聚四氟乙烯中空纤维气态膜法浓海水提取溴素

PTFE Hollow Fiber Supported Gas Membrane Process for Extraction of Bromine from Brine

以浓海水为含溴原料液,Na OH溶液为吸收剂,考察了用聚丙烯(PP)、聚偏氟乙烯(PVDF)和聚四氟乙烯(PTFE)3种材料制作的微孔疏水中空纤维气态膜组件从浓海水中提溴的性能和使用寿命。实验结果表明PTFE中空纤维膜具有更高的传质系数和更强的耐溴氧化能力,更适合用于浓海水提溴。进而考察了各种操作条件对PTFE气态膜组件传质系数K和提溴率η的影响以及该组件的长期操作稳定性。实验结果表明:K随温度增加而增大,随料液中Na Cl含量的增大而略有减小,料液流速和含溴量、吸收液的流速和吸收剂浓度对传质系数影响不大。PTFE膜组件在连续运行的3个月内表现了良好的操作稳定性,为PTFE中空纤维气态膜法提溴工艺的工业化应用提供了技术基础。

In this paper,bromine extraction from brine by supported gas membrane process was investigated by using PP,PVDF and PTFE porous hollow fiber membrane modules with Na OH as absorbent. The experimental results demonstrated that PTFE modules was with higher mass transfer coefficient and high oxidation resistance and thus more suitable for bromine extraction from brine. Therefore,PTFE modules were further employed to test the influence of the operating conditions on overall mass transfer coefficient K and bromine extraction rate η and the long term operation stability performance in subsequent experiments. Experiment results showed that K increased with the increase of operation temperature,and decreased with the increase of salt content of feed slightly; feed-in flow rate,feed-in bromine concentration,absorbent concentration and flow rate of absorbent solution had little influence on K. PTFE module showed an excellent operational stability in a test lasting for 3 months. This study offered a technical basis for the industrialized application of the supported gas membrane process for bromine extraction.