Continuous and perfect single-layer B-Al-ZSM-5 zeolite membranes with c-axis orientation, self-transformation from B-containing porous gla ss disks w ith rough and uneven surfaces full of pits, have been in-situ prepa...Continuous and perfect single-layer B-Al-ZSM-5 zeolite membranes with c-axis orientation, self-transformation from B-containing porous gla ss disks w ith rough and uneven surfaces full of pits, have been in-situ prepared on the su bstrates surfaces in a mixed vapor of ethylenediamine, tri-n-propylamine a nd H 2O . The thickness of the membranes is ca. 60 μm. Under the conditions of 20 ℃ and 0.1 MPa pressure difference, the permeabilities of H 2, O 2 and N 2 thro ugh the calcined B-Al-ZSM-5 zeolite membranes are 2 298×10 -8 , 1 176 ×10 -8 and 1 368×10 -9 mol/(m 2·s·Pa), respectively. The calculated values of ideal se lectivities of H 2 an d O 2 over N 2 are 16 8 and 8 60, respectively. The data indicate that the c alcin ed zeolite membranes are non-pinhole, non-crack, continuous and perfect.展开更多
ZSM-5 zeolite membrane reactor was used in ethylbenzene dehydrogenation to styrene under the circumstances of commercial production.The experimental results indicated that the conversion of ethylbenzene in the membran...ZSM-5 zeolite membrane reactor was used in ethylbenzene dehydrogenation to styrene under the circumstances of commercial production.The experimental results indicated that the conversion of ethylbenzene in the membrane reactor increased with increasing pressure of the membrane tube.Using the inert sweep gas instead of vacuumizing, the result of long term steady operation under the same condition showed that the selectivity of styrene increased and the conversion of ethylbenzene in the membrane reactor increased by 7.52% in comparison with the fixed-bed reactor.展开更多
High-permeance ZSM-5 zeolite membrane was prepared on porous tubular α-Al 2O 3 support by varying-temperature hydrothermal synthesis. XRD patterns show that the membrane consists of ZSM-5 zeolite crystals. SEM analys...High-permeance ZSM-5 zeolite membrane was prepared on porous tubular α-Al 2O 3 support by varying-temperature hydrothermal synthesis. XRD patterns show that the membrane consists of ZSM-5 zeolite crystals. SEM analysis indicates that few defects exist in the membrane and the thickness of the membrane is about 9 μm. The hydrogen permeance through the membrane is about 2.4×10 -6 mol/(m 2·s·Pa), and the separation factor for n-C 4H 10/i-C 4H 10 mixture (volume ratio 1∶1) is 40, which indicates that it has a high quality with high permeance and selectivity. Repeated nucleation and re-growth of the crystals on the support result in the dense membrane formation.展开更多
Zeolite ZSM 5 membrane, whose permeance was up to 10 -6 mol/(m 2·s·Pa) and a magnitude higher than that of other groups, was prepared on α Al 2O 3 support by multi in situ hydrothermal treatments, using opt...Zeolite ZSM 5 membrane, whose permeance was up to 10 -6 mol/(m 2·s·Pa) and a magnitude higher than that of other groups, was prepared on α Al 2O 3 support by multi in situ hydrothermal treatments, using optimized sol prescription and cheap n butane as the structure directing agent. The membrane was characterized by means of XRD, SEM and single gas permeances measurements, which showed that it was dense and integral without large intercrystal pores and cracks. The permeance of H 2, N 2, C 3H 8 and n C 4H 10 was up to 2.35×10 -6 , 1.0×10 -6 , 1.13×10 -7 and 4.9×10 -8 mol/(m 2·s·Pa), respectively. Ideal selectivity of H 2/N 2, H 2/C 3H 8 and H 2/ n C 4H 10 was 2.45, 20.8 and 48, respectively. [WT5HZ]展开更多
文摘Continuous and perfect single-layer B-Al-ZSM-5 zeolite membranes with c-axis orientation, self-transformation from B-containing porous gla ss disks w ith rough and uneven surfaces full of pits, have been in-situ prepared on the su bstrates surfaces in a mixed vapor of ethylenediamine, tri-n-propylamine a nd H 2O . The thickness of the membranes is ca. 60 μm. Under the conditions of 20 ℃ and 0.1 MPa pressure difference, the permeabilities of H 2, O 2 and N 2 thro ugh the calcined B-Al-ZSM-5 zeolite membranes are 2 298×10 -8 , 1 176 ×10 -8 and 1 368×10 -9 mol/(m 2·s·Pa), respectively. The calculated values of ideal se lectivities of H 2 an d O 2 over N 2 are 16 8 and 8 60, respectively. The data indicate that the c alcin ed zeolite membranes are non-pinhole, non-crack, continuous and perfect.
文摘ZSM-5 zeolite membrane reactor was used in ethylbenzene dehydrogenation to styrene under the circumstances of commercial production.The experimental results indicated that the conversion of ethylbenzene in the membrane reactor increased with increasing pressure of the membrane tube.Using the inert sweep gas instead of vacuumizing, the result of long term steady operation under the same condition showed that the selectivity of styrene increased and the conversion of ethylbenzene in the membrane reactor increased by 7.52% in comparison with the fixed-bed reactor.
文摘High-permeance ZSM-5 zeolite membrane was prepared on porous tubular α-Al 2O 3 support by varying-temperature hydrothermal synthesis. XRD patterns show that the membrane consists of ZSM-5 zeolite crystals. SEM analysis indicates that few defects exist in the membrane and the thickness of the membrane is about 9 μm. The hydrogen permeance through the membrane is about 2.4×10 -6 mol/(m 2·s·Pa), and the separation factor for n-C 4H 10/i-C 4H 10 mixture (volume ratio 1∶1) is 40, which indicates that it has a high quality with high permeance and selectivity. Repeated nucleation and re-growth of the crystals on the support result in the dense membrane formation.
文摘Zeolite ZSM 5 membrane, whose permeance was up to 10 -6 mol/(m 2·s·Pa) and a magnitude higher than that of other groups, was prepared on α Al 2O 3 support by multi in situ hydrothermal treatments, using optimized sol prescription and cheap n butane as the structure directing agent. The membrane was characterized by means of XRD, SEM and single gas permeances measurements, which showed that it was dense and integral without large intercrystal pores and cracks. The permeance of H 2, N 2, C 3H 8 and n C 4H 10 was up to 2.35×10 -6 , 1.0×10 -6 , 1.13×10 -7 and 4.9×10 -8 mol/(m 2·s·Pa), respectively. Ideal selectivity of H 2/N 2, H 2/C 3H 8 and H 2/ n C 4H 10 was 2.45, 20.8 and 48, respectively. [WT5HZ]
