化工进展 ›› 2022, Vol. 41 ›› Issue (5): 2285-2291.DOI: 10.16085/j.issn.1000-6613.2021-1013

• 化工过程与装备 • 上一篇    下一篇

焦耳效应强化气隙式膜蒸馏脱盐过程的实验研究

石一慈(), 潘艳秋(), 王成宇, 范嘉禾, 俞路   

  1. 大连理工大学化工学院,辽宁 大连 116024
  • 收稿日期:2021-05-12 修回日期:2021-06-08 出版日期:2022-05-05 发布日期:2022-05-24
  • 通讯作者: 潘艳秋
  • 作者简介:石一慈(1994—),女,硕士研究生,研究方向为膜蒸馏及过程强化。E-mail:shiyici@dlut.edu.cn

Experimental investigations on Joule effect enhanced air gap membrane distillation for water desalination

SHI Yici(), PAN Yanqiu(), WANG Chengyu, FAN Jiahe, YU Lu   

  1. School of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
  • Received:2021-05-12 Revised:2021-06-08 Online:2022-05-05 Published:2022-05-24
  • Contact: PAN Yanqiu

摘要:

以膜蒸馏海水淡化为背景,通过对自制导电炭膜通入直流电产生焦耳效应,开展焦耳效应强化膜蒸馏氯化钠水溶液脱盐过程实验研究。结果表明,制备的煤基炭膜在100℃内具有良好的结构稳定性;在实验范围内,炭膜对氯化钠的截留率在99.96%以上;焦耳效应对膜蒸馏渗透通量的提高率最高可达60%,且低温时焦耳效应对膜蒸馏的强化效果更好、电转换效率更高;引入的焦耳热除用于水分汽化外,还可提高料液温度、改善温度极化、增加传质推动力;焦耳效应同时对膜蒸馏过程传质系数产生影响,在进料温度为50~80℃时,受努森扩散和分子扩散影响,电流为1A时传质系数值将减小,电流为3A和5A时传质系数值将增大;膜蒸馏过程引入焦耳效应不会产生氧化还原反应和额外膜结垢;在炭膜中引入电流不会破坏炭膜及其表面PDMS层的结构。本文研究内容丰富了膜蒸馏海水淡化过程的强化方法,也可为焦耳效应影响膜蒸馏过程的模拟研究及工业应用提供依据。

关键词: 膜蒸馏, 脱盐, 温度极化, 焦耳效应, 过程强化

Abstract:

For desalination by membrane distillation, direct current was applied to self-made conductive carbon membrane to produce Joule effect which can enhance the air gap membrane distillation process. Experimental results showed that the prepared coal-based carbon membrane has good structural stability within 100℃. In the experimental range, the rejection rate of carbon membrane for sodium chloride was over 99.96%, and the introduction of Joule effect during membrane distillation process would not produce additional membrane fouling. The Joule effect could increase the permeate flux up to 60%, and it gave better enhancement on the membrane distillation and higher electric conversion efficiency at low temperature. The introduced Joule heat can not only evaporate water but also increase the temperature of material and liquid, improving temperature polarization and increasing the driving force of mass transfer. The Joule effect also affects the mass transfer coefficient in the process of membrane distillation. When the feed temperature was 50—80℃, affected by Knudsen diffusion and molecular diffusion, the mass transfer coefficient would reduce at 1A current, and increase at 3A and 5A current. Meanwhile, the introduction of current into the carbon membrane will not damage the structure of the carbon membrane and the PDMS layer on its surface, and there is no synergistic effect such as REDOX in the carbon membrane. The research content of this paper enriches the methods of membrane distillation seawater desalination process and also provides a basis for simulation research and industrial application of the Joule effect affecting the membrane distillation process.

Key words: membrane distillation, desalination, temperature polarization, Joule effect, process intensification

中图分类号: 

京ICP备12046843号-2;京公网安备 11010102001994号
版权所有 © 《化工进展》编辑部
地址:北京市东城区青年湖南街13号 邮编:100011
电子信箱:hgjz@cip.com.cn
本系统由北京玛格泰克科技发展有限公司设计开发 技术支持:support@magtech.com.cn