility with UF6. (orig./PW)

  6. Use of separating nozzles or ultra-centrifuges for obtaining helium from gas mixtures containing helium

    Reimann, T.

    1987-01-01

    To obtain helium from gas mixtures containing helium, particularly from natural gas, it is proposed to match the dimensions of the separation devices for a ratio of the molecular weights to be separated of 4:1 of more, which ensures a higher separation factor and therefore a smaller number of separation stages to be connected in series. The process should make reasonably priced separation of helium possible. (orig./HP) [de

  7. Application of gas chromatography in hydrogen isotope separation

    Ye Xiaoqiu; Sang Ge; Peng Lixia; Xue Yan; Cao Wei

    2008-01-01

    The principle of gas chromatographic separation of hydrogen isotopes was briefly introduced. The main technology and their development of separating hydrogen isotopes, including elution chromatography, hydrogen-displacement chromatography, self-displacement chromatography and frontal chromatography were discussed in detail. The prospect of hydrogen isotope separation by gas chromatography was presented. (authors)

  8. Gas ultracentrifuge separative parameters modeling using hybrid neural networks

    Crus, Maria Ursulina de Lima

    2005-01-01

    A hybrid neural network is developed for the calculation of the separative performance of an ultracentrifuge. A feed forward neural network is trained to estimate the internal flow parameters of a gas ultracentrifuge, and then these parameters are applied in the diffusion equation. For this study, a 573 experimental data set is used to establish the relation between the separative performance and the controlled variables. The process control variables considered are: the feed flow rate F, the cut θ and the product pressure Pp. The mechanical arrangements consider the radial waste scoop dimension, the rotating baffle size D s and the axial feed location Z E . The methodology was validated through the comparison of the calculated separative performance with experimental values. This methodology may be applied to other processes, just by adapting the phenomenological procedures. (author)

  9. Have oil and gas prices got separated?

    Erdős, Péter

    2012-01-01

    This paper applies vector error correction models that show that oil and natural gas prices decoupled around 2009. Before 2009, US and UK gas prices had a long-term equilibrium with crude prices to which gas prices always reverted after exogenous shocks. Both US and UK gas prices adjusted to the crude oil price individually, and departure from the equilibrium gas price on one continent resulted in a similar departure on the other. After an exogenous shock, the adjustment between US and UK gas prices took approximately 20 weeks on average, and the convergence was mediated mainly by crude oil with a necessary condition that arbitrage across the Atlantic was possible. After 2009, however, the UK gas price has remained integrated with oil price, but the US gas price decoupled from crude oil price and the European gas price, as the Atlantic arbitrage has halted. The oversupply from shale gas production has not been mitigated by North American export, as there has been no liquefying and export capacity. - Highlights: ► VEC models are applied to investigate the relationship between oil and natural gas prices. ► While natural gas prices in Europe and Asia react to oil price, US gas price decoupled from oil in 2009. ► Since 2009, the US gas price has decoupled from the European and Asian gas prices.

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

    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.

  11. Aerospace gas/liquid separator for terrestrial applications

    Mondt, J.F.

    1996-01-01

    The space gas/liquid separator, a key component in the heat transport subsystem of a space reactor power system, was developed to remove helium gas from liquid lithium in zero gravity. Helium is generated from lithium irradiation in the reactor core and would reach saturation in lithium after 48 hours of full power operations. The gas/liquid separator is also applicable for large commercial powerplants to deaerate the water before and after the feedwater heaters. Another terrestrial application is for industrial companies to use the gas/liquid separator and wet chemistry to remove all the gases from the air and only discharge clean air to the atmosphere. An additional application that resulted from this gas/liquid separator technology, was separating liquid carbon dioxide from nitrogen. This application is opposite from the space application in that it is removing a liquid from a gas rather than a gas from a liquid

  12. Process gas solidification system

    1980-01-01

    A process for withdrawing gaseous UF 6 from a first system and directing same into a second system for converting the gas to liquid UF 6 at an elevated temperature, additionally including the step of withdrawing the resulting liquid UF 6 from the second system, subjecting it to a specified sequence of flash-evaporation, cooling and solidification operations, and storing it as a solid in a plurality of storage vessels. (author)

  13. Intrinsically Microporous Polymer Membranes for High Performance Gas Separation

    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

  14. Separation processes, I: Azeotropic rectification

    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.

  15. Separation process for boron isotopes

    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.

  16. Qualification of a novel deepwater gas / liquid separator

    Abrand, Stephanie

    2010-07-01

    The implementation of subsea boosting and processing systems is becoming a common development scheme for the development of deep and ultra-deep water fields. Those subsea processing systems shall address the mechanical and functional constraints that are imposed by the deepwater installation and operation along with the obvious reliability requirements. Saipem has developed a deepwater gas separation and liquid boosting system that encompasses a good flexibility in handling a wide range of steady and unsteady multiphase input streams and a relatively simple mechanical arrangement. The system is composed of an array of vertical pipes that contributes in providing the required separation and liquid hold up volumes. The reduced diameter and wall thickness of the vertical pipes, as compared with the equivalent single separation vessel, is particularly suited in deep and ultra-deep water applications and/or high pressure services. Furthermore, the system relies on the gravity separation whose efficiency is ensured by its ability to accommodate large variety of input flowrate and un-steady regimes. In the continuous effort of providing reliable and proven process solutions to the market, Saipem has undertaken a qualification program focused to characterise and demonstrate the system versatility and separation performances, that will involve model testing in multiphase conditions. (Author)

  17. Gas isotope separation method using plasma sheet

    Takayama, K.; Takagi, K.; Fukvi, R.

    1988-03-01

    A high frequency electric field is applied to a plasma sheet with a frequency equal to the cyclotronic frequency of the ions to be separated. Because of resonance the cyclotronic radius of the isotope has increased and the electric charge is eliminated by collision with a separator and the isotope is separated in neutral particles [fr

  18. Oil/gas collector/separator for underwater oil leaks

    Henning, C.D.

    1992-12-31

    This invention is comprised of an oil/gas collector/separator for recovery of oil leaking, for example, from an offshore or underwater oil well. The separator is floated over the point of the leak and tethered in place so as to receive oil/gas floating, or forced under pressure, toward the water surface from either a broken or leaking oil well casing, line, or sunken ship. The separator is provided with a downwardly extending skirt to contain the oil/gas which floats or is forced upward into a dome wherein the gas is separated from the oil/water, with the gas being flared (burned) at the top of the dome, and the oil is separated from water and pumped to a point of use. Since the density of oil is less than that of water it can be easily separated from any water entering the dome.

  19. Separation of isotopes by cyclical processes

    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

  20. PROJECT OF POLLUTANTS SEPARATOR FROM THE GAS STATION

    Barbara Kościelnik

    2016-06-01

    Full Text Available Oily wastewater are dangerous for the environment, because they can contaminate ground water or surface, which can lead to contamination of the biosystem or poisoning of humans and animals. The treatment plant of this kind may include petroleum products or substances derived from natural gas, crude oil, asphalt or natural wax. Of course, in the wastewater oily you cannot forget about vegetable oils used in catering. Waste water of this type to be cleaned are subjected to the following processes: flotation, sedimentation, filtration, flowing out, thermal methods, biodegradation, adsorption or chemical and thermal methods to destabilize the emulsion. The aim of this study was to design a separator pollution from the gas station. We present the investment and operating costs. In designing the system chosen individual process units based on the requirements of the quality of wastewater specified in PN - EU 858.

  1. Effect of geometric parameters of liquid-gas separator units on phase separation performance

    Mo, Songping; Chen, Xueqing; Chen, Ying [Guangdong University of Technology, Seoul (China); Yang, Zhen [Tsinghua University, Beijing (China)

    2015-07-15

    Five liquid-gas separator units were designed and constructed based on a new concept of a validated high-performance condenser. Each separator unit consists of two united T-junctions and an apertured baffle. The separator units have different header diameters or different baffles with different diameters of the liquid-gas separation hole. The phase separation characteristics of the units were investigated at inlet air superficial velocities from 1.0m/s to 33.0m/s and water superficial velocities from 0.0015 m/s to 0..50 m/s. The experimental results showed that the liquid height, liquid flow rate through the separation hole, and liquid separation efficiency increased with increased header diameter and decreased diameter of the separation hole. The geometric structures of the separator units affected the phase separation characteristics by influencing the liquid height in the header and the liquid flow rate through the separation hole.

  2. Separative power of an optimised concurrent gas centrifuge

    Bogovalov, Sergey; Boman, Vladimir [National Research Nuclear University (MEPHI), Moscow (Russian Federation)

    2016-06-15

    The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s)2(300 K/T)(L/1 m) kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  3. Numerical investigation of gas separation in T-junction

    Pao, William; Hashim, Fakhruldin M.; Ming, Low Huei

    2015-05-01

    T-junctions are commonly used in distributing two-phase flow by piping networks especially in oil and gas industries. Understanding the behavior of two-phase flow through a T-junction is very important as it has significant effect on the operation, maintenance and efficiency of the components downstream from the junction. The objective of this paper is to determine the effect of ratio of side arm to main arm diameters, initial inlet gas saturation and gas density variation on passive separation performance in T-junction. Via computational fluid dynamics tool, preliminary investigation found that separation efficiency is proportional to diameter ratio in between 0.5-0.75. Beyond diameter ratio 0.75, there is a flattening of separation efficiency. The change of fraction of gas taken off is inversely proportional to initial inlet gas saturation and the trend is almost inversely linear for diameter ratio 0.5. Beyond that, the relationship between initial inlet gas saturation and separation efficiency exhibits mild non-linearity behavior. For diameter ratios 0.75-1.0, the fraction of gas taken off is almost similar as far as the initial gas saturation is concerned. Gas density affects phase separation efficiency when the initial gas saturation is low. Interestingly, the effects of the inlet flow velocity and gravity distribution is almost negligible relative to the mass split ratio, side to main arm diameter ratio, initial gas saturation and density differential.

  4. Fabrication of Separator Demonstration Facility process vessel

    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

  5. Intrinsically Microporous Polymer Membranes for High Performance Gas Separation

    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

  6. Process and component for isotope separation

    Girodin, M.G.H.

    1974-01-01

    The description is given of a component for isotope separation by static centrifugation, the characteristic of which is that the gas, of single chemical composition, in other words without a diluting gas mixture, passes into a sonic collar then into a symmetrical supersonic diffuser where it acquires a uniform and rectilinear velocity above or very much above the speed of sound before going into its curved trajectory [fr

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

    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.

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

    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.

  9. Radioactive waste gas processing systems

    Kita, Kaoru; Minemoto, Masaki; Takezawa, Kazuaki.

    1981-01-01

    Purpose: To effectively separate and remove only hydrogen from hydrogen gas-containing radioactive waste gases produced from nuclear power plants without using large scaled facilities. Constitution: From hydrogen gas-enriched waste gases which contain radioactive rare gases (Kr, Xe) sent from the volume control tank of a chemical volume control system, only the hydrogen is separated in a hydrogen separator using palladium alloy membrane and rare gases are concentrated, volume-decreased and then stored. In this case, an activated carbon adsorption device is connected at its inlet to the radioactive gas outlet of the hydrogen separator and opened at its outlet to external atmosphere. In this system, while only the hydrogen gas permeates through the palladium alloy membrane, other gases are introduced, without permeation, into the activated carbon adsorption device. Then, the radioactive rare gases are decayed by the adsorption on the activated carbon and then released to the external atmosphere. (Furukawa, Y.)

  10. Multicomponent Matrimid Membrane for Gas Separation

    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.

  11. Condensed Rotational Separation to upgrade sour gas

    Brouwers, J.J.H.; Kemenade, van H.P.

    2010-01-01

    A steadily increasing amount of newly located natural gas fields is severely contaminated with CO2 and/or H2S. Percentages of 30 % CO2/H2S or even larger are not uncommon. Fields with such high degrees of contaminant can not be economically exploited by conventional techniques based on amine

  12. Simplified simulation of multicomponent isotope separation by gas centrifuge

    Guo Zhixiong; Ying Chuntong

    1995-01-01

    The expressions of diffusion equation for multicomponent isotope separation by gas centrifuge are derived by utilizing the simplified diffusion transport vector. A method of radial averaging which was restricted to a binary mixture is extended to multicomponent isotope mixtures by using an iterative scheme. A numerical analysis of tetradic UF 6 or SF 6 gas isotope separation by centrifuge is discussed when a special model of velocity distribution is given. The dependence of mutual separation factor for the components on their molecular weights' difference is obtained. Some aspects of the given model of gas fluid are also discussed

  13. GAS SEPARATION MEMBRANES COMPRISING PERMEABILITY ENHANCING ADDITIVES

    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

  14. The gas filled separator as a separation method to detect transuranic elements

    Ninov, V.

    1992-08-01

    The mass spectrometer NASE (NAchSEparator) built as a post-separator and located behind the velocity filter SHIP at the GSI in Darmstadt, was taken into operation as a gas-filled separator, and its separation properties for fusion products from heavy ion reactions were studied. Chapter 2 describes the principle of separation in a gas-filled magnet. The technical specifications of the separator, the detectors and the setup of detection electronics are outlined in chapter 3. The studies of separation properties are described in chapter 4, and chapter 5 deals with preliminary applications of the gas-filled separator to detect isotopes poor in neutrons, with an atomic number Z = 92, 93. Chapter 6 is concerned with preliminary tests to detect heavy nuclei with an atomic number Z > = 100 by means of light radiation and actinide targets. The experimental results of comparative measurements between the velocity filter SHIP and the gas-filled separator are pointed out in chapter 7, and future application possibilities of gas-filled separators for synthesis of heaviest nuclei through asymmetric reactions are discussed. (orig./BBR) [de

  15. Gas-chromatographic separation of hydrogen isotopic mixtures

    Preda, Anisoara; Bidica, Nicolae

    2005-01-01

    Full text: Gas chromatographic separation of hydrogen isotopes have been reported in the literature since late of 1950's. Gas chromatography is primarily an analytical method, but because of its properties it may be used in many other fields with excellent results. A simple method is proposed for the gas-chromatographic analysis of complex gas mixtures containing hydrogen isotopes; the method is based on the substantial difference in the thermal conductivity of these isotopes. One of the main disadvantages of the conventional gas chromatography is the long retention times required for the analysis of hydrogen gas mixtures while the column is operated at very low temperature. The method described in this paper was based on using a capillary molecular sieve 5A column operated for this kind of separation at 173 K. The carrier gas was Ne and the detector was TCD. In the paper chromatograms for various carrier flow rates and various hydrogen isotope mixtures are presented. (authors)

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

    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

  17. The Efficient Separations and Processing Integrated Program

    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

  18. WATER-GAS SHIFT WITH INTEGRATED HYDROGEN SEPARATION; A

    Maria Flytzani-Stephanopoulos; Jerry Meldon; Xiaomei Qi

    2001-01-01

    Optimization of the water-gas shift (WGS) reaction system for hydrogen production for fuel cells is of particular interest to the energy industry. To this end, it is desirable to couple the WGS reaction to hydrogen separation using a semi-permeable membrane, with both processes carried out at high temperature to improve reaction kinetics. Reduced equilibrium conversion of the WGS reaction at high temperatures is overcome by product H(sub 2) removal via the membrane. This project involves fundamental research and development of novel cerium oxide-based catalysts for the water-gas-shift reaction and the integration of these catalysts with Pd-alloy H(sub 2)-separation membranes supplying high purity hydrogen for fuel cell use. Conditions matching the requirements of coal gasifier-exit gas streams will be examined in the project. In the first year of the project, we prepared a series of nanostructured Cu- and Fe-containing ceria catalysts by a special gelation/precipitation technique followed by air calcination at 650 C. Each sample was characterized by ICP for elemental composition analysis, BET-N2 desorption for surface area measurement, and by temperature-programmed reduction in H(sub 2) to evaluate catalyst reducibility. Screening WGS tests with catalyst powders were conducted in a flow microreactor at temperatures in the range of 200-550 C. On the basis of both activity and stability of catalysts in simulated coal gas, and in CO(sub 2)-rich gases, a Cu-CeO(sub 2) catalyst formulation was selected for further study in this project. Details from the catalyst development and testing work are given in this report. Also in this report, we present H(sub 2) permeation data collected with unsupported flat membranes of pure Pd and Pd-alloys over a wide temperature window

  19. Gas manufacture, processes for: condensers

    Young, W

    1876-11-29

    In the production of illuminating gas from coal, shale, hydrocarbon oil, or other substance used in the production of gas, the volatile products inside the retort are agitated by means of moving pistons or jets of compressed gas, steam, or vapor in order to decompose them into permanent gases, and in some cases to increase the volume of gas by the decomposition of the injected gas, etc. or by blending or carburetting this gas with the decomposition products of the volatile matters. To separate the condensible hydrocarbons from the crude gas it is passed through heated narrow tortuous passages or is caused to impinge on surfaces. If the crude gases are cold these surfaces are heated and vice versa.

  20. Gas Separation Ability of the Liquid Bubble Film.

    Řezníčková Čermáková, Jiřina; Petričkovič, Roman; Vejražka, Jiří; Setničková, Kateřina; Uchytil, Petr

    2016-01-01

    Roč. 166, JUN 22 (2016), s. 26-33 ISSN 1383-5866 Institutional support: RVO:67985858 Keywords : liquid film membrane * bubble * gas separation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  1. Liquid absorbent solutions for separating nitrogen from natural gas

    Friesen, Dwayne T.; Babcock, Walter C.; Edlund, David J.; Lyon, David K.; Miller, Warren K.

    2000-01-01

    Nitrogen-absorbing and -desorbing compositions, novel ligands and transition metal complexes, and methods of using the same, which are useful for the selective separation of nitrogen from other gases, especially natural gas.

  2. Amine-oxide hybrid materials for acid gas separations

    Bollini, Praveen; Didas, Stephanie A.; Jones, Christopher W.

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams

  3. Gas treatment processes for keeping the environment of nuclear plants free from gas-borne activity

    Schiller, H.

    1977-01-01

    The separation processes in gas treatment steps for the decontamination of circuit or offgas streams are described and their practicability is evaluated. Examples of the effectiveness of gas separation plants for keeping the environment within and without nuclear plants free from harmful gas-borne activity are presented. (orig.) [de

  4. Emergency gas processing device

    Taruishi, Yoshiaki; Sasaki, Susumu.

    1984-01-01

    Purpose: To enable the reduction of radioactive substances released out of reactor buildings irrespective of the aging change in the buildings. Constitution: There are provided an exhaust gas flow channel for cleaning contaminated airs within a reactor building by way of a series of filters and exhausting the cleaned airs by means of exhaust fans to the outside and a gas recycling flow channel having a cooler in connection with the exhaust gas flow channel at a position downstream of the exhaust fans for returning the cleaned airs in the exhaust gas flow channel to the inside of the reactor buildings. The pressure difference between the outside and the inside of the reactor buildings is made constant by controlling the air flow channel within the gas recycling flow channel by a flow control valve. The airs cleaned by the series of the filters are recycled to the inside of the buildings to decrease the radioactive substance within the buildings. (Horiuchi, T.)

  5. Method and apparatus for isotope separation from a gas stream

    Szoke, A.

    1978-01-01

    A method and apparatus are described for isotope separation and in particular for separating the desired isotope from the gas in which it is contained by irradiating it with a laser. The laser selectively provides kinetic energy to the isotope through inelastic events, monomolecular or bimolecular, in order to cause it to segregate within or fly out of the gas stream in which it is contained

  6. Numerical optimization for separation power of gas centrifuge

    Jiang Dongjun; Zeng Shi; Liu Bing

    2012-01-01

    In order to obtain higher separation power of the gas centrifuge, the code was developed to solve the flow-field of the counter-current to acquire the separation power, which was integrated with the iSight software, so a numerical optimization model for separation power was presented, in which the driver conditions and the geometry parameters of the waste baffle were optimized to get the maximum separation power using the sequential quadratic programming arithmetic, and the 12% higher results was acquired, which shows the feasibility of this method. The results also note that the separation power of gas centrifuge is sensitive to the driver conditions and the structure parameters of the waste baffle, so it is necessary to perform the optimization calculation for the certain gas centrifuge model. (authors)

  7. Development of new microporous silica membranes for gas separation

    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)

  8. Functionalized inorganic membranes for gas separation

    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.

  9. Gas processing industrial hygiene needs

    D'Orsie, S.M.

    1992-01-01

    Handling of gases and natural gas liquids provides many opportunities for workers to be exposed to adverse chemical and physical agents. A brief overview of common hazards found in the processing of gas and natural gas liquids is presented in this paper. Suggestions on how an employer can obtain assistance in evaluating his workplace are also presented.presented

  10. Gas-Liquid Separator design of SWRPRS in PGSFR

    Yoon, Jung; Lee, Tae-ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    There is the Sodium-Water Reaction Pressure Relief System (SWRPRS) in PGSFR to prevent the Sodium- Water Reaction (SWR) due to the break of the steam generator tube. The piping to atmosphere includes several components such as gasliquid separator, backpressure rupture disk, and hydrogen igniter. Among these components, gas-liquid separator separates the liquid sodium which is included in gas SWR products not to react sodium and air. In this study, the size of gas-liquid separator, which is based on the hydrogen volume which is exhausted in the sodium dump tank, is determined. To determine the gas-liquid separator for the separation of gas and sodium particle dumped the SDT, Stairmand's model which has high performance among standard cyclone separator models is selected. The body diameter is determined, and other dimensions are determined due to the ratio about the body diameter. Shepherd and Lapple's model is selected as the pressure drop calculation model considering the conservation.

  11. Substituted polynorbornenes as promising materials for gas separation membranes

    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.

  12. Novel silica membranes for high temperature gas separations

    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

  13. Niobia-silica and silica membranes for gas separation

    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

  14. Optimisation énergétique des procédés de séparation en raffinage et en traitement de gaz naturel Optimal Use of Energy in Separation Processes for Refining and Natural Gas Treatment

    Rojey A.

    2006-11-01

    Full Text Available Cet article présente une méthode d'optimisation des procédés de séparation basée sur une analyse thermodynamique. Cette analyse s'appuie sur un bilan exergétique qui est établi dans le cas général d'un système quelconque opérant en régime permanent. Les facteurs qui conditionnent le rendement exergétique d'un procédé de séparation sont ensuite examinés. Il en résulte une méthode d'optimisation basée sur une réduction des irréversibilités thermodynamiques. Des exemples concrets d'application en raffinage et en traitement de gaz naturel sont présentés, et on montre comment cette analyse peut déboucher sur la conception de procédés innovants. The optimization of separation units in refining and natural-gas processing must take into consideration new needs and constraints that may seem incompatible. New installations must be designed not only on the basis of energy optimization but also by seeking to minimize investments and to respect new rules concerning environmental protection. The optimization described in this article is based on a thermodynamic analysis of different material and energy exchanges, The energybalance provides a suitable basis for making this analysis. It leads to the defining of an exergy efficiency that is all the higher as the thermodynamic irreversibilities are reduced, and that tends toward one for an ideal reversible system. For a separation process, a separation exergyterm is defined that correspond to the minimum separation work . Distillation is the basic separation operation. The exergy efficiency of this operation is low, and we show that, even in a relatively favorable cas, it is no greater than a value of about 6%. For an atmospheric distillation operation of crude oil, the exergy efficiency is about 4%. This overall exergy efficiency is the product of an external exergy efficiency and an internal exergy efficiency. The external exergy efficiency can be improved by better thermal

  15. Gas Separation in the Ranque-Hilsch Vortex tube

    Linderstrøm-Lang, C. U.

    1964-01-01

    The gas separation taking place in the vortex tube is studied in detail. Both enrichment and depletion of a given component in any one of the two resultant streams may take place; the sign of this separation effect depends on certain parameters, notably the hot to cold flow ratio. A comparison...

  16. Amine-oxide hybrid materials for acid gas separations

    Bollini, Praveen

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams. In particular, these materials are being extensively studied for the adsorption of CO 2 from simulated flue gas streams, with an eye towards utilizing these materials as part of a post-combustion carbon capture process at large flue gas producing installations, such as coal-fired electricity-generating power plants. In this Application Article, the utilization of amine-modified organic-inorganic hybrid materials is discussed, focusing on important attributes of the materials, such as (i) CO 2 adsorption capacities, (ii) adsorption and desorption kinetics, and (iii) material stability, that will determine if these materials may one day be useful adsorbents in practical CO 2 capture applications. Specific research needs and limitations associated with the current body of work are identified. © 2011 The Royal Society of Chemistry.

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

    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)

  18. Computational simulation of the blood separation process.

    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.

  19. Synthesis of Zeolite Materials for Noble Gas Separation

    Achey, R.; Rivera, O.; Wellons, M.; Hunter, D.

    2017-01-01

    Microporous zeolite adsorbent materials are widely used as a medium for separating gases. Adsorbent gas separation systems can run at ambient temperature and require minimal pressure to flow the input gas stream across the adsorbent bed. This allows for low energy consumption relative to other types of separation systems. Specific zeolites also have a high capacity and selectivity for the gases of interest, leading to compact and efficient separation systems. These characteristics are particularly advantageous for the application of signatures detection for non-proliferation, which often requires portable systems with low power draw. Savannah River National Laboratory currently is the leader in using zeolites for noble gas sampling for non-proliferation detection platforms. However, there is a constant customer need for improved sampling capabilities. Development of improved zeolite materials will lead to improved sampling technology. Microwave-assisted and conventional hydrothermal synthesis have been used to make a variety of zeolites tailored for noble gas separation. Materials characterization data collected in this project has been used to help guide the synthesis of improved zeolite materials. Candidate materials have been down-selected based on highest available surface area, maximum overall capacity for gas adsorption and highest selectivity. The creation of improved adsorbent materials initiated in this project will lead to development of more compact, efficient and effective noble gas collectors and concentrators. The work performed in this project will be used as a foundation for funding proposals for further material development as well as possible industrial applications.

  20. Synthesis of Zeolite Materials for Noble Gas Separation

    Achey, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Rivera, O. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wellons, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hunter, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-02

    Microporous zeolite adsorbent materials are widely used as a medium for separating gases. Adsorbent gas separation systems can run at ambient temperature and require minimal pressure to flow the input gas stream across the adsorbent bed. This allows for low energy consumption relative to other types of separation systems. Specific zeolites also have a high capacity and selectivity for the gases of interest, leading to compact and efficient separation systems. These characteristics are particularly advantageous for the application of signatures detection for non-proliferation, which often requires portable systems with low power draw. Savannah River National Laboratory currently is the leader in using zeolites for noble gas sampling for non-proliferation detection platforms. However, there is a constant customer need for improved sampling capabilities. Development of improved zeolite materials will lead to improved sampling technology. Microwave-assisted and conventional hydrothermal synthesis have been used to make a variety of zeolites tailored for noble gas separation. Materials characterization data collected in this project has been used to help guide the synthesis of improved zeolite materials. Candidate materials have been down-selected based on highest available surface area, maximum overall capacity for gas adsorption and highest selectivity. The creation of improved adsorbent materials initiated in this project will lead to development of more compact, efficient and effective noble gas collectors and concentrators. The work performed in this project will be used as a foundation for funding proposals for further material development as well as possible industrial applications.

  1. Development of high purity CO gas recovery system for BOF gas by modified PSA process

    Sakuraya, Toshikazu; Fujii, Tetsuya; Yaji, Motoyasu; Matsuki, Takao; Matsui, Shigeo; Hayashi, Shigeki

    1985-01-01

    COPISA process (where two processes for separating CO-adsorptive gases and desorbing desorption-difficult gas are added to conventional PSA gas separation process) is outlined. In two units of PSA, CO/sub 2/ gas is adsorbed and separated in first PSA unit. The gas excluding CO/sub 2/ is fed to second PSA unit, where CO is adsorbed and separated from N/sub 2/ and H/sub 2/, and then desorbed and recovered under reduced pressure. For optimizing the process, a pilot plant was operated for about 1000 hrs. in a half year. The results confirm possibility of simplifying pre-treatment of coal gas. CO-PSA pressure swing pattern suitable for elimination of Co-adsorptive N/sub 2/ is established. Recovery of CO gas is enhanced. Optimization of gas flow pattern between adsorption towers required for reduction in operating cost is performed. (7 figs, 1 tab, 8 refs)

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

    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.

  3. Noble gas absorption process

    Thomas, J.W.

    1975-01-01

    A method of removing a noble gas from air comprising the use of activated carbon filters in stages in which absorption and desorption steps in succession are conducted in order to increase the capacity of the filters is described. (U.S.)

  4. High mass isotope separation process and arrangement

    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

  5. Sustainable development of gree solvent separation process

    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...

  6. Ceramic membrane technologies for gas separation

    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

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

    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.)

  8. Lasers for isotope separation processes and their properties

    George, E.V.; Krupke, W.F.

    1976-08-01

    The laser system requirements for isotope enrichment are presented in the context of an atomic uranium vapor process. Coherently pumped dye lasers using as the pump laser either the frequency doubled Nd:YAG or copper vapor are seen to be quite promising for meeting the near term requirements of a laser isotope separation (LIS) process. The utility of electrical discharge excitation of the rare gas halogens in an LIS context is discussed

  9. Separation process of zirconium and hafnium

    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

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

    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.

  11. Oil/gas collector/separator for underwater oil leaks

    Henning, C.D.

