Title Page
ABSTRACT
국문 요약
Contents
Chapter 1. Introduction 30
1.1. Zeolite membrane 30
1.2. Membrane and module properties of the zeolite membrane 31
1.3. References 32
Chapter 2. Low-Temperature Ozone Treatment for p-Xylene Perm-Selective MFI Type Zeolite Membranes: Unprecedented Revelation of Performance-Negating Cracks Larger than 10 nm in Polycrystalline Membrane Structures 37
2.1. Introduction 37
2.2. Experimental 40
2.2.1. Synthesis of as-synthesized MFI membranes 40
2.2.2. Calcination of the as-synthesized MFI membranes 41
2.2.3. Characterization 42
2.3. Results and discussion 46
2.3.1. Membrane properties of ozone-treated MFI membranes 46
2.3.2. Defect structures of ozone-treated MFI membranes 51
2.3.3. Quantitative effects of defects on the membrane permeation properties 60
2.3.4. Evaluation of p-/o-xylene separation performance of ozone-treated MFI membranes 78
2.4. Conclusions 81
2.5. References 83
Chapter 3. High Performance CO₂-Perm-Selective SSZ-13 Membranes: Elucidation of the Link between Membrane Material and Module Properties 89
3.1. Introduction 89
3.2. Experimental 93
3.2.1. Synthesis of SSZ-13 seed particles 93
3.2.2. Synthesis of SSZ-13 membranes on different supports 94
3.2.3. Characterization 97
3.3. Results and discussion 101
3.3.1. Properties of heterogeneously grown zeolite membranes 101
3.3.2. CO₂/N₂ separation performance of DM and TM 106
3.3.3. Long-term stability of TM for CO₂/N₂ separation 117
3.3.4. CO₂/CH₄ separation performance of DM and TM 120
3.3.5. Evaluation of the CO₂ perm-selectivities of DM and TM 122
3.3.6. Effect of the total feed flow rate 126
3.3.7. Membrane module properties 134
3.3.8. Correlation between the mass transfer in the feed stream and the feed stream properties 138
3.4. Conclusions 147
3.5. References 149
Chapter 4. Understanding and Improving the Modular Properties of High-Performance SSZ-13 Membranes for Effective Flue Gas Treatment 157
4.1. Introduction 157
4.2. Experimental 161
4.2.1. Synthesis of SSZ-13 seed particles 161
4.2.2. Fabrication of SSZ-13 membranes 161
4.2.3. Modularization of SSZ-13 membranes 165
4.3. Results and discussion 175
4.3.1. Formation of SSZ-13 membranes (Tm membranes) 175
4.3.2. Relationship between feed stream properties and membrane properties under dry conditions 185
4.3.3. Relationship between feed stream properties and module properties under dry conditions 199
4.3.4. Relationship between feed stream properties and CO₂/N₂ separation performances under wet conditions 204
4.3.5. Evaluation of MT9 for CO₂ separation[이미지참조] 220
4.3.6. Improvement and prediction of the process-based separation performance in a double-stage membrane system 226
4.4. Conclusions 238
4.5. Nomenclature 240
4.6. References 241
Chapter 5. Summary and perspective 250
Table 2.1. Tortuosity and area fraction of defects in the MFI membranes 64
Table 3.1. Detailed information concerning membranes and supports reported in the literature. 125
Table 4.1. Separation performances of LT1 containing Tm samples used for MT9 with respect to the CO₂/N₂ mixture (mol: mol = 15: 85 on a dry basis) under T30_W3 conditions. FSATP and Pfeed were 380 mL·min-1 and 1 bar, respectively.[이미지참조] 171
Table 4.2. Separation performances of LT1 containing Tm samples used for MT14 with respect to the CO₂/N₂ mixture (mol: mol = 15: 85 on a dry basis) under T30_W3 conditions. FSATP and Pfeed were 1000 mL·min-1 and 1 bar, respectively.[이미지참조] 172
