High-temperature hydrogen/propane separations in asymmetric carbon molecular sieve hollow fiber membranes
High-temperature hydrogen/propane separations in asymmetric carbon molecular sieve hollow fiber membranes
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DOI：
10.1016/j.memsci.2021.119978
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发表时间：
2021-10-23
影响因子：
9.5
通讯作者：
Zhang, Chen
中科院分区：
文献类型：
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作者：
Liu, Lu;Liu, Dongxia;Zhang, Chen
催化丙烷脱氢膜反应器要求膜具有极佳的高温H-2/C3H8分离性能。在这项工作中，我们证明了聚酰亚胺衍生的不对称碳分子筛(CMS)中空纤维膜具有薄的(类似于5微米)分离层，可以提供出色的高温(高达600℃)H-2/C3H8分离因子，是微孔氧化物膜的2-100倍。系统考察了CMS膜热解条件、渗透温度和进料组成对高温H2/C3H8分离性能的影响。在675℃下裂解的CMS中空纤维膜在600℃下，以50%/50%的H-2/C3H8为原料，在-130 h的连续渗透试验中，H-2渗透率和H-2/C3H8分离系数分别稳定在430gPU和511。结果表明，在高温渗透条件下，H-2/C3H8混合物的加氢和积炭对CMS膜的孔结构和分离性能有影响。通过控制H-2/C3H8的组成，在这两个潜在反应之间实现了权衡，从而在高温条件下获得了稳定的CMS。结果表明，在可控高温反应条件下，不对称CMS中空纤维膜在丙烷脱氢催化膜反应器中具有潜在的应用前景。
Catalytic propane dehydrogenation membrane reactors require membranes with highly attractive high-temperature H-2/C3H8 separation performance. In this work, we show that polyimide-derived asymmetric carbon molecular sieve (CMS) hollow fiber membranes with thin (similar to 5 mu m) separation layers can provide outstanding high-temperature (up to 600 degrees C) H-2/C3H8 separation factors 2-100 folds higher than microporous oxide membranes. The effects of CMS membrane pyrolysis condition, permeation temperature, and feed composition on high-temperature H-2/C3H8 separation performance were systematically investigated. CMS hollow fiber membranes pyrolyzed at 675 degrees C showed stable H-2 permeance of 430 GPU and H-2/C3H8 separation factor of 511 at 600 degrees C using a 50%/50% H-2/C3H8 feed mixture under a continuous permeation test of-130 h. It was found that CMS membrane pore structure and separation performance may be modulated by hydrogenation and coke deposition by the H-2/C3H8 mixture under high-temperature permeation. A trade-off between these two potential reactions is achieved by controlling H-2/C3H8 compositions, leading to stable CMS under high-temperature conditions. The results suggest that asymmetric CMS hollow fiber membranes are potentially attractive for catalytic propane dehydrogenation membrane reactors under controlled high-temperature reaction conditions.