    1993-01-01

    An oil/gas collector/separator for underwater oil leaks is described comprising: a cylindrical tank; a hollow float member for supporting said tank in a substantially upright position; a skirt assembly secured to said hollow float member and extending in a direction away from said float member opposite said tank; means for removing oil from said tank; and means for removing gas from said tank

  12. Basic research on nuclear track microfilters for gas separation

    Sudowe, R; Ensinger, W; Vetter, J; Penzhorn, R D; Brandt, R

    1999-01-01

    Basic research on nuclear track microfilters, NTMF, made from the polyimide foil UPILEX, has been carried out to investigate the possible use of NTMF for gas separation in an environment containing large amounts of tritium. NTMF with a pore diameter as low as 0.1 mu m have been etched and metal replicas of the pores have been produced to determine the pore shape. An experimental setup for determining the separation factor of a NTMF for a given gas mixture has been constructed, and first experiments have been carried out.

  13. Detection of outliers by neural network on the gas centrifuge experimental data of isotopic separation process; Aplicacao de redes neurais para deteccao de erros grosseiros em dados de processo de separacao de isotopos de uranio por ultracentrifugacao

    Andrade, Monica de Carvalho Vasconcelos

    2004-07-01

    This work presents and discusses the neural network technique aiming at the detection of outliers on a set of gas centrifuge isotope separation experimental data. In order to evaluate the application of this new technique, the result obtained of the detection is compared to the result of the statistical analysis combined with the cluster analysis. This method for the detection of outliers presents a considerable potential in the field of data analysis and it is at the same time easier and faster to use and requests very less knowledge of the physics involved in the process. This work established a procedure for detecting experiments which are suspect to contain gross errors inside a data set where the usual techniques for identification of these errors cannot be applied or its use/demands an excessively long work. (author)

  14. Process synthesis and intensification of hybrid separations

    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...

  15. New directions in gas processing

    Anon.

    1996-01-01

    Papers presented at the Insight conference held on January 30, 1996 in Calgary, Alberta, were contained in this volume. The conference was devoted to a discussion of new directions in the gas processing business, the changing business environment, new processing technologies, and means by which current facilities agreements can be adapted to the new commercial reality. High operating costs which have resulted in the downsizing and restructuring of the industry, and partnering with a third party in the gathering and processing operations, with apparently beneficial result both to plant owners, as well to third party processors, received the most attention. The relationship between the gas processor and the gas producer as they relate to the Petroleum Joint Venture Association (PJVA) Gas Processing Agreement, which defines the obligations of third parties, was the center of discussion. Regulatory changes and the industry's response to the changes was also on the agenda. Refs., tabs., figs

  16. Restoring solvent for nuclear separation processes

    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

  17. Assessment of parameters of gas centrifuge and separation cascade basing on integral characteristics of separation plant

    Borisevich, Valentin, E-mail: VDBorisevich@mephi.ru [National Research Nuclear University MEPhI, Kashirskoe Shosse 31, Moscow 115409 (Russian Federation); National Research Center “Kurchatov Institute”, Kurchatov Square 1, Moscow 123182 (Russian Federation); Borshchevskiy, Michael, E-mail: Michael_mephi@mail.ru [National Research Nuclear University MEPhI, Kashirskoe Shosse 31, Moscow 115409 (Russian Federation); Andronov, Igor, E-mail: andronov@imp.kiae.ru [National Research Center “Kurchatov Institute”, Kurchatov Square 1, Moscow 123182 (Russian Federation); Senchenkov, Sergey, E-mail: senchenkov@imp.kiae.ru [National Research Center “Kurchatov Institute”, Kurchatov Square 1, Moscow 123182 (Russian Federation)

    2013-12-15

    Highlights: • We developed the calculation method to assess a feed flow rate into a gas centrifuge. • It is based on the knowledge of the integral characteristics of a separation plant. • Our method is verified by comparison with the results of the independent one. • The method also allows to specify other features of the separation cascade work. - Abstract: A calculation technique to assess a feed flow rate into a single GC, a total number of centrifuges in a separation cascade and to determine its likely configurations basing on the known integral characteristics of a centrifugal plant is developed. Evaluation of characteristics of the industrial gas centrifuge TC-12 and separation cascades of the NEF plant performed by two independent calculation techniques demonstrates their satisfactory agreement. This methodology would help to some extent the nuclear inspectors in evaluating and assessing the capability of an enrichment facility, and discovering any use for undeclared purposes.

  18. The effect of gas release on column separator

    Kranenburg, C.

    1974-01-01

    A mathematical model has been considered in which the influence of gas release on transient cavitating flow and column separation in pipel ines is taken into account. A rei iable numerical method has been developed for the computation of the wave propagation and cavitation phenomena following pump

  19. Gas separation properties of new polyoxadiazole and polytriazole membranes

    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

  20. Process for separating liquid hydrocarbons from waxes

    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.

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

    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.

  2. Recent achievements in facilitated transport membranes for separation processes

    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.

  3. Separating uranium by laser: the atomic process

    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)

  4. Improvements in or relating to separation processes

    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.)

  5. Separating uranium by laser: the atomic process

    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. New technological developments in gas processing

    Draper, R.C.

    1996-01-01

    The changes that the natural gas industry has undergone over the last few years was discussed. Low natural gas prices forced companies to react to their high reserves replacements costs. They were forced to downsize and undergo major restructuring because they were losing money due to high operating costs; the future for natural gas prices looked pessimistic. The changes have led to a new kind of business practice, namely 'partnering with third party processor', mid-stream companies known as aggregators, to build and operate facilities as part of a move towards cost effective improvements for gas producers. Besides reducing capital and operating costs, the producer under this arrangements can dedicate his capital to finding new gas which is the basis of growth. Recent technological changes in the gas processing industry were also touched upon. These included enhanced technologies such as increased liquid hydrocarbon recovery, segregation of C3+ and C5+, installation of gas separation membrane systems, small sulphur plants, acid gas injection and selective or mixed solvents. Details of some of these technologies were described. 2 refs., 2 figs

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

    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.

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

    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.

  9. Gas phase adsorption technology for nitrogen isotope separation and its feasibility for highly enriched nitrogen gas production

    Inoue, Masaki; Asaga, Takeo

    2000-04-01

    Highly enriched nitrogen-15 gas is favorable to reduce radioactive carbon-14 production in reactor. The cost of highly enriched nitrogen-15 gas in mass production is one of the most important subject in nitride fuel option in 'Feasibility Study for FBR and Related Fuel Cycle'. In this work gas phase adsorption technology was verified to be applicable for nitrogen isotope separation and feasible to produce highly enriched nitrogen-15 gas in commercial. Nitrogen isotopes were separated while ammonia gas flows through sodium-A type zeolite column using pressure swing adsorption process. The isotopic ratio of eight samples were measured by high resolution mass spectrometry and Fourier transform microwave spectroscopy. Gas phase adsorption technology was verified to be applicable for nitrogen isotope separation, since the isotopic ratio of nitrogen-15 and nitrogen-14 in samples were more than six times as high as in natural. The cost of highly enriched nitrogen-15 gas in mass production were estimated by the factor method. It revealed that highly enriched nitrogen-15 gas could be supplied in a few hundred yen per gram in mass production. (author)

  10. Radioactive gas waste processing device

    Soma, Koichi.

    1996-01-01

    The present invention concerns a radioactive gas waste processing device which extracts exhaust gases from a turbine condensator in a BWR type reactor and releases them after decaying radioactivity thereof during temporary storage. The turbine condensator is connected with an extracting ejector, a preheater, a recombiner for converting hydrogen gas into steams, an off gas condensator for removing water content, a flow rate control valve, a dehumidifier, a hold up device for removing radiation contaminated materials, a vacuum pump for sucking radiation decayed-off gases, a circulation water tank for final purification and an exhaustion cylinder by way of connection pipelines in this order. An exhaust gas circulation pipeline is disposed to circulate exhaust gases from an exhaust gas exit pipeline of the recycling water tank to an exhaust gas exit pipeline of the exhaust gas condensator, and a pressure control valve is disposed to the exhaust gas circulation pipeline. This enable to perform a system test for the dehumidification device under a test condition approximate to the load of the dehumidification device under actual operation state, and stabilize both of system flow rate and pressure. (T.M.)

  11. Potential flue gas impurities in carbon dioxide streams separated from coal-fired power plants.

    Lee, Joo-Youp; Keener, Tim C; Yang, Y Jeffery

    2009-06-01

    For geological sequestration of carbon dioxide (CO2) separated from pulverized coal combustion flue gas, it is necessary to adequately evaluate the potential impacts of flue gas impurities on groundwater aquifers in the case of the CO2 leakage from its storage sites. This study estimated the flue gas impurities to be included in the CO2 stream separated from a CO2 control unit for a different combination of air pollution control devices and different flue gas compositions. Specifically, the levels of acid gases and mercury vapor were estimated for the monoethanolamine (MEA)-based absorption process on the basis of published performance parameters of existing systems. Among the flue gas constituents considered, sulfur dioxide (SO2) is known to have the most adverse impact on MEA absorption. When a flue gas contains 3000 parts per million by volume (ppmv) SO2 and a wet flue gas desulfurization system achieves its 95% removal, approximately 2400 parts per million by weight (ppmw) SO2 could be included in the separated CO2 stream. In addition, the estimated concentration level was reduced to as low as 135 ppmw for the SO2 of less than 10 ppmv in the flue gas entering the MEA unit. Furthermore, heat-stable salt formation could further reduce the SO2 concentration below 40 ppmw in the separated CO2 stream. In this study, it is realized that the formation rates of heat-stable salts in MEA solution are not readily available in the literature and are critical to estimating the levels and compositions of flue gas impurities in sequestered CO2 streams. In addition to SO2, mercury, and other impurities in separated CO2 streams could vary depending on pollutant removal at the power plants and impose potential impacts on groundwater. Such a variation and related process control in the upstream management of carbon separation have implications for groundwater protection at carbon sequestration sites and warrant necessary considerations in overall sequestration planning

  12. Gas separation performance of tapered cascade with membrane

    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.)

  13. Sustainable process design & analysis of hybrid separations

    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...

  14. Gas adsorption and gas mixture separations using mixed-ligand MOF material

    Hupp, Joseph T [Northfield, IL; Mulfort, Karen L [Chicago, IL; Snurr, Randall Q [Evanston, IL; Bae, Youn-Sang [Evanston, IL

    2011-01-04

    A method of separating a mixture of carbon dioxiode and hydrocarbon gas using a mixed-ligand, metal-organic framework (MOF) material having metal ions coordinated to carboxylate ligands and pyridyl ligands.

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

    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.

  16. Fluid Phase Separation (FPS) experiment for flight on a space shuttle Get Away Special (GAS) canister

    Peters, Bruce; Wingo, Dennis; Bower, Mark; Amborski, Robert; Blount, Laura; Daniel, Alan; Hagood, Bob; Handley, James; Hediger, Donald; Jimmerson, Lisa

    1990-01-01

    The separation of fluid phases in microgravity environments is of importance to environmental control and life support systems (ECLSS) and materials processing in space. A successful fluid phase separation experiment will demonstrate a proof of concept for the separation technique and add to the knowledge base of material behavior. The phase separation experiment will contain a premixed fluid which will be exposed to a microgravity environment. After the phase separation of the compound has occurred, small samples of each of the species will be taken for analysis on the Earth. By correlating the time of separation and the temperature history of the fluid, it will be possible to characterize the process. The experiment has been integrated into space available on a manifested Get Away Special (GAS) experiment, CONCAP 2, part of the Consortium for Materials Complex Autonomous Payload (CAP) Program, scheduled for STS-42. The design and the production of a fluid phase separation experiment for rapid implementation at low cost is presented.

  17. Automation of experiments at Dubna Gas-Filled Recoil Separator

    Tsyganov, Yu. S.

    2016-01-01

    Approaches to solving the problems of automation of basic processes in long-term experiments in heavy ion beams of the Dubna Gas-Filled Recoil Separator (DGFRS) facility are considered. Approaches in the field of spectrometry, both of rare α decays of superheavy nuclei and those for constructing monitoring systems to provide accident-free experiment running with highly radioactive targets and recording basic parameters of experiment, are described. The specific features of Double Side Silicon Strip Detectors (DSSSDs) are considered, special attention is paid to the role of boundary effects of neighboring p-n transitions in the "active correlations" method. An example of an off-beam experiment attempting to observe Zeno effect is briefly considered. Basic examples for nuclear reactions of complete fusion at 48Ca ion beams of U-400 cyclotron (LNR, JINR) are given. A scenario of development of the "active correlations" method for the case of very high intensity beams of heavy ions at promising accelerators of LNR, JINR, is presented.

  18. Pilot plant development for adsorptive krypton separation from dissolver off-gas

    Ringel, H.; Printz, R.

    1987-01-01

    In view of hot cell application a separation process was investigated for the retention of Kr-85 from gaseous effluents. In the flow sheet only adsorption beds are applied. The most efficient process scheme is adsorption of the noble gas on activated charcoal and thereafter separation of the coadsorbed gas species like N 2 , O 2 , Xe and CO 2 from the krypton by gas chromatography. Adsorption is at normal pressure and low temperatures of up to -160 0 C, whereas desorption is at elevated temperatures and under helium purge. Influences on the process operation like off-gas composition, adsorption temperatures and adsorbent are experimentally investigated, as well as the behavior of trace impurities in the adsorption columns. On the basis of pilot plant operation the main components for a full scale facility are being designed

  19. Design of Separation Processes with Ionic Liquids

    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. Treatment of gas from an in situ conversion process

    Diaz, Zaida [Katy, TX; Del Paggio, Alan Anthony [Spring, TX; Nair, Vijay [Katy, TX; Roes, Augustinus Wilhelmus Maria [Houston, TX

    2011-12-06

    A method of producing methane is described. The method includes providing formation fluid from a subsurface in situ conversion process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. At least the olefins in the first gas stream are contacted with a hydrogen source in the presence of one or more catalysts and steam to produce a second gas stream. The second gas stream is contacted with a hydrogen source in the presence of one or more additional catalysts to produce a third gas stream. The third gas stream includes methane.

  1. The separation nozzle process for uranium isotope enrichment

    Becker, E.W.

    1977-01-01

    In the separation nozzle process, uranium isotope separation is brought about by the mass dependence of the centrifugal forces in a curved flow of a UF 6 /H 2 -mixture. Due to the large excess in hydrogen the high ration of UF 6 flow velocity to thermal velocity required for an effective isotope separation is obtained at relatively low expansion ratios and, accordingly, with relatively low gas-dynamic losses. As the optimum Reynolds number of the curved jet is comparatively low and a high absolute pressure is essential for economic reasons, the characteristic dimensions of the nozzle systems are made as small as possible. For commercial application in the near future systems involving mechanical jet deflection were developed. However, promising results were also obtained with separation nozzle systems generating a streamline curvature by the interaction of opposed jets. Most of the development work has been done at the Nuclear Research Center of Karlsruhe. Since 1970 the German company STEAG has been involved in the commercial implementation of the process. Two industrial-scale separative stages were tested successfully. This work constitutes the basis of planning of a separation nozzle demonstration plant to be built in Brazil

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

    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.

  3. Flow and separation in gas centrifuge with Beams type circulation

    Ajsen, Eh.M.; Borisevich, V.D.; Levin, E.V.

    1992-01-01

    Structure of the secondary circulation flows in the working chamber of gas centrifuge for uranium isotope separation is studied using the numerical methods. Influence of the circulation thermal component on the centrifuge efficiency is analyzed. The contribution of useful component concentration difference of binary isotope mixture in feeding flows to the centrifuge efficiency is determined. Dependence of concentration optimal difference, whereby the maximum efficiency is achieved, on temperature distribution on the rotor side wall is found

  4. Gas separation device based on electrical swing adsorption

    Judkins, Roddie R.; Burchell, Timothy D.

    1999-10-26

    A method and apparatus for separating one constituent, especially carbon dioxide, from a fluid mixture, such as natural gas. The fluid mixture flows through an adsorbent member having an affinity for molecules of the one constituent, the molecules being adsorbed on the adsorbent member. A voltage is applied to the adsorbent member, the voltage imparting a current flow which causes the molecules of the one constituent to be desorbed from the adsorbent member.

  5. Biohydrogen recovery and purification by gas separation method

    Búcsú, D.; Pientka, Zbyněk; Kovács, S.; Bélafi-Bakó, K.

    2006-01-01

    Roč. 200, 1-3 (2006), s. 227-229 ISSN 0011-9164. [Conference Euromembrane. Giardini Naxos - Taormina, 24.09.2006-28.09.2006] R&D Projects: GA ČR GA203/06/1207 Grant - others:Czech-Hungarian Bilateral Research Programme(HU) CZN-16/2005 Institutional research plan: CEZ:AV0Z40500505 Keywords : biohydrogen * gas separation membranes * polymer membranes Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.917, year: 2006

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

    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. Gas storage and processing device

    Kobayashi, Yoshihiro.

    1988-01-01

    Purpose: To improve the gas solidification processing performance in a gas storing and processing device for solidifying treatment of radioactive gaseous wastes (krypton 85) by ion injection method. Constitution: The device according to the present invention is constituted by disposing a coil connected with a magnetic field power source to the outer circumference of an outer cathode vessel, so that axial magnetic fields are formed to the inside of the outer cathode vessel. With such a device, thermoelectrons released from the thermocathode downwardly collide against gaseous radioactive wastes at high probability while moving spirally by the magnetic fields. The thus formed gas ions are solidified by sputtering in the cathode in the vessel. (Horiuchi, T.)

  8. Investigations on the applicability of pure gases in the transport of nuclear reaction products in a gas jet, and the use of this gas jet for radiochemical separation processes

    Aumann, D.C.; Presuhn, R.; Weismann, D.

    1975-01-01

    Earlier investigations on the effectivity of the transport of nuclear reaction products in a gas jet were continued where the transporting properties of ethylene and CO 2 in particular were examined in detail. By means of selected measurements, it is shown what influence the temperature of the gas bottle and that of the pressure releaser has on the transport yield. It is attempted from the results to explain the formation of aerosols in pure gases. The fission fragments of the spontaneous fission of Cf-252 are gamma-spectrometrically measured to determine the yields, or the total yield is determined by simple activity measurements. The determination of the isomeric ratio of Cs 138 m/g is described as an example of the possible application of a gas jet. Furthermore, an experiment for the search of super-heavy elements is suggested. (RB/LH) [de

  9. Investigations on the applicability of pure gases in the transport of nuclear reaction products in a gas jet, and the use of this gas jet for radiochemical separation processes

    Aumann, D.C.; Presuhn, R.; Weismann, D.

    1975-01-01

    Earlier investigations on the effectivity of the transport of nuclear reaction products in a gas jet were continued, the transporting properties of ethylene and CO 2 being particularly examined in detail. By means of selected measurements, it is shown what influence the temperature of the gas bottle and that of the pressure releaser has on the transport yield. It is attempted from the results to explain the formation of aerosols in pure gases. The fission fragments of the spontaneous fission of Cf-252 are gamma-spectrometrically measured to determine the yields, or the total yield is determined by simple activity measurements. The determination of the isomeric ratio of Cs 138 m/g is described as an example of the possible application of a gas jet. Furthermore, an experiment for the search of super-heavy elements is suggested. (RB/LH) [de

  10. Conditions for maximum isolation of stable condensate during separation in gas-condensate systems

    Trivus, N.A.; Belkina, N.A.

    1969-02-01

    A thermodynamic analysis is made of the gas-liquid separation process in order to determine the relationship between conditions of maximum stable condensate separation and physico-chemical nature and composition of condensate. The analysis was made by considering the multicomponent gas-condensate fluid produced from Zyrya field as a ternary system, composed of methane, an intermediate component (propane and butane) and a heavy residue, C/sub 6+/. Composition of 5 ternary systems was calculated for a wide variation in separator conditions. At each separator pressure there is maximum condensate production at a certain temperature. This occurs because solubility of condensate components changes with temperature. Results of all calculations are shown graphically. The graphs show conditions of maximum stable condensate separation.

  11. Over all separation factors for stable isotopes by gas centrifuge

    Chuntong Ying; Nie Yuguang; Zeng Shi; Shang Xiuyong; Wood, Houston G.

    1999-01-01

    The separation factor for the elements with molar wight differences, γ 0 , is an important characteristic parameter for separation of varied isotopes. Besides the dependence on construction parameters of the gas centrifuge it depends on many variables. Some of them are operation conditions, such as feeding flow rate F, pressure at wall p w , temperature T 0 and distribution temperature on the wall and others. Separation factor γ 0 depends on physical properties, such as molar weight M, viscosity μ, product of ρD, where ρ is density of working media and D is its diffusion coefficient. It was taken four examples: UF 6 , WF 6 , OsO 4 and Xe [ru

  12. Characteristics of isotope-selective chemical reactor with gas-separating device

    Gorshunov, N.M.; Kalitin, S.A.; Laguntsov, N.I.; Neshchimenko, Yu.P.; Sulaberidze, G.A.

    1988-01-01

    A study was made on characteristics of separating stage, composed of isotope-selective chemical (or photochemical) reactor and membrane separating cascade (MSC), designated for separation of isotope-enriched products from lean reagents. MSC represents the counterflow cascade for separation of two-component mixtures. Calculations show that for the process of carton isotope separation the electric power expences for MSC operation are equal to 20 kWxh/g of CO 2 final product at 13 C isotope content in it equal to 75%. Application of the membrane gas-separating cascade at rather small electric power expenses enables to perform cascading of isotope separation in the course of nonequilibrium chemical reactions

  13. Adsorptive separation of NOsub(x) from dissolver off-gas

    Ringel, H.

    1984-06-01

    After precleaning the dissolver off-gas contains, besides the noble gases Xe and Kr, about 0.5 vol.% each of NOsub(x) and H 2 O. For the removal of these NOsub(x) and H 2 O residues to below 1 ppm, an adsorptive gas cleaning process has been developed and tested on a lab-scale. For the process, an acid resistant molecular sieve was selected and its properties investigated with respect to application; e.g. the dependence of the adsorption capacity on temperature, gas composition and face velocity. By the operation of a lab-scale facility with 400 Nl/h continuous off-gas throughput the suitability of the adsorption process has been demonstrated for off-gas cleaning and recycling of the separated NO 2 and H 2 O to the dissolver. (orig.) [de

  14. Study on atmospheric hydrogen enrichment by cryopump method and isotope separation by gas chromatography

    Taniyama, Yuki; Momoshima, Noriyuki

    2001-01-01

    To obtain the information of source of atmospheric hydrogen tritium an analysis of tritium isotopes is thought to be effective. So an atmospheric hydrogen enrichment apparatus and a cryogenic gas chromatographic column were made. Experiments were carried out to study the performance of cryopump to enrich atmospheric hydrogen and the column to separate hydrogen isotopes that obtained by cryopump method. The cryopump was able to process about 1000 1 atmosphere and the column was able to separate hydrogen isotopes with good resolution. (author)

  15. Use of exhaust gas as sweep flow to enhance air separation membrane performance

    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.

  16. First status seminar `Druckflamm`. Development of a coal-fuelled combined cycle process with liquid ash separation. Conference report; Erstes Statusseminar `Druckflamm`. Entwicklung eines kohlegefeuerten Gas- und Dampfturbinenprozesses mit Fluessigascheabscheidung. Tagungsband

    Hannes, K. [ed.

    1999-09-01

    Six industrial enterprises in the Ruhr, plus several universities and national rsearch centers are working on the `Druckflamm` process of pressurized coal dust combustion, which is described in this status report and is scheduled to be implementable within the next 20 years. To this end, an experimental facility (DKSF) was constructed at Dorsten. The plant works by a coal-fuelled combined cycle process in which the flue gas can be led directly onto a gas turbine after purification. This means that the flue gas must be free of particulate materials and noxious vapours, i.e. a particle size of less than 3 mg/m{sup 3}, a particle diameter of less than 3 {mu}m and an alkali concentration of less than 1 ppm. The Dorsten plant is fuelled with coal; it has a thermal capacity of 1 MW and can be operated at pressures up to 20 bar. The contribution presents an outline drawing of the plant and a survey of the results and information obtained so far. Material problems and methods of measurement are reported separately. The fuel coals were of different composition, with slag flow points between 1200 and 1400 degrees centigrade. [Deutsch] Im Ruhrgebiet wird an einem neuen Verfahren zur Verstromung von Steinkohle gearbeitet. Es soll in etwa 20 Jahren mit einem neuen Kraftwerkstyp einsetzbar sein. Kennzeichen dieses Verfahrens sind ein hoher Wirkungsgrad von mehr als 50% und eine geringe CO{sub 2}-Emission. Entwickelt wird das ``Druckkohlenstaubfeuerung`` genannte Projekt von sechs Industrieunternehmen. Zusaetzlich arbeiten an diesem Thema weitere Unternehmen sowie Universitaeten und Grossforschungseinrichtungen unter dem Arbeitstitel ``Druckflamm``. Bisherige Ergebnisse der grundlegenden Entwicklungsarbeiten sind in diesem Statusbericht zusammengefasst. Ziel des Verbundprojektes Druckkohlenstaubfeuerung (DKSF) in Dorsten ist, einen GUD-Prozess auf Kohlebasis zu entwickeln, der dadurch charakterisiert ist, dass das Rauchgas nach Reinigung unmittelbar auf eine Gasturbine geleitet

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

    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.

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

    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.

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

    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.

  20. Cryogenic system with GM cryocooler for krypton, xenon separation from hydrogen-helium purge gas

    Chu, X. X.; Zhang, D. X.; Qian, Y.; Liu, W. [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800 (China); Zhang, M. M.; Xu, D. [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190 (China)

    2014-01-29

    In the thorium molten salt reactor (TMSR), fission products such as krypton, xenon and tritium will be produced continuously in the process of nuclear fission reaction. A cryogenic system with a two stage GM cryocooler was designed to separate Kr, Xe, and H{sub 2} from helium purge gas. The temperatures of two stage heat exchanger condensation tanks were maintained at about 38 K and 4.5 K, respectively. The main fluid parameters of heat transfer were confirmed, and the structural heat exchanger equipment and cold box were designed. Designed concentrations after cryogenic separation of Kr, Xe and H{sub 2} in helium recycle gas are less than 1 ppb.

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

    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

  2. High flux polyethersulfone-polyimide blend hollow fiber membranes for gas separation

    Kapantaidakis, G.; Koops, G.H.

    2002-01-01

    In this work, the preparation of gas separation hollow fibers based on polyethersulfone Sumikaexcel (PES) and polyimide Matrimid 5218 (PI) blends, for three different compositions (i.e. PES/PI: 80/20, 50/50 and 20/80 wt.%), is reported. The dry/wet spinning process has been applied to prepare

  3. Plutonium Chemistry in the UREX+ Separation Processes

    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.

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

    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)

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

    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

  6. Plutonium Chemistry in the UREX Separation Processes

    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.

  7. Cascade theory in isotopic separation processes

    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

  8. Foam films as thin liquid gas separation membranes.

    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.

  9. Modelling carbon membranes for gas and isotope separation.

    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.

  10. Gas separation by composite solvent-swollen membranes

    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.

  11. Adsorption and Gas Separation of Molecules by Carbon Nanohorns.

    Gatica, Silvina M; Nekhai, Anton; Scrivener, Adam

    2016-05-19

    In this paper, we report the results of Monte Carlo simulations of the adsorption of neon, argon, methane and carbon dioxide in carbon nanohorns. We model the nanohorns as an array of carbon cones and obtained adsorption isotherms and isosteric heats. The main sites of adsorption are inside the cones and in the interstices between three cones. We also calculated the selectivity of carbon dioxide/methane, finding that nanohorns are a suitable substrate for gas separation. Our simulations are compared to available experimental data.

  12. Methods of calculating engineering parameters for gas separations

    Lawson, D. D.

    1980-01-01

    A group additivity method has been generated which makes it possible to estimate, from the structural formulas alone, the energy of vaporization and the molar volume at 25 C of many nonpolar organic liquids. From these two parameters and appropriate thermodynamic relationships it is then possible to predict the vapor pressure of the liquid phase and the solubility of various gases in nonpolar organic liquids. The data are then used to evaluate organic and some inorganic liquids for use in gas separation stages or as heat exchange fluids in prospective thermochemical cycles for hydrogen production.

  13. Device for separating and concentrating rare gases containing krypton gas

    Kimura, S; Sugimoto, K

    1975-06-11

    In orer to highly concentrate krypton by means of adsorption and desorption of activated carbon, in a device for continuously separating and concentrating rare gases containing krypton gas by means of adsorbing and desorbing operation of activated carbon, the device includes adsorbers arranged in parallel and more than two stages of adsorbers arranged in series with the first mentioned adsorbers with the amount of activated carbon filled successively reduced, and a cooling mechanism for cooling the adsorbers when adsorbed and a heating mechanism for heating the adsorbers when desorbed.

  14. Gas separation by composite solvent-swollen membranes

    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.

  15. Gas storing and processing device

    Kobayashi, Yoshihiro; Takano, Yosoko.

    1988-01-01

    Purpose: To increase the gas injection processing performance and obtain stable accumulation layers by increasing the thickness of the accumulation layers of amorphous alloy. Constitution: The gas storing processing device comprises a cylindrical vessel constituting an outer cathode for introducing gases to be processed, an inner cathode in which transition metal material and rare earth metal material as a sputtering target disposed in the vessel are combined by way of insulating material, an anode cover disposed to the upper portion of the vessel and an anode bottom disposed at the bottom thereof. It is adapted such that DC high voltage sources are connected respectively to the outer and the inner cathodes and sputtering voltage can be applied, removed and controlled independently to the transition metal and the rare earth metal of the inner cathode. This enables to control the composition ratio of the accumulation layers of amorphous alloy formed to the surface of the outer cathode, thereby enabling operation related with the gas injection ratio. (Sekiya, K.)

