Polyimide and PEBAX flat and hollow fiber membranes for gas separation

Date

2017

Author

Özdemir, Nur Konçüy

Metadata

Show full item record

Item Usage Stats

342
views

0
downloads

This thesis analyzes the effect of polyimide (PI) hollow fiber membrane spinning conditions including dope solution flow rate, bore liquid flow rate, addition of more volatile solvent to dope solution, air gap height and heating zone temperature on the ideal gas separation performance and membrane morphology. The effect of PEBAX1657 coating of PI hollow fiber membrane was also investigated. The effect of incorporation of ZIF-8 crystals to PEBAX1657 flat sheet membrane, the effect of coagulant type for the preparation of porous polyethersulfone (PES) flat sheet membrane, the effect of PEBAX1657 and PEBAX1657/ZIF-8 coating of PES flat sheet membrane on the membrane gas separation performance and morphology were investigated. In this study, asymmetric PI hollow fiber membranes were produced by dry-wet spinning method via twin orifice spinneret at room conditions from dope liquid containing dimethylformamide (DMF) and tetrahydrofuran (THF) and bore liquid solution containing 90 wt. % of DMF and 10 wt. % of distilled water. Tap water was used as non-solvent in the coagulation bath. Gas separation membrane performance of virgin hollow fiber membranes were not sufficiently high for biogas refining. PEBAX1657 coating enhanced gas separation performance of the virgin hollow fiber membranes. PEBAX1657 and PEBAX1657/ZIF-8 coating of porous PES flat sheet membranes increased ideal CO2/N2 and CO2/CH4 selectivity. Hollow fiber membranes were characterized by scanning electron microscopy (SEM). Flat sheet membranes were characterized by SEM, Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA). ZIF-8 crystals were characterized by N2 adsorption desorption isotherms, SEM, X-ray diffraction (XRD). ZIF-8 particles having high crystallinity was synthesized with average size of 69 ± 14 nm

Subject Keywords

Gases, Gas separation membranes.

URI

http://etd.lib.metu.edu.tr/upload/12621080/index.pdf
https://hdl.handle.net/11511/26580

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Experimental research on in-tube condensation under steady-state and transient conditions Tanrikut, A; Yesin, O (2005-01-01) In this research study, in-tube condensation in the presence of air was investigated experimentally at a heat exchanger of countercurrent type for different operating conditions. The test matrix for the steady-state condition covers the range of pressures P = 1.8 to 5.5 bars, vapor Reynolds numbers Re, = 45 000 to 94 000, and inlet air mass fraction values Xi = 0 to 52%. The effect of air manifests itself by a reduction in the local heat flux and the local heat transfer coefficient. The local heat transfer ...
Polycarbonate based zeolite 4a filled mixed matrix membranes: preparation, characterization and gas separation performances Şen, Değer; Yılmaz, Levent; Department of Chemical Engineering (2008) Developing new membrane morphologies and modifying the existing membrane materials are required to obtain membranes with improved gas separation performances. The incorporation of zeolites and low molecular-weight additives (LMWA) into polymers are investigated as alternatives to modify the permselective properties of polymer membranes. In this study, these two alternatives were applied together to improve the separation performance of a polymeric membrane. The polycarbonate (PC) chain characteristics was a...
Development of alumina supported ternary mixed matrix membranes for separation of H-2/light-alkane mixtures Topuz, Berna; Yılmaz, Levent; Kalıpçılar, Halil (2012-10-01) Ternary component mixed matrix membrane was prepared from PES, SAPO-34 and 2-hydroxy 5-methyl aniline on a macroporous alumina disk by the solvent evaporation method in order to investigate the effect of existence of an inorganic support. The membrane and its pure PES/Alumina counterpart were characterized by single gas permeability measurements of H-2, CH4, C2H6 and C3H8. The corresponding H-2/CH4 selectivities of membranes were 71.3 and 41. The membranes were also used to separate equimolar mixtures of H-...
ANALYTICAL EXPRESSIONS FOR LIQUID-COLUMN VELOCITIES IN PIPELINES WITH ENTRAPPED GAS Tijsseling, Arris S.; Hou, Qingzhi; Bozkuş, Zafer (2015-01-01) High pressures and high temperatures may arise in pipelines when a liquid column is suddenly accelerated into a gas pocket trapped at a closed end. A mass oscillation occurs that is described by nonlinear equations for both liquid and gas. Analytical expressions are derived for the uniform velocity of the liquid column, from which pressures and gas temperatures follow. The obtained results are validated against theoretical and experimental results published by fellow researchers.
PEM fuel cell short stack performances of silica doped nanocomposite membranes DEVRİM, YILSER; Devrim, Huseyin (2015-06-29) In this study, an air-cooled Proton Exchange Membrane Fuel Cell (PEMFC) short stack with Nafion/Silica nanocomposite membrane was designed and fabricated for net 100 W net power output to improve the stack performance at low relative humidity conditions. Composite membrane was prepared by solution casting method. Gas Diffusion Electrodes (GDE's) were produced by ultrasonic spray coating technique. Short stack design was based on electrochemical data obtained at 0.60 V was 0.45 A/cm(2) from performance tests...

Citation Formats

N. K. Özdemir, “Polyimide and PEBAX flat and hollow fiber membranes for gas separation,” M.S. - Master of Science, Middle East Technical University, 2017.