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gas-separation
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Supersonic Separation
, M.Sc. Thesis Sharif University of Technology ; Moosavi, Ali (Supervisor) ; Nouri Borujerdi, Ali (Supervisor)
Abstract
Supersonic separators with neither rotating parts nor chemical process, physically separate particles in a multi-phase flow. In comparison with general separation techniques, which are utilized in industries, specifically this equipment is cheaper, smaller and lighter. Condensation and separation at supersonic velocity is the key to achieve a significant reduction in both capital and operating costs. In this study, a two dimensional de Laval nozzle and few three-dimensional supersonic separator have been modeled. The 3D models modified in shape and dimensions. Impellers were created to form swirl flow. The models were simulated by the use of CFD software ANSYS FLUENT. Diverse inlet pressures...
Thin film UV-curable acrylate polyurethane/MOF mixed matrix membranes for CO2 separation
, Article 18th European Conference on Composite Materials, ECCM 2018, 24 June 2018 through 28 June 2018 ; 2020 ; Molavi, H ; Mousavi, S. A ; Adamant Composites Ltd.; Hellenic Aerospace Industry S.A; JEC Group; Materials Today; Photron; Shimadzu Europa GmbH ; Sharif University of Technology
Applied Mechanics Laboratory
2020
Abstract
The major obstacles in gas separation by mixed-matrix composite membranes (MMCMs) are poor dispersion and poor affinity between polymers and fillers. The present study demonstrates that these challenges can be overcome appropriately by utilizing a series of synthesized MMCMs. MMCMs were prepared with UV-curable polyurethane acrylate and UiO-66 as selective layer and polyester/polysulfone (PS/PSF) as support layer. The physical properties of prepared MMCMs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Microscopic analysis by FESEM revealed that desirable nanoscale dispersion of UiO-66,...
Thin film graphene oxide membrane: challenges and gas separation potential
, Article Korean Journal of Chemical Engineering ; Volume 35, Issue 5 , May , 2018 , Pages 1174-1184 ; 02561115 (ISSN) ; Karimi Sabet, J ; Ghotbi, C ; Abbasi, Z ; Sharif University of Technology
Springer New York LLC
2018
Abstract
Graphene oxide membranes were prepared by vacuum and pressurized ultrafiltration methods on the 12% modified Polyacrylonitrile (12mPAN) substrate to specify challenges, salient features, future directions, and potential of GO membrane for separation fields using characterization techniques and gas separation test (studied gases are CO2, He and N2), which is an efficient tool for better understanding of GO membrane behavior. GO membrane structure was examined over a wide range of parameters, such as pore size range of substrate and its surface properties, pH of GO dispersion, GO content, synthesis pressure, operating pressure and temperature. The results show that the GO content does not hold...
The effect of water vapor on the performance of commercial polyphenylene oxide and Cardo-type polyimide hollow fiber membranes in CO2/CH4 separation applications
, Article Journal of Membrane Science ; Volume 285, Issue 1-2 , 2006 , Pages 265-271 ; 03767388 (ISSN) ; Soltanieh, M ; Matsuura, T ; Tabe Mohammadi, A ; Khulbe, K. C ; Sharif University of Technology
2006
Abstract
The effects of water vapor on CO2/CH4 separation using commercially available poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and Cardo-type polyimide hollow fiber membranes were investigated. Pure methane and CO2/CH4 mixture permeation experiments were carried out in the absence and presence of water vapor (60% RH). Pure methane permeance decreased in the presence of water vapor for both membrane types. The decrease was 28% for hydrophilic Cardo-type polyimide and 6% for hydrophobic PPO membranes. The decline in the permeance was also observed for CO2/CH4 mixture separation through both membranes. However, selectivities of the two membranes were affected differently by water vapor. The...
The effect of ethane on the performance of commercial polyphenylene oxide and cardo-type polyimide hollow fiber membranes in CO 2/CH 4 separation applications
, Article Korean Journal of Chemical Engineering ; Volume 27, Issue 6 , 2010 , Pages 1876-1881 ; 02561115 (ISSN) ; Savoji, H ; Soltanieh, M ; Matsuura, T ; Tabe, S ; Sharif University of Technology
2010
Abstract
Impurities such as hydrogen sulfide, water vapor and heavy hydrocarbons in natural gas have considerable effects on the membrane performance. Small amounts of condensable and polymer soluble components in the feed gas cause swelling or plasticization of glassy membranes, leading to a reduction in membrane selectivity. In the present research the influence of ethane was investigated on the permeance and selectivity of two commercially available hollow fiber membranes, namely Cardo-type polyimide and PPO hollow fibers for CO 2/CH 4 separations. It was concluded that the gas mixture permeation rate was increased in the presence of C 2H 6. However, the CO 2/CH 4 separation factors remained...