  16. An energetic analysis of CO2 capture on a gas turbine combining flue gas recirculation and membrane separation

    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.

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

    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)

  18. Transient Simulations of Gas-Oil-Water Separation Plants

    Tor S. Schei

    1991-01-01

    Full Text Available A set of mathematical models for the dynamic simulation of offshore processing plants is developed. Each process unit is modeled separately, and the various models are integrated into a system for the simulation of an entire plant. The purpose of the simulation system is to study the effects of various disturbances and investigate appropriate control strategies. Important variables subject to control are pressure, flow rate, temperature, vessel liquid level and compressor speed. In separators the rate of interfacial mass transfer between the liquid and vapour phases at non-equilibrium is modeled as a first order time lag. The vapour liquid equilibrium ratio is linearized with respect to variations in pressure and temperature for each separator stage. A realistic scenario is chosen in order to demonstrate the capabilities of the simulation system.

  19. Hydraulic and separation characteristics of an industrial gas centrifuge calculated with neural networks

    Butov, Vladimir; Timchenko, Sergey; Ushakov, Ivan; Golovkov, Nikita; Poberezhnikov, Andrey

    2018-03-01

    Single gas centrifuge (GC) is generally used for the separation of binary mixtures of isotopes. Processes taking place within the centrifuge are complex and non-linear. Their characteristics can change over time with long-term operation due to wear of the main structural elements of the GC construction. The paper is devoted to the determination of basic operation parameters of the centrifuge with the help of neural networks. We have developed a method for determining the parameters of the industrial GC operation by processing statistical data. In this work, we have constructed a neural network that is capable of determining the main hydraulic and separation characteristics of the gas centrifuge, depending on the geometric dimensions of the gas centrifuge, load value, and rotor speed.

  20. Process for the gas extraction of coal

    Urquhart, D B

    1976-05-20

    The object of the invention is a process for the hydroextraction of coal is treated with water and carbon monoxide at a temperature in the region of 300 - 380/sup 0/C. After treatment is completed, the gases are separated from the treated gas; the treated coal is then extracted with an extraction medium during the gas phase at a temperature of at least 400/sup 0/C, the remainder is separated from the gas phase and the coal extract is obtained from the extraction medium. Hydrogenation is preferably carried out at a temperature in the region of 320 - 370/sup 0/C and at a pressure of 200 - 400 at. The time required for treatment with carbon monoxide and water is 1/4 - 2 hours, and in special cases 3/4 - 1 1/2 hours. The coal material itself is nutty slack, of which more than 95% of the coal particles pass through a 1.5 mm mesh sieve. After the hydrogenation the extraction is carried out at a temperature in the region of 400 - 450/sup 0/C. The patent claims relate to the types of extraction media used.

  1. Analysis of CO2 Separation from Flue Gas, Pipeline Transportation, and Sequestration in Coal

    Eric P. Robertson

    2007-09-01

    This report was written to satisfy a milestone of the Enhanced Coal Bed Methane Recovery and CO2 Sequestration task of the Big Sky Carbon Sequestration project. The report begins to assess the costs associated with separating the CO2 from flue gas and then injecting it into an unminable coal seam. The technical challenges and costs associated with CO2 separation from flue gas and transportation of the separated CO2 from the point source to an appropriate sequestration target was analyzed. The report includes the selection of a specific coal-fired power plant for the application of CO2 separation technology. An appropriate CO2 separation technology was identified from existing commercial technologies. The report also includes a process design for the chosen technology tailored to the selected power plant that used to obtain accurate costs of separating the CO2 from the flue gas. In addition, an analysis of the costs for compression and transportation of the CO2 from the point-source to an appropriate coal bed sequestration site was included in the report.

  2. Krypton separation from waste gas of a reprocessing plant by low temperature rectification

    1987-01-01

    6 lectures at this seminar describe and evaluate the results of the research and development work on low temperature krypton separation from the waste gas of the reprocessing of nuclear fuels. They are used for making decisions for the process to be used in the future on a large scale at the Wackersdorf reprocessing plant. 2 further lectures deal with alternatives to this process, which were also developed: the freon washing and low temperature adsorption of krypton. All the lectures were included separately in the INIS and ENERGY databases. (RB) [de

  3. Off-gas processing method in reprocessing plant

    Kobayashi, Yoshihiro; Seki, Eiji.

    1990-01-01

    Off-gases containing a radioactive Kr gas generated in a nuclear fuel reprocessing plant are at first sent to a Kr gas separator. Then, the radioactive Kr gas extracted there is introduced to a Kr gas fixing device. A pretreatment and a post-treatment are applied by using a non-radioactive clean inert gas except for the Kr gas as a purge gas. If the radioactive Kr gas is contained in the off-gases discharged from the Kr gas fixing device after applying the post-treatment, the off gases are returned to the Kr gas separator. Accordingly, in a case where the radioactive Kr gas is contained in the off-gases discharged from the Kr gas fixing device, it is not necessary to apply the fixing treatment to all of the off gases. In view of the above, increase of the amount of processing gases can be suppressed and the radioactive Kr gas can be fixed efficiently and economically. (I.N.)

  4. Development for a process for the adsorptive separation of krypton-85

    Messler, M.

    1985-03-01

    In the final process step of dissolver waste gas purification in a reprocessing facility, the radioactive noble gas Kr-85 is separated by physical separation processes. The experiments showed that the available mixture of air/Kr/Xe can be appropriately separated by chromatography. In principle, the adsorption column is laded with the waste gas and subsequently regenerated by puring with a carrier gas. A complete separation of the waste gas components can thus be achieved. He suggests itself as a purge gas. Fine-grained activated charcoals are to be preferred as adsorbing agents. Among the adsorptive process alternatives studied, one variant in which the adsorber was split into two halves and loaded at -130 0 C or -160 0 C proved to be particularly suitable. It can be seen that a total of only 0.2 m 3 of activated charcoal would be required for a commerical facility with a waste gas throughput of 100 nm 3 /h. The helium flux required only amounts to 4% of the waste gas flow to be purified. If valuable xenon is also to be recovered then this value increases to 7%. In this case the quantity of activated charcoal necessary would be 0.28 m 3 . A comparison with alternative process principles indicated that the adsorptive concept has advantages with respect to process engineering and regarding high safety standards in nuclear engineering facilities. (orig./HP) [de

  5. Separation of silicon carbide-coated fertile and fissile particles by gas classification

    Vaughen, V.C.A.

    1976-07-01

    The separation of 235 U and 233 U in the reprocessing of HTGR fuels is a key feature of the feed-breed fuel cycle concept. This is attained in the Fort St. Vrain (FSV) reactor by coating the fissile (Th- 235 U) particles and the fertile (Th- 233 U) particles separately with silicon carbide (SiC) layers to contain the fission products and to protect the kernels from burning in the head-end reprocessing steps. Pneumatic (gas) classification based on size and density differences is the reference process for separating the SiC-coated particles into fissile and fertile streams for subsequent handling. Terminal velocities have been calculated for the +- 2 sigma ranges of particle sizes and densities for ''Fissile B''--''Fertile A'' particles used in the FSV reactor. Because of overlapping particle fractions, a continuous pneumatic separator appears infeasible; however, a batch separation process can be envisioned. Changing the gas from air to CO 2 and/or the temperature to 300 0 C results in less than 10 percent change in calculated terminal velocities. Recently reported work in gas classification is discussed in light of the theoretical calculations. The pneumatic separation of fissile and fertile particles needs more study, specifically with regard to (1) measuring the recoveries and separation efficiencies of actual fissile and fertile fractions in the tests of the pneumatic classifiers; and (2) improving the contactor design or flowsheet to avoid apparent flow separation or flooding problems at the feed point when using the feed rates required for the pilot plant

  6. Hydrogen separation from coke oven gas using PSA

    Takeuchi, M.: Tanibashi, N.; Nishida, S

    1983-01-01

    Twin column apparatus was used to study the adsorption characteristics of various components of coke oven gas at an adsorption pressure of 5 kg/cm/SUP/2G. The following results were obtained. Over 99.99% Of the H/sub 2/ could be separated, and for this a 5 angstrom zeolite was optimal. Since the break-through order is H/sub 2/, O/sub 2/, N/sub 2/, CH/SUB/4, CO there is a tendency for the product H/sub 2/ to be adulterated with O/sub 2/ and N/sub 2/. Although there was a large adsorption of CO/sub 2/ and C/sub 2/H/sub 4/, desorption was difficult, even under reduced pressure and H/sub 2/ flushing. Hence, the industrial version of this apparatus will have to include activated carbon. 5 references.

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

    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.

  8. Gas/liquid separator for BWR type reactor

    Soma, Naoshi; Akimoto, Seiichi; Yokoyama, Iwao.

    1993-01-01

    A two phase gas/liquid flow generated at a heating portion of a nuclear reactor is swirled by inlet vanes. The phase gas/liquid flow uprises as a vortex flow in a vortex cylinder, and a liquid phase of a high density gathers at the outer circumference of the vortex cylinder. The liquid phase gathered at the outer circumference is collected at the inlet of a discharge flow channel which protrude into the vortex cylinder and in a three-step structure, and introduced into a recycling liquid phase passing through the discharge flow channel for liquid phase. There is provided a structure that separated liquid collected at the lowermost state in the inlet of the three-step discharge flow channel inlet descends in the discharge flow channel, then uprises in an uprising flow channel and is introduced into the recycling liquid phase by way of a discharge flow channel exit. The height of the discharge flow channel exit is determined equal to that of a liquid level of the recycling liquid phase during rated operation of the reactor. Accordingly, even in a case where the liquid level in the recycling liquid phase is lowered, the liquid level of the uprising flow channel is kept equal to that during rated operation. (I.N.)

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

    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.

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

    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.

  11. Separation of Flue-Gas Scrubber Sludge into Marketable Products

    1998-01-01

    The reduction of sulfur oxides from high sulfur coal burning utility companies has resulted in the production of huge quantities of wet flue-gas desulfurization scrubber sludge. A typical 400 MW power station burning a coal containing 3.5% sulfur by weight and using a limestone absorbent would produce approximately 177,000 tons (dry weight) of scrubber sludge per year. This brownish colored, finely divided material contains calcium sulfite (CaSO 3 · 1/2 H 2 O), calcium sulfate (CaSO 4 · 2H 2 O), unreacted limestone (CaCO 3 ), and various other impurities such as fly-ash and iron oxide particles. The physical separation of the components of scrubber sludge would result in the re-use of this material. The primary use would be conversion to a highly pure synthetic gypsum. This technical report concentrates on the effect of baffle configuration on the separation of calcium sulfite/sulfate from limestone. The position of the baffles as they related to the feed inlet, and the quantity of the baffles were examined. A clean calcium sulfite/sulfate (less than 2.0% limestone by weight) was achieved with the combination of water-only cyclone and horizontally baffled column

  12. Modeling of filling gas centrifuge cascade for nickel isotope separation by feed flow input to different stages

    Orlov Alexey A.

    2017-01-01

    Full Text Available The article presents results of research filling gas centrifuge cascade by process gas fed into different stages. The modeling of filling cascade was done for nickel isotope separation. Analysis of the research results shows that nickel isotope concentrations of light and heavy fraction flows after filling cascade depend on feed stage number.

  13. On-line optimal control improves gas processing

    Berkowitz, P.N.; Papadopoulos, M.N.

    1992-01-01

    This paper reports that the authors' companies jointly funded the first phase of a gas processing liquids optimization project that has the specific purposes to: Improve the return of processing natural gas liquids, Develop sets of control algorithms, Make available a low-cost solution suitable for small to medium-sized gas processing plants, Test and demonstrate the feasibility of line control. The ARCO Willard CO 2 gas recovery processing plant was chosen as the initial test site to demonstrate the application of multivariable on-line optimal control. One objective of this project is to support an R ampersand D effort to provide a standardized solution to the various types of gas processing plants in the U.S. Processes involved in these gas plants include cryogenic separations, demethanization, lean oil absorption, fractionation and gas treating. Next, the proposed solutions had to be simple yet comprehensive enough to allow an operator to maintain product specifications while operating over a wide range of gas input flow and composition. This had to be a supervisors system that remained on-line more than 95% of the time, and achieved reduced plant operating variability and improved variable cost control. It took more than a year to study various gas processes and to develop a control approach before a real application was finally exercised. An initial process for C 2 and CO 2 recoveries was chosen

  14. Tail gas treatment of SEWGS technology. Literature review on CO2 and H2S separation

    Fabbri, E.N.; Van Dijk, H.A.J. [ECN Biomass and Energy Efficiency, Petten (Netherlands)

    2011-12-15

    This literature review is the result of an investigation of the most important way to remove sulphur for the last decades. We will discuss Claus and Claus tail gas process options to solve the problem. Next to solutions which come from membranes, direct oxidation catalysis, from acid gas removal technology, sorbent technology, and liquid oxidation. Each field will be described and explained to understand in which way it could be suitable to separate CO2 and H2S and reach our goals with regard to CO2 transport and storage conditions. Finally, the target of this work will be to propose some interesting and promising solutions in view of future experiments.

  15. Wet separation processes as method to separate limestone and oil shale

    Nurme, Martin; Karu, Veiko

    2015-04-01

    Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

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

    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

  17. Gas turbine with two circuits and intermediate fuel conversion process

    Bachl, H.

    1978-01-01

    The combination of a fuel conversion process with a thermal process saves coolant and subsequent separation plant, in order to achieve the greatest possible use of the mechanical or electrical energy. The waste heat of a thermal circuit is taken to an endothermal chemical fuel conversion process arranged before a second circuit. The heat remaining after removal of the heat required for the chemical process is taken to a second thermal circuit. The reaction products of the chemical process which condense out during expansion in the second thermal process are selectively separated from the remaining gas mixture in the individual turbine stages. (HGOE) [de

  18. Gas prices and price process

    Groenewegen, G.G.

    1992-01-01

    On a conference (Gas for Europe in the 1990's) during the Gasexpo '91 the author held a speech of which the Dutch text is presented here. Attention is paid to the current European pricing methods (prices based on the costs of buying, transporting and distributing the natural gas and prices based on the market value, which is deducted from the prices of alternative fuels), and the transparency of the prices (lack of information on the way the prices are determined). Also attention is paid to the market signal transparency and gas-gas competition, which means a more or less free market of gas distribution. The risks of gas-to-gas competition for a long term price stability, investment policies and security of supply are discussed. Opposition against the Third Party Access (TPA), which is the program to implement gas-to-gas competition, is caused by the fear of natural gas companies for lower gas prices and lower profits. Finally attention is paid to government regulation and the activities of the European Commission (EC) in this matter. 1 fig., 6 ills., 1 tab

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

    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.

  20. Significance of the molecular diffusion for chemical and isotopic separation during the formation and degradation of natural gas reservoirs

    Hermichen, W.D.; Schuetze, H.

    1987-01-01

    Investigations at natural gas fields as well as modelling experiments have pointed out that changes of the chemical and isotopic composition occur in the course of migration, accumulation and dispersion of natural gas. Dissolution and sorption processes as well as in particular the diffusion process are considered to be the elementary separation processes. The influences on dissolved and freely flowing gases and on stationary gas accumulation are described by differential equations. The simulation of the following phenomena is shown: (1) immigration of gas into the pore space which is hydrodynamically passive, (2) diffusive migration of gas into the environment of the accumulation, and (3) diffusive 'decompression' into the roof and the floor of a gas bed and a gas containing subsoil water stratum, respectively. (author)

  1. Method of processing radioactive gas

    Saito, Masayuki.

    1978-01-01

    Purpose: To reduce the quantity of radioactive gas discharged at the time of starting a nuclear power plant. Method: After the stoppage of a nuclear power plant air containing a radioactive gas is extracted from a main condenser by operating an air extractor. The air is sent into a gaseous waste disposal device, and then introduced into the activated carbon adsorptive tower of a rare gas holdup device where xenon and krypton are trapped. Thereafter, the air passes through pipelines and returned to the main condenser. In this manner, the radioactive gas contained in air within the main condenser is removed during the stoppage of the operation of the nuclear power plant. After the plant has been started, when it enters the normal operation, a flow control valve is closed and another valve is opened, and a purified gas exhausted from the rare gas holdup device is discharged into the atmosphere through an exhaust cylinder. (Aizawa, K.)

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

    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 of gas manufacture: retorts

    Henderson, N M

    1883-01-01

    Improvements in the process and apparatus for the destructive distillation of shale, etc., described in Specification No. 1327, A.D. 1873. According to one modification a series of vertical retorts are arranged opposite to each other in two rows, the retorts in each row having flue spaces between them. The retorts have inclined bottoms beneath which are combustion chambers connected by flues to the spaces, and by flues to regenerative chambers, provided with flues, arranged with suitable valves. The fresh air and combustible gas enter at the bottom of one pair of regenerators, and after being heated enter one of the chambers, where they are ignited. The products pass through the adjacent spaces, which are connected at the top, and having heated the retorts pass through the other chamber and through the other pair of regenerators to the chimney. The retorts opposite to each other are connected by a port at the top, and they are charged alternately with fresh material. Each retort is fitted with an outlet pipe leading to a main, and with a steam jet by which air and steam may be forced into the mouth piece. The fresh charge is subjected to a comparatively low temperature at first to distill the oil, and then a higher heat is applied to the partially-spent shale and highly-superheated steam, and air admitted to the retort to decompose the coke and drive off the remaining carbon and ammonia.

  4. Evaluation of the separation by pyrochemical processes

    2004-01-01

    This report takes stock on the studies conducted by the CEA since the years 90 in the domain of the pyrochemical process, applied to the nuclear fuels reprocessing. After a presentation of the transmutation targets and fuels, the document presents the pyrochemical processes concepts and studies. In this part the author details the process developed foreign, the studies realized at the CEA, the fuel reprocessing of the molten salts reactors and the ionic liquids at ambient temperature. (A.L.B.)

  5. Conceptual design of distillation-based hybrid separation processes.

    Skiborowski, Mirko; Harwardt, Andreas; Marquardt, Wolfgang

    2013-01-01

    Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task. The large number of operational and design degrees of freedom requires a systematic and optimization-based design approach. To this end, a structured approach, the so-called process synthesis framework, is proposed. This article reviews available computational methods for the conceptual design of distillation-based hybrid processes for the separation of liquid mixtures. Open problems are identified that must be addressed to finally establish a structured process synthesis framework for such processes.

  6. Cryogenic separation of krypton and xenon from dissolver off-gas

    Bohnenstingl, J.; Heidendael, M.; Laser, M.; Mastera, S.; Merz, E.

    1976-03-15

    Although the release of fission product noble gas Kr-85 has not posed a health problem to date, a process is being developed for the removal and storage of fission product noble gases from dissolution process stream of fuel reprocessing. The separation process described for noble gas in air being proved in semi-technical scale includes cryogenic distillation and consists of the following steps: (1) removal of 129 +131iodine on silver-coated silica gel; (2) deposition of particulate materials by HEPA-filters; (3) elimination of O2 and NOx by catalytic conversion with H2/ to N2 and H2O; (4) drying of the gas stream with molecular sieve; (5) deposition of xenon in solid form at about 80 K, while the remaining gas components are liquified; (6) enrichment of Kr by low temperature distillation of liquid-gas mixture; (7) withdrawal of the highly enriched Kr-fraction at the bottom of the still to be bottled in pressurized steel cylinders for final disposal; and (8) purification of Kr-85 contaminated Xe for further industrial reuse by batch distillation.

  7. Petroleum refining. Separation processes; Le raffinage du petrole. Procedes de separation

    Wauquier, J.P. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Bonfils, P. [AB Industries (France); Company, J.P. [Compagnie de Raffinage et de Distribution TOTAL France, 75 - Paris (France); Deschamps, A. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Gourlia, J.P. [Elf Aquitaine (France); Gouzien, L. [Compagnie de Raffinage et de Distribution TOTAL France, 75 - Paris (France); Hombourger, T. [Mobil (France); Jullian, S. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Marty, C. [Compagnie de Raffinage et de Distribution TOTAL France, 75 - Paris (France); Mikitenko, P. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Ptak, C. [Technip, 92 - Rueil-Malmaison (France); Rojey, A.; Streicher, C.; Vidal, J. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)

    1998-12-01

    After having given into details the conventional separation processes used in petroleum refining, the author describes the development future prospects: improvement of the existing technologies, introduction of new techniques or separation processes still not used today in this industry. This book is particularly devoted to students and to engineers and technical men who work in refineries. (O.M.) 308 refs.

  8. Flue Gas Cleaning With Alternative Processes and Reaction Media

    Rasmussen, Søren Birk; Huang, Jun; Riisager, Anders

    2007-01-01

    Alternative methods to the traditional industrial NOX and SOXflue gas cleaning processes working at lower temperatures and/orleading to useful products are desired. In this work we presentour latest results regarding the use of molten ionic media inelectrocatalytic membrane separation, ionic liquid...... reversibleabsorption and supported ionic liquid deNOX catalysis. Furtherdevelopment of the methods will hopefully make them suitable forinstallation in different positions in the flue gas duct ascompared to the industrial methods available today....

  9. Basic separative power of multi-component isotopes separation in a gas centrifuge

    Jiang, Hongmin; Lei, Zengguang; Zhuge, Fu

    2008-01-01

    On condition that the overall separation factor per unit exists in centrifuge for multi-component isotopes separation, the relations between separative power of each component and molecular weight have been investigated in the paper while the value function and the separative power of binary-component separation are adopted. The separative power of each component is proportional to the square of the molecular weight difference between its molecular weight and the average molecular weight of other remnant components. In addition, these relations are independent on the number of the components and feed concentrations. The basic separative power and related expressions, suggested in the paper, can be used for estimating the separative power of each component and analyzing the separation characteristics. The most valuable application of the basic separative power is to evaluate the separative capacity of centrifuge for multi-component isotopes. (author)

  10. Analysis of hollow fibre membrane systems for multicomponent gas separation

    Khalilpour, Rajab; Abbas, Ali; Lai, Zhiping; Pinnau, Ingo

    2013-01-01

    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

  11. Carbon-fiber composite molecular sieves for gas separation

    Jagtoyen, M.; Derbyshire, F. [Univ. of Kentucky, Lexington, KY (United States)

    1996-08-01

    This report describes continuing work on the activation and characterization of formed carbon fiber composites. The composites are produced at the Oak Ridge National Laboratory (ORNL) and activated at the Center for Applied Energy Research (CAER) using steam, CO{sub 2}, or O{sub 2} at different conditions of temperature and time, and with different furnace configurations. The general aims of the project are to produce uniformly activated samples with controlled pore structures for specialist applications such as gas separation and water treatment. In previous work the authors reported that composites produced from isotropic pitch fibers weighing up to 25g can be uniformly activated through the appropriate choice of reaction conditions and furnace configurations. They have now succeeded in uniformly activating composites of dimensions up to 12 x 7 x 6 cm, or up to about 166 gram - a scale-up factor of about six. Part of the work has involved the installation of a new furnace that can accommodate larger composites. Efforts were made to achieve uniform activation in both steam and CO{sub 2}. The authors have also succeeded in producing materials with very uniform and narrow pore size distributions by using a novel method involving low temperature oxygen chemisorption in combination with heat treatment in N{sub 2} at high temperatures. Work has also started on the activation of PAN based carbon fibers and fiber composites with the aim of producing composites with wide pore structures for use as catalyst supports. So far activation of the PAN fiber composites supplied by ORNL has been difficult which is attributed to the low reactivity of the PAN fibers. As a result, studies are now being made of the activation of the PAN fibers to investigate the optimum carbonization and activation conditions for PAN based fibers.

  12. Processing of coke oven gas. Primary gas cooling

    Ullrich, H [Otto (C.) und Co. G.m.b.H., Bochum (Germany, F.R.)

    1976-11-01

    The primary cooler is an indispensable part of all byproduct processing plants. Its purpose is to cool the raw gas from the coke oven battery and to remove the accompanying water vapor. The greater part of the cooling capacity is utilized for the condensation of water vapor and only a small capacity is needed for the gas cooling. Impurities in the gas, like naphthalene, tar and solid particles, necessitate a special design in view of the inclination to dirt accumulation. Standard types of direct and indirect primary gas coolers are described, with a discussion of their advantages and disadvantages.

  13. Glycerol extracting dealcoholization for the biodiesel separation process.

    Ye, Jianchu; Sha, Yong; Zhang, Yun; Yuan, Yunlong; Wu, Housheng

    2011-04-01

    By means of utilizing sunflower oil and Jatropha oil as raw oil respectively, the biodiesel transesterification production and the multi-stage extracting separation were carried out experimentally. Results indicate that dealcoholized crude glycerol can be utilized as the extracting agent to achieve effective separation of methanol from the methyl ester phase, and the glycerol content in the dealcoholized methyl esters is as low as 0.02 wt.%. For the biodiesel separation process utilizing glycerol extracting dealcoholization, its technical and equipment information were acquired through the rigorous process simulation in contrast to the traditional biodiesel distillation separation process, and results show that its energy consumption decrease about 35% in contrast to that of the distillation separation process. The glycerol extracting dealcoholization has sufficient feasibility and superiority for the biodiesel separation process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Rule of thumb for binary isotope separations in a gas centrifuge

    Berger, M.H.

    1985-12-01

    A very simple hypothetical model of the binary isotope separation process in a countercurrent Gas Centrifuge is proposed. Like the usual Cohen-Onsager separation theory it involves the internal fluid dynamics, but unlike the usual isotopic separation theory it completely obviates the usual flow integrals for Cohen's E. Thereby allowing an immediate estimate of the flow efficiency of a given design, which can and sometimes should be checked later by the usual analyses. To shed some light on our idea, two simple derivations for assumed idealized hydrodynamics are given, but a rigorous proof remains an open question. Then our hypothesis is tested against a battery of about 10 new ''exact'' formulas for E based upon analytical solutions to several variants of Onsager's pancake equation and found to be ''reasonably'' accurate and surprisingly robust. Finally, some limitations of our rule are explored

  15. Venturi scrubber with integrated separating column for aerosol precipitation and gas sorption

    Mayinger, F.; Lehner, M.

    1992-01-01

    A concept for a novel, compact process combination in the form of a Venturi scrubber with integrated separating column was developed. The design of the system is such as to meet the boundary conditions encountered in practice. Comprehensive tests were carried through with this high-performance Venturi scrubber in a wide range of parameters, using the superfine dusts titanium dioxide and zinc oxide as test aerosols. Separating efficiency was found to be excellent, especially for multi-stage spray injection of the scrubbing fluid. Multi-stage spray injection achieves a more favourable pulse exchange between gas and fluid so that pressure losses are relatively low even though loading may be high. A provisional experimental set-up is used for further optimization of separating efficiency and pressure loss. (orig.) [de

  16. Carbon capture by hybrid separation processes

    van Benthum, R.J.; van Kemenade, H.P.; Brouwers, J.J.H.

    2014-01-01

    Even though there is an increasing development of carbon capture technology over the last decade, large-scale implementation is still far from common practice, mainly caused by the energy intensiveness of carbon capture processes and the lack of regulation. In absence of strict regulation, less

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

    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.

  18. A catalytic distillation process for light gas oil hydrodesulfurization

    Vargas-Villamil, F.D.; Marroquin, J.O.; Paz, C. de la; Rodriguez, E. [Prog. de Matematicas Aplicadas y Computacion, Prog. de Tratamiento de Crudo Maya, Instituto Mexicano del Petroleo, Mexico City, DF (Mexico)

    2004-07-01

    A light gas oil hydrodesulfurization process via catalytic distillation is developed and compared to a conventional process. By integrating the separation and reaction into a single unit, the catalytic distillation may produce a diesel with low concentration of sulfur compounds at a lower cost than the traditional reaction/separation process. The process proposed in this work is compared to an optimised conventional hydrodesulfurization unit which represents fairly well a plant that belongs to the National System of Refineries. During the optimisation of the conventional process, a compromise is established among the production of diesel and naphtha and the operating costs. The results show that the light gas oil hydrodesulfurization via catalytic distillation is as or more efficient than the conventional process. However, the removal of the sulfur compounds is carried out under less rigorous conditions. This design reduces the fix and operational costs. (author)

  19. Separation of British Gas' transportation and storage business

    McGregor, G.

    1992-12-01

    In making his substantive reference of the transportation and storage business of British Gas to the Monopolies and Mergers Commission, the Director General of Gas Supply identified the following principal effects adverse to the public interest: ''The absence of provision for the establishment of an independent undertaking to operate the pipe-line system and other facilities used by British Gas for the conveyance and storage of gas which would not be subject to conflicting interests in securing (a) transparency of the prices charged, the costs incurred and the operating methods in respect of the conveyance and storage of gas; (b) proper allocation to various parts of the Gas Supply Business of costs incurred and returns by that business; and (c) protection of information relating to the conveyance and storage of gas from which British Gas might obtain unfair commercial advantage, and thereby avoid the restriction or distortion of competition between British Gas and other persons whose business consists of or includes the supply of gas''. This paper considers the structural issues associated with achieving effective competition and looks at how the relationship between the businesses of supply and transportation might be organised in the short and longer term. (Author)

  20. Exhaust gas clean up process

    Walker, R.J.