Table 4.3. Separation performances of St1 containing tm samples used for SSt2 with respect to the CO₂/N₂ mixture (mol: mol = 15: 85 on a dry basis) under T30_W3...[이미지참조] 173
Table 4.4. Detailed information regarding the membranes used for Fig. 4.24 and Fig. 4.31 and the corresponding permeation measurements conditions reported in the literature. 225
Fig. 2.1. Schematic of molar flux estimation through a zeolite membrane based on a 1D permeation model (adopted from our previous study). For the modeling, we... 45
Fig. 2.2. Top view SEM images of (a) MFI seed particles and (b) a MFI seed layer comprising the particles shown in (a), along with (c) the corresponding XRD patterns.... 48
Fig. 2.3. (a1)-(c1) Top view and (a2)-(c2) cross-sectional view SEM images of (a1)-(a2) M_CC, (b1)-(b2) M_RTP, and (c1)-(c2) M_O₃, along with (a3)-(c3) the... 49
Fig. 2.4. (a1)-(c1) p- and o-Xylene single-component permeation performance and (a2)-(c2) p-/o-xylene binary mixture separation performance of (a1)-(a2) M_CC,... 50
Fig. 2.5. (a1)-(c1) Cross-sectional view and (a2)-(c2) and (a3)-(c3) top view FCOM images of the three types of MFI membranes obtained after 8-d dyeing; (a1)-(a3)... 54
Fig. 2.6. (a1)-(c1) Top view and (a2)-(c2) cross-sectional view SEM images of the MFI membranes exposed to 8-d dyeing: (a1)-(a2) M_CC, (b1)-(b2) M_RTP, and (c1)-... 55
Fig. 2.7. (a1)-(c1) Cross-sectional view and (a2)-(c2) top view FCOM images of an as-synthesized MFI membrane obtained at different dyeing times: (a1)-(a2) 2 d, (b1)-... 56
Fig. 2.8. (a1)-(c1) Cross-sectional view and (a2)-(c4) top view FCOM images of M_CC obtained at different dyeing times: (a1)-(a4) 2 d, (b1)-(b4) 4 d, and (c1)-(c4)... 57
Fig. 2.9. (a1)-(c1) Cross-sectional view and (a2)-(c4) top view FCOM images of M_RTP obtained at different dyeing times: (a1)-(a4) 2 d, (b1)-(b4) 4 d, and (c1)-(c4)... 58
Fig. 2.10. (a1)-(c1) Cross-sectional view and (a2)-(c4) top view FCOM images of M_O₃ obtained at different dyeing times: (a1)-(a4) 2 d, (b1)-(b4) 4 d, and (c1)-(c4) 8... 59
Fig. 2.11. (a1)-(d1) Top view FCOM images showing different types of defects, (a2)-(d2) reconstructed top view defect structures, and (a3)-(d3) titled view defect... 63
Fig. 2.12. Porosities of defective and zeolitic regions and their corresponding contributions to p- and o-xylene molar fluxes for (a) M_O₃, (b) M_CC, and (c) M_RTP. Quantitative analyses were conducted on the permeation results obtained at 100 ℃ with respect... 65
Fig. 2.13. Maxwell-Stefan diffusion coefficients of p- and o-xylene calculated from the p-/o-xylene separation performance of M_O₃ assuming that the grain boundary... 66
Fig. 2.14. Temperature-dependent p-/o-xylene separation performance of M_O₃, for which different ozone treatment durations (2, 12, 48, and 80 h) were used; in particular, the separation performance of M_O₃ (equivalent to M_O₃ (48 h)) is identical to that... 67
Fig. 2.15. FT-IR spectra of MFI membranes prepared with different calcination methods; as-synthesized MFI membrane, M_O₃ (obtained by ozone treatment for... 68
Fig. 2.16. Sizes of cracks in (a) M_CC and (b) M_RTP estimated by combining the quantitative properties extracted from the FCOM images with 1D permeation... 69
Fig. 2.17. Porosities of the defective and zeolitic parts and their corresponding contributions to the p- and o-xylene molar fluxes of M_CC given the grain boundary defect (GB) sizes of (a) 1, (b) 2, and (c) 3 nm. Quantitative analyses were conducted on the... 72
