New air gap membrane distillation module for desalination

doi:10.11949/j.issn.0438-1157.20150105

Abstract

Abstract:

A new air gap membrane distillation module based on hollow fiber with energy recovery was developed for desalination using 70 g·L^-1 NaCl solution as the feed. The effects of membrane module length and membrane pore size were investigated. For measuring directly the effects of operating conditions, membrane module properties, and temperature and concentration polarization on the mass transfer coefficient, the total mass transfer coefficient was introduced. The effects of membrane pore size, feeding temperature and feeding flow rate were studied. The results showed that the total mass transfer coefficient increased with the increase of membrane pore size and feeding temperature. The membrane flux and gained-out put ratio were increased effectively with increasing membrane pore size. Since increasing membrane module length would reduce the membrane flux while enhance the gained-out put ratio, the membrane flux and gained-out put ratio should be considered comprehensively for selection of the appropriate membrane module length in the application process.

Key words: air gap membrane module, membrane distillation, desalination, mass transfer

摘要：

利用基于聚丙烯中空纤维膜和聚丙烯中空纤维换热管的新型能量回收式膜组件(AGMD-HF),以70 g·L^-1的氯化钠溶液为研究对象,考察了膜组件长度和膜孔径大小对膜组件脱盐性能的影响。为直接衡量操作条件、组件参数以及温差、浓差极化现象对传质系数的影响,引入总传质系数,并研究进料温度和膜孔径对总传质系数的影响。实验结果表明,总传质系数随着温度的升高、膜孔径的增大而增大,提高膜孔径可有效提高总传质系数,同时可有效提高通量和造水比。通量随组件长度的增大而减小,而造水比增大,因此在应用过程中可综合考虑通量和造水比以便选择合适的组件长度。

关键词: 气隙式膜组件, 膜蒸馏, 脱盐, 传质

CLC Number:

TQ028.8

ZHANG Chunyao, GENG Hongxin, LANG Qingcheng, LI Pingli, WU Xiaoyan. New air gap membrane distillation module for desalination[J]. CIESC Journal, 2015, 66(10): 4000-4006.

张春尧, 耿洪鑫, 郎庆成, 李凭力, 武晓燕. 新型气隙式膜蒸馏组件脱盐过程[J]. 化工学报, 2015, 66(10): 4000-4006.

References 20

[1]	Morillo J, Usero J, Rosado D, et al. Comparative study of brine management technologies for desalination plants [J]. Desalination, 2014, 336: 32-49.
[2]	Camacho L M, Dumée L, Zhang Jianhua, Li Junde, et al. Advances in membrane distillation for water desalination and purification applications [J]. Water, 2013, 5(1): 94-196.
[3]	AI-Nory M T, Graves S C. Water desalination supply chain modeling and optimization: case of Saubi Arabia [J]. IDA Journal of Desalination and Water Reuse, 2013, 5(2): 64-74.
[4]	Tun C M, Groth A M. Sustainable integrated membrane contactor process for water reclamation, sodium sulfate salt and energy recovery from industrial effluent [J]. Desalination, 2011, 283: 187-192.
[5]	Martinetti C R, Childress A E, Cath T Y. High recovery of concentrated RO brines using forward osmosis and membrane distillation [J]. Journal of Membrane Science, 2009, 331(1/2): 31-39.
[6]	Alklaibi A M, Lior N. Membrane-distillation desalination: status and potential [J]. Desalination, 2004, 171: 111-131.
[7]	Gryta M. Concentration of NaCl solution by membrane distillation integrated with crystallization [J]. Separation Science and Technology, 2002, 37(15): 3535-3558.
[8]	Gryta M. Direct contact membrane distillation with crystallization applied to NaCl solutions [J]. Chemical Papers, 2002, 56(1): 14-20
[9]	Liu Jie(刘捷), Wu Chunrui(武春瑞), Lü Xiaolong(吕晓龙). Heat and mass transfer in vacuum membrane distillation [J]. CIESC Journal (化工学报), 2011, 62(4):908-915.
[10]	Yan Jianmin (阎建民), Yuan Qipeng (袁其朋), Ma Runyu (马润宇). Mass and heat transfer in air gap membrane distillation process [J]. Journal of Chemical Engineering of Chinese Universities (China) (高校化学工程学报), 2000, 14(2):109-114.
[11]	Yao Kun, Qin Yingjie, Yuan Yingjin, Liu Liqiang, He Fei, Wu Yin. A continuous-effect membrane distillation process based on hollow fiber AGMD module with internal latent-heat recovery [J]. AIChE Journal, 2013, 59(4):1278-1297.
[12]	Cheng Lihua, Wu Pingchung, Chen Junghui. Numerical simulation and optimal design of AGMD-based hollow fiber modules for desalination [J]. Ind. Eng. Chem. Res., 2009, 48(10): 4948-4959.
[13]	Guijt C M. Influence of membrane properties and air gap on the performance of a membrane distillation module [D]. Enschede, The Netherlands: University of Twente, 2003.
[14]	Lee Hanyong, He Fei, Song Liming, et al. Desalination with a cascade of cross-flow hollow fiber membrane distillation devices integrated with a heat exchanger [J]. AIChE Journal, 2011, 57(7): 1780-1795.
[15]	Qtaishat M, Matsuura T, Kruczek B, et al. Heat and mass transfer analysis in direct contact membrane distillation [J]. Desalination, 2008, 219(1): 272-292.
[16]	Ding Zhongwei, Ma Runyu, Fane A G. A new model for mass transfer in direct contact membrane distillation [J]. Desalination, 2003, 151(3): 217-227.
[17]	Kast W, Hohenthanner C R. Mass transfer within the gas-phase of porous media [J]. International Journal of Heat and Mass Transfer, 2000, 43(5): 807-823.
[18]	Schofield R W. Membrane distillation [D]. Sydney: The University of New South Wales, 1989.
[19]	Geng Hongxin, Wu Haoyun, Li Pingli, He Qingfeng. Study on a new air-gap membrane distillation module for desalination [J]. Desalination, 2014, 334(1): 29-38.
[20]	Geng Hongxin, He Qingfeng, Wu Haoyun, Li Pingli, Zhang Chunyao, Chang Heying. Experimental study of hollow fiber AGMD modules with energy recovery for high saline water desalination [J]. Desalination, 2014, 344: 55-63.