    1988-06-16

    A method of cleaning an exhaust gas containing particulates, SO/sub 2/ and NO/sub x/ is described. The method involves prescrubbing with water to remove HCl and most of the particulates, scrubbing with an aqueous absorbent containing a metal chelate and dissolved sulfite salt to remove NO/sub x/ and SO/sub 2/, and regenerating the absorbent solution by controlled heating, electrodialysis and carbonate salt addition. The NO/sub x/ is removed as N/sub 2/ gas or nitrogen sulfonate ions and the oxides of sulfur are removed as a valuable sulfate salt. 4 figs.

  1. Method for treating a nuclear process off-gas stream

    Pence, D.T.; Chou, C.-C.

    1981-01-01

    A method is described for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. The method involves a sequence of adsorption and desorption steps which are specified. Particular reference is made to the separation of xenon and krypton from the off-gas stream, and to the use of silver-exchanged mordenite as the adsorbent. (U.K.)

  2. Total site integration of light hydrocarbons separation process

    Ulyev, L.; Vasilyev, M.; Maatouk, A.; Duic, Neven; Khusanovc, Alisher

    2016-01-01

    Ukraine is the largest consumer of hydrocarbons per unit of production in Europe (Ukraine policy review, 2006). The most important point is a reduction of energy consumption in chemical and metallurgical industries as a biggest consumer. This paper deals with energy savings potential of light hydrocarbons separation process. Energy consumption of light hydrocarbons separation process processes typical of Eastern European countries were analysed. Process Integration (PI) was used to perform a ...

  3. Process for generating substitute natural gas. Verfahren zur Erzeugung von Erdgasersatzgas

    Messerschmidt, D

    1984-09-13

    The invention deals with a process for the production of a substitute for natural gas from coal gas or other feed gases containing hydrogen and methane. For a simpler and economically more efficient process it is suggested to separate the feed gas, purified or unpurified, by selection of the molar sieve in a PSA plant so that the sweep gas of the PSA plant can reach the quality of a substitute gas. (orig.).

  4. Process and device for U isotope separation

    Aubert, Jacques; Carles, Maurice; Neige, Roger.

    1976-01-01

    The description is given of a process for enriching uranium with one of its isotopes by isotopic exchange in sub-cascades assembled to form a cascade, each sub-cascade having facilities for bringing into contact an aqueous phase charged with uranium of a lower valency with an organic phase charged with uranium of a higher valency, in conditions that restrict the transfer of upper valency uranium into the aqueous phase. Each sub-cascade has the following stages at least: isotopic exchange in a set of contact systems between the aqueous phase and the organic phase where the aqueous phase depletes and the organic phase becomes enriched with isotope 235; uranium extraction until depletion of the organic phase in a first extractor; reduction of the liquid phase uranium and acidification before this reduced aqueous phase passes into the isotopic exchange system then oxidation of the uranium of this aqueous phase coming from the system; extraction of the aqueous phase uranium until depletion in the second extractor by the organic phase [fr

  5. Gas-liquid reactor / separator: dynamics and operability characteristics

    Ranade, V.; Kuipers, J.A.M.; Versteeg, Geert

    1999-01-01

    A comprehensive mathematical model is developed to simulate gas¿liquid reactor in which both, reactants as well as products enter or leave the reactor in gas phase while the reactions take place in liquid phase. A case of first-order reaction (isothermal) was investigated in detail using the dynamic

  6. Opportunities in the United States' gas processing industry

    Meyer, H.S.; Leppin, D.

    1997-01-01

    To keep up with the increasing amount of natural gas that will be required by the market and with the decreasing quality of the gas at the well-head, the gas processing industry must look to new technologies to stay competitive. The Gas Research Institute (GR); is managing a research, development, design and deployment program that is projected to save the industry US dollar 230 million/year in operating and capital costs from gas processing related activities in NGL extraction and recovery, dehydration, acid gas removal/sulfur recovery, and nitrogen rejection. Three technologies are addressed here. Multivariable Control (MVC) technology for predictive process control and optimization is installed or in design at fourteen facilities treating a combined total of over 30x10 9 normal cubic meter per year (BN m 3 /y) [1.1x10 12 standard cubic feet per year (Tcf/y)]. Simple pay backs are typically under 6 months. A new acid gas removal process based on n-formyl morpholine (NFM) is being field tested that offers 40-50% savings in operating costs and 15-30% savings in capital costs relative to a commercially available physical solvent. The GRI-MemCalc TM Computer Program for Membrane Separations and the GRI-Scavenger CalcBase TM Computer Program for Scavenging Technologies are screening tools that engineers can use to determine the best practice for treating their gas. (au) 19 refs

  7. Catalyst functionalized buffer sorbent pebbles for rapid separation of carbon dioxide from gas mixtures

    Aines, Roger D

    2015-03-31

    A method for separating CO.sub.2 from gas mixtures uses a slurried media impregnated with buffer compounds and coating the solid media with a catalyst or enzyme that promotes the transformation of CO.sub.2 to carbonic acid. Buffer sorbent pebbles with a catalyst or enzyme coating are provided for rapid separation of CO.sub.2 from gas mixtures.

  8. Catalyst functionalized buffer sorbent pebbles for rapid separation of carbon dioxide from gas mixtures

    Aines, Roger D.

    2013-03-12

    A method for separating CO.sub.2 from gas mixtures uses a slurried media impregnated with buffer compounds and coating the solid media with a catalyst or enzyme that promotes the transformation of CO.sub.2 to carbonic acid. Buffer sorbent pebbles with a catalyst or enzyme coating are provided for rapid separation of CO.sub.2 from gas mixtures.

  9. Evaluation and Modification of Processes for Bioethanol Separation and Production

    Johnner P Sitompul

    2012-04-01

    Full Text Available This paper concerns on process evaluation and modification for bioethanol separation and production by applying pinch technology. Further, the paper is also focused on obtaining a most energy-efficient process among several processes. Three basic process configurations of bioethanol separation and production were selected for this study. The three separations and production systems are Othmer process, Barbet process and a separation process that operates under vacuum condition. Basically, each process is combination of Danish Distilleries process with a separation system yielding 95% (v/v bioethanol. The production capacity of the plant is estimated about 4 x 107 litre of bioethanol 95% (v/v per year. The result of the studies shows that the most energy efficient process among the three processes evaluated is the Othmer process, followed by the Barbet process and the process involving vacuum operation. The evaluation also shows that further energy saving can be carried for Barbet and Othmer process configuration when Tmin = 10oC for heat exchange possible.

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

    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

  11. A comparative study of gas-gas miscibility processes in underground gas storage reservoirs

    Rafiee, M.M.; Schmitz, S. [DBI - Gastechnologisches Institut gGmbH, Freiberg (Germany)

    2013-08-01

    Intermixture of gases in underground gas reservoirs have had great weight for natural gas storage in UGS projects with substitution of cushion gas by inert gases or changing the stored gas quality or origin, as for the replacement of town gas by natural gas. It was also investigated during the last years for Enhanced Gas Recovery (EGR) and Carbon Capture and Storage (CCS) projects. The actual importance of its mechanisms is discussed for the H{sub 2} storage in Power to Gas to Power projects (PGP). In these approaches miscibility of the injected gas with the gas in place in the reservoir plays an important role in the displacement process. The conditions and parameters for the gas-gas displacement and mixing have been investigated in previous projects, as e.g. the miscibility of CO{sub 2} with natural gas (CLEAN). Furthermore the miscibility process of town gas with natural gas and sauer gas with sweet gas were also previously measured and compared in laboratory. The objective of this work is to investigate the miscibility of H{sub 2} injection into natural gas reservoirs using a compositional and a black oil reservoir simulator. Three processes of convection, dispersion and diffusion are considered precisely. The effect of gas miscibility is studied for both simulators and the results are compared to find optimum miscibility parameters. The findings of this work could be helpful for further pilot and field case studies to predict and monitor the changes in gas composition and quality. In future this monitoring might become more important when PGP together with H{sub 2}-UGS, as storage technology, will help to successfully implement the change to an energy supply from more renewable sources. Similarly the method confirms the use of the black oil simulator as an alternative for gas-gas displacement and sequestration reservoir simulation in comparison to the compositional simulator. (orig.)

  12. Basic characteristics of hollow-filament polyimide membrane in gas separation and application to tritium monitors

    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)

  13. Separation of carbon dioxide and methane in continuous countercurrent gas centrifuges

    Wissen, van R.J.E.; Golombok, M.; Brouwers, J.J.H.

    2005-01-01

    The goal of this study is to determine the order of magnitude of the maximum achievable separation for decontaminating a natural gas well using a gas centrifuge. Previously established analytical approximations are not applicable for natural gas decontamination. Numerical simulations based on the

  14. Polyaniline/polybenzimidazole blends: characterisation of its physico-chemical properties and gas separation behaviour

    Giel, Verena; Kredatusová, Jana; Trchová, Miroslava; Brus, Jiří; Žitka, Jan; Peter, Jakub

    2016-01-01

    Roč. 77, April (2016), s. 98-113 ISSN 0014-3057 R&D Projects: GA ČR(CZ) GPP106/12/P643 Institutional support: RVO:61389013 Keywords : gas separation * gas sorption * gas permeation Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.531, year: 2016

  15. Statistical 21-cm Signal Separation via Gaussian Process Regression Analysis

    Mertens, F. G.; Ghosh, A.; Koopmans, L. V. E.

    2018-05-01

    Detecting and characterizing the Epoch of Reionization and Cosmic Dawn via the redshifted 21-cm hyperfine line of neutral hydrogen will revolutionize the study of the formation of the first stars, galaxies, black holes and intergalactic gas in the infant Universe. The wealth of information encoded in this signal is, however, buried under foregrounds that are many orders of magnitude brighter. These must be removed accurately and precisely in order to reveal the feeble 21-cm signal. This requires not only the modeling of the Galactic and extra-galactic emission, but also of the often stochastic residuals due to imperfect calibration of the data caused by ionospheric and instrumental distortions. To stochastically model these effects, we introduce a new method based on `Gaussian Process Regression' (GPR) which is able to statistically separate the 21-cm signal from most of the foregrounds and other contaminants. Using simulated LOFAR-EoR data that include strong instrumental mode-mixing, we show that this method is capable of recovering the 21-cm signal power spectrum across the entire range k = 0.07 - 0.3 {h cMpc^{-1}}. The GPR method is most optimal, having minimal and controllable impact on the 21-cm signal, when the foregrounds are correlated on frequency scales ≳ 3 MHz and the rms of the signal has σ21cm ≳ 0.1 σnoise. This signal separation improves the 21-cm power-spectrum sensitivity by a factor ≳ 3 compared to foreground avoidance strategies and enables the sensitivity of current and future 21-cm instruments such as the Square Kilometre Array to be fully exploited.

  16. A Fine-Tuned MOF for Gas and Vapor Separation: A Multipurpose Adsorbent for Acid Gas Removal, Dehydration, and BTX Sieving

    Haja Mohideen, Mohamed Infas; Pillai, Renjith S.; Adil, Karim; Bhatt, Prashant; Belmabkhout, Youssef; Shkurenko, Aleksander; Maurin, Guillaume; Eddaoudi, Mohamed

    2017-01-01

    Summary The development of highly stable separation agents is recognized as a decisive step toward the successful deployment of energy-efficient and cost-effective separation processes. Here, we report the synthesis and construction of a metal-organic framework (MOF), kag-MOF-1, that has adequate structural and chemical features and affords a stable adsorbent with unique and appropriate adsorption properties for gas processing akin to acid gas removal, dehydration, and benzene-toluene-xylene (BTX) sieving. A combination of X-ray diffraction experiments, adsorption studies, mixed-gas breakthrough adsorption column testing, calorimetric measurements, and molecular simulations corroborated the exceptional separation performance of kag-MOF-1 and its prospective use as a multifunctional adsorbent. The unique adsorption properties of kag-MOF-1, resulting from the contracted pore system with aligned periodic array of exposed functionalities, attest to the prominence of this new generation of ultra-microporous material as a prospective practical adsorbent toward cost-effective and more simplified gas and vapor processing flowcharts for natural gas upgrading and flue gas scrubbing.

  17. A Fine-Tuned MOF for Gas and Vapor Separation: A Multipurpose Adsorbent for Acid Gas Removal, Dehydration, and BTX Sieving

    Haja Mohideen, Mohamed Infas

    2017-10-19

    Summary The development of highly stable separation agents is recognized as a decisive step toward the successful deployment of energy-efficient and cost-effective separation processes. Here, we report the synthesis and construction of a metal-organic framework (MOF), kag-MOF-1, that has adequate structural and chemical features and affords a stable adsorbent with unique and appropriate adsorption properties for gas processing akin to acid gas removal, dehydration, and benzene-toluene-xylene (BTX) sieving. A combination of X-ray diffraction experiments, adsorption studies, mixed-gas breakthrough adsorption column testing, calorimetric measurements, and molecular simulations corroborated the exceptional separation performance of kag-MOF-1 and its prospective use as a multifunctional adsorbent. The unique adsorption properties of kag-MOF-1, resulting from the contracted pore system with aligned periodic array of exposed functionalities, attest to the prominence of this new generation of ultra-microporous material as a prospective practical adsorbent toward cost-effective and more simplified gas and vapor processing flowcharts for natural gas upgrading and flue gas scrubbing.

  18. CFD modeling of particle behavior in supersonic flows with strong swirls for gas separation

    Yang, Yan; Wen, Chuang

    2017-01-01

    flow from the dry gas outlet. The separation efficiency reached over 80%, when the droplet diameter was more than 1.5 μm. The optimum length of the cyclonic separation section was approximate 16–20 times of the nozzle throat diameter to obtain higher collection efficiency for the supersonic separator...

  19. Radionuclide separations and processing for defense water management

    Fryberger, T.B.

    1993-01-01

    An overview is given of the Department of Energy's Efficient Separations and Processing Integrated Program (ESPIP). This program sponsors research in advanced chemical separations for removal of radionuclides and hazardous components from radioactive defense wastes. Separations processing will reduce the volume of high-level waste that must be disposed of in a deep geological repository and will improve the quality of low-level wastes acceptable for near-surface disposal. DOE defense complex processing needs as well as technologies that are currently under development in the program are discussed

  20. Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures

    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.

  1. Fundamental studies of separation processes. Technical progress report

    Rogers, L.B.

    1975-06-01

    Studies using high-precision gas chromatography and supercritical fluid chromatography have produced new types of information on liquid crystals and on behavior of substances in the region of the critical temperature, respectively. In addition, the first successful studies of the effects of pressure on cation exchange have been made using aqueous solutions of alkali metal nitrates. In contrast, progress on separations of isotopic species using gas chromatography has been disappointing. In that area, the chief accomplishment has been a determination of the levels of accuracy and precision with which isotopic abundances can be measured using our quadrupole mass spectrometer. (U.S.)

  2. Innovative in-line separators: removal of water or sand in oil/water and gas/liquid/solid pipelines

    Jepson, Paul; Cheolho Kang; Gopal, Madan [CC Technologies, Dublin, OH (United States)

    2003-07-01

    In oil and gas production, multiphase mixtures are often separated before downstream processing. The separators are large, often 20 - 40 feet long and large diameter and use sophisticated internals. The costs are in the millions of dollars. Further, the sand and water in the flow can cause severe internal erosion and corrosion respectively before the flow reaches the separators. The CC Technologies/MIST In line Separation System is a cost-effective, efficient device for use in multiphase environments. The device is applicable for gas/solid, gas/liquid/solid and oil/water systems and offers exceptional separation between phases for a fraction of the cost of expensive gravity separators and hydro cyclones. The System contains no moving parts and is designed to be of the same diameter as the pipe, and experiences low shear forces. It can be fabricated with standard pipes. The efficiency of the separator has been determined in an industrial scale, pilot plant test facility at CC Technologies in 4-inch diameter pipes and has been found to be in excess of 98-99% for the removal of sand. Two phase oil/water separation effectiveness is in excess of 90% in 1-stage and 95% in 2 - stage. (author)

  3. An isotope-enrichment unit and a process for isotope separation

    1981-01-01

    A process and equipment for isotope enrichment using gas-centrifuge cascades are described. The method is described as applied to the separation of uranium isotopes, using natural-abundance uranium hexafluoride as the gaseous-mixture feedstock. (U.K.)

  4. Methanation process utilizing split cold gas recycle

    Tajbl, Daniel G.; Lee, Bernard S.; Schora, Jr., Frank C.; Lam, Henry W.

    1976-07-06

    In the methanation of feed gas comprising carbon monoxide and hydrogen in multiple stages, the feed gas, cold recycle gas and hot product gas is mixed in such proportions that the mixture is at a temperature sufficiently high to avoid carbonyl formation and to initiate the reaction and, so that upon complete reaction of the carbon monoxide and hydrogen, an excessive adiabatic temperature will not be reached. Catalyst damage by high or low temperatures is thereby avoided with a process that utilizes extraordinarily low recycle ratios and a minimum of investment in operating costs.

  5. ELECTROCHEMICAL SEPARATION AND CONCENTRATION OF HYDROGEN SULFIDE FROM GAS MIXTURES

    Winnick, Jack; Sather, Norman F.; Huang, Hann S.

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  6. Laser isotope separation - a new class of chemical process

    Woodall, K.B.; Mannik, L.; O'Neill, J.A.; Mader, D.L.; Nickerson, S.B.; Robins, J.R.; Bartoszek, F.E.; Gratton, D.

    1983-01-01

    Lasers may soon find several applications in chemical processing. The applications that have attracted the most research funding to date involve isotope separation for the nuclear industry. These isotopes have an unusually high value (≥$1000/kg) compared to bulk chemicals (∼$1/kg) and are generally required in very large quantities. In a laser isotope separation process, light is used to convert a separation that is very difficult or even impossible by conventional chemical engineering techniques to one that is readily handled by conventional separation technology. For some isotopes this can result in substantial capital and energy savings. A uranium enrichment process developed at the Lawrence Livermore National Laboratory is the closest to commercialization of the large scale laser isotope separation processes. Of particular interest to the Canadian nuclear industry are the laser separation of deuterium, tritium, zirconium-90 and carbon-14. In this paper, the basic principles behind laser isotope separation are reviewed and brief dscriptions of the more developed processes are given

  7. Working under the PJVA gas processing agreement

    Collins, S.

    1996-01-01

    The trend in the natural gas industry is towards custom processing. New gas reserves tend to be smaller and in tighter reservoirs than in the past. This has resulted in plants having processing and transportation capacity available to be leased to third parties. Major plant operators and owners are finding themselves in the business of custom processing in a more focused way. Operators recognize that the dilution of operating costs can result in significant benefits to the plant owners as well as the third party processor. The relationship between the gas processor and the gas producer as they relate to the Petroleum Joint Venture Association (PJVA) Gas Processing Agreement were discussed. Details of the standard agreement that clearly defines the responsibilities of the third party producer and the processor were explained. In addition to outlining obligations of the parties, it also provides a framework for fee negotiation. It was concluded that third party processing can lower facility operating costs, extend facility life, and keep Canadian gas more competitive in holding its own in North American gas markets

  8. Large scale gas chromatographic demonstration system for hydrogen isotope separation

    Cheh, C.H.

    1988-01-01

    A large scale demonstration system was designed for a throughput of 3 mol/day equimolar mixture of H,D, and T. The demonstration system was assembled and an experimental program carried out. This project was funded by Kernforschungszentrum Karlsruhe, Canadian Fusion Fuel Technology Projects and Ontario Hydro Research Division. Several major design innovations were successfully implemented in the demonstration system and are discussed in detail. Many experiments were carried out in the demonstration system to study the performance of the system to separate hydrogen isotopes at high throughput. Various temperature programming schemes were tested, heart-cutting operation was evaluated, and very large (up to 138 NL/injection) samples were separated in the system. The results of the experiments showed that the specially designed column performed well as a chromatographic column and good separation could be achieved even when a 138 NL sample was injected

  9. Flue gas carbon capture using hollow fiber membrane diffuser-separator

    Ariono, D.; Chandranegara, A. S.; Widodo, S.; Khoiruddin; Wenten, I. G.

    2018-01-01

    In this work, CO2 removal from flue gas using membrane diffuser-separator was investigated. Hollow fiber polypropylene membrane was used as the diffuser while pure water was used as the absorbent. Separation performance of the membrane diffuser-separator as a function of CO2 concentration (6-28%-vol.) and flow rate (gas: 0.8-1.55 L.min-1 and liquid: 0.2-0.7 L.min-1) was investigated and optimized. It was found that CO2 removal was significantly affected by CO2 concentration in the feed gas. On the other hand, CO2 flux was more influenced by flow rates of liquid and gas rather than concentration. The optimized CO2 removal (64%) and flux (1 x 10-4 mol.m-2.s-1) were obtained at the highest gas flow rate (1.55 L.min-1), the lowest liquid flow rate (0.2 L.min-1), and 6.2%-vol. of CO2 concentration. Outlet gas of the membrane diffuser system tends to carry some water vapor, which is affected by gas and liquid flow rate. Meanwhile, in the steady-state operation of the separator, the gas bubbles generated by the membrane diffuser take a long time to be completely degassed from the liquid phase, thus a portion of gas stream was exiting separator through liquid outlet.

  10. Gas permeation process for post combustion CO2 capture

    Pfister, Marc

    2017-01-01

    CO 2 Capture and Storage (CCS) is a promising solution to separate CO 2 from flue gas, to reduce the CO 2 emissions in the atmosphere, and hence to reduce global warming. In CCS, one important constraint is the high additional energy requirement of the different capture processes. That statement is partly explained by the low CO 2 fraction in the inlet flue gas and the high output targets in terms of CO 2 capture and purity (≥90%). Gas permeation across dense membrane can be used in post combustion CO 2 capture. Gas permeation in a dense membrane is ruled by a mass transfer mechanism and separation performance in a dense membrane are characterized by component's effective permeability and selectivity. One of the newest and encouraging type of membrane in terms of separation performance is the facilitated transport membrane. Each particular type of membrane is defined by a specific mass transfer law. The most important difference to the mass transfer behavior in a dense membrane is related to the facilitated transport mechanism and the solution diffusion mechanism and its restrictions and limitations. Permeation flux modelling across a dense membrane is required to perform a post combustion CO 2 capture process simulation. A CO 2 gas permeation separation process is composed of a two-steps membrane process, one drying step and a compression unit. Simulation on the energy requirement and surface area of the different membrane modules in the global system are useful to determine the benefits of using dense membranes in a post combustion CO 2 capture technology. (author)

  11. Lasers for the SILVA laser isotope separation process

    Lapierre, Y.

    1997-01-01

    The main principles of the laser isotope separation process for the production of enriched uranium at lower cost, are reviewed and the corresponding optimal laser characteristics are described. The development of the SILVA laser isotope separation process involved researches in the various domains of pump lasers, dye lasers, laser and optics systems and two test facilities for the feasibility studies which are expected for 1997

  12. Process for separating U isotopes by infrared excitation

    Lyon, R.K.; Kaldor, Andrew.

    1976-01-01

    This invention concerns a process for separating a substance into at least two parts in which the isotopic abundances of a given element differ from those of the isotopes of the substance prior to separation. Specifically, the invention concerns a process for the selective excitation of the isotopes of a gaseous phase UF 6 by absorption of infra-red photons, then by selective reaction of UF 6 excited with atomics chlorine, bromine or iodine, forming a product that may be separated by a standard method. The preference criteria of the atomic chlorine, bromine and iodine are related to the thermal dilution problem [fr

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

    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.

  14. Study on methane separation from steam reforming product gas with polyimide membrane

    Koiso, Hiroshi; Inagaki, Yoshiyuki; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Hino, Ryutaro.

    1997-10-01

    In the HTTR hydrogen production system by steam reforming of natural gas (main component: CH 4 ), CH 4 conversion rate is limited to approximately 65% due to high pressure and low temperature conditions (4.5 MPa, 800degC). The one of the measures to improve CH 4 conversion is recycling of residual CH 4 extracted from steam reforming product gas with a gas separator. Experimental and analytical studies on CH 4 separation from gas mixture composed of CH 4 , H 2 , CO 2 and CO were carried out to investigate gas separation characteristics of a polyimide membrane gas separator. Measured permeability of each gas in gas mixture was reduced from 1/3 to 1/14 of that obtained with a single gas (catalog value). The polyimide membrane could extracted CH 4 of approximately 80% from gas mixture, then, H 2 and CO 2 more than 98% were removed. It was confirmed that the polyimide membrane could be available to residual CH 4 recycling. The analytical results by a difference method gave good prospects of experimental results such as permeated flow rate, mol-fraction profiles and so on. Therefore, it can be said the analysis method was established. (author)

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

    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.

  16. Combined electrolysis catalytic exchange (CECE) process for hydrogen isotope separation

    Hammerli, M.; Stevens, W.H.; Butler, J.P.

    1978-01-01

    Hydrogen isotopes can be separated efficiently by a process which combines an electrolysis cell with a trickle bed column packed with a hydrophobic platinum catalyst. The column effects isotopic exchange between countercurrent streams of electrolytic hydrogen and liquid water while the electrolysis cell contributes to isotope separation by virtue of the kinetic isotope effect inherent in the hydrogen evolution reaction. The main features of the CECE process for heavy water production are presented as well as a discussion of the inherent positive synergistic effects, and other advantages and disadvantages of the process. Several potential applications of the process in the nuclear power industry are discussed. 3 figures, 2 tables

  17. Uranium enrichment in Europe by the gas centrifuge process

    Severin, D.J.E.

    1975-01-01

    To begin with, this lesson gives an outline of the expected energy demand of the Western World and the concentration of the European companies participating in uranium enrichment by the gas centrifuge method. Next, a) the principles of the gas centrifuge method are outlined, b) its advantages over other industrial processes are stressed, and c) the characteristic data of complete plants are given. The existing German, Dutch, and British pilot plants are mentioned as examples for the perfected state of the process. The Capenhurst (UK) and Almedo (NL) demonstration plants, each with a capacity of 200 t SW/a, will have been extended to 2 x 1.000 t SW/a by 1982. Finally, economic data of the gas centrifuge process are given. The term 'separative work' is explained in an annex. (GG) [de

  18. Analysis of hollow fibre membrane systems for multicomponent gas separation

    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.

  19. The comparative effect of FUV, EUV and X-ray disc photoevaporation on gas giant separations

    Jennings, Jeff; Ercolano, Barbara; Rosotti, Giovanni P.

    2018-04-01

    Gas giants' early (≲ 5 Myr) orbital evolution occurs in a disc losing mass in part to photoevaporation driven by high energy irradiance from the host star. This process may ultimately overcome viscous accretion to disperse the disc and halt migrating giants by starving their orbits of gas, imprinting on giant planet separations in evolved systems. Inversion of this distribution could then give insight into whether stellar FUV, EUV or X-ray flux dominates photoevaporation, constraining planet formation and disc evolution models. We use a 1D hydrodynamic code in population syntheses for gas giants undergoing Type II migration in a viscously evolving disc subject to either a primarily FUV, EUV or X-ray flux from a pre-solar T Tauri star. The photoevaporative mass loss profile's unique peak location and width in each energetic regime produces characteristic features in the distribution of giant separations: a severe dearth of ≲ 2 MJ planets interior to 5 AU in the FUV scenario, a sharp concentration of ≲ 3 MJ planets between ≈1.5 - 2 AU in the EUV case, and a relative abundance of ≈2 - 3.5 MJ giants interior to 0.5 AU in the X-ray model. These features do not resemble the observational sample of gas giants with mass constraints, though our results do show some weaker qualitative similarities. We thus assess how the differing photoevaporative profiles interact with migrating giants and address the effects of large model uncertainties as a step to better connect disc models with trends in the exoplanet population.

  20. Filter case for separating out radioactive effluents from gas flows

    Jannakos, K.; Zabel, G.

    1982-01-01

    A remotely operated change of filter in a filter case can be done with an annular or cylindrical filter insert, where the contaminated air side remains separate from the clean air side. A lid is provided which can be divided into two parts, and by which the openings of the filter insert and also in the intermediate floor can be opened or closed using the double lid technique. When closing the filter case lid, the double lid closure is always opened. (DG) [de

  1. Adsorbent filled membranes for gas separation. Part 1. Improvement of the gas separation properties of polymeric membranes by incorporation of microporous adsorbents

    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

  2. Comparison of methods for separating small quantities of hydrogen isotopes from an inert gas

    Willms, R.S.; Tuggle, D.; Birdsell, S.; Parkinson, J.; Price, B.; Lohmeir, D.

