Thematische Bibliographien / Gas Separation Techniques

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Auswahl der wissenschaftlichen Literatur zum Thema „Gas Separation Techniques“

Autor: Grafiati

Veröffentlicht am 1. Juli 2021

Zuletzt aktualisiert am 10. Februar 2022

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Zeitschriftenartikel zum Thema "Gas Separation Techniques"

Durand, J., und V. Rouessac. „CVD techniques for gas separation membranes synthesis - characterization - applications“. Le Journal de Physique IV 11, PR3 (August 2001): Pr3–1053—Pr3–1063. http://dx.doi.org/10.1051/jp4:20013132.

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Sattar, Muhammad Awais, Matheus Martinez Garcia, Robert Banasiak, Luis M. Portela und Laurent Babout. „Electrical Resistance Tomography for Control Applications: Quantitative Study of the Gas-Liquid Distribution inside A Cyclone“. Sensors 20, Nr. 21 (25.10.2020): 6069. http://dx.doi.org/10.3390/s20216069.

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Phase separation based centrifugal forces is effective, and thus widely explored by the process industry. In an inline swirl separator, a core of the light phase is formed in the center of the device and captured further downstream. Given the inlet conditions, this gas core created varies in shape and size. To predict the separation behavior and control the process in an optimal way, the gas core diameter should be measured with the minimum possible intrusiveness. Process tomography techniques such as electrical resistance tomography (ERT) allows us to measure the gas core diameter in a fast and non-intrusive way. Due to the soft-field nature and ill-posed problem in solving the inverse problem, especially in the area of low spatial resolution, the reconstructed images often overestimate the diameter of the object under consideration leading to unreliable measurements. To use ERT measurements as an input for the controller, the estimated diameters should be corrected based on secondary measurements, e.g., optical techniques such as high-speed cameras. In this context, image processing and image analysis techniques were adapted to compare the diameter calculated by an ERT system and a fast camera. In this paper, a correction method is introduced to correct the diameter obtained by ERT based on static measurements. The proposed method reduced the ERT error of dynamic measurements of the gas core size from over 300% to below 20%, making it a reliable sensing technique for controlled separation processes.

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Elhenawy, Salma, Majeda Khraisheh, Fares AlMomani und Mohamed Hassan. „Key Applications and Potential Limitations of Ionic Liquid Membranes in the Gas Separation Process of CO2, CH4, N2, H2 or Mixtures of These Gases from Various Gas Streams“. Molecules 25, Nr. 18 (18.09.2020): 4274. http://dx.doi.org/10.3390/molecules25184274.

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Heightened levels of carbon dioxide (CO2) and other greenhouse gases (GHGs) have prompted research into techniques for their capture and separation, including membrane separation, chemical looping, and cryogenic distillation. Ionic liquids, due to their negligible vapour pressure, thermal stability, and broad electrochemical stability have expanded their application in gas separations. This work provides an overview of the recent developments and applications of ionic liquid membranes (ILMs) for gas separation by focusing on the separation of carbon dioxide (CO2), methane (CH4), nitrogen (N2), hydrogen (H2), or mixtures of these gases from various gas streams. The three general types of ILMs, such as supported ionic liquid membranes (SILMs), ionic liquid polymeric membranes (ILPMs), and ionic liquid mixed-matrix membranes (ILMMMs) for the separation of various mixed gas systems, are discussed in detail. Furthermore, issues, challenges, computational studies and future perspectives for ILMs are also considered. The results of the analysis show that SILMs, ILPMs, and the ILMMs are very promising membranes that have great potential in gas separation processes. They offer a wide range of permeabilities and selectivities for CO2, CH4, N2, H2 or mixtures of these gases. In addition, a comparison was made based on the selectivity and permeability of SILMs, ILPMs, and ILMMMs for CO2/CH4 separation based on a Robeson’s upper bound curves.

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El-Naggar, Ashraf Yehia. „Thermal and Hydrothermal Treatment of Silica Gels as Solid Stationary Phases in Gas Chromatography“. Journal of Analytical Methods in Chemistry 2013 (2013): 1–6. http://dx.doi.org/10.1155/2013/931067.

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Silica gel was prepared and treated thermally and hydrothermally and was characterized as solid stationary phase in gas chromatography. The characteristics have been evaluated in terms of polarity, selectivity, and separation efficiencies. These parameters were used to assess the outer silica surface contributions and the degree of surface deactivation brought about by different treatment techniques. The parent silica elutes the paraffinic hydrocarbons with high efficiency of separation and elutes aromatic hydrocarbons with nearly good separation and has bad separation of alcohols. The calcined silica at 500°C and 1000°C has a pronounced effect on the separation of aromatic hydrocarbons compared with the parent silica and hydrothermal treatment of silica. With respect to alcohols separation, the obtained bad separations using treated and untreated silica reflect the little effect of the thermal and hydrothermal treatment on the silica surface deactivation.

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Shekhah, Osama, Valeriya Chernikova, Youssef Belmabkhout und Mohamed Eddaoudi. „Metal–Organic Framework Membranes: From Fabrication to Gas Separation“. Crystals 8, Nr. 11 (31.10.2018): 412. http://dx.doi.org/10.3390/cryst8110412.

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Gas membrane-based separation is considered one of the most effective technologies to address energy efficiency and large footprint challenges. Various classes of advanced materials, including polymers, zeolites, porous carbons, and metal–organic frameworks (MOFs) have been investigated as potential suitable candidates for gas membrane-based separations. MOFs possess a uniquely tunable nature in which the pore size and environment can be controlled by connecting metal ions (or metal ion clusters) with organic linkers of various functionalities. This unique characteristic makes them attractive for the fabrication of thin membranes, as both the diffusion and solubility components of permeability can be altered. Numerous studies have been published on the synthesis and applications of MOFs, as well as the fabrication of MOF-based thin films. However, few studies have addressed their gas separation properties for potential applications in membrane-based separation technologies. Here, we present a synopsis of the different types of MOF-based membranes that have been fabricated over the past decade. In this review, we start with a short introduction touching on the gas separation membrane technology. We also shed light on the various techniques developed for the fabrication of MOF as membranes, and the key challenges that still need to be tackled before MOF-based membranes can successfully be used in gas separation and implemented in an industrial setting.

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Sadiq, Muhammad Munir, Kiyonori Suzuki und Matthew R. Hill. „Towards energy efficient separations with metal organic frameworks“. Chemical Communications 54, Nr. 23 (2018): 2825–37. http://dx.doi.org/10.1039/c8cc00331a.

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The huge energy requirement for industrial separations of chemical mixtures has necessitated the need for the development of energy efficient and alternative separation techniques in order to mitigate the negative environmental impacts associated with greenhouse gas emissions from fossil fuel combustions for energy generation.