Fig. 2.18. (a) Maxwell-Stefan diffusion coefficients of p- and o-xylene calculated from the p-/o-xylene separation performance of M_RTP, which was assumed to be... 74
Fig. 2.19. (a1)-(c1) Top (upper) and (a2)-(c2) cross-sectional (lower) view SEM images of M_CC. In (a1)-(a2), conspicuous cracks could not be seen. In (b1)-(b2),... 76
Fig. 2.20. (a) Top view and (b) cross-sectional view SEM images of M_CC and (c)-(f) cross-sectional view TEM images of M_CC. In (a)-(c), yellow arrows indicate... 77
Fig. 2.21. p-/o-Xylene separation performances of M_CC, M_RTP, and M_O₃, along with those of previously reported MFI membranes ; (a) p-... 80
Fig. 3.1. Top view SEM images of SSZ-13 seed layers: (a) DS and (d) TS. Top view and cross-sectional view SEM images of SSZ-13 membranes obtained by conducting... 102
Fig. 3.2. Size distribution of grains in DM and TM. The grain sizes were measured along the longest length of each grain. The resulting average sizes and corresponding... 103
Fig. 3.3. XRD patterns of (a) DS and DM and (b) TS and TM. In particular, α and β indicate the α- and β-alumina phases of the supports, respectively. For better... 105
Fig. 3.4. CO₂/N₂ separation performance of (a1)-(a2) DM_x, (b1)-(b2) TM_L_x, and (c1)-(c2) TM_S_x (x = (a1)-(c1) D1 and (a2)-(c2) W1) as a function of temperature... 108
Fig. 3.5. Contact angles of a water droplet on the membrane surface of (a) DM and (b) TM as a function of the contact time for up to 5 min. 111
Fig. 3.6. Cross-sectional SEM images and EDX results of (a) DM and (b) TM. The chemical profiles of Si (red) and Al (cyan) atoms were obtained along the membrane... 112
Fig. 3.7. Comparison of the CO₂/N₂ separation performances of TM membranes in the large and small permeation cells at 30 ℃ and total feed pressures of (a) 1 and (b)... 115
Fig. 3.8. CO₂/N₂ separation performance of (a1)-(a2) TM_L (left) and (b1)-(b2) TM_S (right) as a function of temperature at a total feed pressure of 2 bar under dry... 116
Fig. 3.9. Long-term stability test results with respect to the water vapor-containing CO₂/N₂ mixtures (mol:mol = 15:85) for (a1)-(a2) TM_L and (b1)-(b2) TM_S. The... 119
Fig. 3.10. Temperature-dependent CO₂/CH₄ separation performance of (a1)-(a2) DM and those of TM using the larger and smaller permeation cells ((b1)-(b2) TM_L and... 121
Fig. 3.11. (a) CO₂/N₂ SF vs. CO₂ permeance and (b) CO₂/CH₄ SF vs. CO₂ permeance measured at 20-40 ℃ for the DM and TM membranes (considered in this work),... 124
Fig. 3.12. CO₂/N₂ separation performance (in terms of CO₂ and N₂ permeances and CO₂/N₂ SF) of (a1)-(a2) TM_L (left) and (b1)-(b2) TM_S (right) as a function of the... 131
Fig. 3.13. CO₂/N₂ separation performance (in terms of CO₂ and N₂ permeances and the CO₂/N₂ SF) of TM as a function of the linear velocity of the feed stream at total... 133
Fig. 3.14. CO₂/N₂ separation performance (in terms of CO₂ recovery and purity) of (a1)-(a2) TM_L (left) and (b1)-(b2) TM_S (right) as a function of the actual feed flow... 137
Fig. 3.15. he Sherwood number in the feed stream (Shf) as a function of (a) the Reynolds number (Re) and (b) (dh/Lm)∙Re. The CO₂ molar flux as a function of (c) Re...[이미지참조] 141
Fig. 3.16. Wilson plots for estimating the mass transfer resistance across the membrane (Rm). The filled and open symbols indicate the CO₂ recovery below and...[이미지참조] 142