    1998-03-01

    It is frequent within tritium processing systems that a small amount of hydrogen isotopes (Q 2 ) must be separated from an inert gas such as He, Ar and N 2 . Thus, a study of presently available technologies for effecting such a separation was performed. A base case and seven technology alternatives were identified and a simple design of each was prepared. These technologies included oxidation-adsorption-metal bed reduction, oxidation-adsorption-palladium membrane reactor, cryogenic adsorption, cryogenic trapping, cryogenic distillation, hollow fiber membranes, gettering and permeators. It was found that all but the last two methods were unattractive for recovering Q 2 from N 2 . Reasons for technology rejection included (1) the method unnecessarily turns the hydrogen isotopes into water, resulting in a cumbersome and more hazardous operation, (2) the method would not work without further processing, and (3) while the method would work, it would only do so in an impractical way. On the other hand, getters and permeators were found to be attractive methods for this application. Both of these methods would perform the separation in a straightforward, essentially zero-waste, single step operation. The only drawback for permeators was that limited low-partial Q 2 pressure data is available. The drawbacks for getters are their susceptibility to irreversible and exothermic reaction with common species such as oxygen and water, and the lack of long-term operation of such beds. More research is envisioned for both of these methods to mature these attractive technologies

  3. Gas/vapour separation using ultra-microporous metal–organic frameworks: insights into the structure/separation relationship

    Adil, Karim; Belmabkhout, Youssef; Pillai, Renjith S.; Cadiau, Amandine; Bhatt, Prashant; Assen, Ayalew Hussen Assen; Maurin, Guillaume; Eddaoudi, Mohamed

    2017-01-01

    The separation of related molecules with similar physical/chemical properties is of prime industrial importance and practically entails a substantial energy penalty, typically necessitating the operation of energy-demanding low temperature fractional distillation techniques. Certainly research efforts, in academia and industry alike, are ongoing with the main aim to develop advanced functional porous materials to be adopted as adsorbents for the effective and energy-efficient separation of various important commodities. Of special interest is the subclass of metal-organic frameworks (MOFs) with pore aperture sizes below 5-7 Å, namely ultra-microporous MOFs, which in contrast to conventional zeolites and activated carbons show great prospects for addressing key challenges in separations pertaining to energy and environmental sustainability, specifically materials for carbon capture and separation of olefin/paraffin, acetylene/ethylene, linear/branched alkanes, xenon/krypton, etc. In this tutorial review we discuss the latest developments in ultra-microporous MOF adsorbents and their use as separating agents via thermodynamics and/or kinetics and molecular sieving. Appreciably, we provide insights into the distinct microscopic mechanisms governing the resultant separation performances, and suggest a plausible correlation between the inherent structural features/topology of MOFs and the associated gas/vapour separation performance.

  4. Gas/vapour separation using ultra-microporous metal–organic frameworks: insights into the structure/separation relationship

    Adil, Karim

    2017-05-30

    The separation of related molecules with similar physical/chemical properties is of prime industrial importance and practically entails a substantial energy penalty, typically necessitating the operation of energy-demanding low temperature fractional distillation techniques. Certainly research efforts, in academia and industry alike, are ongoing with the main aim to develop advanced functional porous materials to be adopted as adsorbents for the effective and energy-efficient separation of various important commodities. Of special interest is the subclass of metal-organic frameworks (MOFs) with pore aperture sizes below 5-7 Å, namely ultra-microporous MOFs, which in contrast to conventional zeolites and activated carbons show great prospects for addressing key challenges in separations pertaining to energy and environmental sustainability, specifically materials for carbon capture and separation of olefin/paraffin, acetylene/ethylene, linear/branched alkanes, xenon/krypton, etc. In this tutorial review we discuss the latest developments in ultra-microporous MOF adsorbents and their use as separating agents via thermodynamics and/or kinetics and molecular sieving. Appreciably, we provide insights into the distinct microscopic mechanisms governing the resultant separation performances, and suggest a plausible correlation between the inherent structural features/topology of MOFs and the associated gas/vapour separation performance.

  5. Development of membrane moisture separator for BWR off-gas system

    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)

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

    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

  7. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    Edhaim, Fatimah A.

    2017-01-01

    as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated

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

    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.)

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

    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.)

  10. Experimental substantiation of combined methods for designing processes for the commercial preparation of gas at gas condensate fields

    Gurevich, G R; Karlinskii, E D; Posypkina, T V

    1977-04-01

    An analysis is made of the possibility of using two analytical methods for studying vapor--liquid equilibrium of hydrocarbon mixtures that are used in designing the separation of natural gas and the stabilization of condensate--the Chao and Sider method, which uses computations by equilibrium constants. A combined computational method is proposed for describing a unified process of natural gas separation and condensate stabilization. The method of preparing the original data for the computation of the separation and stabilization processes can be significantly simplified. 10 references, 1 table.

  11. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  12. A simple method for the measurement of radioactivity of samples separated by gas chromatography

    Farkas, T.

    1981-01-01

    Gas chromatographs with flame ionization detector can be used to determine the radioactivity ( 14 C) of separated peaks. After a suitable change in the detector output the combustion product 14 CO 2 can be trapped by hyamine hydroxyde and measured by liquid scintigraphy. 90% of peak activity can be collected and measured, thus the method can be applied to determine the distribution and specific radioactivity of the components separated by gas chromatography. (author)

  13. Ultra-microporous triptycene-based polyimide membranes for high-performance gas separation

    Ghanem, Bader

    2014-03-11

    A highly permeable and highly selective polyimide of intrinsic microporosity is prepared using a 9,10-diisopropyl-triptycene contortion center. The three-dimensionality and shape-persistence of triptycene afford exceptional sieving-based gas separation performance transcending the latest permeability/selectivity trade-offs for industrial gas separations involving oxygen and hydrogen. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Ultra-microporous triptycene-based polyimide membranes for high-performance gas separation

    Ghanem, Bader; Swaidan, Raja; Litwiller, Eric; Pinnau, Ingo

    2014-01-01

    A highly permeable and highly selective polyimide of intrinsic microporosity is prepared using a 9,10-diisopropyl-triptycene contortion center. The three-dimensionality and shape-persistence of triptycene afford exceptional sieving-based gas separation performance transcending the latest permeability/selectivity trade-offs for industrial gas separations involving oxygen and hydrogen. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Separation of gases through gas enrichment membrane composites

    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.

  16. Dynamic modeling of ultrafiltration membranes for whey separation processes

    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

  17. Improved processes of light hydrocarbon separation from LNG with its cryogenic energy utilized

    Gao Ting; Lin Wensheng; Gu Anzhong

    2011-01-01

    Research highlights: → We propose two new light hydrocarbon separation processes utilizing LNG cold energy. → Both processes produce liquefied ethane and LPG with high ethane recovery rate. → CH 4 -riched gas from the high pressure process is compressed to final pressure. → Re-liquefied CH 4 -riched gas from the low pressure one is pumped to final pressure. → Both processes have good performance; the low pressure one is economically better. -- Abstract: Liquefied natural gas (LNG) often consists of some kinds of light hydrocarbons other than methane, such as ethane, propane and butane, which are of high additional value. By efficiently utilization of LNG cryogenic energy, these light hydrocarbons (C 2 + ) can be separated from LNG with low power consumption and LNG is gasified meanwhile. Two novel light hydrocarbon separation processes are proposed in this paper. The first process uses a demethanizer working at higher pressure (about 4.5 MPa). The methane-riched natural gas from the demethanizer can be compressed to pipeline pressure with low power consumption. The other one uses a demethanizer working at lower pressure (about 2.4 MPa). By cascade utilization of LNG cryogenic energy, the methane-riched natural gas from the demethanizer is entirely re-liquefied. Then the liquid product is pressurized to pipeline pressure by pumps instead of compressors, reducing the power consumption greatly. By both of the two processes, liquefied ethane and LPG (liquefied petroleum gas, i.e. C 3 + ) at atmosphere pressure can be obtained directly, and high ethane recovery rate can be gained. On the basis of one typical feed gas composition, the effects of the ethane content and the ethane price to the economics of the light hydrocarbon separation plants are studied, and the economics are compared for these two processes. The results show that recovering light hydrocarbons from LNG can gain great profits by both of the two processes, and from the view of economics, the

  18. Gas-separation membranes loaded with porous aromatic frameworks that improve with age.

    Lau, Cher Hon; Konstas, Kristina; Thornton, Aaron W; Liu, Amelia C Y; Mudie, Stephen; Kennedy, Danielle F; Howard, Shaun C; Hill, Anita J; Hill, Matthew R

    2015-02-23

    Porosity loss, also known as physical aging, in glassy polymers hampers their long term use in gas separations. Unprecedented interactions of porous aromatic frameworks (PAFs) with these polymers offer the potential to control and exploit physical aging for drastically enhanced separation efficiency. PAF-1 is used in the archetypal polymer of intrinsic microporosity (PIM), PIM-1, to achieve three significant outcomes. 1) hydrogen permeability is drastically enhanced by 375% to 5500 Barrer. 2) Physical aging is controlled causing the selectivity for H2 over N2 to increase from 4.5 to 13 over 400 days of aging. 3) The improvement with age of the membrane is exploited to recover up to 98% of H2 from gas mixtures with N2 . This process is critical for the use of ammonia as a H2 storage medium. The tethering of polymer side chains within PAF-1 pores is responsible for maintaining H2 transport pathways, whilst the larger N2 pathways gradually collapse. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    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.

  20. Electron beam flue gas treatment process. Review

    Honkonen, V.A.

    1996-01-01

    The basis of the process for electron beam flue gas treatment are presented in the report. In tabular form the history of the research is reviewed. Main dependences of SO 2 and NO x removal efficiencies on different physico-chemical parameters are discussed. Trends concerning industrial process implementation are presented in the paper,finally. (author). 74 refs, 11 figs, 1 tab

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

    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

  2. Role of functional nanoparticles to enhance the polymeric membrane performance for mixture gas separation

    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

  3. The practical use of resistance modelling to interpret the gas separation properties of hollow fiber membranes

    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)

  4. Separation process of zirconium and hafnium; Procede de separation du zirconium et du hafnium

    Hure, J; Saint-James, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    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{sub 3}{sup -} ions concentration, the role of the cation coming with NO{sub 3}{sup -}, as well as the influence of the concentration of zirconium in the solution on the separation coefficient {beta} = {alpha}{sub Zr} / {alpha}{sub Hf}. (M.B.) [French] Des differents procedes de separation zirconium-hafnium, l'extraction par solvant en contre-courant est le procede le plus facilement utilisable a l'echelle industrielle. On utilise comme solvant le phosphate de tributyle, dilue avec du white spirit pour faciliter les decantations. Des essais preliminaires ont montre que le milieu nitrique semblait le plus favorable a l'extraction; mais beaucoup d'autres facteurs interviennent dans le processus de separation. Nous avons etudie successivement l'influence de l'acidite, celle de la concentration en ions NO{sub 3}{sup -}, le role du cation accompagnant NO{sub 3}{sup -}, ainsi que l'influence de la concentration en zirconium de la solution sur le coefficient de separation {beta} = {alpha}{sub Zr} / {alpha}{sub Hf}. (MB)

  5. Separation of Process Wastewater with Extractive Heterogeneous-Azeotropic Distillation

    Tóth András József

    2016-10-01

    Full Text Available The application of vapour-liquid equilibria-based separation alternatives can be extraordinarily complicated for the treatment of process wastewaters containing heterogeneous-azeotropic. Despite dissimilar successfully tested methods for separation, there is possibility to get better distillation method by enabling the separation of more and more specific process wastewater. Extractive heterogeneous-azeotropic distillation (EHAD is a new advance in treatment of fine chemical wastewater showing special features to cope with the treatment of highly non-ideal mixtures. This method combines the worth of heterogeneous-azeotropic and extractive distillations in one apparatus without addition of any extra materials. The study of the separations of ternary component process wastewater from the fine chemical industry shows both in the modelled and experimental results that EHAD can be successfully applied. The measured and modelled compositions at extreme purities, that is, close to 0% or 100%, can be different because of the inaccuracies of the modelling. This highlights the paramount importance of the experiments if special extra-fine chemicals with almost no impurities, e.g. of pharmacopoeial quality are to be produced by special distillation technique. This study expands the application of EHAD technique, this new field is the separation of process wastewaters.

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

    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)

  7. Functionalized carbon nanotubes mixed matrix membranes of polymers of intrinsic microporosity for gas separation.

    Khan, Muntazim Munir; Filiz, Volkan; Bengtson, Gisela; Shishatskiy, Sergey; Rahman, Mushfequr; Abetz, Volker

    2012-09-06

    The present work reports on the gas transport behavior of mixed matrix membranes (MMM) which were prepared from multi-walled carbon nanotubes (MWCNTs) and dispersed within polymers of intrinsic microporosity (PIM-1) matrix. The MWCNTs were chemically functionalized with poly(ethylene glycol) (PEG) for a better dispersion in the polymer matrix. MMM-incorporating functionalized MWCNTs (f-MWCNTs) were fabricated by dip-coating method using microporous polyacrylonitrile membrane as a support and were characterized for gas separation performance. Gas permeation measurements show that MMM incorporated with pristine or functionalized MWCNTs exhibited improved gas separation performance compared to pure PIM-1. The f-MWCNTs MMM show better performance in terms of permeance and selectivity in comparison to pristine MWCNTs. The gas permeances of the derived MMM are increased to approximately 50% without sacrificing the selectivity at 2 wt.% of f-MWCNTs' loading. The PEG groups on the MWCNTs have strong interaction with CO2 which increases the solubility of polar gas and limit the solubility of nonpolar gas, which is advantageous for CO2/N2 selectivity. The addition of f-MWCNTs inside the polymer matrix also improved the long-term gas transport stability of MMM in comparison with PIM-1. The high permeance, selectivity, and long term stability of the fabricated MMM suggest that the reported approach can be utilized in practical gas separation technology.

  8. Towards a magnetic field separation in Ion Beam Sputtering processes

    Malobabic, Sina, E-mail: s.malobabic@lzh.de [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany); Jupé, Marco [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany); Kadhkoda, Puja [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Ristau, Detlev [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany)

    2015-10-01

    Defects embedded in coatings due to particle contamination are considered as a primary factor limiting the quality of optical coatings in Ion Beam Sputtering. An approach combining the conventional Ion Beam Sputtering process with a magnetic separator in order to remove these particles from film growth is presented. The separator provides a bent axial magnetic field that guides the material flux towards the substrate positioned at the exit of the separator. Since there is no line of sight between target and substrate, the separator prevents that the particles generated in the target area can reach the substrate. In this context, optical components were manufactured that reveal a particle density three times lower than optical components which were deposited using a conventional Ion Beam Sputtering process. - Highlights: • We use bent magnetic fields to guide and separate the sputtered deposition material. • No line of sight between substrate and target prevents thin films from particles. • The transport efficiency of binary and ternary oxides is investigated. • The defect statistics of manufactured dielectric ternary multilayers are evaluated. • The phase separation leads to a drastically reduction of particle contamination.

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

    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.

  10. Novel design of LNG (liquefied natural gas) reliquefaction process

    Baek, S., E-mail: s.baek@kaist.ac.kr [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Hwang, G.; Lee, C. [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Jeong, S., E-mail: skjeong@kaist.ac.kr [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Choi, D. [Cryogenic Engineering Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Ship/Plant System R and D Team, Daewoo Shipbuilding and Marine Engineering Co., Ltd., 1, Ajoo, Koje, Kyungnam 656-714 (Korea, Republic of)

    2011-08-15

    Highlights: {yields} We performed experiments with LN2 to mock up the new LNG reliquefaction process. {yields} Subcooled liquid goes to heat exchanger, heater, and phase separator. {yields} Reliquefaction occurs when vapor enters heat exchanger and verified by experiments. {yields} Reliquefaction ratio increases when subcooling degree or system pressure increases. - Abstract: This paper presents an investigation of novel LNG reliquefaction process where the cold exergy of subcooled LNG is utilized to recondense the vaporized light component of LNG after it is separated from the heavier component in a phase separator. The regeneration of cold exergy is especially effective as well as important in thermodynamic sense when a cryogenic process is involved. To verify the proposed idea, we performed an experimental study by facilitating liquid nitrogen apparatus to mock up the LNG reliquefaction process. Subcooled liquid nitrogen is produced for a commercial transportation container with a house-made atmospheric liquid nitrogen heat exchanger and then, having subooled degree of up to 19 K, it simulates the behavior of subcooled LNG in the lab-scale reliquefaction experiment. Recondensation of the vaporized gas is possible by using the cold exergy of subcooled liquid in a properly fabricated heat exchanger. Effect of heat exchanger performance factor and degree of subcooling on recondensation portion has been discussed in this paper. It is concluded that utilizing pressurized subcooled liquid that is obtained by liquid pump can surely reduce the pumping power of the vaporized natural gas and save the overall energy expenditure in LNG reliquefaction process.

  11. Novel design of LNG (liquefied natural gas) reliquefaction process

    Baek, S.; Hwang, G.; Lee, C.; Jeong, S.; Choi, D.

    2011-01-01

    Highlights: → We performed experiments with LN2 to mock up the new LNG reliquefaction process. → Subcooled liquid goes to heat exchanger, heater, and phase separator. → Reliquefaction occurs when vapor enters heat exchanger and verified by experiments. → Reliquefaction ratio increases when subcooling degree or system pressure increases. - Abstract: This paper presents an investigation of novel LNG reliquefaction process where the cold exergy of subcooled LNG is utilized to recondense the vaporized light component of LNG after it is separated from the heavier component in a phase separator. The regeneration of cold exergy is especially effective as well as important in thermodynamic sense when a cryogenic process is involved. To verify the proposed idea, we performed an experimental study by facilitating liquid nitrogen apparatus to mock up the LNG reliquefaction process. Subcooled liquid nitrogen is produced for a commercial transportation container with a house-made atmospheric liquid nitrogen heat exchanger and then, having subooled degree of up to 19 K, it simulates the behavior of subcooled LNG in the lab-scale reliquefaction experiment. Recondensation of the vaporized gas is possible by using the cold exergy of subcooled liquid in a properly fabricated heat exchanger. Effect of heat exchanger performance factor and degree of subcooling on recondensation portion has been discussed in this paper. It is concluded that utilizing pressurized subcooled liquid that is obtained by liquid pump can surely reduce the pumping power of the vaporized natural gas and save the overall energy expenditure in LNG reliquefaction process.

  12. Gas processing in the nuclear industry

    Kovach, J.L.

    1995-02-01

    This article is a brief overview of code requirements in the nuclear air cleaning arena. NRC standards, which employ the various ASME codes, are noted. It is also noted that DOE facilities do not fall under the purview of the NRC and that DOE facilities (especially fuel cycle facilities) typically have broader gas processing activities than for power reactors. The typical differences between DOE facilities` and power reactor facilities` gas processing needs are listed, as are DOE facility components not covered by the ASME AG-1 code.

  13. Terminal separation plant for collecting petroleum and by-product gas

    Marinin, N S; Shcherbina, V E; Burma, A I

    1966-06-08

    A separation plant at a transportation terminal, for collecting petroleum and by-product gas, consists of 1 or 2 vessels with gas separating device, automatic control devices, demulsifier distributors, a mixer for mixing hot water with the demulsified residue and raw crude oil stream, an apparatus for supplying oil-in-water emulsion under a water cushion, and 2 separating partitions which are located at the end of the vessel. In order to fully use the volume of the vessel, one partition does not touch the bottom, while the other does not touch the top of the tank.

  14. Effect of swirling device on flow behavior in a supersonic separator for natural gas dehydration

    Wen, Chuang; Li, Anqi; Walther, Jens Honore

    2016-01-01

    is designed for an annular supersonic separator. The supersonic swirling separation flow of natural gas is calculated using the Reynolds Stress model. The results show that the viscous heating and strong swirling flow cause the adverse pressure in the annular channel, which may negatively affect......The supersonic separator is a revolutionary device to remove the condensable components from gas mixtures. One of the key issues for this novel technology is the complex supersonic swirling flow that is not well understood. A swirling device composed of an ellipsoid and several helical blades...

  15. Method for treating a nuclear process off-gas stream

    Pence, Dallas T.; Chou, Chun-Chao

    1984-01-01

    Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO.sub.x, hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140.degree. to -160.degree. C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140.degree. to -160.degree. C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton.

  16. Method for treating a nuclear process off-gas stream

    Pence, D.T.; Chou, C.C.

    1984-01-01

    Disclosed is a method for selectively removing and recovering the noble gas and other gaseous components typically emitted during nuclear process operations. The method is adaptable and useful for treating dissolver off-gas effluents released during reprocessing of spent nuclear fuels whereby to permit radioactive contaminant recovery prior to releasing the remaining off-gases to the atmosphere. Briefly, the method sequentially comprises treating the off-gas stream to preliminarily remove NO /SUB x/ , hydrogen and carbon-containing organic compounds, and semivolatile fission product metal oxide components therefrom; adsorbing iodine components on silver-exchanged mordenite; removing water vapor carried by said stream by means of a molecular sieve; selectively removing the carbon dioxide components of said off-gas stream by means of a molecular sieve; selectively removing xenon in gas phase by passing said stream through a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from oxygen by means of a molecular sieve comprising silver-exchanged mordenite; selectively separating krypton from the bulk nitrogen stream using a molecular sieve comprising silver-exchanged mordenite cooled to about -140 0 to -160 0 C.; concentrating the desorbed krypton upon a molecular sieve comprising silver-exchange mordenite cooled to about -140 0 to -160 0 C.; and further cryogenically concentrating, and the recovering for storage, the desorbed krypton

  17. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    Sypula, Michal

    2013-01-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF Ln/Am obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as a Zr

  18. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    Sypula, Michal

    2013-07-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF{sub Ln/Am} obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as

  19. Combustible gas recombining method and processing facility for gas waste

    Watabe, Atsushi; Murakami, Kazuo

    1998-01-01

    Combustible gases (hydrogen, oxygen) generated by radiation decomposition of reactor water in the vicinity of a reactor core in a reactor pressure vessel of a BWR type nuclear power plant pass, together with flow of steams, through a gas/water separator and a steam dryer disposed at the upper portion of a reactor core. A catalyst for allowing hydrogen and oxygen to react efficiently and recombine them into water is plated on the surface of the steam dryer. The catalyst comprises palladium (Pd) or platinum (Pt) or a Pd-Pt alloy. The combustible gases passing through the steam dryer are recombined and formed into steams by the catalyst. A slight amount of hydrogen and oxygen which are not recombined transfers, together with main steams, from a main steam pipe to a main condensator by way of a turbine. Then they are released, together with air from an air extraction device, from an activated carbon-type rare gas hold up tower. (I.N.)

  20. Data supporting the validation of a simulation model for multi-component gas separation in polymeric membranes.

    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.

  1. Gas processing at DOE nuclear facilities

    Jacox, J.

    1995-02-01

    The term {open_quotes}Gas Processing{close_quotes} has many possible meanings and understandings. In this paper, and panel, we will be using it to generally mean the treatment of gas by methods other than those common to HVAC and Nuclear Air Treatment. This is only a working guideline not a rigorous definition. Whether a rigorous definition is desirable, or even possible is a question for some other forum. Here we will be discussing the practical aspects of what {open_quotes}Gas Processing{close_quotes} includes and how existing Codes, Standards and industry experience can, and should, apply to DOE and NRC Licensed facilities. A major impediment to use of the best engineering and technology in many nuclear facilities is the administrative mandate that only systems and equipment that meet specified {open_quotes}nuclear{close_quotes} documents are permissible. This paper will highlight some of the limitations created by this approach.

  2. Production of stable isotopes utilizing the plasma separation process

    Bigelow, T. S.; Tarallo, F. J.; Stevenson, N. R.

    2005-12-01

    A plasma separation process (PSP) is being operated at Theragenics Corporation's®, Oak Ridge, TN, facility for the enrichment of stable isotopes. The PSP utilizes ion cyclotron mass discrimination to separate isotopes on a relatively large scale. With a few exceptions, nearly any metallic element could be processed with PSP. Output isotope enrichment factor depends on natural abundance and mass separation and can be fairly high in some cases. The Theragenics™ PSP facility is believed to be the only such process currently in operation. This system was developed and formerly operated under the US Department of Energy Advanced Isotope Separation program. Theragenics™ also has a laboratory at the PSP site capable of harvesting the isotopes from the process and a mass spectrometer system for analyzing enrichment and product purity. Since becoming operational in 2002, Theragenics™ has utilized the PSP to separate isotopes of several elements including: dysprosium, erbium, gadolinium, molybdenum and nickel. Currently, Theragenics™ is using the PSP for the separation of 102Pd, which is used as precursor for the production of 103Pd. The 103Pd radioisotope is the active ingredient in TheraSeed®, which is used in the treatment of early stage prostate cancer and being investigated for other medical applications. New industrial, medical and research applications are being investigated for isotopes that can be enriched on the PSP. Pre-enrichment of accelerator or reactor targets offers improved radioisotope production. Theragenics operates 14 cyclotrons for proton activation and has access to HFIR at ORNL for neutron activation of radioisotopes.

  3. Gas separation techniques with liquid Ar for production of 11C ions

    Hojo, Satoru; Honma, Toshihiro; Kanazawa, Mitsutaka; Muramatsu, Masayuki; Sakamoto, Yukio; Sugiura, Akinori; Suzuki, Naokata; Noda, Koji

    2009-01-01

    Heavy-ion cancer therapy with 12 C-beam has been carried out at HIMAC (Heavy Ion Medical Accelerator in Chiba) in NIRS (National Institute of Radiological Sciences) since 1994. One of the feasibility study in HIMAC is to use a positron emitter beam such as 11 C-beam for the cancer therapy. A nuclear reaction, 14 N (p,α) 11 C will be applied in the present study; it can be expected to obtain a considerably large number of 11 C-particles by utilizing the commonly used short-lives RI production techniques for PET (Positron Emission Tomography). The amount of 11 C gas is limited in this technique. The 11 CO 2 gas was produced from N 2 gas that is irradiated high-energy proton beam. Therefore, CO 2 gas separation from N 2 gas is very important. The gas-separation techniques with cryogenic system utilizing a liquid Ar were tested by dummy gas (N 2 + 12 CO 2 ). Details of the gas-separation techniques and measurement of CO 2 partial pressure are discussed. (author)

  4. A Rapid Process for Fabricating Gas Sensors

    Chun-Ching Hsiao

    2014-07-01

    Full Text Available Zinc oxide (ZnO is a low-toxicity and environmentally-friendly material applied on devices, sensors or actuators for “green” usage. A porous ZnO film deposited by a rapid process of aerosol deposition (AD was employed as the gas-sensitive material in a CO gas sensor to reduce both manufacturing cost and time, and to further extend the AD application for a large-scale production. The relative resistance change (△R/R of the ZnO gas sensor was used for gas measurement. The fabricated ZnO gas sensors were measured with operating temperatures ranging from 110 °C to 180 °C, and CO concentrations ranging from 100 ppm to 1000 ppm. The sensitivity and the response time presented good performance at increasing operating temperatures and CO concentrations. AD was successfully for applied for making ZnO gas sensors with great potential for achieving high deposition rates at low deposition temperatures, large-scale production and low cost.

  5. Efficient Separations and Processing Crosscutting Program. Technology summary

    1995-06-01

    The Efficient Separations and Processing (ESP) Crosscutting Program was created in 1991 to identify, develop, and perfect separations technologies and processes to treat wastes and address environmental problems throughout the DOE Complex. The ESP funds several multi-year 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 and D) leading to demonstration or use of these separations technologies by other organizations within DOE-EM. Treating essentially all DOE defense wastes requires separation methods that concentrate the contaminants and/or purify waste streams for release to the environment or for downgrading to a waste form less difficult and expensive to dispose of. Initially, ESP R and D efforts focused on treatment of high-level waste (HLW) from underground storage tanks (USTs) because of the potential for large reductions in disposal costs and hazards. As further separations needs emerge and as waste management and environmental restoration priorities change, the program has evolved to encompass the breadth of waste management and environmental remediation problems

  6. Fluid Phase Separation (FPS) experiment for flight on the shuttle in a Get Away Special (GAS) canister: Design and fabrication

    1990-01-01

    The separation of fluid phases in microgravity environments is of importance to environmental control and life support systems (ECLSS) and materials processing in space. A successful fluid phase separation experiment will demonstrate a proof of concept for the separation technique and add to the knowledge base of material behavior. The phase separation experiment will contain a premixed fluid that will be exposed to a microgravity environment. After the phase separation of the compound has occurred, small samples of each of the species will be taken for analysis on Earth. By correlating the time of separation and the temperature history of the fluid, it will be possible to characterize the process. The phase separation experiment is totally self-contained, with three levels of containment on all fluids, and provides all necessary electrical power and control. The controller regulates the temperature of the fluid and controls data logging and sampling. An astronaut-activated switch will initiate the experiment and an unmaskable interrupt is provided for shutdown. The experiment has been integrated into space available on a manifested Get Away Special (GAS) experiment, CONCAP 2, part of the Consortium for Materials Complex Autonomous Payload (CAP) Program, scheduled for STS 42 in April 1991. Presented here are the design and the production of a fluid phase separation experiment for rapid implementation at low cost.

  7. System efficiency for two-step metal oxide solar thermochemical hydrogen production – Part 2: Impact of gas heat recuperation and separation temperatures

    Ehrhart, Brian D.

    2016-09-22

    The solar-to-hydrogen (STH) efficiency is calculated for various operating conditions for a two-step metal oxide solar thermochemical hydrogen production cycle using cerium(IV) oxide. An inert sweep gas was considered as the O2 removal method. Gas and solid heat recuperation effectiveness values were varied between 0 and 100% in order to determine the limits of the effect of these parameters. The temperature at which the inert gas is separated from oxygen for an open-loop and recycled system is varied. The hydrogen and water separation temperature was also varied and the effect on STH efficiency quantified. This study shows that gas heat recuperation is critical for high efficiency cycles, especially at conditions that require high steam and inert gas flowrates. A key area for future study is identified to be the development of ceramic heat exchangers for high temperature gas-gas heat exchange. Solid heat recuperation is more important at lower oxidation temperatures that favor temperature-swing redox processing, and the relative impact of this heat recuperation is muted if the heat can be used elsewhere in the system. A high separation temperature for the recycled inert gas has been shown to be beneficial, especially for cases of lower gas heat recuperation and increased inert gas flowrates. A higher water/hydrogen separation temperature is beneficial for most gas heat recuperation effectiveness values, though the overall impact on optimal system efficiency is relatively small for the values considered. © 2016 Hydrogen Energy Publications LLC.