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Lungu, Mihai, Raluca Giugiulan, Antoanetta Lungu, Madalin Bunoiu und Adrian Neculae. „The Aharonov-Bohm Effect and Transport Properties in Graphene Nanostructures“. Annals of West University of Timisoara - Physics 57, Nr. 1 (01.12.2013): 86–95. http://dx.doi.org/10.1515/awutp-2015-0110.

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Abstract This paper investigates the possibility to improve the filtering process of flue gas by separation of suspended nanoparticle using dielectrophoresis. The study focuses on the particles having an average radius of about 50-150 nm, that cannot be filtrated by classical techniques but have a harmful effect for environment and human health. The size distribution nanoparticles collected from the flue gas filters of a hazardous waste incinerator plant were evaluated. Based on obtained experimental data and a proposed mathematical model, the concentration distribution of nanoparticle suspended in flue gas inside a microfluidic separation device was analyzed by numerical simulations, using the finite element method. The performances of the device were described in terms of three new specific quantities related to the separation process, namely Recovery, Purity and Separation Efficiency. The simulations could provide the optimal values of control parameters for separation process, and aim to be a useful tool in designing microfluidic devices for separating nanoparticle from combustion gases.

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Mohammad R. Gharibzahedi, Sayyed, und Javad Karimi-Sabet. „Gas Separation in Nanoporous Graphene from Molecular Dynamics Simulation“. Chemical Product and Process Modeling 11, Nr. 1 (01.03.2016): 29–33. http://dx.doi.org/10.1515/cppm-2015-0059.

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Abstract Membrane separation processes are energetically efficient compared to the other techniques such as cryogenic distillation and gas adsorption techniques. It is well known that a membrane's permeance is inversely proportional to its thickness. Regard to its single atom thickness and its mechanical strength, nanoporous graphene has been proposed as a very promising candidate for highly efficient gas separation applications. In this work, using classical molecular dynamics, we report the separation performance of such membrane in a molecular-sieving process as a function of pore size and chemical functionalization of pore rim. To investigate the membrane separation capability, we have calculated the permeance of each gas molecule of the considered binary mixtures through the membranes and therefore the separation selectivity. We investigated the separation performance of nanoporous graphene for CO2/N2, H2/CH4 and He/CH4 with 50:50 proportions of each component and the separation selectivity has been calculated. We also calculated the potential of the mean force to characterize the energy profile for gas transmission. The separation selectivity reduced by increasing the pore size. However, presence of chemical functionally pores in the membrane increased the separation selectivity. Furthermore, the gas permeance through nanoporous graphene membranes is related not only to transport rate to the graphene surface as well as kinetic diameters but also to molecular adsorbed layer which is formed on the surface. The flux of molecules through the nanopores is also dependent on pore chemistry which is considered as gas-pore interactions in the molecular simulations and can be a sizable factor in simulation in contrast to experimental observations. This study suggests that nanoporous graphene could represent a suitable membrane for gas separation.

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Gil-Ramírez, Alicia, und Irene Rodriguez-Meizoso. „Purification of Natural Products by Selective Precipitation Using Supercritical/Gas Antisolvent Techniques (SAS/GAS)“. Separation & Purification Reviews 50, Nr. 1 (21.05.2019): 32–52. http://dx.doi.org/10.1080/15422119.2019.1617737.

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Faghihian, H., und M. Pirouzi. „Nitrogen separation from natural gas by modified clinoptilolite“. Clay Minerals 44, Nr. 3 (September 2009): 289–92. http://dx.doi.org/10.1180/claymin.2009.044.3.289.

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AbstractSeparation of nitrogen, the major impurity of natural gas, is necessary for quality improvement of the gas. In this study, purified and some ion-exchanged forms of clinoptilolite were used to separate N2 from natural gas. Competitive adsorption of mixtures of N2, CH4 and C2H6 by Cu2+ (Cu-Cp)-, Zn2+ (Zn-Cp)-, Ni2+ (Ni-Cp)- and Mn2+ (Mn-Cp)-exchanged samples was studied at different pressures and ambient temperature. Among the cations studied, Cu2+ has the lowest selectivity towards N2. Samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, BET N2 adsorption and wet chemical analysis techniques.

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Dissertationen zum Thema "Gas Separation Techniques"

Alshehhi, Mohamed. „Electrostatic gas-liquid separation from high speed streams--application to advanced on-line/on-demand separation techniques“. College Park, Md. : University of Maryland, 2009. http://hdl.handle.net/1903/10003.

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Thesis (Ph.D.) -- University of Maryland, College Park, 2009.
Thesis research directed by: Dept. of Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

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Humphrey, Julie L. „The separation and characterisation of sorbitan esters using gas and liquid chromatographic techniques“. Thesis, University of Hull, 2007. http://hydra.hull.ac.uk/resources/hull:1600.

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The aim of the work carried out was to develop an analytical method for characterising sorbitan ester surfactants, which could be used to monitor their manufacture and establish structure activity relationships. HPLC was the first analytical technique used, however despite evaluating various stationary and mobile phases a repeatable method could not be found. High temperature GC with splitless injection was then tried. A range of single polyol esters of varying fatty acid chain lengths were prepared and analysed to establish the ester species that would elute from the column. Using optimised conditions for the injector, detector and final oven temperature of 380 degC and a DB1-ht column, it was found that all possible ester species elute for the short chain fatty acid esters studied. However as the chain length increases the number of ester species eluting decreases, for the longer fatty acid chain length esters based on oleic and stearic acid the sorbitan and sorbitol tri esters are the largest esters to elute. HT-GC analysis of a range of manufactured sorbitan mono esters based on palmitic, stearic and oleic acid was successful with all the mono ester species separated and identified and these separated from the di and tri esters. Validation of the method with sorbitan mono oleate showed that the method was precise and therefore a suitable method for characterising sorbitan mono esters. HT-GC with on-column injection was also investigated and it was found that for the longer chain fatty acid esters more ester species eluted than when using splitless injection. Validation would be required to establish the precision of the method, however it may also be a suitable method for characterising sorbitan esters.

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Van, der Westhuizen Rina. „The use of multidimensional GC techniques for the analysis of complex petrochemical products“. Thesis, Stellenbosch: University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/4639.

