Abstract: Membrane distillation is a new thermally-driven separation process，in which vapor molecules driven by partial pressure gradient across the membrane are able to transfer through the pores and condense outside the membrane. In this paper，the heat and mass transport mechanisms and four mainly used membrane configurations，i.e.，direct contact membrane distillation，air gap membrane distillation，sweeping gas membrane distillation and vacuum membrane distillation are described. New research progress is reviewed，including influence of membrane operation and characteristic parameters，preparation of membrane with high performance，improvement in process and operation parameters aiming at membrane fouling，enhancement of membrane distillation process by optimizing energy utilization and modules. In addition，applications in desalination and water purification，juice concentrate and alcohol fermentation，separation of chemical volatile organic compounds as well as toxic waste water treatment are summarized. Finally，the obstacles faced by membrane distillation：combined influence of pertinent parameters，commercialization of membrane materials，membrane module design and thermal efficiency of the process are presented. To achieve its further application，it is necessary to strengthen energy studies，to develop more commercialized membrane materials，to focus more on other membrane distillation configurations，and to analyze and optimize the process systematically.

Key words: membrane distillation, membranes, heat transfer, optimization, desalination

摘要： 膜蒸馏是一种热驱动的新型分离技术，可使蒸汽分子在膜两侧的压力梯度作用下通过膜孔迁移至膜外侧并冷凝下来。本文简要介绍了膜蒸馏的热质传递原理以及直接接触式、气隙式、气扫式、真空式等几种主要膜蒸馏装置的特点。综述分析了膜蒸馏的相关研究进展，包括：膜蒸馏的操作及膜特性参数的影响机理研究；更多高性能的膜材料的研制；对膜污染在工艺与操作参数方面的改进；通过能源利用与组件优化强化膜蒸馏过程等。概述了膜蒸馏在海水脱盐制备纯水、食品工业中果汁浓缩及酒精发酵、化学可挥发性物质的分离以及有毒有害废水处理方面的最新应用。最后，进一步指出过程参数的综合影响、膜材料的商业化、膜组件设计以及过程热效率是目前阻碍膜蒸馏工业化应用的主要问题。展望了加强能源研究、专注于商业用膜的研发、较多关注于其他膜蒸馏过程以及系统角度的优化分析是膜蒸馏技术未来的发展方向。

关键词: 膜蒸馏, 膜, 传热, 优化, 脱盐