Swirl intensity as a control mechanism for methane purification in supersonic gas separators
, Article Journal of Natural Gas Science and Engineering ; Volume 83 , 2020 ; Amini Magham, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Supersonic gas separator is proposed for methane purification. One-dimensional analysis is performed to examine the design aspects associated with the converging-diverging nozzle and the liquid separation chamber. The results indicate that at low swirl intensities, the separation chamber length is about 100 times of the nozzle throat. Increasing the swirl intensity would lower this length sharply and it will be less than 10 for swirl intensity of unity which is equivalent to a swirl angle of 45°. In addition, a sensitivity analysis of the separator performance to the inlet conditions like the temperature, pressure, and composition of the mixture is carried out. It is observed that increasing...
Supersonic separator's dehumidification performance with specific structure: Experimental and numerical investigation
, Article Applied Thermal Engineering ; Volume 179 , October , 2020 ; Farhadi, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Supersonic separators are used in gas separation processes such as dehumidification of humid air due to high performance and its good pressure recovery. In the present study, a comprehensive numerical and experimental investigation on the hydrodynamic behavior of air as working fluid and dehumidification performance of supersonic separator have been accomplished. The effect of the operational parameters on shockwave's position are examined. The outcomes show that by increasing the pressure level of supersonic separator, relative error between numerical and experimental results decreases from 20% to less than 10%. The effect of the operational parameters and humidity of inlet air on the...
Study of the solubility of CO2, H2S and their mixture in the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate: Experimental and modelling
, Article Journal of Chemical Thermodynamics ; Volume 65 , 2013 , Pages 220-232 ; 00219614 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Jalili, A. H ; Mehdizadeh, A ; Sharif University of Technology
2013
Abstract
New experimental results are presented for the solubility of carbon dioxide, hydrogen sulfide in the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C8mim][PF6]) at temperatures range from (303.15 to 353.15) K and pressures up to about 2 MPa. The solubility of the mixture of CO2/H2S in [C8mim][PF6] under various feed compositions were also measured at temperatures of (303.15, 323.15 and 343.15) K and the pressure up to 1 MPa. The solubility of carbon dioxide and hydrogen sulfide increased with increasing pressure and decreased with increasing temperature and the solubility of H2S is about three times that of CO2 in the particular ionic liquid studied. The measured data were...
Study of gas separation properties of ethylene vinyl acetate (EVA) copolymer membranes prepared via phase inversion method
, Article Separation and Purification Technology ; Volume 62, Issue 3 , 22 September , 2008 , Pages 642-647 ; 13835866 (ISSN) ; Sadeghi, M ; Motamed Hashemi, M. M. Y ; Pourafshari Chenar, M ; Roosta Azad, R ; Sadeghi, M ; Sharif University of Technology
2008
Abstract
The gas separation properties of ethylene vinyl acetate (EVA) membranes containing 18 and 28 wt% of vinyl acetate (VA) were investigated in this study. The effects of membrane preparation conditions, such as thermal and thermal/wet phase inversion, and the type of solvent on the gas separation properties of EVA membranes were investigated. The permeation of pure O2, N2, CH4, and CO2 gases at different feed pressures ranging from 2 to 11 bar were examined. The results indicated that the CO2 permeability was evidently higher than those of the other gases. Furthermore, the solubility mechanism was found to be the dominant mechanism for permeation of gases through EVA membranes. Moreover, the...
Structural and transport properties of polydimethylsiloxane based polyurethane/silica particles mixed matrix membranes for gas separation
, Article Korean Journal of Chemical Engineering ; Volume 31, Issue 5 , 2014 , Pages 841-848 ; ISSN: 02561115 ; Ghalei, B ; Fardi, M ; Esmaeeli, M ; Vakili, E ; Sharif University of Technology
Abstract
Mixed matrix membranes of synthesized polyurethane (PU) based on toluene diisocyanate (TDI), polydimethylsiloxane (PDMS) and polytetramethylene glycol (PTMG) with polyvinyl alcohol based polar silica particles were prepared by solution casting technique. The homogeneity and thermal properties of the prepared PDMS-PU/silica membranes were characterized using scanning electron microscope (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The SEM micrographs confirmed the distribution of silica particles in the polymer matrix without agglomerations. Gas permeation properties of membranes with different silica contents were studied for pure CO2, CH4, O2, He...