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90 leaves on CD format, preliminary i-ix pages and numbered pages 1-81. Includes bibliography, list of figures in color to pdf format (OCR).
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: The composition of petrochemical products obtained from Fischer Tropsch (FT) technologies is of the highest complexity possible and may contain thousands of components. Chemicals produced from FT feedstocks often contain trace level contaminants that can poison catalysts or that affect product performance in down-line processes. Single dimension GC analysis of these mixtures provides incomplete information because of lack of separation power. This study evaluates the separation power of heart-cut GC-GC, comprehensive GCxGC and sequential GC-GC for three selected challenging petrochemical applications. The fundamental theoretical aspects of the techniques are discussed. Oxygenates are removed as far as possible in C10 – C13 alkylation feedstocks, used in the production of linear alkyl benzenes, because the oxygenates may have deactivating effects on some expensive alkylation catalysts. Residual oxygenates may still be present and can consist of hundreds of components. Detection of individual components at ng/g levels is required. Heart-cut GC-GC is used to illustrate the separation and enrichment power for oxygenates in an alkylation feedstock. The stationary phase in the first dimension column was selected to provide separation of the oxygenates from the hydrocarbons in a relatively narrow window. The oxygenate fraction is then enriched by repeated injections and collection on the cryotrap. After sufficient enrichment, the trap is heated and the oxygenates are analysed on the second dimension column. Comprehensive GCxGC and Sequential GC-GC are compared for the separation and analysis of the oxygenated chemical component classes in the alkylation feedstock, before removal of oxygenates. Cyclic alcohols can occur in detergent alcohols produced from FT feedstocks. These cyclics are regarded as impurities because they affect the physical properties of the detergents. The cyclic and noncyclic alcohols in a narrow C12 – C13 detergent alcohol distillation cut have similar boiling points and polarities, and separation of individual components is thus difficult to achieve. Comprehensive GCxGC and sequential GC-GC are evaluated for the separation of the alcohol component classes. The study shows that both approaches provide component class separation but the high resolving power of the second column and the optimal chromatographic operating conditions of sequential GC-GC provide better separation of the individual components. The study illustrates the immense power of the three multidimensional GC techniques namely heart-cut GC-GC, comprehensive GCxGC and sequential GC-GC. The three multidimensional GC techniques each have their own advantages, disadvantages and unique applications and should be used as complementary rather than as competitive analytical tools.
AFRIKAANSE OPSOMMING: Fischer Tropsch (FT) petrochemiese produkte is van baie hoë kompleksiteit en kan uit duisende komponente bestaan. Chemikalië afkomstig van dié voerstrome bevat soms spoorhoeveelhede onsuiwerhede wat deaktiverend op kataliste kan inwerk of wat die werkverrrigting van finale produkte kan beïnvloed. Enkeldimensie GC analises van die komplekse mengsels is meesal onakkuraat as gevolg van geweldige piekoorvleueling. Die studie evalueer die skeidingsvermoë van drie multidimensionele tegnieke, Heart-cut GC-GC, Comprehensive GCxGC en Sequential GC-GC vir geselekteerde petrochemiese toepassings. Die fundamentele teoretiese aspekte van die tegnieke word bespreek en drie analitiese toepassings word beskryf. Oksigenate word so ver moontlik verwyder uit C10 – C13 paraffien-voerstrome, wat gebruik word in die vervaardiging van liniêre alkielbenzene, aangesien dit deaktiverend kan inwerk op alkileringskataliste. Die oorblywende oksigenate kan uit honderde komponente bestaan sodat analise van individuele komponente tot op lae ng/g vlakke nodig is. Heart-cut GC-GC word gebruik om die skeiding en verryking van die oksigenate in die alkileringsvoerstroom te illustreer. Die stationêre fase in die eerste-dimensie kolom is so gekies dat skeiding tussen oksigenate en koolwaterstowwe verkry word. Met herhaalde inspuitings verhoog die oksigenaat-konsentrasie op die cryo val en - na voldoende verryking - word die val verhit en die oksigenate geanaliseer op die tweede dimensie kolom. Die skeiding en analises verkry met Comprehensive GCxGC en Sequential GC-GC word vergelyk vir die chemiese klasse-skeiding van die alkileringsvoer (voor verwydering van oksigenate). Sikliese alkohole kan voorkom in detergent-alkohole vervaardig vanaf FT voerstrome. Dit word as onsuiwerhede beskou aangesien dit die fisiese eienskappe van die finale produkte beïnvloed. Die sikliese en nie-sikliese alkohole se kookpunte en polariteite is baie naby aanmekaar sodat skeiding van individuele komponente moeilik verkry word. Comprehensive GCxGC en Sequential GC-GC word evalueer vir die skeiding van die alkohol. Die studie toon aan dat albei die tegnieke skeiding gee van die chemiese komponent-klasse maar dat die hoë-resolusie tweede-dimensie kolom en die optimisering van die experimentele kondisies van die Sequential GC-GC sisteem beter skeiding van individuele komponente gee. Die uitsonderlike skeidingsvermoë van die drie multidimensionele tegnieke, Heart-cut GC-GC, Comprehensive GCxGC en Sequential GC-GC word geïllustreer in die studie. Elke tegniek het sy eie voordele, nadele en unieke toepassings en die drie tegnieke behoort as komplementêre eerder as kompeterende tegnieke gebruik te word.

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Steimes, Johan. „Performance study and modelling of an integrated pump and gas-liquid separator system: Optimisation for aero-engine lubrication systems“. Doctoral thesis, Universite Libre de Bruxelles, 2013. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209365.

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A system able to simultaneously separate and pump a gas-liquid mixture was developed.

It works efficiently and can be used in many applications (nuclear power plants,

pulp and paper processing, petroleum extraction, etc.). However, this pump and separator

system (PASS) was especially designed to handle air-oil mixture generated in

aero-engine lubrication systems. The PASS combines three important functions of the

scavenge part of the lubrication system: the deaeration and deoiling of the air-oil mixture

generated in the bearing and gearbox sumps and the pumping of the oil towards

the tank. These are critical functions for the engine. Indeed, a poor deoiling efficiency

leads to a high oil consumption. This reduces the flight endurance, increases the size

and weight of the oil tank and has a negative impact on the environment. Poor deaeration

and pumping characteristics lead to problems in the cooling and the lubrication of

the engine bearings.

Integrating a PASS into the lubrication system allows considerable improvements

(and simplification) to the lubrication system architecture. An important number of

components are suppressed: the vent lines, the deoiler, the cyclone deaerator and the

scavenge pumps. This reduces the size and the weight of the lubrication system and

increases its reliability. Furthermore, an important part of this PhD thesis focuses on

reducing the oil consumption in the PASS. This improves the flight endurance, reduces

engine maintenance and working costs and is profitable to the environment.

In addition to the development of an advanced PASS design system, the objective of

this thesis was to obtain a good understanding of the separation processes occurring in

the PASS and to develop theoretical models able to predict the separation performance

for every working condition encountered in a typical aircraft flight. To achieve this

goal, three main tasks were performed: the development of different two-phase measurement

systems, the experimental tests of four different PASS architectures and the

theoretical development (after an extensive literature review) of correlations predicting

the performance of the PASS in function of the working conditions. Five specific aspects

of the PASS were studied: the inlet flow, the deoiling efficiency, the deaeration efficiency,

the pumping efficiency and the pressure drop. Finally, the models that have been developed

with the help of the measurement systems and of the experiments have been

integrated in a complete model of the lubrication system (under the EcosimPro modelling

environment). This helps to predict real in flight PASS working conditions and

performance. Indeed, the PASS is very sensitive to the engine working conditions and

an optimisation of the prototype size and performance is only feasible with an accurate

knowledge of these working conditions and a complete lubrication system model.

