Evaluation of microporous hollow fibre membranes for mass transfer of H 2 into anaerobic digesters for biomethanization
Evaluation of microporous hollow fibre membranes for mass transfer of H 2 into anaerobic digesters for biomethanization
复制标题
微孔中空纤维膜将 H 2 传质至生物甲烷化厌氧消化器的评价
DOI：
10.1002/jctb.6081
复制
发表时间：
2019
影响因子：
3.4
通讯作者：
Nock W
中科院分区：
文献类型：
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作者：
Nock W
中空纤维膜具有高表面体积比，为改善气液传质提供了一种潜在的解决方案。本工作通过实验确定了市售微孔中空纤维膜的传质特性，并将其与气泡塔反应器的传质特性进行了比较。这两种传质系统都被考虑用于生物甲烷化，这一过程面临着提高产甲烷古菌将h2和co2结合成CH4的h2气-液传质的挑战。结果聚丙烯膜的传质率最高，测得的h2传质系数为1.2 × 10−4ms−1。这些结果支持了两膜气液传质理论，随着膜上液体流速的增加，传质率也随之提高。尽管聚丙烯膜的传质速率较高，并且有液体流过膜，但在全尺度生物甲烷化过程中需要的体积表面积为α= 10.34 m−1，而在高倍率生物甲烷化系统中可能需要更大的体积表面积。结论在大型生物甲烷化反应器中，中空纤维膜对h2传质所需的大表面积、膜的污染和替换成本等问题是中空纤维膜面临的挑战。假设初始气泡尺寸足够小（de< 0.5 mm），计算表明，微气泡可以提供一种更简单的方法，将所需的h22在商业规模厌氧消化器中典型的头部转移到液相中。©2019作者。化学技术与生物技术杂志由John Wiley & Sons Ltd代表化学工业协会出版。
BACKGROUNDWith high surface‐to‐volume ratios, hollow fibre membranes offer a potential solution to improving gas–liquid mass transfer. This work experimentally determined the mass transfer characteristics of commercially available microporous hollow fibre membranes and compared these with the mass transfer from bubble column reactors. Both mass transfer systems are considered for biological methanization, a process that faces a challenge to enhance the H2gas–liquid mass transfer for methanogenic Archaea to combine H2and CO2into CH4.RESULTSPolypropylene membranes showed the highest mass transfer rate of membranes tested, with a mass transfer coefficient for H2measured askL= 1.2 × 10−4ms−1. These results support the two‐film gas–liquid mass transfer theory, with higher mass transfer rates measured with an increase in liquid flow velocity across the membrane. Despite the higher mass transfer rate from polypropylene membranes and with a liquid flow across the membrane, a volumetric surface area ofα= 10.34 m−1would be required in a full‐scalein situbiological methanization process with much larger values potentially required for high‐rateex situsystems.CONCLUSIONSThe large surface area of hollow fibre membranes required for H2mass transfer and issues of fouling and replacement costs of membranes are challenges for hollow fibre membranes in large‐scale biological methanization reactors. Provided that the initial bubble size is small enough (de< 0.5 mm), calculations indicate that microbubbles could offer a simpler means of transferring the required H2into the liquid phase at a head typical of that found in commercial‐scale anaerobic digesters. © 2019 The Authors.Journal of Chemical Technology & Biotechnologypublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.