Zainal, Wan Nurul Huda Wan (2015) Carbon Membranes Derived From Polymer Blend Of Polyetherimide And Polyethylene Glycol For Gas Separation. PhD thesis, Universiti Sains Malaysia.
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Abstract
Teknologi membran menawarkan banyak kelebihan berbanding kaedah pemisahan gas konvensional seperti kesederhanaan dan kemudahan operasi. Membran karbon mempunyai rintangan haba yang tinggi dan kestabilan kimia yang baik dalam persekitaran mengakis. Dalam kajian ini, dalam usaha untuk meningkatkan kebolehtelapan gas, membran karbon telah disintesis daripada gaulan polimer polieterimida (PEI) dan polietilena glikol (PEG). Membran karbon PEG/PEI telah disintesis di atas sokongan alumina disalut dengan lapisan pertengahan Al2O3. Kesan parameter penyediaan yang berbeza kepada morfologi, sifat struktur dan prestasi pemisahan membran karbon telah dikaji dengan mengubah nisbah gaulan (0, 0.1, 0.2, 0.3 dan 0.4 PEG:PEI), suhu karbonisasi (550, 600, 650 dan 700 °C), kadar pemanasan (1, 3, 5 dan 7 °C/minit) dan masa rendaman (1, 2 dan 3 jam). Membran karbon PEG/PEI dengan prestasi pemisahan yang terbaik terus diuji pada suhu penyerapan (25, 50, 75 dan 100 °C) dan tekanan suapan (2, 2.5, 3 dan 3.5 bar) yang berbeza. Prestasi pemisahan membran karbon PEG/PEI terus disiasat dengan campuran gas binari CO2/CH4, CO2/N2 dan O2/N2. Daripada keputusan pencirian, membran karbon PEG/PEI terdiri daripada tiga lapisan berbeza; lapisan karbon, lapisan pertengahan Al2O3 dan sokongan alumina. Keputusan XRD menunjukkan bahawa membran karbon PEG/PEI mempunyai struktur amorfus. Luas permukaan BET membran karbon terhasil daripada nisbah gaulan 0.1 PEG:PEI (ditandakan sebagai membran karbon PEG1/PEI) meningkat kepada 544.07 m2/g berbanding 248.75 m2/g oleh membran karbon tulen PEI. Ketelapan CO2 dan O2 membran karbon PEG1/PEI meningkat kepada masingmasing 1685 dan 927 barrer berbanding 421 dan 262 barrer dipamerkan oleh membran karbon PEI. Membran karbon yang diperoleh daripada nisbah gaulan 0.1 PEG:PEI dan dikarbonisasi pada suhu 650 °C dengan kadar pemanasan 1 °C/minit dan masa rendaman 2 jam menunjukkan prestasi pemisahan yang terbaik dengan pemilihan unggul CO2/CH4, CO2/N2 dan O2/N2 yang tertinggi iaitu masing-masing 64.72, 38.02 dan 5.05. Bagi campuran gas binari, sampel ini mempamerkan pemilihan CO2/CH4, CO2/N2 dan O2/N2 masing-masing sebanyak 38.10, 34.74 dan 3.98. Prestasi membran karbon terjejas akibat kesan penuaan membran. Selepas proses pembangunan semula pada suhu 300 °C, ketelapan CO2 dan O2 membran karbon PEG1/PEI pulih sebanyak 80 % daripada ketelapan asal dengan pemilihan unggul CO2/CH4, CO2/N2 dan O2/N2 masing-masing 75.23, 45.54 dan 6.09. Secara keseluruhan, membran karbon PEG1/PEI menunjukkan prestasi pemisahan yang lebih baik dengan peningkatan ketelapan gas dan pemilihan unggul berbanding membran karbon PEI. ________________________________________________________________________________________________________________________ Membrane technology offers many advantages over conventional gas separation methods such as simplicity and ease operation. Carbon membrane has a high thermal resistance and good chemical stability in corrosive environments. In the present study, in order to enhance the gas permeability, carbon membrane was synthesized from polymer blend of polyetherimide (PEI) and polyethylene glycol (PEG). The PEG/PEI carbon membrane was synthesized on the alumina support coated with an Al2O3 intermediate layer. The effect of different preparation parameters on the carbon membranes properties and separation performance were studied by varying the blend ratios (0, 0.1, 0.2, 0.3 and 0.4 PEG:PEI), carbonization temperatures (550, 600, 650 and 700 °C), heating rates (1, 3, 5 and 7 °C/min) and soaking times (1, 2 and 3 h). The PEG/PEI carbon membrane with the best separation performance was further tested at the different permeation temperatures (25, 50, 75 and 100 °C) and feed pressures (2.0, 2.5, 3.0 and 3.5 bar). The PEG/PEI carbon membrane separation performance was further investigated with the binary gas mixtures of the CO2/CH4, CO2/N2 and O2/N2. From the characterization results, the PEG/PEI carbon membranes consist of three distinguish layers; a carbon layer, Al2O3 intermediate layer and alumina support. The XRD results revealed that the PEG/PEI carbon membrane has an amorphous structure. The BET surface area of the carbon membrane derived from 0.1 PEG:PEI blend ratio (denoted as PEG1/PEI carbon membrane) increased to 544.07 m2/g ratio rather than 248.75 m2/g by pure PEI carbon membrane. The CO2 and O2 permeability of the PEG1/PEI carbon membrane increased to 1685 and 927 barrer, respectively rather than 421 and 262 barrer exhibited by PEI carbon membrane, respectively. The carbon membrane derived from 0.1 PEG:PEI blend ratio and carbonized at temperature of 650 °C with heating rate of 1 °C/min and 2 h of soaking time showed the best separation performance with the highest of the CO2/CH4, CO2/N2 and O2/N2 ideal selectivities of 64.72, 38.02 and 5.05, respectively. For binary gas mixtures, this sample exhibited the CO2/CH4, CO2/N2 and O2/N2 selectivities of 38.10, 34.74 and 3.98, respectively. The carbon membrane performance was affected by the effect of membrane aging. After regeneration at temperature of 300 °C, the PEG1/PEI carbon membrane restored about 80 % of the original CO2 and O2 permeability with CO2/CH4, CO2/N2 and O2/N2 ideal selectivity of 75.23, 45.54 and 6.09, respectively. Overall, the PEG1/PEI carbon membranes exhibited better separation performance with enhanced gas permeability and ideal selectivity compared to pure PEI carbon membrane.
| Item Type: | Thesis (PhD) |
|---|---|
| Additional Information: | Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=2792 |
| Subjects: | T Technology T Technology > TP Chemical Technology > TP155-156 Chemical engineering |
| Divisions: | Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Kimia (School of Chemical Engineering) > Thesis |
| Depositing User: | Mr Mohd Jasnizam Mohd Salleh |
| Date Deposited: | 12 Jul 2018 07:37 |
| Last Modified: | 14 Aug 2018 08:59 |
| URI: | http://eprints.usm.my/id/eprint/41017 |
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