Finally, with the results of this PhD thesis, a new PASS design, optimised for different

aero-engine lubrication systems, is presented.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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Saleh, Mostafa, und Sandberg Anton Hedén. „IMPLEMENTATION OF OXYFUEL COMBUSTION IN A WASTE INCINERATION CHP PLANT : A Techno-Economic Assessment“. Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-55210.

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Global energy demand is predicted to rise in the coming decades, necessitating a shift to renewable energy sources to mitigate greenhouse gas emissions. However, due to the inability to supply renewable energy around the clock, it is estimated that only by adding an important technology, carbon capture and storage (CCS), it could be possible to reduce 80% of the 1990s greenhouse gas emissions. CCS aims to reduce anthropogenic carbon emissions by capturing CO2 from flue gases, transporting, and permanently storing or reutilizing industrially. The CCS approach includes three technologies: post-combustion capture, pre-combustion capture, and oxyfuel combustion, with the latter being the emphasis of this thesis. Based on the case study of Mälarenergi’s Refused-derived waste-fired CHP plant, this thesis investigates the viability of converting existing non-fossil fueled CHP plants to oxyfuel combustion. A thorough technical investigation based on analyzing the impact of oxyfuel combustion on system performance was conducted through system modeling using a process simulator, Aspen plus. The model in this thesis considers the development of an air separation unit (ASU), a CHP plant, and a cryogenic CO2 purification unit (CPU). All of which are validated through calibration and comparison with real-world data and similar work. To investigate the influence of employing oxyfuel combustion on the generation of both heat and electricity, two different scenarios were comprised, including recirculating flue gas before and after flue gas condensation. In addition, an analysis of the oxygen purity was conducted to assess the most optimal parameters with the least impact on system performance. Moreover, a detailed eco- nomic assessment comprising the costs of integrating oxyfuel combustion was also conducted. The findings of this thesis show that integrating waste incineration CHP plants with oxyfuel combustion for CO2 capture entails promising features under the condition of 97% oxygen purity and a flue gas recirculation system taking place after flue gas condensation. This is owing to (i) modest imposed energy penalty of approximately 8.7%, (ii) high CO2 recovery ratio, around 92.4%, (iii) total investment cost of approximately 554 M$ during a 20-year lifetime, and (iv) cost of captured CO2 of around 76 $/ton. Aside from system modeling, this thesis pre- sents an overview of the current state-of-the-art technology on the different separation and capture mechanisms. It is important to highlight that the goal of this thesis is not to provide a comprehensive review but rather to present an overall picture of the maturity of the different mechanisms. The findings point to the cryogenic separation mechanism as the most mature technology for both oxygen production and capturing of CO2 during oxyfuel combustion.

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Pierce, Karisa M. „Objectively obtaining information from gas chromatographic separations of complex samples using novel data processing and chemometric techniques /“. Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8575.

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Shalygin, Maxim. „Réalisation et caractérisation du transport sélectif gazeux de contacteurs gaz-liquide à membrane (Selective transport of gases in gas-liquid membrane system)“. Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL022N/document.

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Ce travail rapporte l’étude de systèmes membranaires à valves sélectives (SMV), qui combinent les avantages des techniques de séparation par membrane et par absorption. La 1ère partie du mémoire présente l'étude du transport de matière en régime permanent et transitoire dans les SMV élaborés à partir de membranes polymères denses et de solution aqueuses. Dans la 2ème partie le développement d'un modèle mathématique original pour la simulation des SMV est proposé ainsi que son évaluation expérimentale pour les séparations CO2/CH4/H2, avec des solutions aqueuses confinées de K2CO3. Des améliorations simultanées de la perméabilité (˜ 4 fois) et de la sélectivité (>20 fois) ont été obtenues pour CO2 avec le mélange CO2/H2. Un logiciel basé sur un nouveau modèle de transport de gaz dans ces contacteurs membranaires prenant en compte la sorption physique et chimique dans la phase liquide a été développé pour le calcul de la perméabilité en régime transitoire ou permanent
Combined gas-liquid membrane systems gather the advantages of membrane and absorption separation techniques. Specifically, selective membrane valves (SMV called flowing liquid membranes) were studied, i.e. creation, gas transport experiments, liquid nature and temperature dependences, and modelling. SMV use a flowing layer of liquid supported between two membranes. The 1st part of the dissertation reports the study of steady and non-steady state gas transports in SMV built out dense polymeric membranes. In the 2nd part is given the development of an original mathematical model for SMV simulation and its experimental assessment for CO2/CH4/H2 mixtures with aqueous solutions of K2CO3. From systematic studies of steady and non-steady state processes, both in flow-through and circulating modes, it was found that increasing of temperature and liquid carrier concentration (K2CO3) leads to the simultaneous rise of permeability and selectivity during CO2 recovery from CO2/H2 mixture

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Sales, Silva Luiz Paulo. „Procédé de séparation par formation sélective d'hydrates de gaz pour la valorisation du biogaz“. Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLY021/document.

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Le biogaz, constitué essentiellement de méthane et de dioxyde de carbone, représente une voie alternative aux sources d’énergies fossiles. Pour être valorisé le mélange doit être séparé dans un procédé de séparation de gaz. Ces dernières années, un nouveau procédé basé sur la formation d'hydrates de gaz (GSHF) a suscité une attention particulière dans la communauté scientifique. Basé sur une transition de phase hydrate – liquide – vapeur conduite en présence de promoteurs thermodynamiques, la purification est supposée demander moins d’énergie et moins de réactifs dangereux pour l’environnement que les procédés chimiques traditionnels comme l’absorption dans des solutions d’amines. Une connaissance des équilibres de phase dans les systèmes eau + gaz + additifs est essentielle à la validation du procédé. Dans ce projet, nous avons étudié quatre promoteurs, le bromure de trétrabutylammonium (TBAB), le bromure de tétrabutylphosphonium (TBPB), l’oxyde de tributylphosphine (TBPO) et le tétrahydropyrane (THP), qui ont pour buts d’abaisser la consommation d'énergie et d’améliorer la cinétique et la sélectivité du procédé. Une partie de ce projet a été consacrée à déterminer les conditions d'équilibre d'hydrates de gaz en présence de ces promoteurs et différentes phases gaz (CO2, CH4 et biogaz simulé). Les méthodes de calorimétrie différentielle à balayage (DSC) ont été appliquées pour mesurer les températures de transition de phase. De nouvelles données d'équilibre de phases ont été déterminées pour les systèmes hydrates de gaz + promoteurs. Dans la deuxième partie du projet, nous avons effectué des mesures quantitatives dans un réacteur instrumenté afin d'évaluer le procédé GSFH pour la valorisation du biogaz. Chaque promoteur a été évalué tant sur le plan de la cinétique (temps, d’induction, vitesse de croissance cristalline) que sur celui de la thermodynamique (quantité de gaz piégé, sélectivité). L'optimisation du programme de formation / dissociation des hydrates a montré d'excellents résultats en termes de cinétique
Biogas represents an alternative path to fossil energies. It is composed mainly by methane and carbon dioxide. This couple must be separated in a gas separation process. In recent years, the new process based on gas hydrate formation (GSHF) has taken special attention in academic community. Besides, the use of thermodynamic promoters can increase the efficiency of the process. Since GSFH is based on phase transition phenomenon, knowledge about phase equilibria is essential. In this project, we have selected and studied four thermodynamic promoters (tretrabutylammonium bromide / TBAB; tetrabutylphosphonium bromide / TBPB; tributylphosphine oxide / TBPO; tetrahydropyran / THP) that have potential to improve GSFH process of biogas in terms of stability gain (less energy consumption), kinetics and selectivity. One part of this project consisted in determining the gas hydrate equilibrium conditions involving these promoters and the different gas phases (CO2, CH4 and simulated biogas). Differential scanning calorimetry (DSC) methods were applied to measure the phase transition temperatures. Therefore, new phase equilibrium data were determined for the promoter/gas hydrate systems. In the second part of the project, we carried out quantitative measurements in an instrumented reactor in order to evaluate the GSFH process for upgrading biogas. Each promoter was evaluated in kinetics and thermodynamics aspects, such as crystal growth rate, amount of gas trapped into the hydrate phase, and selectivity. The optimization of the hydrate formation / dissociation cycle showed excellent results in terms of kinetics improvement

