Abstract Hydrophobic alumina hollow fiber membranes were first used for sucrose concentration in a vacuum membrane distillation (VMD) system. The alumina hollow fiber membranes were prepared using the combined phase inversion and sintering method and then grafted with FAS to impart hydrophobicity. The as-prepared hydrophobic alumina hollow fiber membrane had a high mechanical strength of 191 MPa, a high water contact angle of 140° and a high liquid entry pressure of water of 5.0 bar. Fifty-two hydrophobic alumina hollow fibers were packed into a shell-and-tube module. To evaluate the sucrose concentration performance of the prepared membrane module, the effects of various parameters on the permeate flux, such as the feed flow rate, temperature, vacuum pressure and concentration, were investigated in the VMD system. In the batch sucrose concentration tests, an 8 L 10°Brix sucrose solution was successfully concentrated to 50°Brix by removing 6.4 L of water using the VMD system. At a feed flow rate of 5 L/min and temperature of 70 °C, the permeate flux remained as high as 35.1 and 19.0 kg/m2 h when the sucrose solution was concentrated to 10°Brix and 50°Brix. Furthermore, the permeate flux could be recovered in a new concentration cycle after the membrane module was washed with pure water. The results revealed that the hydrophobic alumina hollow fiber membranes are promising and feasible for concentration processes in a VMD system.

中文翻译：

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用于真空膜蒸馏法浓缩蔗糖的疏水性氧化铝中空纤维膜

摘要 疏水性氧化铝中空纤维膜首先用于真空膜蒸馏 (VMD) 系统中的蔗糖浓缩。采用相转化和烧结相结合的方法制备氧化铝中空纤维膜，然后用 FAS 接枝以赋予疏水性。所制备的疏水性氧化铝中空纤维膜具有 191 MPa 的高机械强度、140° 的高水接触角和 5.0 bar 的高水进入压力。52 根疏水性氧化铝中空纤维被装入管壳式模块中。为了评估制备的膜组件的蔗糖浓缩性能，在 VMD 系统中研究了各种参数对渗透通量的影响，例如进料流速、温度、真空压力和浓度。在批量蔗糖浓度测试中，通过使用 VMD 系统去除 6.4 L 水，将 8 L 10°Brix 蔗糖溶液成功浓缩至 50°Brix。在 5 L/min 的进料流速和 70 °C 的温度下，当蔗糖溶液浓缩至 10°Brix 和 50°Brix 时，渗透通量保持高达 35.1 和 19.0 kg/m2 h。此外，在膜组件用纯水洗涤后，可以在新的浓缩循环中恢复渗透通量。结果表明，疏水性氧化铝中空纤维膜在 VMD 系统中的浓缩过程中具有前景和可行性。当蔗糖溶液浓缩至 10°Brix 和 50°Brix 时，分别为 1 和 19.0 kg/m2 h。此外，在膜组件用纯水洗涤后，可以在新的浓缩循环中恢复渗透通量。结果表明，疏水性氧化铝中空纤维膜在 VMD 系统中的浓缩过程中具有前景和可行性。当蔗糖溶液浓缩至 10°Brix 和 50°Brix 时，分别为 1 和 19.0 kg/m2 h。此外，在膜组件用纯水洗涤后，可以在新的浓缩循环中恢复渗透通量。结果表明，疏水性氧化铝中空纤维膜在 VMD 系统中的浓缩过程中具有前景和可行性。