Fig. 3.17. The separation performances (in terms of the CO₂ recovery, purity, and PE) as a function of (Re·Pfeed)1/2·(CO₂ feed flow rate)-1 under (a) dry and (b) wet conditions.[이미지참조] 146
Fig. 4.1. Top-view SEM images of (a) a bare α-alumina tube support (outer surface) and (b)-(c) the SSZ-13 seed layers at different magnifications. 177
Fig. 4.2. (a1)-(a3) Cross-sectional and top view SEM images of Tm. (b1)-(c3) Cross-sectional and top view FCOM images of Tm; (b1)-(b3) conventionally calcined Tm... 178
Fig. 4.3. Top view and cross-sectional view SEM images of (a)-(b) Tm and (c)-(d) tm. (e) XRD patterns of SSZ-13 seed layer, tm, and Tm. In (e), α and β indicate the major... 179
Fig. 4.4. (a) Top view SEM image of a glazed α-alumina tube support. (b)-(f) Top view SEM images of a SSZ-13 membrane near the interface between the glazed and... 180
Fig. 4.5. Size distribution of membrane grains of Tm and tm. The grain sizes were measured along the longest length of the grains. The average sizes are displayed along... 181
Fig. 4.6. Top view and cross-sectional view SEM images of (a)-(b) conventionally calcined Tm and (c)-(d) conventionally calcined tm. (e) XRD patterns of SSZ-13 seed... 182
Fig. 4.7. Membrane-based CO₂/N₂ separation performances of LT1 comprising (a1)-(a2) conventionally calcined Tm and (b1)-(b2) Tm under dry (D;upper) and wet (W3;...[이미지참조] 183
Fig. 4.8. (a1)-(a3) Cross-sectional and top view SEM images of disc-supported Tm. (b1)-(c3) Cross-sectional and top view FCOM images of disc-supported Tm; (b1)-... 184
Fig. 4.9. (a)-(b) Membrane-based CO₂/N₂ separation performance in Tm-mounted modules under T30_D conditions as a function of FSATP·Sm-1·Pfeed-1 : (a) CO₂ and N₂ permeances and (b) CO₂ /N₂ SFs. (c) Shf in the Tm-mounted modules as a function of (dA/Lm)Re....[이미지참조] 186
Fig. 4.10. (a) Sherwood number in the feed stream (Shf), (b) CO₂ molar flux, (c) CO₂/N₂ SF, and (d) N₂ molar flux as a function of the Reynolds number (Re). The...[이미지참조] 189
Fig. 4.11. CO₂ permeances in Tm-mounted modules under T30_D conditions as a function of (a) Re and (b) (dA/Lm)Re·Pfeed ; the values of Pfeed of 1 (closed) or 2 bar...[이미지참조] 193
Fig. 4.12. (a1)-(a2) CO₂ molar flux in Tm-mounted modules as a function of (a1) (dA/Lm)Re·P feed and (a2) (Shf·Pfeed)1/2. (b1)-(b2) CO₂/N₂ SFs in the Tm-mounted...[이미지참조] 194
Fig. 4.13. N₂ molar flux in ST1 and LT1 at various FSATP values as a function of Pfeed. Slopes for datasets are given in the graphs. The averaged datasets for ST1 and LT1 are displayed along with the standard deviations (denoted by error bars). The average value...[이미지참조] 198
Fig. 4.14. (a1)-(a3) Process-based CO₂/N₂ separation performance in Tm-mounted modules under T30_D conditions as a function of FSATP·Sm-1·Pfeed-1 : (a1) Rec, (a2) Pur, and (a3) PE. (b1)-(b3) Process-based CO₂/N₂ separation performance in Tm-mounted...[이미지참조] 203
Fig. 4.15. Membrane-based CO₂/N₂ separation performance in Tm-mounted modules under T30_D or T30_W3 conditions as a function of FSATP·Sm-1·Pfeed-1 : (a1) CO₂ and...[이미지참조] 206
Fig. 4.16. Membrane-based CO₂/N₂ separation performance of LT1 and MT9 under T50_Wx (x = 3, 7, and 10) conditions: (a) CO₂ and N₂ permeances and (b) CO₂/N₂...[이미지참조] 207
Fig. 4.17. Membrane-based CO₂/N₂ separation performance of ST1 and LT1 under T50_Wx (x = 3, 7, and 10) conditions: (a) CO₂ and N₂ permeances and (b) CO₂/N₂...[이미지참조] 208
Fig. 4.18. Cross-sectional view SEM images and EDX results of (a) Tm and (b) tm. The chemical composition profiles of Si (red) and Al (cyan) atoms were obtained... 210