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Kouassi, Komlan Prosper. „Adaptation des techniques actuelles de scoring aux besoins d'une institution de crédit : le CFCAL-Banque“. Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAB004.

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Les institutions financières sont, dans l’exercice de leurs fonctions, confrontées à divers risques, entre autres le risque de crédit, le risque de marché et le risque opérationnel. L’instabilité de ces facteurs fragilise ces institutions et les rend vulnérables aux risques financiers qu’elles doivent, pour leur survie, être à même d’identifier, analyser, quantifier et gérer convenablement. Parmi ces risques, celui lié au crédit est le plus redouté par les banques compte tenu de sa capacité à générer une crise systémique. La probabilité de passage d’un individu d’un état non risqué à un état risqué est ainsi au cœur de nombreuses questions économiques. Dans les institutions de crédit, cette problématique se traduit par la probabilité qu’un emprunteur passe d’un état de "bon risque" à un état de "mauvais risque". Pour cette quantification, les institutions de crédit recourent de plus en plus à des modèles de credit-scoring. Cette thèse porte sur les techniques actuelles de credit-scoring adaptées aux besoins d’une institution de crédit, le CFCAL-banque, spécialisé dans les prêts garantis par hypothèques. Nous présentons en particulier deux modèles non paramétriques (SVM et GAM) dont nous comparons les performances en termes de classification avec celles du modèle logit traditionnellement utilisé dans les banques. Nos résultats montrent que les SVM sont plus performants si l’on s’intéresse uniquement à la capacité de prévision globale. Ils exhibent toutefois des sensibilités inférieures à celles des modèles logit et GAM. En d’autres termes, ils prévoient moins bien les emprunteurs défaillants. Dans l’état actuel de nos recherches, nous préconisons les modèles GAM qui ont certes une capacité de prévision globale moindre que les SVM, mais qui donnent des sensibilités, des spécificités et des performances de prévision plus équilibrées. En mettant en lumière des modèles ciblés de scoring de crédit, en les appliquant sur des données réelles de crédits hypothécaires, et en les confrontant au travers de leurs performances de classification, cette thèse apporte une contribution empirique à la recherche relative aux modèles de credit-scoring
Financial institutions face in their functions a variety of risks such as credit, market and operational risk. These risks are not only related to the nature of the activities they perform, but also depend on predictable external factors. The instability of these factors makes them vulnerable to financial risks that they must appropriately identify, analyze, quantify and manage. Among these risks, credit risk is the most prominent due to its ability to generate a systemic crisis. The probability for an individual to switch from a risked to a riskless state is thus a central point to many economic issues. In credit institution, this problem is reflected in the probability for a borrower to switch from a state of “good risk” to a state of “bad risk”. For this quantification, banks increasingly rely on credit-scoring models. This thesis focuses on the current credit-scoring techniques tailored to the needs of a credit institution: the CFCAL-banque specialized in mortgage credits. We particularly present two nonparametric models (SVM and GAM) and compare their performance in terms of classification to those of logit model traditionally used in banks. Our results show that SVM are more effective if we only focus on the global prediction performance of the models. However, SVM models give lower sensitivities than logit and GAM models. In other words the predictions of SVM models on defaulted borrowers are not satisfactory as those of logit or GAM models. In the present state of our research, even GAM models have lower global prediction capabilities, we recommend these models that give more balanced sensitivities, specificities and performance prediction. This thesis is not completely exhaustive about the scoring techniques for credit risk management. By trying to highlight targeted credit scoring models, adapt and apply them on real mortgage data, and compare their performance through classification, this thesis provides an empirical and methodological contribution to research on scoring models for credit risk management

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Bozorg, Marjan. „Optimization of membrane process architecture“. Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0252.