  8. Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport

    Afrooz Farjoo

    2017-10-01

    Full Text Available Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene was studied within the temperature and pressure ranges of 25–600 °C and 110–160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption–diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

  9. Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport.

    Farjoo, Afrooz; Kuznicki, Steve M; Sadrzadeh, Mohtada

    2017-10-06

    Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene) was studied within the temperature and pressure ranges of 25-600 °C and 110-160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption-diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

  10. The multiple gas-liquid subsea separation system: development and qualification of a novel solution for deep water field production

    Abrand, Stephanie; Butin, Nicolas; Shaiek, Sadia; Hallot, Raymond [Saipem S.p.A., Milano (Italy)

    2012-07-01

    Subsea processing is more and more considered as a viable solution for the development of deep and ultra deep water fields. SAIPEM has developed a deep water gas separation and liquid boosting system, based on its proprietary 'Multi pipe' separator concept, providing a good flexibility in handling a wide range of steady and un-steady multiphase input streams using a relatively simple mechanical arrangement. The Multi pipe Concept features an array of vertical pipes for gas/liquid separation by gravity and adequate liquid hold up volumes. The operating principle is the same as standard gravity vessels. Specific inlet pipe arrangements have been worked out to enhance the separation efficiency and internals can be implemented to further optimize the performances. The limited diameter and wall thickness of the vertical pipes make the Multi pipe Concept particularly suited for deep and ultra-deep water applications and/or high pressure conditions where the selection of a single separator vessel could lead to unpractical wall thicknesses. In most cases, standard API or ASME pipes can be utilized for the Multi pipe Separator, thus enabling conventional fabrication methods, and in turn reducing cost and delivery time and opening opportunities for local content. The qualification testing program has seen two subsequent phases. The first qualification phase aimed at the confirmation of the hydrodynamic behavior of the system. In particular, the homogeneous distribution of the multiphase stream into the pipes and the stability of the liquid levels under un-steady inlet conditions were continuously assessed during the tests. This first qualification phase gave confidence in the viability of the Multi pipe and in its good hydrodynamic behavior under the different inlet conditions that can be encountered during field production. It proved that, having the same liquid level in all the separator pipes, whatever the inlet conditions are, the Multi pipe separator can be

  11. Reactive molecular dynamic simulations on the gas separation performance of porous graphene membrane.

    Esfandiarpoor, Somaye; Fazli, Mostafa; Ganji, Masoud Darvish

    2017-11-29

    The separation of gases molecules with similar diameter and shape is an important area of research. For example, the major challenge to set up sweeping carbon dioxide capture and storage (CCS) in power plants is the energy requisite to separate the CO 2 from flue gas. Porous graphene has been proposed as superior material for highly selective membranes for gas separation. Here we design some models of porous graphene with different sizes and shape as well as employ double layers porous graphene for efficient CO 2 /H 2 separation. The selectivity and permeability of gas molecules through various nanopores were investigated by using the reactive molecular dynamics simulation which considers the bond forming/breaking mechanism for all atoms. Furthermore, it uses a geometry-dependent charge calculation scheme that accounts appropriately for polarization effect which can play an important role in interacting systems. It was found that H-modified porous graphene membrane with pore diameter (short side) of about 3.75 Å has excellent selectivity for CO 2 /H 2 separation. The mechanism of gas penetration through the sub-nanometer pore was presented for the first time. The accuracy of MD simulation results validated by valuable DFT method. The present findings show that reactive MD simulation can propose an economical means of separating gases mixture.

  12. Thermodynamic and Process Modelling of Gas Hydrate Systems in CO2 Capture Processes

    Herslund, Peter Jørgensen

    A novel gas separation technique based on gas hydrate formation (solid precipitation) is investigated by means of thermodynamic modeling and experimental investigations. This process has previously been proposed for application in post-combustion carbon dioxide capture from power station flue gases...... formation may be performed at pressures of approximately 20 MPa and temperatures below 280 K. Thermodynamic promoters are needed, to reduce the pressure requirement of the process, thereby making it competitive to existing capture technologies. A literature study is presented focusing mainly...... on thermodynamic gas hydrate promotion by hydrate formers stabilising the classical gas clathrate hydrate structures (sI, sII and sH) at low to moderate pressures. Much literature is available on this subject. Both experimental and theoretical studies presented in the literature have pointed out cyclopentane...

  13. Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes

    Roughton, Brock C.; White, John; Camarda, Kyle V.

    2011-01-01

    A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using the b...... % [BMPy][BF4] added. The driving force concept is used to design an extractive distillation process that minimizes energy inputs. The methodology given can be expanded to the use of ionic liquids as entrainers in any azeotropic system of interest.......A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using...

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

    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

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

    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

  16. Numerical simulation of onshore separation processes - residence time optimization

    Fonte, Clarissa Bergman; Oliveira Junior, Joao Americo Aguirre [Engineering Simulation and Scientific Software (ESSS), Florianopolis, SC (Brazil)], E-mails: clarissa@esss.com.br, joao.aguirre@esss.com.br; Dutra, Eduardo Stein Soares [PETROBRAS E e P Engenharia de Producao, Rio de Janeiro, RJ (Brazil). Gerencia de Engenharia de Instalacoes de Superficie e Automacao], E-mail: eduardodutra@petrobras.com.br

    2011-04-15

    Cylindrical tanks are commonly used in onshore facilities to process and treat oil and water streams. These tanks generate a gravitational separation and, when sedimentation velocity is reached, the residence time inside the tank is crucial to guarantee proper separation. The ideal geometry for a tank maximizes the effective residence time by providing the largest possible fluid path, along which sedimentation of the denser phase occurs. Large volume tanks can be used for this purpose. However, internal devices, which increase the effective residence time and decrease undesirable hydrodynamic effects, are a commonly used alternative, allowing a reduction in tank size. This study focuses on the application of computational fluid dynamics as a tool to analyze four geometries found in gravitational separation tanks to identify that which offers the highest residence time values. (author)

  17. Ceramic membranes for gas processing in coal gasification

    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.

  18. Tax issues in structuring gas process arrangements

    Iverach, R.J.

    1999-01-01

    The current status of various tax issues regarding ownership, operation and financing of gas processing facilities in Canada was discussed. Frequently, energy companies are not taxed because of their large pools of un-depreciated capital cost and other resource related accounts. In addition, their time horizons for taxability are being extended in line with the expansion of their businesses. However, other investors are fully taxable, hence they wish to shelter their income through the use of tax efficient investment arrangements. This paper provides a detailed description of the tax treatment of gas processing facilities, tax implications of various structures between the producer and the investor such as lease, processing fee arrangements etc., and use of 'Canadian Renewable and Conservation Expense' (CRCE) for cogeneration projects within processing plants. All these need to be considered before completing a financing transaction involving a gas processing facility, since the manner in which the transaction is completed will determine the advantages and benefits from an income tax perspective. The accounting and legal aspects must be similarly scrutinized to ensure that the intended results for all parties are achieved. 8 figs

  19. Economics of natural gas conversion processes

    Gradassi, M.J.; Green, N.W.

    1995-01-01

    This paper examines the potential profitability of a selected group of possible natural gas conversion processes from the perspective of a manufacturing entity that has access to substantial low cost natural gas reserves, capital to invest, and no allegiance to any particular product. The analysis uses the revenues and costs of conventional methanol technology as a framework to evaluate the economics of the alternative technologies. Capital requirements and the potential to enhance cash margins are the primary focus of the analysis. The basis of the analysis is a world-scale conventional methanol plant that converts 3.2 Mm 3 per day (120 MMSCFD) of natural gas into 3510 metric tonnes (3869 shorts tons) per day of methanol. Capital and operating costs are for an arbitrary remote location where natural gas is available at 0.47 US dollars per GJ (0.50 US dollars per MMBtu). Other costs include ocean freight to deliver the product to market at a US Gulf Coast location. Payout time, which is the ratio of the total capital investment to cash margin (revenue less total operating expenses), is the economic indicator for the analysis. Under these conditions, the payout time for the methanol plant is seven years. The payout time for the alternative natural gas conversion technologies is generally much higher, which indicates that they currently are not candidates for commercialization without consideration of special incentives. The analysis also includes an evaluation of the effects of process yields on the economics of two potential technologies, oxidative coupling to ethylene and direct conversion to methanol. This analysis suggests areas for research focus that might improve the profitability of natural gas conversion. 29 refs., 14 figs., 5 tabs

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

    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.

  1. Basic studies of a gas-jet-coupled ion source for on-line isotope separation

    Anderl, R.A.; Novick, V.J.; Greenwood, R.C.

    1980-01-01

    A hollow-cathode ion source was used in a gas-jet-coupled configuration to produce ion beams of fission products transported to it from a 252 Cf fission source. Solid aerosols of NaCl and Ag were used effectively as activity carriers in the gas-jet system. Flat-plate skimmers provided an effective coupling of the ion source to the gas jet. Ge(Li) spectrometric measurements of the activity deposited on an ion-beam collector relative to that deposited on a pre-skimmer collector were used to obtain separation efficiencies ranging from 0.1% to > 1% for Sr, Y, Tc, Te, Cs, Ba, Ce, Pr, Nd and Sm. The use of CCl 4 as a support gas resulted in a significant enhancement of the alkaline-earth and rare-earth separation efficiencies

  2. Introduction to gas lasers with emphasis on selective excitation processes

    Willett, Colin S

    1974-01-01

    Introduction to Gas Lasers: Population Inversion Mechanisms focuses on important processes in gas discharge lasers and basic atomic collision processes that operate in a gas laser. Organized into six chapters, this book first discusses the historical development and basic principles of gas lasers. Subsequent chapters describe the selective excitation processes in gas discharges and the specific neutral, ionized and molecular laser systems. This book will be a valuable reference on the behavior of gas-discharge lasers to anyone already in the field.

  3. Numerical predictions of the separation of heavy components inside the trace gas concentrator

    Mo, J.D.

    1995-01-01

    The component with a heavier molecular weight can be separated from the one with a lighter molecular weight in a binary mixture by applying an appropriate pressure gradient. A centrifugal force field effectively generates the required pressure gradient and a favorable flow field along the radial direction in a trace gas concentrator for such an application. This paper presents the numerical predictions of the mass separation inside a trace gas concentrator, which enriches Xenon in air. A Navier-Stokes solver in primitive variables using a pressure based algorithm has been applied to solve for the flow fields. Subsequently, the transport equations with a strong centrifugal field are solved for the mass concentration. This study is the continued effort for the proof-of-concept of centrifugal separation of components with a considerable difference in their molecular weight in a binary mixture. The significant effects of rotational speed, flow field, and the geometrical configuration on the mass separation are presented in this paper

  4. Numerical Study Of Flue Gas Flow In A Multi Cyclone Separator

    Ganga Reddy C; Umesh Kuppuraj

    2015-01-01

    The removal of harmful particulate matter from power plant flue gas is of critical importance to the environment and its inhabitants. The present work illustrates the use of multi-cyclone separators to remove the particulate matter from the bulk of the gas exhausted to the atmosphere. The method has potential to replace conventional systems like electrostatic precipitator due to inherent low power requirement and low maintenance. A parametric model may be employed to design the sy...

  5. Next-generation TCAP hydrogen isotope separation process

    Heung, L. K.; Sessions, H. T.; Poore, A. S.; Jacobs, W. D.; Williams, C. S.

    2008-01-01

    A thermal cycling absorption process (TCAP) for hydrogen isotope separation has been in operation at Savannah River Site since 1994. The process uses a hot/cold nitrogen system to cycle the temperature of the separation column. The hot/cold nitrogen system requires the use of large compressors, heat exchanges, valves and piping that is bulky and maintenance intensive. A new compact thermal cycling (CTC) design has recently been developed. This new design uses liquid nitrogen tubes and electric heaters to heat and cool the column directly so that the bulky hot/cold nitrogen system can be eliminated. This CTC design is simple and is easy to implement, and will be the next generation TCAP system at SRS. A twelve-meter column has been fabricated and installed in the laboratory to demonstrate its performance. The design of the system and its test results to date is discussed. (authors)

  6. Separation of Metals From Spent Catalysts Waste by Bioleaching Process

    Sirin Fairus, Tria Liliandini, M.Febrian, Ronny Kurniawan

    2010-01-01

    A kind of waste that hard to be treated is a metal containing solid waste. Leaching method is one thealternative waste treatment. But there still left an obstacle on this method, it is the difficulty to find theselective solvent for the type of certain metal that will separated. Bioleaching is one of the carry ablealternative waste treatments to overcome that obstacle. Bioleaching is a metal dissolving process orextraction from a sediment become dissolve form using microorganisms. On this met...

  7. Countercurrent Process for Lignin Separation from Biomass Matrix

    Kiran Kadam; Ed Lehrburger

    2006-03-31

    The overall goal of the project was to test the concept of using a twin-screw extruder to conduct autohydrolysis pretreatment of wheat straw in countercurrent fashion, demonstrate in situ solid/liquid separation, and produce a low-lignin cellulose product using ethanol as an extractant. The resultant solid product is suitable for sugar production through enzymatic hydrolysis and for pulp applications. Pilot-scale equipment was used to successfully demonstrate the process both for sugar and pulp applications.

  8. 1991 worldwide refining and gas processing directory

    Anon.

    1990-01-01

    This book ia an authority for immediate information on the industry. You can use it to find new business, analyze market trends, and to stay in touch with existing contacts while making new ones. The possibilities for business applications are numerous. Arranged by country, all listings in the directory include address, phone, fax and telex numbers, a description of the company's activities, names of key personnel and their titles, corporate headquarters, branch offices and plant sites. This newly revised edition lists more than 2000 companies and nearly 3000 branch offices and plant locations. This east-to-use reference also includes several of the most vital and informative surveys of the industry, including the U.S. Refining Survey, the Worldwide Construction Survey in Refining, Sulfur, Gas Processing and Related Fuels, the Worldwide Refining and Gas Processing Survey, the Worldwide Catalyst Report, and the U.S. and Canadian Lube and Wax Capacities Report from the National Petroleum Refiner's Association

  9. A Mathematical Model of Membrane Gas Separation with Energy Transfer by Molecules of Gas Flowing in a Channel to Molecules Penetrating this Channel from the Adjacent Channel

    Szwast Maciej

    2015-06-01

    Full Text Available The paper presents the mathematical modelling of selected isothermal separation processes of gaseous mixtures, taking place in plants using membranes, in particular nonporous polymer membranes. The modelling concerns membrane modules consisting of two channels - the feeding and the permeate channels. Different shapes of the channels cross-section were taken into account. Consideration was given to co-current and counter-current flows, for feeding and permeate streams, respectively, flowing together with the inert gas receiving permeate. In the proposed mathematical model it was considered that pressure of gas changes along the length of flow channels was the result of both - the drop of pressure connected with flow resistance, and energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel. The literature on membrane technology takes into account only the drop of pressure connected with flow resistance. Consideration given to energy transfer by molecules of gas flowing in a given channel to molecules which penetrate this channel from the adjacent channel constitute the essential novelty in the current study. The paper also presents results of calculations obtained by means of a computer program which used equations of the derived model. Physicochemical data concerning separation of the CO2/CH4 mixture with He as the sweep gas and data concerning properties of the membrane made of PDMS were assumed for calculations.

  10. Recent advances in SRS on hydrogen isotope separation using thermal cycling absorption process

    Xiao, X.; Kit Heung, L.; Sessions, H.T. [Savannah River National Laboratory - SRNL, Aiken, SC (United States)

    2015-03-15

    TCAP (Thermal Cycling Absorption Process) is a gas chromatograph in principle using palladium in the column packing, but it is unique in the fact that the carrier gas, hydrogen, is being isotopically separated and the system is operated in a semi-continuous manner. TCAP units are used to purify tritium. The recent TCAP advances at Savannah River Site (SRS) include compressor-free concept for heating/cooling, push and pull separation using an active inverse column, and compact column design. The new developments allow significantly higher throughput and better reliability from 1/10 of the current production system's footprint while consuming 60% less energy. Various versions are derived in the meantime for external customers to be used in fusion energy projects.

  11. Raw materials for advanced ceramics: rare earths separation processes

    Ricci, D.R.; Nobre, J.S.M.; Paschoal, J.O.A.

    1990-01-01

    The importance of obtaining purified rare earths oxidesis related, mainly to the increasing use of these compounds as raw materials for advanced ceramics. Processes of rare earths separation and purification are almost always based on the solvent extraction, fractional precipitation and ion exchange chromatography techniques, whose association depends on the initial concentrate and on the desired purity. This paper describes some steps of fractionation of didymium carbonate by using the solvent extraction and fractional precipitation techniques. The experimental conditions presented here have enable the production of lantanium, neodimium - praseodimium, samarium - gadolinium and ytrium concentrates, which constitute the intermediate fractions of the overall process to obtain high purity rare earths. (author) [pt

  12. Nitrogen Trifluoride-Based Fluoride- Volatility Separations Process: Initial Studies

    McNamara, Bruce K.; Scheele, Randall D.; Casella, Andrew M.; Kozelisky, Anne E.

    2011-09-28

    This document describes the results of our investigations on the potential use of nitrogen trifluoride as the fluorinating and oxidizing agent in fluoride volatility-based used nuclear fuel reprocessing. The conceptual process uses differences in reaction temperatures between nitrogen trifluoride and fuel constituents that produce volatile fluorides to achieve separations and recover valuable constituents. We provide results from our thermodynamic evaluations, thermo-analytical experiments, kinetic models, and provide a preliminary process flowsheet. The evaluations found that nitrogen trifluoride can effectively produce volatile fluorides at different temperatures dependent on the fuel constituent.

  13. Porous materials as high performance adsorbents for CO2 capture, gas separation and purification

    Wang, Jun

    Global warming resulted from greenhouse gases emission has received a widespread attention. Among the greenhouse gases, CO2 contributes more than 60% to global warming due to its huge emission amount. The flue gas contains about 15% CO2 with N2 as the balance. If CO2 can be separated from flue gas, the benefit is not only reducing the global warming effect, but also producing pure CO2 as a very useful industry raw material. Substantial progress is urgent to be achieved in an industrial process. Moreover, energy crisis is one of the biggest challenges for all countries due to the short life of fossil fuels, such as, petroleum will run out in 50 years and coal will run out in 150 years according to today's speed. Moreover, the severe pollution to the environment caused by burning fossil fuels requires us to explore sustainable, environment-friendly, and facile energy sources. Among several alternative energy sources, natural gas is one of the most promising alternative energy sources due to its huge productivity, abundant feed stock, and ease of generation. In order to realize a substantial adsorption process in industry, synthesis of new adsorbents or modification of existing adsorbent with improved properties has become the most critical issue. This dissertation reports systemic characterization and development of five serials of novel adsorbents with advanced adsorption properties. In chapter 2, nitrogen-doped Hypercross-linking Polymers (HCPs) have been synthesized successfully with non-carcinogenic chloromethyl methyl ether (CME) as the cross-linking agent within a single step. Texture properties, surface morphology, CO2/N2 selectivity, and adsorption heat have been presented and demonstrated properly. A comprehensive discussion on factors that affect the CO2 adsorption and CO2/N 2 separation has also been presented. It was found that high micropore proportion and N-content could effectively enhance CO2 uptake and CO2/N2 separation selectivity. In chapter 3, a

  14. Used nuclear fuel separations process simulation and testing

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D.

    2013-01-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  15. Used nuclear fuel separations process simulation and testing

    Pereira, C.; Krebs, J.F.; Copple, J.M.; Frey, K.E.; Maggos, L.E.; Figueroa, J.; Willit, J.L.; Papadias, D.D. [Argonne National Laboratory: 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2013-07-01

    Recent efforts in separations process simulation at Argonne have expanded from the traditional focus on solvent extraction flowsheet design in order to capture process dynamics and to simulate other components, processing and systems of a used nuclear fuel reprocessing plant. For example, the Argonne Model for Universal Solvent Extraction (AMUSE) code has been enhanced to make it both more portable and more readily extensible. Moving away from a spreadsheet environment makes the addition of new species and processes simpler for the expert user, which should enable more rapid implementation of chemical models that simulate evolving processes. The dyAMUSE (dynamic AMUSE) version allows the simulation of transient behavior across an extractor. Electrochemical separations have now been modeled using spreadsheet codes that simulate the electrochemical recycle of fast reactor fuel. The user can follow the evolution of the salt, products, and waste compositions in the electro-refiner, cathode processors, and drawdown as a function of fuel batches treated. To further expand capabilities in integrating multiple unit operations, a platform for linking mathematical models representing the different operations that comprise a reprocessing facility was adapted to enable systems-level analysis and optimization of facility functions. (authors)

  16. Process for selected gas oxide removal by radiofrequency catalysts

    Cha, Chang Y.

    1993-01-01

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

  17. Generalized Least Energy of Separation for Desalination and Other Chemical Separation Processes

    Karan H. Mistry

    2013-05-01

    Full Text Available Increasing global demand for fresh water is driving the development and implementation of a wide variety of seawater desalination technologies driven by different combinations of heat, work, and chemical energy. This paper develops a consistent basis for comparing the energy consumption of such technologies using Second Law efficiency. The Second Law efficiency for a chemical separation process is defined in terms of the useful exergy output, which is the minimum least work of separation required to extract a unit of product from a feed stream of a given composition. For a desalination process, this is the minimum least work of separation for producing one kilogram of product water from feed of a given salinity. While definitions in terms of work and heat input have been proposed before, this work generalizes the Second Law efficiency to allow for systems that operate on a combination of energy inputs, including fuel. The generalized equation is then evaluated through a parametric study considering work input, heat inputs at various temperatures, and various chemical fuel inputs. Further, since most modern, large-scale desalination plants operate in cogeneration schemes, a methodology for correctly evaluating Second Law efficiency for the desalination plant based on primary energy inputs is demonstrated. It is shown that, from a strictly energetic point of view and based on currently available technology, cogeneration using electricity to power a reverse osmosis system is energetically superior to thermal systems such as multiple effect distillation and multistage flash distillation, despite the very low grade heat input normally applied in those systems.

  18. Separation processes for high-level radioactive waste treatment

    Sutherland, D.G.

    1992-11-01

    During World War II, production of nuclear materials in the United States for national defense, high-level waste (HLW) was generated as a byproduct. Since that time, further quantities of HLW radionuclides have been generated by continued nuclear materials production, research, and the commercial nuclear power program. In this paper HLW is defined as the highly radioactive material resulting from the processing of spent nuclear fuel. The HLW is the liquid waste generated during the recovery of uranium and plutonium in a fuel processing plant that generally contains more than 99% of the nonvolatile fission products produced during reactor operation. Since this paper deals with waste separation processes, spent reactor fuel elements that have not been dissolved and further processed are excluded

  19. Gas-liquid two-phase flows in double inlet cyclones for natural gas separation

    Yang, Yan; Wang, Shuli; Wen, Chuang

    2017-01-01

    The gas-liquid two-phase flow within a double inlet cyclone for natural gasseparation was numerically simulated using the discrete phase model. The numericalapproach was validated with the experimental data, and the comparison resultsagreed well with each other. The simulation results showed...... that the strong swirlingflow produced a high centrifugal force to remove the particles from the gas mixture.The larger particles moved downward on the internal surface and were removeddue to the outer vortex near the wall. Most of the tiny particles went into the innervortex zones and escaped from the up...

  20. ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE REACTOR SYSTEM - APPLICATIONS ANALYSIS REPORT

    The ELI Eco Logic International Inc. (Eco Logic) process thermally separates organics, then chemically reduces them in a hydrogen atmosphere, converting them to a reformed gas that consists of light hydrocarbons and water. A scrubber treats the reformed gas to remove hydrogen chl...

  1. Magnetic separation as a plutonium residue enrichment process

    Avens, L.R.; Gallegos, U.F.; McFarlan, J.T.

    1990-01-01

    Several plutonium contaminated residues have been subjected to Open Gradient Magnetic Separation (OGMS) on an experimental scale. OGMS experiments on graphite and bomb reduction residues resulted in a plutonium rich fraction and a plutonium lean fraction. Values for the bulk quantity rejected to the lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the lean fraction plutonium content was too high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. 6 refs., 1 fig., 9 tabs

  2. Implications of permeation through intrinsic defects in graphene on the design of defect-tolerant membranes for gas separation.

    Boutilier, Michael S H; Sun, Chengzhen; O'Hern, Sean C; Au, Harold; Hadjiconstantinou, Nicolas G; Karnik, Rohit

    2014-01-28

    Gas transport through intrinsic defects and tears is a critical yet poorly understood phenomenon in graphene membranes for gas separation. We report that independent stacking of graphene layers on a porous support exponentially decreases flow through defects. On the basis of experimental results, we develop a gas transport model that elucidates the separate contributions of tears and intrinsic defects on gas leakage through these membranes. The model shows that the pore size of the porous support and its permeance critically affect the separation behavior, and reveals the parameter space where gas separation can be achieved regardless of the presence of nonselective defects, even for single-layer membranes. The results provide a framework for understanding gas transport in graphene membranes and guide the design of practical, selectively permeable graphene membranes for gas separation.

  3. Gas retorts: gas manufacture, process for distillation, destructive

    Bell, J

    1874-05-23

    In apparatus for distilling shale, coal, etc. for making oil and gas, tubular retorts are supported horizontally in a chamber by plates from a brick setting and are heated partly by jets of gas from a pipe supplied through a cock from a gas holder, and partly by the waste gases from a furnace, which heats gas retorts placed in a chamber, air being supplied beneath the grate by a fan.

  4. Azide-based cross-linking of polymers of intrinsic microporosity (PIMs) for condensable gas separation

    Du, Naiying; Dal-Cin, Mauro M D; Pinnau, Ingo; Nicalek, Andrzej; Robertson, Gilles P.; Guiver, Michael D.

    2011-01-01

    Cross-linked polymers of intrinsic microporosity (PIM)s for gas separation membranes, were prepared by a nitrene reaction from a representative PIM in the presence of two different diazide cross-linkers. The reaction temperature was optimized using TGA. The homogenous membranes were cast from THF solutions of different ratios of PIM to azides. The resulting cross-linked structures of the PIMs membranes were formed at 175 °C after 7.5 h and confirmed by TGA, XPS, FT-IR spectroscopy and gel content analysis. These resulting cross-linked polymeric membranes showed excellent gas separation performance and can be used for O 2/N 2 and CO 2/N 2 gas pairs, as well as for condensable gases, such as CO 2/CH 4, propylene/propane separation. Most importantly, and differently from typical gas separation membranes derived from glassy polymers, the crosslinked PIMs showed no obvious CO 2 plasticization up to 20 atm pressure of pure CO 2 and CO 2/CH 4 mixtures. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Azide-based cross-linking of polymers of intrinsic microporosity (PIMs) for condensable gas separation

    Du, Naiying

    2011-03-11

    Cross-linked polymers of intrinsic microporosity (PIM)s for gas separation membranes, were prepared by a nitrene reaction from a representative PIM in the presence of two different diazide cross-linkers. The reaction temperature was optimized using TGA. The homogenous membranes were cast from THF solutions of different ratios of PIM to azides. The resulting cross-linked structures of the PIMs membranes were formed at 175 °C after 7.5 h and confirmed by TGA, XPS, FT-IR spectroscopy and gel content analysis. These resulting cross-linked polymeric membranes showed excellent gas separation performance and can be used for O 2/N 2 and CO 2/N 2 gas pairs, as well as for condensable gases, such as CO 2/CH 4, propylene/propane separation. Most importantly, and differently from typical gas separation membranes derived from glassy polymers, the crosslinked PIMs showed no obvious CO 2 plasticization up to 20 atm pressure of pure CO 2 and CO 2/CH 4 mixtures. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Hybrid gas separation membranes containing star-shaped polystyrene with the fullerene (C60) core

    Pulyalina, A. Y.; Rostovtseva, V. A.; Pientka, Zbyněk; Vinogradova, L. V.; Polotskaya, G. A.

    2018-01-01

    Roč. 58, č. 4 (2018), s. 296-303 ISSN 0965-5441 Institutional support: RVO:61389013 Keywords : gas separation * hybrid membranes * star-shaped macromolecules Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 0.493, year: 2016

  7. Gas separation membranes for zero-emission fossil power plants: MEM-BRAIN

    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

  8. Thin film composite membranes of glossy polymers for gas separation : preparation and characterization

    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

  9. Ionomers of intrinsic microporosity: in silico development of ionic-functionalized gas-separation membranes.

    Hart, Kyle E; Colina, Coray M

    2014-10-14

    This work presents the predictive molecular simulations of a functionalized polymer of intrinsic microporosity (PIM) with an ionic backbone (carboxylate) and extra-framework counterions (Na(+)) for CO2 gas storage and separation applications. The CO2-philic carboxylate-functionalized polymers are predicted to contain similar degrees of free volume to PIM-1, with Brunauer-Emmett-Teller (BET) surface areas from 510 to 890 m(2)/g, depending on concentration of ionic groups from 100% to 17%. As a result of ionic groups enhancing the CO2 enthalpy of adsorption (to 42-50 kJ/mol), the uptake of the proposed polymers at 293 K exceeded 1.7 mmol/g at 10 kPa and 3.3 mmol/g at 100 kPa for the polymers containing 100% and 50% ionic functional groups, respectively. In addition, CO2/CH4 and CO2/N2 mixed-gas separation performance was evaluated under several industrially relevant conditions, where the IonomIMs are shown to increase both the working capacity and selection performance in certain pressure swing applications (e.g., natural gas separations). These simulations reveal that intrinsically microporous ionomers show great potential as the future of energy-efficient gas-separation polymeric materials.