Solubility of CO2 and H2S in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate
, Article Journal of Natural Gas Science and Engineering ; Volume 30 , Volume 30 , 2016 , Pages 583-591 ; 18755100 (ISSN) ; Jalili, A. H ; Ghotbi, C ; Rashtchian, D ; Sharif University of Technology
Elsevier
2016
Abstract
The solubility of carbon dioxide and hydrogen sulfide gases in the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([C2mim][OTf]) was measured at temperatures from (303.15-353.15) K and pressures up to about 3.0 MPa. The Henry's law constants were determined from the new experimental data, which in turn were used to derive the change of some thermodynamic functions of dissolution of the gases in that particular ionic liquid. The new experimental data were correlated by a combination of the extended Henry's law and Pitzer's model for the excess Gibbs energy. The average relative percent deviation (ARD%) of correlated molality values from experimental data are within...
Simultaneous separation of H2S and CO2 from CH4 by a high silica CHA-type zeolite membrane
, Article Journal of Membrane Science ; Vol. 470, issue , 2014 , pp. 159-165 ; ISSN: 03767388 ; Soltanieh, M ; Sharif University of Technology
Abstract
A high silica CHA-type membrane was synthesized by the in-situ crystallization method on a disk like α-alumina porous support to separate both acid (H2S, CO2) gases from methane. The membrane showed a permeance of 3.39×10-8mol/m2sPa for pure CO2with CO2/CH4 ideal selectivity of 21.6 at 303K and 100kPa pressure difference across the membrane. The membrane was also tested with N2 and O2 pure gases indicating a small O2/N2 selectivity of 1.2-1.4, which shows that this type of membrane is not suitable for O2/N2 separation. The membrane performance was also analyzed by binary (CO2-CH4) and ternary (H2S-CO2-CH4) gas mixtures, with compositions near the real sour natural gas (CO2: 2.13mol%, H2S:...
Recent progress in molecular simulation of nanoporous graphene membranes for gas separation
, Article Journal of the Korean Physical Society ; Volume 71, Issue 1 , 2017 , Pages 54-62 ; 03744884 (ISSN) ; Baniasadi, A ; Moradi, M ; Sharif University of Technology
Abstract
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 sp2 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...
Polymeric mixed matrix membranes containing zeolites as a filler for gas separation applications: A review
, Article Journal of Industrial and Engineering Chemistry ; Volume 19, Issue 2 , 2013 , Pages 375-393 ; 1226086X (ISSN) ; Esmaeili, N ; Asadollahi, M ; Sharif University of Technology
2013
Abstract
Polymeric membrane technology has received extensive attention in the field of gas separation, recently. However, the tradeoff between permeability and selectivity is one of the biggest problems faced by pure polymer membranes, which greatly limits their further application in the chemical and petrochemical industries. To enhance gas separation performances, recent works have focused on improving polymeric membranes selectivity and permeability by fabricating mixed matrix membranes (MMMs). Inorganic zeolite materials distributed in the organic polymer matrix enhance the separation performance of the membranes well beyond the intrinsic properties of the polymer matrix. This concept combines...
Plasticization effect on performance of polyphenylene oxide hollow fiber membrane at high concentrations of hydrogen sulfide
, Article 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7, 28 August 2010 through 1 September 2010 ; 2010 ; Niknejad, S. M. S ; Soltanieh, M ; Sharif University of Technology
Abstract
Natural gas contains several impurities, e.g., CO 2 and H 2S, which have undesirable effects on the performance of the glassy polymeric membranes. The plasticization effect of H 2S at high concentrations on the gas separation performance of polyphenylene oxide hollow fiber membrane has been studied at different compositions of H 2S and feed pressures. The existence of high concentrations of H 2S in CH 4 feed mixture, which is present in many natural gas sources in Iran, enhances plasticization. For a H 2S/CH 4 mixture containing 5008 ppm H 2S at ≈ 75 psig, the H 2S permeance reduces by > 45% from its initial value. H 2S acts as a plasticizer in H 2S/CH 4 membrane separation at elevated...