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Les procédés de séparation membranaire sont une technologie bien connue et déjà largement utilisée dans le domaine de la purification des gaz. Ces procédés sont applicables à de nombreux secteurs d’activités industriels. Selon les performances de séparation recherchées, elles peuvent constituer une alternative intéressante aux technologies existantes de traitement des gaz (adsorption, cryogénie, contacteurs gaz/liquide). Pour exploiter au mieux cette technologie, le développement d'outils d’aide à la décision permettant d’identifier les procédés et les conditions opératoires économiquement avantageux est absolument nécessaire. Bien que les approches expérimentales d'optimisation appliquées à différentes études de cas conservent un intérêt certain, une approche générale et sa validation dans le cadre de différentes études de cas font toujours défaut. L’objectif principal de cette thèse est de développer un outil numérique le plus générique possible d’optimisation de procédés de séparation membranaire. Dans ce travail, la synthèse du procédé membranaire est traitée et modélisée comme un problème d'optimisation mathématique non linéaire et non convexe basé sur un paradigme de superstructure couvrant une combinatoire d'unités (modules membranaires, compresseurs, pompes à vide) et de connexions la plus exhaustive possible. Des fonctions de coûts réalistes et détaillées sont utilisées comme fonction objectif dans l'optimisation. Une stratégie d'optimisation globale continue, qui peut se considérer comme la composition de deux algorithmes : Multistart et Monotonic Basin Hopping (MBH) ; est présentée pour résoudre le problème d'optimisation susmentionné. L'efficacité de cette démarche d'optimisation est dans un premier temps validée en comparant sa solution à celles présentées dans la littérature. La méthode proposée est ensuite appliquée à l'optimisation de plusieurs cas emblématiques de la séparation de gaz (CO2 de gaz de haut fourneaux, séparation O2/N2 de l’air, traitement du biogaz et du gaz naturel). Différents degrés de liberté du système sont permis et analysés selon les cas (pressions variables, type de membrane variable). L'analyse détaillée des résultats est discutée en termes d’architecture de procédés et de distribution des coûts (CAPEX, OPEX)
Membrane separation is a well-known technology in gas purification, which is applicable in different aspects of the industry. Over the last decades, depending on the required separation performances, it became a viable alternative to several gas separation technologies (adsorption, cryogenics, gas /liquid contactors). To exploit at best this technology, nevertheless, tools to find cost-effective designs and operating conditions are necessary. While experimental optimization approaches applied to different case studies have been investigated extensively, a more generic optimization approach and its validation along different case studies are still missing. The work of this thesis starts with this key observation and tries to fill this gap. The membrane process synthesis is modelled as a nonlinear and non-convex mathematical optimization problem based on a superstructure paradigm covering a wide range of possible units (membrane modules, compressors, and vacuum pumps) and connections as exhaustive as possible. Realistic and detailed cost functions are used as the objective in the optimization. A continues global optimization strategy, that can be considered as the composition of two algorithms: Multistart and Monotonic Basin Hopping (MBH); is presented to solve the aforementioned optimization problem. The efficiency of this overall optimization approach is, first, validated by comparing its solution with the ones presented in the literature. Then, the proposed method is applied to the optimization of several important gas separation cases (CO2 recovery from blast furnace gas, O2/N2 air separation, and biogas and natural gas purification) by increasing the membrane system degree of freedom step by step. Detailed analysis of the results is discussed in terms of process architecture and cost distribution (CAPEX, OPEX)

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Bücher zum Thema "Gas Separation Techniques"

Geall, Louise. The Analysis of some organotins in water using solid phase extraction techniques with separation and detection by gas chromatography electron capture. Poole: Bournemouth University, 1999.

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author, Feng Jiuchao 1964, und Xie Zhigang 1965-, Hrsg. Chuan gan qi wang luo zhong de mang yuan fen li yu xin hao chong gou: Blind Source Separation and Signal Reconstruction in Sensor Networks. Beijing Shi: Dian zi gong ye chu ban she, 2012.

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Gas Separation: Techniques, Applications and Effects. Nova Science Publishers, Incorporated, 2018.

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Guthrie, Graeme. Narrowing the Gap. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780190641184.003.0004.

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Manager-shareholder conflict arises due to low levels of managerial ownership and the resulting wide separation of ownership and control. However, strong boards of directors can make even small ownership stakes more effective at motivating executives to work in shareholders’ best interests by granting stock options, repurchasing shares, and issuing debt. Ultimately they can approve a leveraged buyout, although a strong board is needed to overcome the conflicts of interest involved in management-led buyouts. This chapter uses events at HCA, the for-profit hospital chain that undertook the world’s largest leveraged buyout followed a few years later by the largest private equity IPO, to explain how boards can narrow the gap between ownership and control. It uses a novel representation of a firm’s capital structure to analyze the techniques for boosting ownership-generated incentives at relatively low cost to shareholders.

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Buchteile zum Thema "Gas Separation Techniques"

Ismail, Ahmad Fauzi, Kailash Chandra Khulbe und Takeshi Matsuura. „Membrane Fabrication/Manufacturing Techniques“. In Gas Separation Membranes, 193–220. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-01095-3_4.

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Bruner, F. „Gas Chromatographic Techniques to Elucidate the Working Mechanism of Graphitized Carbon Black-Liquid Modifier-Eluate Interactions“. In Theoretical Advancement in Chromatography and Related Separation Techniques, 369–95. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2686-1_14.

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Findenegg, G. H. „Principles of Adsorption at Solid Surfaces and their Significance in Gas/Solid and Liquid/Solid Chromatography“. In Theoretical Advancement in Chromatography and Related Separation Techniques, 227–60. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2686-1_8.

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Cramers, Carel A., Peter J. Schoenmakers und Hans-Gerd Janssen. „The Position of Supercritical-Fluid Chromatography Between Gas- and Liquid Chromatography from a Kinetic Point of View“. In Theoretical Advancement in Chromatography and Related Separation Techniques, 289–314. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2686-1_11.

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Nolvachai, Yada, und Philip J. Marriott. „Green Separation Techniques for Omics Platforms—Gas Chromatography“. In Comprehensive Foodomics, 609–26. Elsevier, 2021. http://dx.doi.org/10.1016/b978-0-08-100596-5.22809-6.

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Kosheleva, Ramonna I., George Z. Kyzas und Athanasios C. Mitropoulos. „Low-cost materials in gas-phase adsorption“. In Advanced Low-Cost Separation Techniques in Interface Science, 125–49. Elsevier, 2019. http://dx.doi.org/10.1016/b978-0-12-814178-6.00006-6.

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Luque de Castro, Maria Dolores. „Membrane-Based Separation Techniques: Dialysis, Gas Diffusion and Pervaporation“. In Advances in Flow Injection Analysis and Related Techniques, 203–34. Elsevier, 2008. http://dx.doi.org/10.1016/s0166-526x(08)00608-9.

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Lucci, Paolo, Ana Srbinovska, Dennis Fiorini, Andrea Milani, Deborah Pacetti und Sabrina Moret. „Application of Gas Chromatography for Quality and Authenticity Assessment of Olive Oil“. In Chromatographic and Related Separation Techniques in Food Integrity and Authenticity, 1–19. WORLD SCIENTIFIC (EUROPE), 2021. http://dx.doi.org/10.1142/9781786349972_0001.

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Nartea, Ancuta, Edoardo Bartolucci, Paolo Lucci, Natale G. Frega und Deborah Pacetti. „Application of the Gas Chromatography Technique in the Characterization and Authentication of Food Products“. In Chromatographic and Related Separation Techniques in Food Integrity and Authenticity, 43–69. WORLD SCIENTIFIC (EUROPE), 2021. http://dx.doi.org/10.1142/9781786349958_0003.

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Carazzone, Chiara, Julie P.G. Rodríguez, Mabel Gonzalez und Gerson-Dirceu López. „Volatilomics of Natural Products: Whispers from Nature“. In Metabolomics - Methodology and Applications in Medical Sciences and Life Sciences. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97228.