  10. Formation of defect-free 6FDA-DAM asymmetric hollow fiber membranes for gas separations

    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

  11. In-beam electron spectrometer used in conjunction with a gas-filled recoil separator

    Kankaanpaeae, H.; Butler, P.A.; Greenlees, P.T.; Bastin, J.E.; Herzberg, R.D.; Humphreys, R.D.; Jones, G.D.; Jones, P.; Julin, R.; Keenan, A.; Kettunen, H.; Leino, M.; Miettinen, L.; Page, T.; Rahkila, P.; Scholey, C.; Uusitalo, J.

    2004-01-01

    The conversion-electron spectrometer SACRED has been redesigned for use in conjunction with the RITU gas-filled recoil separator. The system allows in-beam recoil-decay-tagging (RDT) measurements of internal conversion electrons. The performance of the system using standard sources and in-beam is described

  12. Synthesis and characterization of polybenzoxazinone and its prepolymer using gas separation

    Pientka, Zbyněk; Brožová, Libuše; Pulyalina, A. Y.; Goikhman, M. Y.; Podeshvo, I. V.; Gofman, I. V.; Saprykina, N. N.; Polotskaya, G. A.

    2013-01-01

    Roč. 214, č. 24 (2013), s. 2867-2874 ISSN 1022-1352 R&D Projects: GA ČR GA104/09/1165 Institutional support: RVO:61389013 Keywords : gas separation * polybenzoxazinone * polymer membranes Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.451, year: 2013

  13. ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel

    Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil; Drnevich, Raymond Francis

    2013-04-02

    The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

  14. Mathematical modeling of filling of gas centrifuge cascade for nickel isotope separation by various feed flow rate

    Ushakov, Anton; Orlov, Alexey; Sovach, Victor P.

    2018-03-01

    This article presents the results of research filling of gas centrifuge cascade for separation of the multicomponent isotope mixture with process gas by various feed flow rate. It has been used mathematical model of the nonstationary hydraulic and separation processes occurring in the gas centrifuge cascade. The research object is definition of the regularity transient of nickel isotopes into cascade during filling of the cascade. It is shown that isotope concentrations into cascade stages after its filling depend on variable parameters and are not equal to its concentration on initial isotope mixture (or feed flow of cascade). This assumption is used earlier any researchers for modeling such nonstationary process as set of steady-state concentration of isotopes into cascade. Article shows physical laws of isotope distribution into cascade stage after its filling. It's shown that varying each parameters of cascade (feed flow rate, feed stage number or cascade stage number) it is possible to change isotope concentration on output cascade flows (light or heavy fraction) for reduction of duration of further process to set of steady-state concentration of isotopes into cascade.

  15. Advanced Acid Gas Separation Technology for the Utilization of Low Rank Coals

    Kloosterman, Jeff

    2012-12-31

    Air Products has developed a potentially ground-breaking technology – Sour Pressure Swing Adsorption (PSA) – to replace the solvent-based acid gas removal (AGR) systems currently employed to separate sulfur containing species, along with CO{sub 2} and other impurities, from gasifier syngas streams. The Sour PSA technology is based on adsorption processes that utilize pressure swing or temperature swing regeneration methods. Sour PSA technology has already been shown with higher rank coals to provide a significant reduction in the cost of CO{sub 2} capture for power generation, which should translate to a reduction in cost of electricity (COE), compared to baseline CO{sub 2} capture plant design. The objective of this project is to test the performance and capability of the adsorbents in handling tar and other impurities using a gaseous mixture generated from the gasification of lower rank, lignite coal. The results of this testing are used to generate a high-level pilot process design, and to prepare a techno-economic assessment evaluating the applicability of the technology to plants utilizing these coals.

  16. Performance of a Novel Gas Separation Research Column at Sanford Laboratory

    Alanson Chiller, Angela; Chiller, Christopher; Mei, Dongming

    2014-03-01

    A world-wide rise in demand for ultrapure materials has necessitated innovation in the production of low impurity and isotopically separated materials that either has not been utilized in these new applications or relies on aging or energy intensive methods. These materials are sought after for large physics investigations, nuclear non-proliferation detection industries, medical imaging and new frontiers in electronic applications. Techniques in separating and purifying nuclear magnetic resonance isotopes of carbon, oxygen, xenon, krypton, and nitrogen are being developed at Sanford Laboratory, Lead, SD. A two-meter laboratory scale selective phase change column designed specifically for real-time sampling of the gas space at specific temperature and pressure is operated at gas/liquid and gas/solid equilibrium temperatures and pressures for selected gases. We report initial results and future applications. Research Funded by SD Governors 2010 Center.

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

    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)

  18. Influence of riser-induced slugs on the downstream separation processes

    Pedersen, Simon; Løhndorf, Petar Durdevic; Yang, Zhenyu

    2017-01-01

    In Oil & Gas installations the severe slug is an undesired flow regime due to the negative impact on the production rate and facility safety. This study will evaluate the severe riser-induced slugs’ influence to a typical separation process, consisting of a 3-phase gravity separator physically...... linked to a de-oiling hydrocyclone, based on experimental tests performed on a laboratory testing facility. Several scenarios are compared, while three PID controllers’ coefficients are kept constant for all the tests: The separator pressure, water level, and hydrocyclone pressure-drop-ratio (PDR......) controllers. Each respective scenario makes a comparison between uncontrolled, open-, and closed-loop anti-slug control configurations. It is concluded that both open- and closed-loop anti-slug control strategies improve the water level and PDR setpoint tracking equally well, but that the closed-loop strategy...

  19. Gasoline from natural gas by sulfur processing

    Erekson, E.J.; Miao, F.Q. [Institute of Gas Technology, Des Plaines, IL (United States)

    1995-12-31

    The overall objective of this research project is to develop a catalytic process to convert natural gas to liquid transportation fuels. The process, called the HSM (Hydrogen Sulfide-Methane) Process, consists of two steps that each utilize a catalyst and sulfur-containing intermediates: (1) converting natural gas to CS{sub 2} and (2) converting CS{sub 2} to gasoline range liquids. Catalysts have been found that convert methane to carbon disulfide in yields up to 98%. This exceeds the target of 40% yields for the first step. The best rate for CS{sub 2} formation was 132 g CS{sub 2}/kg-cat-h. The best rate for hydrogen production is 220 L H{sub 2} /kg-cat-h. A preliminary economic study shows that in a refinery application hydrogen made by the HSM technology would cost $0.25-R1.00/1000 SCF. Experimental data will be generated to facilitate evaluation of the overall commercial viability of the process.

  20. Recent progress of chiral stationary phases for separation of enantiomers in gas chromatography.

    Xie, Sheng-Ming; Yuan, Li-Ming

    2017-01-01

    Chromatography techniques based on chiral stationary phases are widely used for the separation of enantiomers. In particular, gas chromatography has developed rapidly in recent years due to its merits such as fast analysis speed, lower consumption of stationary phases and analytes, higher column efficiency, making it a better choice for chiral separation in diverse industries. This article summarizes recent progress of novel chiral stationary phases based on cyclofructan derivatives and chiral porous materials including chiral metal-organic frameworks, chiral porous organic frameworks, chiral inorganic mesoporous materials, and chiral porous organic cages in gas chromatography, covering original research papers published since 2010. The chiral recognition properties and mechanisms of separation toward enantiomers are also introduced. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Numerical simulation of bellows effect on flow and separation of uranium isotopes in a supercritical gas centrifuge

    Borisevich, V.D.; Morozov, O.E.; Godisov, O.N.

    2000-01-01

    Numerical solving of the Navier-Stokes and convection-diffusion equations by the finite difference technique has been applied to study the influence of bellows on the flow and separation of uranium isotopes in a single supercritical gas centrifuge. Dependence of the separative power of a gas centrifuge on geometric parameters and position of a bellows on a rotor wall as well as the effect of scoop drag and feed flow on isotope separation in a gas centrifuge with a bellows have been obtained in computing experiments. It was demonstrated that increase of the separative power with increase of the gas centrifuge length is less considerable than predicted by the Dirac's law

  2. Method and apparatus for rapid adjustment of process gas inventory in gaseous diffusion cascades

    1980-01-01

    A method is specified for the operation of a gaseous diffusion cascade wherein electrically driven compressors circulate a process gas through a plurality of serially connected gaseous diffusion stages to establish first and second countercurrently flowing cascade streams of process gas, one of the streams being at a relatively low pressure and enriched in a component of the process gas and the other being at a higher pressure and depleted in the same, and wherein automatic control systems maintain the stage process gas pressures by positioning process gas flow control valve openings at values which are functions of the difference between reference-signal inputs to the systems, and signal inputs proportional to the process gas pressures in the gaseous diffusion stages associated with the systems, the cascade process gas inventory being altered, while the cascade is operating, by simultaneously directing into separate process-gas freezing zones a plurality of substreams derived from one of the first and second streams at different points along the lengths thereof to solidify approximately equal weights of process gas in the zone while reducing the reference-signal inputs to maintain the positions of the control valves substantially unchanged despite the removal of process gas inventory via the substreams. (author)

  3. Citrate based ''TALSPEAK'' lanthanide-actinide separation process

    Del Cul, G.D.; Bond, W.D.; Toth, L.M.; Davis, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The potential hazard posed to future generations by long-lived radionuclides such as the transuranic elements (TRU) is perceived as a major problem associated with the use of nuclear power. TRU wastes have to remain isolated from the environment for ''geological'' periods of time. The costs of building, maintaining, and operating a ''geological TRU repository'' can be very high. Therefore, there are significant economical advantages in segregating the relatively low volume of TRU wastes from other nuclear wastes. The chemical behavior of lanthanides and actinides, 4f and 5f elements respectively, is rather similar. As a consequence, the separation of these two groups is difficult. The ''TALSPEAK'' process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. The method is based on the preferential complexation of the trivalent actinides by an aminopolyacetic acid. Cold experiments showed that by using citric acid the deleterious effects produced by impurities such as zirconium are greatly reduced

  4. Cascade theory in isotopic separation processes; Theorie des cascades en separation isotopique

    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.

  5. Process for producing synthetic ammonia gas. Verfahren zur Erzeugung von Ammoniak-Synthesegas

    Meckel, J F; Messerschmidt, D; Wagener, D

    1984-01-12

    The invention refers to a process for producing synthetic ammonia gas from gases containing hydrocarbons, which is reformed catalytically and autothermally with a synthesis gas containing oxygen and then subjected to conversion to synthesis gas containing carbon dioxide and hydrogen. In order to simplify the plant required for such a process, the invention provides that part of the gas main flow is subjected to a multistage alternating pressure absorption plant (PSA plant) in a bypass of the gas main flow and the separated hydrogen is returned to the remaining gas main flow, in order to set the required H/sub 2/N/sub 2/ ratio and that the fission gas is subject to carbon dioxide washing and methanizing after conversion. This process therefore does not need a pipe splitting furnace and enrichment of the air with oxygen.

  6. Process for purification of gas mixtures

    Vasiliev, S Z; Letitschevskij, V I; Maergojz, I I; Michailov, L A; Puschkarev, L I

    1977-06-23

    The process relates to the purification of gas mixtures of N, H, and Ar, or N and H, or N and O which contain CO, CO/sub 2/ and water vapour. Single-stage adsorption occurs under standard pressure at temperatures from -40 to +4/sup 0/C up to the point of CO penetration through the zeolite layer. Zeolite is of type A or X combined with Ca, Na, Ag, Cd, Co, Ni, Mn or a natural zeolite of the type klinoptilolite. Regeneration is achieved at constant temperature and pressure of 1-5x10/sup -1/ Torr or by heating to 120-600/sup 0/C.

  7. Sensing the gas metal arc welding process

    Carlson, N. M.; Johnson, J. A.; Smartt, H. B.; Watkins, A. D.; Larsen, E. D.; Taylor, P. L.; Waddoups, M. A.

    1994-01-01

    Control of gas metal arc welding (GMAW) requires real-time sensing of the process. Three sensing techniques for GMAW are being developed at the Idaho National Engineering Laboratory (INEL). These are (1) noncontacting ultrasonic sensing using a laser/EMAT (electromagnetic acoustic transducer) to detect defects in the solidified weld on a pass-by-pass basis, (2) integrated optical sensing using a CCD camera and a laser stripe to obtain cooling rate and weld bead geometry information, and (3) monitoring fluctuations in digitized welding voltage data to detect the mode of metal droplet transfer and assure that the desired mass input is achieved.

  8. Carbon dioxide-krypton separation and radon removal from nuclear-fuel-reprocessing off-gas streams

    Hirsch, P.M.; Higuchi, K.Y.; Abraham, L.

    1982-07-01

    General Atomic Company (GA) is conducting pilot-plant-scale tests that simulate the treatment of radioactive and other noxious volatile and gaseous constituents of off-gas streams from nuclear reprocessing plants. This paper reports the results of engineering-scale tests performed on the CO 2 /krypton separation and radon holdup/decay subsystems of the GA integrated off-gas treatment system. Separation of CO 2 from krypton-containing gas streams is necessary to facilitate subsequent waste processing and krypton storage. Molecular sieve 5A achieved this separation in dissolver off-gas streams containing relatively low krypton and CO 2 concentrations and in krypton-rich product streams from processes such as the krypton absorption in liquid carbon dioxide (KALC) process. The CO 2 /krypton separation unit is a 30.5-cm-diameter x 1.8-m-long column containing molecular sieve 5A. The loading capacity for CO 2 was determined for gas mixtures containing 250 ppM to 2.2% CO 2 and 170 to 750 ppM krypton in either N 2 or air. Gas streams rich in CO 2 were diluted with N 2 to reduce the temperature rise from the heat of adsorption, which would otherwise affect loading capacity. The effluent CO 2 concentration prior to breakthrough was less than 10 ppM, and the adsorption capacity for krypton was negligible. Krypton was monitored on-line with a time-of-flight mass spectrometer and its concentration determined quantitatively by a method of continuous analysis, i.e., selected-ion monitoring. Radon-220 was treated by holdup and decay on a column of synthetic H-mordenite. The Rn-220 concentration was monitored on-line with flow-through diffused-junction alpha detectors. Single-channel analyzers were utilized to isolate the 6.287-MeV alpha energy band characteristic of Rn-220 decay from energy bands due to daughter products

  9. Origins and Evolution of Inorganic-Based and MOF-Based Mixed-Matrix Membranes for Gas Separations

    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.

  10. Prediction of Mass Flow Rate in Supersonic Natural Gas Processing

    Wen Chuang

    2015-11-01

    Full Text Available The mass flow rate of natural gas through the supersonic separator was numerically calculated by various cubic equations of state. The numerical results show that the compressibility factor and specific heat ratio for ideal gas law diverge remarkably from real gas models at a high inlet pressure. Simultaneously, the deviation of mass flow calculated by the ideal and real gas models reaches over 10 %. The difference increases with the lower of the inlet temperature regardless of the inlet pressure. A higher back pressure results in an earlier location of the shock wave. The pressure ratio of 0.72 is the first threshold to get the separator work normally. The second threshold is 0.95, in which case the whole flow is subsonic and cannot reach the choked state. The shock position moves upstream with the real gas model compared to the ideal gas law in the cyclonic separation section.

  11. Gas separation performance of 6FDA-based polyimides with different chemical structures

    Qiu, Wulin

    2013-10-01

    This work reports the gas separation performance of several 6FDA-based polyimides with different chemical structures, to correlate chemical structure with gas transport properties with a special focus on CO2 and CH 4 transport and plasticization stability of the polyimides membranes relevant to natural gas purification. The consideration of the other gases (He, O2 and N2) provided additional insights regarding effects of backbone structure on detailed penetrant properties. The polyimides studied include 6FDA-DAM, 6FDA-mPDA, 6FDA-DABA, 6FDA-DAM:DABA (3:2), 6FDA-DAM:mPDA (3:2) and 6FDA-mPDA:DABA (3:2). Both pure and binary gas permeation were investigated. The packing density, which is tunable by adjusting monomer type and composition of the various samples, correlated with transport permeability and selectivity. The separation performance of the polyimides for various gas pairs were also plotted for comparison to the upper bound curves, and it was found that this family of materials shows attractive performance. The CO 2 plasticization responses for the un-cross-linked polyimides showed good plasticization resistance to CO2/CH4 mixed gas with 10% CO2; however, only the cross-linked polyimides showed good plasticization resistance under aggressive gas feed conditions (CO 2/CH4 mixed gas with 50% CO2 or pure CO 2). For future work, asymmetric hollow fibers and carbon molecular sieve membranes based on the most attractive members of the family will be considered. © 2013 Elsevier Ltd. All rights reserved.

  12. ELEX process for tritium separation from aqueous effluents

    Bruggeman, A.; Doyen, W.; Leysen, R.; Meynendonckx, L.; Monsecour, M.; Goossens, W.R.A.

    1980-01-01

    Within the framework of the European Communities' indirect action program on management and storage of radioactive waste the Belgian Nuclear Research Centre, S.C.K./C.E.N., is developing the ELEX process for tritium separation from aqueous reprocessing effluents. This process is a combination of water electrolysis and tritium exchange between hydrogen and water, the exchange being promoted by a hydrophobic catalyst. For classical electrolysis under normal working conditions with elementary tritium separation factor of 11.6 with a standard deviation of 6% was obtained. As to the exchange step an appropriate hydrophobic catalyst has been developed, and overall tritium exchange rates were measured in a countercurrent packed-bed reactor. Extrapolation of these results to the 3 m 3 per day scale of a reprocessing plant leads to an electrolyser capacity of about 1 MW and to an exchange volume of about 1 m 3 for an ELEX installation that concentrates 90% of the original tritium in 1% of the original volume. At the moment the construction of a small integrated detritiation unit is nearly finished. A larger pilot installation will be built later on

  13. Carbon molecular sieve gas separation membranes based on an intrinsically microporous polyimide precursor

    Ma, Xiaohua

    2013-10-01

    We report the physical characteristics and gas transport properties for a series of pyrolyzed membranes derived from an intrinsically microporous polyimide containing spiro-centers (PIM-6FDA-OH) by step-wise heat treatment to 440, 530, 600, 630 and 800 C, respectively. At 440 C, the PIM-6FDA-OH was converted to a polybenzoxazole and exhibited a 3-fold increase in CO2 permeability (from 251 to 683 Barrer) with a 50% reduction in selectivity over CH4 (from 28 to 14). At 530 C, a distinct intermediate amorphous carbon structure with superior gas separation properties was formed. A 56% increase in CO2-probed surface area accompanied a 16-fold increase in CO2 permeability (4110 Barrer) over the pristine polymer. The graphitic carbon membrane, obtained by heat treatment at 600 C, exhibited excellent gas separation properties, including a remarkable CO2 permeability of 5040 Barrer with a high selectivity over CH4 of 38. Above 600 C, the strong emergence of ultramicroporosity (<7 Å) as evidenced by WAXD and CO2 adsorption studies elicits a prominent molecular sieving effect, yielding gas separation performance well above the permeability-selectivity trade-off curves of polymeric membranes. © 2013 Elsevier Ltd. All rights reserved.

  14. Process for separation of tungsten and molybdenum by extraction

    Zelikman, A.N.; Voldman, G.M.; Rumyantsev, V.K.; Ziberov, G.N.; Kagermanian, V.S.

    1976-01-01

    A process for the separation of tungsten and molybdenum by extraction involves the addition of HCl or HNO 3 to an aqueous solution containing tungsten and molybdenum to obtain a pH from 0.5 to 4.3, and introduction of a stabilizer comprising water-soluble phosphorus salts and a complexing agent, hydrogen peroxide, in an amount from 1.5 to 2 mole per 1 g-atom of the total content of tungsten and molybdenum. Then molybdenum is selectively extracted from the resulting aqueous solution with tri-n-butylphosphate with equal volumetric proportioning of the aqueous and organic solutions. Re-extraction of molybdenum and partially tungsten is carried out from the organic extracting agent with an alkali or soda solution. The process makes possible the preparation of tungsten solution containing no more than 0.001 g/l of molybdenum, and an increase in the degree of extraction of tungsten and molybdenum

  15. Separation process design for isolation and purification of natural products

    Malwade, Chandrakant R.

    Natural products are defined as secondary metabolites produced by plants and form a vast pool of compounds with unlimited chemical and functional diversity. Many of these secondary metabolites are high value added chemicals that are frequently used as ingredients in food, cosmetics, pharmaceuticals...... and other consumer products. Therefore, process technology towards industrial scale production of such high value chemicals from plants has significant value. Natural products can be obtained in pure form via synthetic or semi-synthetic route, but due to their complicated nature these methods have not been...... developed to the extent of industrial production for majority of natural products. Thus, isolation and purification of such natural products from plants is the most viable way to obtain natural products in pure form. This PhD project is mainly concerned with the design of separation process to isolate...

  16. Modified molecular sieves: stationary phase for the gas chromatographic separation of hydrogen isotopes

    Pushpa, K.K.; Annaji Rao, K.; Iyer, R.M.

    1993-01-01

    Gas chromatographic separation of hydrogen isotopes on different molecular sieves at liquid nitrogen temperature has been investigated. Normal molecular sieves 5A, 13X and AW500 are not satisfactory for the purpose both in the partially dehydrated as well as totally dehydrated state. Molecular sieve 4A in partially dehydrated state separated H 2 and D 2 while H 2 and HD are not well resolved. Iron exchanged or coated molecular sieves 4A, 5A, 13X and AW500 in the partially dehydrated state separated the isotopic mixtures H 2 , HD, D 2 and H 2 , HT, T 2 . The resolution varied depending on the amount of iron content and the residual moisture in the molecular sieves. Good separations were obtained on 15% Fe coated molecular sieve 5A and 5% Fe coated molecular sieve 4A. (author). 18 refs., 6 figs., 3 tabs

  17. Remarkable separability of circulation response to Arctic sea ice loss and greenhouse gas forcing

    McCusker, K. E.; Kushner, P. J.; Fyfe, J. C.; Sigmond, M.; Kharin, V. V.; Bitz, C. M.

    2017-08-01

    Arctic sea ice loss may influence midlatitude climate by changing large-scale circulation. The extent to which climate change can be understood as greenhouse gas-induced changes that are modulated by this loss depends on how additive the responses to the separate influences are. A novel sea ice nudging methodology in a fully coupled climate model reveals that the separate effects of doubled atmospheric carbon dioxide (CO2) concentrations and associated Arctic sea ice loss are remarkably additive and insensitive to the mean climate state. This separability is evident in several fields throughout most of the year, from hemispheric to synoptic scales. The extent to which the regional response to sea ice loss sometimes agrees with and sometimes cancels the response to CO2 is quantified. The separability of the responses might provide a means to better interpret the diverse array of modeling and observational studies of Arctic change and influence.

  18. Research on the Flow Field and Structure Optimization in Cyclone Separator with Downward Exhaust Gas

    Wang Weiwei

    2017-01-01

    Full Text Available A numerical software analysis of the turbulent and strongly swirling flow field of a cyclone separator with downward exhaust gas and its performances is described. The ANSYS 14.0 simulations based on DPM model are also used in the investigation. A new set of geometrical design has been optimized to achieve minimum pressure drop and maximum separation efficiency. A comparison of numerical simulation of the new design confirm the superior performance of the new design compared to the conventional design. The influence of the structure parameters such as the length of the guide pipe, the shape of the guide, the inlet shape on the separation performance was analyzed in this research. This research result has certain reference value for cyclone separator design and performance optimization.

  19. Engineering of Mixed Matrix Membranes for Water Treatment, Protective Coating and Gas Separation

    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

  20. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    Edhaim, Fatimah A.

    2017-11-01

    In this dissertation, the metathesis route of metal chalcogenide aerogel synthesis was expanded by conducting systematic studies between polysulfide building blocks and the 1st-row transition metal linkers. Resulting materials were screened as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated. The effect of the presence of different counter-ion within chalcogel frameworks on the adsorption capacity of the chalcogels was studied on AFe3Zn3S17 (A= K, Na, and Rb) chalcogels. The highest adsorption capacity toward hydrocarbons and gases was observed on Rb based chalcogels. Adopting a new building block [BiTe3]3- with the 1st-row transition metal ions results in the formation of three high BET surface area chalcogels, KCrBiTe3, KZnBiTe3, and KFeBiTe3. The resulting chalcogels showed preferential adsorption of toluene vapor, and remarkable selectivity of CO2, indicating the potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. The synthesis and characterization of the rare earth chalcogels NaYSnS4, NaGdSnS4, and NaTbSnS4 are also reported. Rare earth metal ions react with the thiostannate clusters in formamide solution forming extended polymeric networks by gelation. Obtained chalcogels have high BET surface areas, and showed notable adsorption capacity toward CO2 and toluene vapor. These chalcogels have also been engaged in the absorption of different organic molecules. The results reveal the ability of the chalcogels to distinguish among organic molecules on their electronic structures; hence, they could be used as sensors. Furthermore, the synthesis of metal chalcogenide aerogels Co0.5Sb0.33MoS4 and Co0.5Y0.33MoS4 by the sol-gel method is reported. In this system, the building blocks [MoS4]2- chelated with Co2+ and (Sb3

  1. Hydrogen enrichment and separation from synthesis gas by the use of a membrane reactor

    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

  2. Studies on the separation of hydrogen isotopes and spin isomers by gas chromatography

    Pushpa, K.K.; Annaji Rao, K.

    2000-08-01

    Separation and analysis of mixture of hydrogen isotopes has gained considerable importance because of various applications needing different isotopes in lasers, nuclear reactions and tracer or labelled compounds. In the literature gas chromatographic methods are reported using columns packed with partly dehydrated or thoroughly dehydrated alumina/molecular sieve stationary phase at 77 deg K with helium, neon and even hydrogen or deuterium as carrier gas. In the present study an attempt is made to compare the chromatographic behaviour of these two stationary phases using virgin and Fe doped form in partly dehydrated and thoroughly dehydrated state, using helium, neon, hydrogen and deuterium as carrier gas. The results of this study show that helium or neon carrier gas behave similarly broad peaks with some tailing. Sharp symmetric peaks are obtained with hydrogen or deuterium carrier gas. This is attributed to large hold up capacity for H 2 or D 2 at 77 deg K in these materials as compared to helium or neon. Spin isomers of H 2 or D 2 are separated on Fe free stationary phases, though ortho H 2 and HD are not resolved. Using a combination of Fe doped short column and plain alumina column, both maintained in dehydrated form, the effect of Fe doping on thermal equilibrium of ortho/para forms at 77 deg K is clearly demonstrated. (author)

  3. Interfacial Design of Mixed Matrix Membranes for Improved Gas Separation Performance.

    Wang, Zhenggong; Wang, Dong; Zhang, Shenxiang; Hu, Liang; Jin, Jian

    2016-05-01

    High-performance metal-organic framework (MOF)/polyimide (PI) mixed matrix membranes (MMMs) are fabricated by a facile strategy by designing the MOF/PI matrix interface via poly dopamine coating. The overall separation performance of the designed MMMs surpasses the state-of-the-art 2008 Robeson upper bound for the H2 /CH4 and H2 /N2 gas pairs and approaches the 2008 upper bound for the O2 /N2 gas pair. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Separation Process by Porous Membranes: A Numerical Investigation

    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.

  5. Development of a novel heavy element chemistry apparatus using the RIKEN gas-field recoil separator as a pre-separator

    Haba, H.; Morita, K.; Enomoto, S.; Morimoto, K.; Kaji, D.; Nagame, Yuichiro

    2004-01-01

    A new system was developed, that supplied the super-heavy element separated physically as the former steps to the chemical analysis devices such as a gas or liquid chromatographs. The gas jet transportation device was newly set up on the edge of existing accelerator research facilities in the Institute of Physical and Chemical Research linac building (GARIS). To conduct the chemical separation experiment of a super-heavy element of 112 in future a radioactive isotope of mercury of light homology elements was manufactured with a gas jet uniting type online multi-tracer manufacturing device. The adsorption chromatograph experiment to the gold was performed using this system. (H. Katsuta)

  6. RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES

    MONIKA ŠUPOVÁ

    2012-03-01

    Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000°C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000°C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

  7. FABRICATION AND CHARACTERIZATION OF POLYIMIDE/POLYETHERSULFONE-FUMED SILICA MIXED MATRIX MEMBRANE FOR GAS SEPARATION

    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.

  8. Swift heavy ion induced modification in polycarbonate membrane for gas separation

    Rajesh Kumar; Prasad, Rajendra; Vijay, Y.K.; Das, D.