Fig. 4.19. Contact angles of a water droplet on the membrane surface of (a) Tm and tm and (b) conventionally calcined Tm and tm as a function of contact time up to 5 min. 211
Fig. 4.20. (a1)-(a3) Process-based CO₂/N₂ separation performance of LT1 and MT9 under T50_Wx (x = 3, 7, and 10) conditions as a function of FSATP·Sm-1·Pfeed-1 : (a1) Rec, (a2) Pur, and (a3) PE. (b1)-(b3) Process-based CO₂/N₂ separation performance of LT1 and...[이미지참조] 216
Fig. 4.21. (a1)-(a3) Process-based CO₂/N₂ separation performance of ST1 and LT1 under T50_Wx (x = 3, 7, and 10) conditions as a function of FSATP·Sm-1·Pfeed-1 : (a1) Rec, (a2) Pur, and (a3) PE. (b1)-(b3) Process-based CO₂/N₂ separation performance of ST1 and...[이미지참조] 217
Fig. 4.22. Long-term stability test results of (a1)-(a2) LT1 and (b1)-(b2) MT9. The values of FSATP for LT1 and MT9 was 1000 and 3300 mL·min-1, respectively. The values...[이미지참조] 218
Fig. 4.23. Long-term stability test results of ST1 with respect to CO₂/N₂/O₂ mixtures (mol: mol: mol = 14: 80: 6 on a dry basis) under T50_D (black) and T50_W10 (blue)...[이미지참조] 219
Fig. 4.24. CO₂/N₂ separation performances of the SSZ-13 membranes (considered in this work) from the perspectives of (a) membrane properties (CO₂/N₂ SF vs. CO₂... 224
Fig. 4.25. Process-based CO₂/N₂ separation performance of MT9-SSt2 (closed symbols) and their predicted values (open symbols) as a function of FSATP under T30_W3 (left),...[이미지참조] 229
Fig. 4.26. (a1)-(a3) Cross-sectional and top view SEM images of tm. (b1)-(c3) Cross-sectional and top view and FCOM images of tm; (b1)-(b3) conventionally calcined... 230
Fig. 4.27. (a1)-(a3) Cross-sectional and top view SEM images of disc-supported tm. (b1)-(c3) Cross-sectional and top view and FCOM images of disc-supported tm; (b1)-... 231
Fig. 4.28. CO₂/N₂ separation performances of SSt2 under (a1)-(a2) T30_W3, (b1)-(b2) T50_W3, (c1)-(c2) T50_W7, and (d1)-(d2) T50_W10 conditions as a function of FSATP·Sm-1·Pfeed-1 (Pfeed was 1 bar). The CO₂/N₂ separation performances are shown from the...[이미지참조] 232
Fig. 4.29. Process-based CO₂/N₂ separation performance of MT9-SSt2 (closed symbols) and their predicted values (open symbols) as a function of FSATP under T30_W3 (left),...[이미지참조] 233
Fig. 4.30. Prediction of the CO₂/N₂ separation performance of MT9-SSt2 at an FSATP of 1667 mL·min-1 under T30_W3 conditions, which correspond to the points indicated...[이미지참조] 236
Fig. 4.31. CO₂ separation performance of MT9 and MT9-SSt2 with respect to module properties (DoP vs. Rec), along with those of the membrane modules for flue gas...[이미지참조] 237
Scheme 4.1. Schematics of the (a) S (small), (b) L (large), (c)-(d) M (multi- membrane), and (e) SS (double small) permeation cells. 167
Scheme 4.2. Cross-sectional view photo (left) and corresponding scheme (right) of (a) MT9 and (b) MT14. In the scheme, representative dimensions are displayed.[이미지참조] 168
Scheme 4.3. (a1)-(b1) Front view and (a2)-(b2) rear view photos and (a3)-(b3) the corresponding tightening photos of (a1)-(a3) spanner-type screw and (b1)-(b3)... 169
Scheme 4.4. Photos to show a sealing of the SSZ-13 membranes in the multi-membrane-mounted modules (MT9 or MT14). (a) An empty hole of a permeation cell.... 170
Scheme 4.5. Schematic of the MT9-SSt2 double-stage membrane system. The feed inlet of the 1st stage (MT9), the permeate stream of the 1st stage (to be fed to the 2nd...[이미지참조] 174