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Volatilomics studies the emission of volatile compounds from living organisms like plants, flowers, animals, fruits, and microorganisms, using metabolomics tools to characterize the analytes. This is a complex process that involves several steps like sample preparation, extraction, instrumental analysis, and data processing. In this chapter, we provide balanced coverage of the different theoretical and practical aspects of the study of the volatilome. Static and dynamic headspace techniques for volatile capture will be discussed. Then, the main techniques for volatilome profiling, separation, and detection will be addressed, emphasizing gas chromatographic separation, mass spectrometry detection, and non-separative techniques using mass spectrometry. Finally, the whole volatilome data pre-processing and multivariate statistics for data interpretation will be introduced. We hope that this chapter can provide the reader with an overview of the research process in the study of volatile organic compounds (VOCs) and serve as a guide in the development of future volatilomics studies.

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Konferenzberichte zum Thema "Gas Separation Techniques"

Kenawy, F. A., und M. E. Kandil. „Comparative Evaluation between a Modified CFP Separator and All Other Available Oil-Water Separation Techniques“. In SPE International Conference on Health, Safety, and Environment in Oil and Gas Exploration and Production. Society of Petroleum Engineers, 1998. http://dx.doi.org/10.2118/46817-ms.

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Rathore, P. S., und R. Thundil Karuppa Raj. „Numerical Investigation of Transverse Jet in Supersonic Cross-Flow Using CFD Techniques“. In ASME 2013 Gas Turbine India Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gtindia2013-3516.

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High speed jets in cross flows are central to fuel injection in supersonic combustion scramjet engines. In supersonic combustion scramjet engines, the sonic under expanded transverse jet of fuel is injected into a supersonic cross flow of air, where efficient mixing of fuel and air is one of the major critical issues. Due to the limited flow residence time inside the combustion chamber, the enhancement of supersonic turbulent mixing of jet fuel and cross-flow air is a critical issue in developing supersonic air-breathing engines. The accurate estimation and detailed physical understanding of the turbulent mixing mechanisms plays an important role in combustor design of scramjet engines. This numerical study aims at understanding the complex physical phenomenon involved in mixing of fuel jet and air and the associated turbulence characteristics, boundary layer capture and flow separation. In the current study the flow field resulting from the transverse injection of fuel jet into cross-flow of air is simulated numerically by solving the appropriate governing equations for a 2-dimensional flow. Numerical simulations are used to study an under-expanded jet injected into a supersonic cross flow. This study examines the flow structure, separation topology and performance characteristics of an under expanded transverse jet issuing normally into supersonic free stream. The influence of the compressibility effect on the shock wave structure and on the vortex system ahead and behind of the jet are studied by solving Favre averaged Navier Stokes (FANS) equations with SST k-ω turbulence model. The influence of the jet Mach number and jet-to-cross-flow pressure ratio on shock wave structure of the flow and jet penetration depth are studied. The simulated numerical results are compared with the experimental data available in the literature. Grid independence study is carried out for all the simulations carried out in the work to have good accurate results. It was found out that wall pressure profile of transverse jet injection for the high jet-to-cross-flow pressure ratio is predicted more accurately by the SST k-ω turbulence model. The jet penetration depth found out to be increasing with the increase in jet-to-cross-flow pressure ratio and fuel jet slot width.

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Radhakrishnan, Anand N. P., Marc Pradas, Serafim Kalliadasis und Asterios Gavriilidis. „Nonlinear Dynamics of Gas-Liquid Separation in a Capillary Microseparator“. In ASME 2018 16th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/icnmm2018-7613.

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Micro-engineered devices (MED) are seeing a significant growth in performing separation processes1. Such devices have been implemented in a range of applications from chemical catalytic reactors to product purification systems like microdistillation. One of the biggest advantages of these devices is the dominance of capillarity and interfacial tension forces. A field where MEDs have been used is in gas-liquid separations. These are encountered, for example, after a chemical reactor, where a gaseous component being produced needs immediate removal from the reactor, because it can affect subsequent reactions. The gaseous phase can be effectively removed using an MED with an array of microcapillaries. Phase-separation can then be brought about in a controlled manner along these capillary structures. For a device made from a hydrophilic material (e.g. Si or glass), the wetted phase (e.g. water) flows through the capillaries, while the non-wetted dispersed phase (e.g. gas) is prevented from entering the capillaries, due to capillary pressure. Separation of liquid-liquid flows can also be achieved via this approach. However, the underlying mechanism of phase separation is far from being fully understood. The pressure at which the gas phase enters the capillaries (gas-to-liquid breakthrough) can be estimated from the Young-Laplace equation, governed by the surface tension (γ) of the wetted phase, capillary width (d) and height (h), and the interface equilibrium contact angle (θeq). Similarly, the liquid-to-gas breakthrough pressure (i.e. the point at which complete liquid separation ceases and liquid exits through the gas outlet) can be estimated from the pressure drop across the capillaries via the Hagen-Poiseuille (HP) equation. Several groups reported deviations from these estimates and therefore, included various parameters to account for the deviations. These parameters usually account for (i) flow of wetted phase through ‘n’ capillaries in parallel, (ii) modification of geometric correction factor of Mortensen et al., 2005 2 and (iii) liquid slug length (LS) and number of capillaries (n) during separation. LS has either been measured upstream of the capillary zone or estimated from a scaling law proposed by Garstecki et al., 2006 3. However, this approach does not address the balance between the superficial inlet velocity and net outflow of liquid through each capillary (qc). Another shortcoming of these models has been the estimation of the apparent contact angle (θapp), which plays a critical role in predicting liquid-to-gas breakthrough. θapp is either assumed to be equal to θeq or measured with various techniques, e.g. through capillary rise or a static droplet on a flat substrate, which is significantly different from actual dynamic contact angles during separation. In other cases, the Cox-Voinov model has been used to calculate θapp from θeq and capillary number. Hence, the empirical models available in the literature do not predict realistic breakthrough pressures with sufficient accuracy. Therefore, a more detailed in situ investigation of the critical liquid slug properties during separation is necessary. Here we report advancements in the fundamental understanding of two-phase separation in a gas-liquid separation (GLS) device through a theoretical model developed based on critical events occurring at the gas-liquid interfaces during separation.

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Gan, Xiaohua, und Qishou Zhao. „Inner Operation of Prefilming Airblast Atomizers“. In ASME 1991 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1991. http://dx.doi.org/10.1115/91-gt-106.

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In this paper research is focused on the inner operation of prefilming airblast atomizers and its effect on liquid atomization. Liquid wavy film thickness and wavelength-frequency spectra, which characterize the liquid motion inside the atomizers, are measured with specifical techniques. The motion and separation of liquid wavy film are picturized by means of laser pulse micrography technique. The spray is measured with the Malvern Particle Sizer. The experiments show the liquid atomization is initiated by separation of the liquid film waves from their main film. The atomization characteristics are dominated by the extent of air/liquid interaction inside the atomizers. In addition, liquid flow rate effect on atomization is comfirmed. No liquid collection near the atomizer edges is found.

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Al-Ajlouni, Musa, und Nick Syred. „Studies of the Rotor Dynamics of Gas Centrifuges for Fine Particulate Separation“. In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0497.