    2003-01-01

    Polymeric membranes are extensively used for commercial gas separation applications. Makrofol-KG (polycarbonate) is a glassy polymer. 40 μm thick sheet of Makrofol-KG was irradiated with 40 Ar (14.9 MeV/n) of fluence 10 3 ions/cm 2 and 20 μm thick sheet with 5.3 MeV α-particles of fluence 10 7 ions/cm 2 . The permeability of these polycarbonate membranes for H 2 and CO 2 was measured and also after etching in 6 N NaOH at 60 degC for different periods. Permeability is found to be increased with etching time. At a definite time, critical etching time, the permeability rapidly increases in PC. Positron annihilation lifetimes for unirradiated and irradiated membranes were measured with fast fast coincidence system to study the correlation of free volume hole concentration with gas separation properties. (author)

  9. Progress on Incorporating Zeolites in Matrimid®5218 Mixed Matrix Membranes towards Gas Separation

    Roberto Castro-Muñoz

    2018-06-01

    Full Text Available Membranes, as perm-selective barriers, have been widely applied for gas separation applications. Since some time ago, pure polymers have been used mainly for the preparation of membranes, considering different kinds of polymers for such preparation. At this point, polyimides (e.g., Matrimid®5218 are probably one of the most considered polymers for this purpose. However, the limitation on the performance relationship of polymeric membranes has promoted their enhancement through the incorporation of different inorganic materials (e.g., zeolites into their matrix. Therefore, the aim of this work is to provide an overview about the progress of zeolite embedding in Matrimid®5218, aiming at the preparation of mixed matrix membranes for gas separation. Particular attention is paid to the relevant experimental results and current findings. Finally, we describe the prospects and future trends in the field.

  10. Optimization of the gas chromatographic separations; Optimacion de las separaciones cromatograficas en fase gaseosa

    Gasco Sanchez, L

    1973-07-01

    A review and a critical study on the optimization of the gas chromatographic separations are made. After dealing with the fundamental gas chromatographic equations, some methods of expressing column performances are discussed: performance indices, performance parameters, resolution and effective plate number per unit time. This is completed with a comparative study on performances of various types of columns. Moreover, optimization methods for operating chromatographic conditions are extensively dealt with: as resolution optimization, separation time, and normalization techniques for the time of analysis in order to achieve the maximum resolution at constant time. Finally, some others non operating parameters such as: selectivity of stationary phases, column preparation and optimization methods by means of computers are studied. (Author) 68 refs.

  11. Applications of covalent organic frameworks (COFs): From gas storage and separation to drug delivery

    Ming-Xue Wu; Ying-Wei Yang

    2017-01-01

    Covalent organic frameworks (COFs) are an emerging class of porous covalent organic structures whose backbones were composed of light elements (B,C,N,O,Si) and linked by robust covalent bonds to endow such material with desirable properties,i.e.,inherent porosity,well-defined pore aperture,ordered channel structure,large surface area,high stability,and multi-dimension.As expected,the abovementioned properties of COFs broaden the applications of this class of materials in various fields such as gas storage and separation,catalysis,optoelectronics,sensing,small molecules adsorption,and drug delivery.In this review,we outlined the synthesis of COFs and highlighted their applications ranging from the initial gas storage and separation to drug delivery.

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

    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.

  13. Molten salt extractive distillation process for zirconium-hafnium separation

    McLaughlin, D.F.; Stoltz, R.A.

    1989-01-01

    This patent describes an improvement in a process for zirconium-hafnium separation. It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a liquid phase, and with molten salt solvent containing zirconium chloride being taken from the bottom of the distillation column. The improvements comprising: utilizing a molten salt solvent consisting principally of lithium chloride and at least one of sodium, potassium, magnesium and calcium chlorides; stripping of the zirconium chloride taken from the bottom of the distillation column by electrochemically reducing zirconium from the molten salt solvent; and utilizing a pressurized reflux condenser on the top of the column to add the hafnium chloride enriched overheads to the molten salt solvent previously stripped of zirconium chloride

  14. Separation and Purification of Mineral Salts from Spacecraft Wastewater Processing via Electrostatic Beneficiation

    Miles, John D., II; Lunn, Griffin

    2013-01-01

    Electrostatic separation is a class of material processing technologies commonly used for the sorting of coarse mixtures by means of electrical forces acting on charged or polarized particles. Most if not all of the existing tribo-electrostatic separators had been initially developed for mineral ores beneficiation. It is a well-known process that has been successfully used to separate coal from minerals. Potash (potassium) enrichment where underground salt mines containing large amounts of sodium is another use of this techno logy. Through modification this technology can be used for spacecraft wastewater brine beneficiation. This will add in closing the gap beeen traveling around Earth's Gravity well and long-term space explorations. Food has been brought on all man missions, which is why plant growth for food crops continues to be of interest to NASA. For long-term mission considerations food productions is one of the top priorities. Nutrient recovery is essential for surviving in or past low earth orbit. In our advance bio-regenerative process instead of nitrogen gas produced; soluble nitrate salts that can be recovered for plant fertilizer would be produced instead. The only part missing is the beneficiation of brine to separate the potassium from the sodium. The use of electrostatic beneficiation in this experiment utilizes the electrical charge differences between aluminum and dried brine by surface contact. The helixes within the aluminum tribocharger allows for more surface contact when being agitated. When two materials are in contact, the material with the highest affinity for electrons becomes negatively charged, while the other becomes positively charged. This contact exchange of charge may cause the particles to agglomerate depending on their residence time within the tribocharger, compromising the efficiency of separation. The aim of this experiment is to further the development in electrostatic beneficiation by optimizing the separation of ersatz and

  15. Molecularly Designed Stabilized Asymmetric Hollow Fiber Membranes for Aggressive Natural Gas Separation.

    Liu, Gongping; Li, Nanwen; Miller, Stephen J; Kim, Danny; Yi, Shouliang; Labreche, Ying; Koros, William J

    2016-10-24

    New rigid polyimides with bulky CF 3 groups were synthesized and engineered into high-performance hollow fiber membranes. The enhanced rotational barrier provided by properly positioned CF 3 side groups prohibited fiber transition layer collapse during cross-linking, thereby greatly improving CO 2 /CH 4 separation performance compared to conventional materials for aggressive natural gas feeds. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Separation and Molecular Identification of Resistant Bacteria to Lead from Behbahan Bidboland Gas Refinery Wastewater (Iran)

    Azam Mehrbakhsh; Monir Doudi; Hossein Motamedi

    2016-01-01

    Heavy metals are one of the pollution sources in environment. The pollution due to these metals is the problem that could have negative impact on water. Human is faced with these poisons effects due to occupational reasons. The lead is regarded as heavy metal whose industrial applications cause environmental pollution in high rate.The aim of this project was Separation and Molecular Identification of Resistant Bacteria to Lead from Behbahan Bidboland Gas Refinery Wastewater (Iran). For thi...

  17. Analysis and optimization of gas-centrifugal separation of uranium isotopes by neural networks

    Migliavacca S.C.P.

    2002-01-01

    Full Text Available Neural networks are an attractive alternative for modeling complex problems with too many difficulties to be solved by a phenomenological model. A feed-forward neural network was used to model a gas-centrifugal separation of uranium isotopes. The prediction showed good agreement with the experimental data. An optimization study was carried out. The optimal operational condition was tested by a new experiment and a difference of less than 1% was found.

  18. An apparatus for separating and continuously recovering a particulate material carried by a gas stream

    Becker, W.R.; Dada, A.G.; Dehollander, W.R.; Sloat, R.J.

    1974-01-01

    Description is given of an apparatus adapted to separate and recover a particulate material carried by hot corrosive gases. The apparatus comprises a flow-channel connected to a gas stream source carrying a particulate material, a first and second tubes connected to said flow-channel, filtrating devices, recovery containers and flow-restricting valves. This can be applied to the recovery of uranium oxides generated by flame reactions [fr

  19. Separation of the fission product noble gases krypton and xenon from dissolver off-gas in reprocessing HTGR-fuel

    Bohnenstingl, J.; Djoa, S. H.; Laser, M.; Mastera, S.; Merz, E.; Morschl, P.

    1976-04-15

    This paper describes a process developed for the retainment and separation of volatile (3H, 129 +131I) and gaseous (85Kr, Xe) fission products from the off-gas produced during dissolution of HTGR-fuel. To prevent unnecessary dilution of liberated noble gases by surrounding atmosphere, a helium purge-gas cycle is applied to enable a coarse fractionating of krypton and xenon by cold-trapping at about 80 deg K after precleaning the gas stream. The process consists of the following steps: deposition of droplets and solid aerosols; chemisorption of iodine on silver impregnated silica gel; catalytic removal of nitrogen oxides and oxygen; drying of the process gas stream; final filtering of abraded solids; deposition of xenon in solid form at 80 deg K and low subpressure; deposition of krypton in solid form at 80 deg K after compression to about 6 bar; decontamination of 85krypton-containing xenon by batch distillation for eventual industrial utilization; and removal of nitrogen and argon enrichment during continuous operation in the purge-gas stream by inleaking air with charcoal. A continuously operating dissolver vessel, closed to the surrounding atmosphere, yields a very high content of noble gases, e.g., 0.35 vol % krypton and 2.0 vol % xenon. The presented off-gas treatment unit is operated in cold runs with 1/3 of the full capacity and can treat about 1 m3 STP/h helium, corresponding to a quantity of about 10,000 MW(e) HTGR-fuel reprocessing plant.

  20. Separation of the fission product noble gases krypton and xenon from dissolver off-gas in reprocessing HTGR-fuel

    Bohnenstingl, J.; Djoa, S.H.; Laser, M.; Mastera, S.; Merz, E.; Morschl, P.

    1976-01-01

    This paper describes a process developed for the retainment and separation of volatile ( 3 H, 129+131 I) and gaseous ( 85 Kr, Xe) fission products from the off-gas produced during dissolution of HTGR-fuel. To prevent unnecessary dilution of liberated noble gases by surrounding atmosphere, a helium purge-gas cycle is applied to enable a coarse fractionating of krypton and xenon by cold-trapping at about 80 0 K after precleaning the gas stream. The process consists of the following steps: deposition of droplets and solid aerosols; chemisorption of iodine on silver impregnated silica gel; catalytic removal of nitrogen oxides and oxygen; drying of the process gas stream; final filtering of abraded solids; deposition of xenon in solid form at 80 0 K and low subpressure; deposition of krypton in solid form at 80 0 K after compression to about 6 bar; decontamination of 85 Kr-containing xenon by batch distillation for eventual industrial utilization; and removal of nitrogen and argon enrichment during continuous operation in the purge-gas stream by inleaking air with charcoal. A continuously operating dissolver vessel, closed to the surrounding atmosphere, yields a very high content of noble gases, i.e., 0.35 vol % krypton and 2.0 vol % xenon. The presented off-gas treatment unit is operated in cold runs with 1 / 3 of the full capacity and can treat about 1 m 3 STP/h helium, corresponding to a quantity of about 10,000 MW/sub e/ HTGR-fuel reprocessing plant

  1. Process for catalytic flue gas denoxing

    Woldhuis, A.; Goudriaan, F.; Groeneveld, M.; Samson, R.

    1991-01-01

    With the increasing concern for the environment, stringency of legislation and industry's awareness of its own environmental responsibility, the demand for the reduction of emission levels of nitrogen oxides is becoming increasingly urgent. This paper reports that Shell has developed a low temperature catalytic deNOx system for deep removal of nitrogen oxides, which includes a low-pressure-drop reactor. This process is able to achieve over 90% removal of nitrogen oxides and therefore can be expected to meet legislation requirements for the coming years. The development of a low-temperature catalyst makes it possible to operate at temperatures as low as 120 degrees C, compared to 300-400 degrees C for the conventional honeycomb and plate-type catalysts. This allows an add-on construction, which is most often a more economical solution than the retrofits in the hot section required with conventional deNOx catalysts. The Lateral Flow Reactor (LFR), which is used for dust-free flue gas applications, and the Parallel Passage Reactor (PPR) for dust-containing flue gas applications, have been developed to work with pressure drops below 10 mbar

  2. Helping Emotionally Disturbed Children Deal with the Separation Process.

    Kreger, Robert D.; Kreger, Linda R.

    1989-01-01

    The article presents examples of emotionally disturbed children's reactions to separation from a teacher with whom they have become involved. Suggestions are offered for facilitating healthy separation from the teacher. (JDD)

  3. Remarkably enhanced gas separation by partial self-conversion of a laminated membrane to metal-organic frameworks.

    Liu, Yi; Pan, Jia Hong; Wang, Nanyi; Steinbach, Frank; Liu, Xinlei; Caro, Jürgen

    2015-03-02

    Separation methods based on 2D interlayer galleries are currently gaining widespread attention. The potential of such galleries as high-performance gas-separation membranes is however still rarely explored. Besides, it is well recognized that gas permeance and separation factor are often inversely correlated in membrane-based gas separation. Therefore, breaking this trade-off becomes highly desirable. Here, the gas-separation performance of a 2D laminated membrane was improved by its partial self-conversion to metal-organic frameworks. A ZIF-8-ZnAl-NO3 layered double hydroxide (LDH) composite membrane was thus successfully prepared in one step by partial conversion of the ZnAl-NO3 LDH membrane, ultimately leading to a remarkably enhanced H2 /CH4 separation factor and H2 permeance. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Alloy Effects on the Gas Nitriding Process

    Yang, M.; Sisson, R. D.

    2014-12-01

    Alloy elements, such as Al, Cr, V, and Mo, have been used to improve the nitriding performance of steels. In the present work, plain carbon steel AISI 1045 and alloy steel AISI 4140 were selected to compare the nitriding effects of the alloying elements in AISI 4140. Fundamental analysis is carried out by using the "Lehrer-like" diagrams (alloy specific Lehrer diagram and nitriding potential versus nitrogen concentration diagram) and the compound layer growth model to simulate the gas nitriding process. With this method, the fundamental understanding for the alloy effect based on the thermodynamics and kinetics becomes possible. This new method paves the way for the development of new alloy for nitriding.

  5. Separation of different valency states of neptunium from processing solutions

    Shabana, R.; EL-Naggar, H.A.

    1990-01-01

    The three main oxidation states of neptunium (Np(IV),Np(V) and Np(V I)) have been separated from each other by solvent extraction and extraction chromatographic techniques. The separation procedure is based on a systematic study of the extraction behaviour of each oxidation state using TBP as an extractant. The purity of separated species is identified using spectrophotometry

  6. A monolithically fabricated gas chromatography separation column with an integrated high sensitivity thermal conductivity detector

    Kaanta, Bradley C; Zhang, Xin; Chen, Hua

    2010-01-01

    The monolithic integration of a high sensitivity detector with a gas chromatography (GC) separation column creates many potential advantages over the discrete components of a traditional chromatography system. In miniaturized high-speed GC systems, component interconnections can cause crucial errors and loss of fidelity during detection and analysis. A monolithically integrated device would eliminate the need to create helium-tight interconnections, which are bulky and labor intensive. Additionally, batch fabrication of integrated devices that no longer require expensive and fragile detectors can decrease the cost of micro GC systems through economies of scale. We present the design, fabrication and operation of a monolithic GC separation column and detector. Our device is able to separate nitrogen, methane and carbon dioxide within 30 s. This method of device integration could be applied to the existing wealth of column geometries and chemistries designed for specialized applications.

  7. Separation process of heavy rare earth elements from xenotime ore

    Sri Sukmajaya; Tri Handini; Wahyu Rachmi Pusparini; Dwi Biyantoro

    2016-01-01

    Separation process of heavy rare earth elements from xenotime ore had been done. A 100 mesh of xenotime ore was upgrade using water, sodium silicate and oleic acid in pH 9. Mixed of slurry by air blown in room temperature along 30 minutes. The middle of slurry xenotime was be separated, then dried and so added soda caustic, potassium carbonate and ammonium dihydrogen phosphate. The mix was be homogenized then leached in furnace to 700°C temperature along 4 hours. The frits of leaching product would be leached using 1200 mL volume of water that made oxidation by HCl onto pH 4 by agitated heated in 70°C temperature. The mix was filtered, then solid settled was be dried and then to processed again in water HCl acidified leaching alike before until pH 4 with minimized HCl added least 2 mL. The solid settled filled into 1000 mL of beker glass, added HCl viscous in 300 mL volume, hydrogen peroxide and BaCl_2/Na_2SO_4/Na_2S then heated to 100°C temperature. Let in room temperature then was filtrated. The solid settled as ThSO_4/ThS, RaSO_4/RaS. The filtrate to be settled using 15g (NH_4)_2CO_3 in 100 mL volume of water while mixed until the solution reached pH 2. The solid settled was be dried, then into the filtrate added 10 mL volume of formic acid. The solid settled of filtration was be dried. The solution of filtrate to be settled using (NH_4)_2CO_3 until pH 4. The solid settled was be filtered and dried. The filtrate was be settled using oxalic acid. The analysis of standard of oxide rare earth had been done using XRF Am"2"4"1 source. Result of these process got 100 mesh xenotime upgrade those leached in 700°C along 4 hours used (NH_4)H_2PO_4 so HRE total lifted up from 4.31 to 8.16%. Resulted of HRE oxide yield was 17.76% in pH 2. HRE oxide yield in pH 4 was 38.45%, and HRE oxide yield was 6.38% as oxalic compound, so the total HRE oxide yield was 62.59%. (author)

  8. [Baseflow separation methods in hydrological process research: a review].

    Xu, Lei-Lei; Liu, Jing-Lin; Jin, Chang-Jie; Wang, An-Zhi; Guan, De-Xin; Wu, Jia-Bing; Yuan, Feng-Hui

    2011-11-01

    Baseflow separation research is regarded as one of the most important and difficult issues in hydrology and ecohydrology, but lacked of unified standards in the concepts and methods. This paper introduced the theories of baseflow separation based on the definitions of baseflow components, and analyzed the development course of different baseflow separation methods. Among the methods developed, graph separation method is simple and applicable but arbitrary, balance method accords with hydrological mechanism but is difficult in application, whereas time series separation method and isotopic method can overcome the subjective and arbitrary defects caused by graph separation method, and thus can obtain the baseflow procedure quickly and efficiently. In recent years, hydrological modeling, digital filtering, and isotopic method are the main methods used for baseflow separation.

  9. Reactor modeling and process analysis for partial oxidation of natural gas

    Albrecht, B.A.

    2004-01-01

    This thesis analyses a novel process of partial oxidation of natural gas and develops a numerical tool for the partial oxidation reactor modeling. The proposed process generates syngas in an integrated plant of a partial oxidation reactor, a syngas turbine and an air separation unit. This is called

  10. Fundamental laws of separation by the gaseous diffusion process; Lois de separation elementaires en diffusion gazeuse

    Bouligand, G M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Using the Knudsen's law for the flow of each component of a gaseous mixture through a porous membrane, we derive the overall separation laws and the separation power for one stage of diffusion: Various types of stages differing by the geometrical configuration and the flow nature are considered. For the sake of simplicity physical phenomena causing a loss of separation efficiency are neglected. Computation show the advantages of counter-current type stage with one entering and two leaving flows. A more refined theory of separation can be derived with the same basis of this work. (author) [French] A partir de la loi de Knudsen exprimant les debits elementaires des constituants d'un melange gazeux a travers une membrane poreuse on determine les lois et la puissance de separation de differents modeles de diffuseurs definie par leurs configurations et la nature des ecoulements gazeux. Four simplifier il n'a pas ete tenu compte des divers phenomenes physiques inherents a la diffusion et qui reduisent generalement le facteur de separation. Ces calculs font prevoir les avantages des diffuseurs du type contrecourant a trois ouvertures et peuvent servir de guide dans une theorie plus complete de la separation. (auteur)

  11. Fundamental laws of separation by the gaseous diffusion process; Lois de separation elementaires en diffusion gazeuse

    Bouligand, G.M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Using the Knudsen's law for the flow of each component of a gaseous mixture through a porous membrane, we derive the overall separation laws and the separation power for one stage of diffusion: Various types of stages differing by the geometrical configuration and the flow nature are considered. For the sake of simplicity physical phenomena causing a loss of separation efficiency are neglected. Computation show the advantages of counter-current type stage with one entering and two leaving flows. A more refined theory of separation can be derived with the same basis of this work. (author) [French] A partir de la loi de Knudsen exprimant les debits elementaires des constituants d'un melange gazeux a travers une membrane poreuse on determine les lois et la puissance de separation de differents modeles de diffuseurs definie par leurs configurations et la nature des ecoulements gazeux. Four simplifier il n'a pas ete tenu compte des divers phenomenes physiques inherents a la diffusion et qui reduisent generalement le facteur de separation. Ces calculs font prevoir les avantages des diffuseurs du type contrecourant a trois ouvertures et peuvent servir de guide dans une theorie plus complete de la separation. (auteur)

  12. Sulfur oxides and nitrogen oxides gas treating process

    Forbes, J. T.

    1985-01-01

    A process is disclosed for treating particle-containing gas streams by removing particles and gaseous atmospheric pollutants. Parallel passage contactors are utilized to remove the gaseous pollutants. The minimum required gas flow rate for effective operation of these contactors is maintained by recycling a variable amount of low temperature gas which has been passed through a particle removal zone. The recycled gas is reheated by heat exchange against a portion of the treated gas

  13. Review of the gas centrifuge until 1962. Part I: Principles of separation physics

    Whitley, S.

    1984-01-01

    There are two sets of principles involved in the development of the gas centrifuge, the internal separation physics and the external means of spinning a rotor at very high speeds. Only the first aspect is discussed in this part of the review. First, the industrial requirement for the separation of the uranium isotopes is defined so that the separation history can be put in a modern perspective. The history of separation physics itself is then traced back to the theory of centrifugal force by Huygens and the equivalence of this force to that of gravity. The barometric equation giving the variation of atmospheric pressure with height and the law of partial pressures can then be adapted to the centrifuge to give the steady-state theory of separation. This work was completed in the last century but was not confirmed in its application to isotope separation until 1936. The detailed separation physics for non-steady-state conditions required for a production centrifuge was developed during the American wartime Manhattan Project. During this work the theory giving the maximum output of a centrifuge was developed by Dirac, and soon afterwards Cohen and Kaplan showed that the best method of operation for a production centrifuge is in a countercurrent mode of operation. This method gives a large separation factor at relatively small flow rates through the rotor. The theory of how to set up an internal countercurrent was given by Martin during an equivalent wartime German project, and refinements to the theory, showing how the countercurrent persists along a centrifuge rotor, was given by Dirac and Steenbeck, the latter during a postwar Russian project. This theory was extended by Parker, Ging, and Mayo of the University of Virginia, whose work was completed by 1962, the limit of this review

  14. Minimization of entropy production in separate and connected process units

    Roesjorde, Audun

    2004-08-01

    The objective of this thesis was to further develop a methodology for minimizing the entropy production of single and connected chemical process units. When chemical process equipment is designed and operated at the lowest entropy production possible, the energy efficiency of the equipment is enhanced. We have found for single process units that the entropy production could be reduced with up to 20-40%, given the degrees of freedom in the optimization. In processes, our results indicated that even bigger reductions were possible. The states of minimum entropy production were studied and important painter's for obtaining significant reductions in the entropy production were identified. Both from sustain ability and economical viewpoints knowledge of energy efficient design and operation are important. In some of the systems we studied, nonequilibrium thermodynamics was used to model the entropy production. In Chapter 2, we gave a brief introduction to different industrial applications of nonequilibrium thermodynamics. The link between local transport phenomena and overall system description makes nonequilibrium thermodynamics a useful tool for understanding design of chemical process units. We developed the methodology of minimization of entropy production in several steps. First, we analyzed and optimized the entropy production of single units: Two alternative concepts of adiabatic distillation; diabatic and heat-integrated distillation, were analyzed and optimized in Chapter 3 to 5. In diabatic distillation, heat exchange is allowed along the column, and it is this feature that increases the energy efficiency of the distillation column. In Chapter 3, we found how a given area of heat transfer should be optimally distributed among the trays in a column separating a mixture of propylene and propane. The results showed that heat exchange was most important on the trays close to the re boiler and condenser. In Chapter 4 and 5, we studied how the entropy

  15. Cross-Linkable Polyimide Membranes for Improved Plasticization Resistance and Permselectivity in Sour Gas Separations

    Kraftschik, Brian

    2013-09-10

    A series of cross-linkable membrane materials based on the 6FDA-DAM:DABA (3:2) polyimide backbone were synthesized for improved sour gas separation performance, in terms of both membrane stability and permselectivity. Short-chain poly(ethylene glycol) (PEG) molecules were used as cross-linking agents in an esterification-based cross-linking reaction. Pure and mixed gas permeation and pure gas sorption experiments were performed on dense films of these materials. Compared to unmodified 6FDA-DAM:DABA (3:2), higher sour gas permselectivity and membrane stability were achieved under aggressive feed conditions. H2S-induced plasticization was not evident until pure H2S feed pressures greater than approximately 6-8 bar. Pure CO 2-induced plasticization only occurred at feed pressures greater than about 25 bar. Under mixed gas feed conditions with 20% H2S, 20% CO2, and 60% CH4 at 35 C, attractive selectivities above 22 and 27 for H2S/CH4 and CO2/CH4, respectively, were observed for a feed pressure of 62 bar with both triethylene glycol and tetraethylene glycol cross-linking agents. © 2013 American Chemical Society.

  16. Adsorption separation of carbon dioxide from flue gas by a molecularly imprinted adsorbent.

    Zhao, Yi; Shen, Yanmei; Ma, Guoyi; Hao, Rongjie

    2014-01-01

    CO2 separation by molecularly imprinted adsorbent from coal-fired flue gas after desulfurization system has been studied. The adsorbent was synthesized by molecular imprinted technique, using ethanedioic acid, acrylamide, and ethylene glycol dimethacrylate as the template, functional monomer, and cross-linker, respectively. According to the conditions of coal-fired flue gas, the influencing factors, including adsorption temperature, desorption temperature, gas flow rate, and concentrations of CO2, H2O, O2, SO2, and NO, were studied by fixed bed breakthrough experiments. The experimental conditions were optimized to gain the best adsorption performance and reduce unnecessary energy consumption in future practical use. The optimized adsorption temperature, desorption temperature, concentrations of CO2, and gas flow rate are 60 °C, 80 °C, 13%, and 170 mL/min, respectively, which correspond to conditions of practical flue gases to the most extent. The CO2 adsorption performance was nearly unaffected by H2O, O2, and NO in the flue gas, and was promoted by SO2 within the emission limit stipulated in the Chinese emission standards of air pollutants for a thermal power plant. The maximum CO2 adsorption capacity, 0.57 mmol/g, was obtained under the optimized experimental conditions, and the SO2 concentration was 150 mg/m(3). The influence mechanisms of H2O, O2, SO2, and NO on CO2 adsorption capacity were investigated by infrared spectroscopic analysis.

  17. Cross-Linkable Polyimide Membranes for Improved Plasticization Resistance and Permselectivity in Sour Gas Separations

    Kraftschik, Brian; Koros, William J.

    2013-01-01

    A series of cross-linkable membrane materials based on the 6FDA-DAM:DABA (3:2) polyimide backbone were synthesized for improved sour gas separation performance, in terms of both membrane stability and permselectivity. Short-chain poly(ethylene glycol) (PEG) molecules were used as cross-linking agents in an esterification-based cross-linking reaction. Pure and mixed gas permeation and pure gas sorption experiments were performed on dense films of these materials. Compared to unmodified 6FDA-DAM:DABA (3:2), higher sour gas permselectivity and membrane stability were achieved under aggressive feed conditions. H2S-induced plasticization was not evident until pure H2S feed pressures greater than approximately 6-8 bar. Pure CO 2-induced plasticization only occurred at feed pressures greater than about 25 bar. Under mixed gas feed conditions with 20% H2S, 20% CO2, and 60% CH4 at 35 C, attractive selectivities above 22 and 27 for H2S/CH4 and CO2/CH4, respectively, were observed for a feed pressure of 62 bar with both triethylene glycol and tetraethylene glycol cross-linking agents. © 2013 American Chemical Society.

  18. Portable spectrometer monitors inert gas shield in welding process

    Grove, E. L.

    1967-01-01

    Portable spectrometer using photosensitive readouts, monitors the amount of oxygen and hydrogen in the inert gas shield of a tungsten-inert gas welding process. A fiber optic bundle transmits the light from the welding arc to the spectrometer.

  19. Implementing process safety management in gas processing operations

    Rodman, D.L.

    1992-01-01

    The Occupational Safety and Health Administration (OSHA) standard entitled Process Safety Management of Highly Hazardous Chemicals; Explosives and Blasting Agents was finalized February 24, 1992. The purpose of the standard is to prevent or minimize consequences of catastrophic releases of toxic, flammable, or explosive chemicals. OSHA believes that its rule will accomplish this goal by requiring a comprehensive management program that integrates technologies, procedures, and management practices. Gas Processors Association (GPA) member companies are significantly impacted by this major standard, the requirements of which are extensive and complex. The purpose of this paper is to review the requirements of the standard and to discuss the elements to consider in developing and implementing a viable long term Process Safety Management Program

  20. Numerical simulation of gas-solid two-phase flow in U-beam separator

    Zhou, X Y; Chen, X P; Dou, H S; Zhang, H Z; Ruan, J M

    2015-01-01

    Numerical simulation is carried out for gas-solid two-phase flow in a U-beam separator. In this study, the U-beam is altered with the inlet fins in order to improve the performance of the separator. The inlet fin angle of the separator are 30°, 35°, 40°, 45°, 50°, 55 ° and 60°. The governing equations are the Reynolds-Averaged Navier-Stokes equation with the standard k-ε model and the discrete phase model (DPM) describing the discrete two - phase flow as well as stochastic tracking model. Results show that the pressure drop deviation with fins is within 3% from those without fins. It is found that there is a maximum separation efficiency at the fin angle of 35°. Fin induces generation of a stagnation region which could collect particles and lead to change of vortical structures. The fin induced flow also causes the turbulent intensity inside the baffle to decrease to facilitate separation