Photo-curable acrylate polyurethane as efficient composite membrane for CO2 separation
, Article Polymer ; Volume 149 , 2018 , Pages 178-191 ; 00323861 (ISSN) ; Shojaei, A ; Mousavi, S. A ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The current investigation was to present composite membranes with strong interfacial adhesion between top polymeric selective layer and the bottom micro-porous support layer with appropriate gas permeation behavior and practically suitable processing characteristics. To this end, a series of acrylate-terminated polyurethanes (APUs) based on poly (ethylene glycol) (PEG) with different molecular weights (Mn) of 600, 1000, 1500, 2000 and 4000 g/mol, toluene diisocyanate (TDI), and 2-hydroxyethyl methacrylate (HEMA) were synthesized. Composite membranes were prepared with UV-curable acrylate-terminated polyurethane/acrylate diluent (APUAs) as selective layer and polyester/polysulfone (PS/PSF) as...
Permeation of single gases through TEG liquid membranes modified by Na-Y nano-zeolite particles
, Article Separation and Purification Technology ; Volume 76, Issue 2 , 2010 , Pages 120-125 ; 13835866 (ISSN) ; Bastani, D ; Kazemian, H ; Sharif University of Technology
2010
Abstract
In this research, a triethylene glycol (TEG)/nano-zeolite Na-Y liquid membrane was developed in order to investigate the effect of zeolite nanoparticles on separation performance of a liquid membrane. To do this, a high yield nano-zeolite Na-Y was synthesized using mid-synthesis addition method. The synthesized samples were characterized by XRD, FT-IR, and SEM (EDX) instrumental techniques. A supported liquid membrane was prepared by impregnating a porous hydrophilic PVDF support with TEG and nano-zeolite Na-Y. The permeation tests of single gas components of O2, N2 and CO2 were carried out at pressure differences of 0.8 and 1.8 bar. The permeances of the single gases were found to be: CO2 >...
Novel surface modifying macromolecules (SMMs) blended polysulfone gas separation membranes by phase inversion technique
, Article Journal of Applied Polymer Science ; Volume 124, Issue 3 , 2012 , Pages 2287-2299 ; 00218995 (ISSN) ; Rana, D ; Matsuura, T ; Soltanieh, M ; Tabe, S ; Sharif University of Technology
2012
Abstract
In this article an attempt was made to fabricate defect-free asymmetric polysulfone (PSf) membranes for the separation of oxygen and nitrogen. The approach is based on the enhanced delayed demixing by blending surface modifying macromolecules (SMMs) in the casting solution and by immersing the cast film in isopropanol for a certain period before it is immersed in water. Different SMMs, including hydrophobic and charged SMMs, were synthesized, characterized, and blended to the host PSf. It was found that the charged SMM could indeed contribute to the removal of defective pores from the skin layer and enhancement of oxygen/nitrogen selectivity. The experimental results were further interpreted...
Mixed-matrix composite membranes based on uio-66-derived MOFs for CO 2 separation
, Article ACS Applied Materials and Interfaces ; Volume 11, Issue 9 , 2019 , Pages 9448-9461 ; 19448244 (ISSN) ; Shojaei, A ; Sharif University of Technology
American Chemical Society
2019
Abstract
We demonstrated a novel mixed-matrix composite membrane (MMCM) based on acrylated polyurethane (APU) and UiO-66 nanoparticles to separate CO 2 /N 2 mixture. UiO-66 and functionalized UiO-66 including NH 2 -UiO-66 and glycidyl methacrylate (GMA)-UiO-66 were loaded into APU/2-hydroxyethyl methacrylate (APUH) matrix at variable concentrations between 3 and 30 wt %. APUH/GMA-UiO-66 MMCMs exhibited strong adhesion with a support layer of polyester/polysulfone, which was not deteriorated after immersion in water for a long time (20 days). Incorporation of UiO-66 and its functionalized forms increased simultaneously permeability and CO 2 /N 2 selectivity, which were indeed superior in comparison...
Mathematical modeling and simulation of hollow fiber membranes for separation of gas mixtures: Case study with separation of H 2S/CH 4 by polyphenylene oxide (PPO) hollow fiber module
, Article 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7, Prague, 28 August 2010 through 1 September 2010 ; 2010 ; Savoji, H ; Soltanieh, M ; Sharif University of Technology
2010
Abstract
A mathematical model has been developed that is based the dual sorption in the dense layer and pore flow in the porous layer. In the porous layer a resistance model is applied where four mechanisms, i.e., Knudsen, Viscous, Slip, and Surface flows, are superimposed. Steady-state, constant pressure along the membrane and constant physical properties are assumed. Its application to the separation of H 2S/CH 4 gas mixtures as a sour gas in natural gas sweetening by using a PPO hollow fiber module is put forward. The Quasi Newton method is used to determine the parameters of membrane transport model for the case of H 2S/CH 4 separation. The H 2S and CH 4 permeances increased by increasing the...