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Abstract A range of techniques have been used to evaluate the performance of an existing design of gas centrifuge for separating sub-micron particles from gas streams. The rotor dynamics of the system are complex, very dependant on the bearing type, design, and layout. The first harmonic typically occurs at low speeds of about 15,000 rpm and can be of sufficient a high amplitude to require special bearing systems. This paper analyses the performance of an existing unit with a number of tools, including a computer aided package called ROMAX II that carries out a dynamic vibrational analysis of the self acting foil and annular air thrust bearing system. Results are compared with experiment. It is shown that the first harmonic vibrational mode is well predicted. Changes in performance occurring from detail design alterations made to the thrust bearings are also shown to be sensibly predicted. Finally extrapolations are made to units of 1 metre in length and performance predictions made. It is clearly shown that by an appropriate choice of bearing system the first natural frequency can be raised to well above that required for sensible centrifuge operation.

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Quinn, Casey, Daniel Zimmerle und Daniel B. Olsen. „Flare Gas Utilization at Combined Oil-Gas Well Sites“. In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90041.

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Many natural gas well sites produce significant quantities of oil as a byproduct of gas production. Producers use standard gas separation techniques to recover gas dissolved in the oil, but additional light hydrocarbons are released during final depressurization and storage of the oil at atmospheric pressure. Gas produced in oil storage is often contaminated with air, cannot be introduced into midstream pipelines, and is flared at the well site. The flare gas represents a significant energy resource that could be utilized to improve overall site efficiency. This work documents a comprehensive energy analysis performed on a non-electrified site in Colorado. Data collection and simulations demonstrated that energy available in flare gas is sufficient to support the major energy loads at the well site. However, due to low flare gas pressures, high and variable air contamination, and temporal misalignment between the gas availability and energy needs, on-site utilization requires modified engine technology and application of energy buffering. Simulation results are presented, along with conceptual designs for well site modifications.

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Snyder, Philip H., Dominic Barone und Eric Loth. „Unsteady Flow Dynamics Within an Inertial Particle Separator“. In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43783.

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Inertial Particle Separators are utilized in the inlet of a gas turbine engine to remove a significant fraction of the damaging sand and dust particulate ingested by the engine. In gas turbine propulsion applications these devices have pressure loss, space claim, and maintainability characteristics that are more favorable than other types of particle separating devices. Maximizing the particle separation efficient of such devices is the subject of continuing importance. A more complete understanding of the underlying fluid and particulate flow mechanisms present has been undertaken. This study focuses on the how particulate is affected by the unsteady flow dynamics within the inertial particle separator (IPS). The work utilized a particle separator test rig with flow path scale and airflow velocities relevant to that used in current production designs. The techniques of surface flow visualization, net separation efficiency measurement, specific geometry changes, traditional Particle Image Velocimetry (PIV), Multi-Phase PIV (MP-PIV), and high speed video were each applied to examine the fundamental flow physics of the fluid flow field and the particle motion created by the IPS geometries.

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Carscallen, W. E., T. C. Currie, S. I. Hogg und J. P. Gostelow. „Measurement and Computation of Energy Separation in the Vortical Wake Flow of a Turbine Nozzle Cascade“. In ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/98-gt-477.

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This paper describes the observation, measurement and computation of vortex shedding behind a cascade of turbine nozzle guide vanes which have a blunt trailing edge. At subsonic discharge speeds periodic wake vortex shedding was observed at all times at a shedding frequency in the range 7–11 kHz. At high subsonic speeds the wake was susceptible to strong energy redistribution. The effect was greatest around an exit Mach number of 0.95 and results are presented for that condition. An unusually cold flow on the wake center line and hot spots at the edges of the wake were measured. These were found to be a manifestation of Eckert-Weise effect energy separation in the shed vortex street. Experimental identification of these phenomena was achieved using a new stagnation temperature probe of bandwidth approaching 100 kHz. Using phase averaging techniques it was possible to plot contours of time-resolved entropy increase at the downstream traverse plane. Computational work has been undertaken which gives qualitative confirmation of the experimental results and provides a more detailed explanation of the fine scale structure of the vortex wake. The topology of the wake vortical structures behind blunt trailing-edged turbine blades is becoming clearer. These measurements are the first instantaneous observations of the energy separation process occurring in turbine blade wake flows. This was also the first demonstration of the use of the probe in the frequency, Mach number and temperature ranges typical of operation behind the rotors of high performance turbomachines such as transonic fans.

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Zierke, W. C., und S. Deutsch. „The Measurement of Boundary Layers on a Compressor Blade in Cascade: Part 4 — Flow Fields for Incidence Angles of −1.5 and −8.5 Degrees“. In ASME 1989 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1989. http://dx.doi.org/10.1115/89-gt-72.

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Measurements, made with laser Doppler velocimetry, about a double-circular-arc compressor blade in cascade are presented for −1.5 and −8.5 degree incidence angles and a chord Reynolds number near 500,000. Comparisons between the results of the current study and those of our earlier work at a 5.0 degree incidence are made. It is found that in spite of the relative sophistication of the measurement techniques, transition on the pressure surface at the −1.5 degree incidence is dominated by a separation “bubble” too small to be detected by the laser Doppler velocimeter. The development of the boundary layers at −1.5 and 5.0 degrees are found to be similar. In contrast to the flow at these two incidence angles, the leading edge separation “bubble” is on the pressure surface for the −8.5 degree incidence. Here, all of the measured boundary layers on the pressure surface are turbulent — but extremely thin — while on the suction surface, a laminar separation/turbulent reattachment “bubble” lies between roughly 35% and 60% chord. This “bubble” is quite thin, and some problems in interpreting backflow data.

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Hatman, Anca, und Ting Wang. „Separated-Flow Transition: Part 1 — Experimental Methodology and Mode Classification“. In ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/98-gt-461.

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This first part of the paper presents techniques implemented for the experimental investigation of the transition mechanism in 2-D pressure driven separated boundary layer flows over a flat plate at inlet free-stream turbulence intensities ranging from 0.3 to 0.6% and imposed adverse pressure gradients ranging from K = − 0.68 × 10−6 to − 6.25 × 10−6. The structure and behavior of the separation bubble were investigated for various flow conditions. The separated-flow transition modes were identified and classified. The distribution end strength of the adverse pressure gradient were obtained by varying the test section outer wall divergence angle. Specific methods identifying the main parameters that characterize separated-flow transition are introduced and issues regarding measurements of reverse flow are discussed. The methods implemented in determining the separation point, maximum displacement location, the unsteady reattachment region, the start and end of transition, etc. are described.

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Berichte der Organisationen zum Thema "Gas Separation Techniques"

Poku, J., und J. Plunkett. Assessment of membrane gas separation applications to METC (Morgantown Energy Technology Center) supported techniques. Office of Scientific and Technical Information (OSTI), August 1989. http://dx.doi.org/10.2172/6987247.

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