Loading...
Search for:
ideal-selectivities
0.01 seconds
Preparation of TEG Supported Liquid Membrane with Nano Particles of LTA Type Zeolite and Investigation of The Membrane Performance in Gas Separation
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daryush (Supervisor) ; Kazemian, Hossein (Supervisor)
Abstract
The purpose of this research project was to improve the performance of TEG liquid membrane in separation of gas mixtures by adding zeolite LTA nanoparticles. Therefore, the NaA zeolite particles with nano size were synthesized with hydrothermal method at optimized condition. The supported liquid membrane with hydrophilic PVDF membrane and triethylene Glycol (TEG) was prepared in two different conditions. In the first one, the pores of the supporting membrane were filled with triethylene Glycol, whereas in the second one the pores were filled with the mixture of triethylene Glycol along with the 5 wt% and 10 wt% zeolite nanoparticles. The performances of prepared membranes were investigated...
Adsorption isotherms and ideal selectivities of hydrogen sulfide and carbon dioxide over methane for the Si-CHA zeolite: Comparison of carbon dioxide and methane adsorption with the all-silica DD3R zeolite
, Article Adsorption ; Volume 19, Issue 5 , 2013 , Pages 1045-1053 ; 09295607 (ISSN) ; Soltanieh, M ; Bozorgzadeh, H ; Mohamadalizadeh, A ; Sharif University of Technology
2013
Abstract
Adsorption isotherms of H2S, CO2, and CH4 on the Si-CHA zeolite were measured over pressure range of 0-190 kPa and temperatures of 298, 323, and 348 K. Acid gases adsorption isotherms on this type of zeolite are reported for the first time. The isotherms follow a typical Type-I shape according to the Brunauer classification. Both Langmuir and Toth isotherms describe well the adsorption isotherms of methane and acid gases over the experimental conditions tested. At room temperature and pressure of 100 kPa, the amount of CO2 adsorption for Si-CHA zeolite is 29 % greater than that reported elsewhere (van den Bergh et al. J Mem Sci 316:35-45 (2008); Surf Sci Catal 170:1021-1027 (2007)) for the...
Improving mixed-matrix membrane performance: Via PMMA grafting from functionalized NH2-UiO-66
, Article Journal of Materials Chemistry A ; Volume 6, Issue 6 , 2018 , Pages 2775-2791 ; 20507488 (ISSN) ; Shojaei, A ; Mousavi, S. A ; Sharif University of Technology
Royal Society of Chemistry
2018
Abstract
The major obstacles in gas separation by mixed-matrix membranes (MMMs) 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 stand-alone MMMs. The matrix used was polymethyl methacrylate (PMMA) and the MMMs were synthesized by in situ polymerization of methyl methacrylate (MMA) in the presence of UiO-66, NH2-UiO-66 and vinyl group attached UiO-66. In situ polymerization of MMA in the presence of vinyl attached UiO-66 resulted in PMMA grafted UiO-66 with a high degree of grafting. Microscopic analysis by field emission scanning electron microscopy (FESEM)...
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:...
Improvement in CO2/H2 separation by fabrication of poly(ether-b-amide6)/glycerol triacetate gel membranes
, Article Journal of Membrane Science ; Vol. 469, issue , 2014 , pp. 43-58 ; ISSN: 03767388 ; Soltanieh, M ; Mousavi, S. A ; Ghadimi, A ; Sharif University of Technology
Abstract
The purpose of this study is to investigate separation performance of poly(ether-b-amide6) (Pebax1657)/glycerol triacetate (GTA) gel membranes for CO2 removal from H2, N2 and CH4. GTA as a low molecular weight and highly CO2-phill compound was added to membrane structure at various weight fractions, 20%, 40%, 60% and 80% of Pebax, to fabricate a new high solubility selective membrane with improved performance. Permeation of pure gases was studied at different temperatures from 25 to 65°C and pressures from 4 to 24bar and ideal selectivities were calculated. Results indicated enhancement in permeation for all tested gases. For example, at a pressure of 4bar and a temperature of 25°C, membrane...