以氢溴酸为吸收剂的气态膜法脱氨过程研究  

Study on the supported gas membrane for ammonia removal by using hydrobromic acid as absorbent

作　　者：刘一 秦英杰[1] 许玉壮 贾雨萌 蔡腾豪 于文凯 LIU Yi;QIN Yingjie;XU Yuzhuang;JIA Yumeng;CAI Tenghao;YU Wenkai(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300350,China;The 718th Research Institute of CSSC,Handan 056027,China;PureSea Spring Membrane Technology,Ltd.,Tianjin 300350,China)

机构地区：[1]天津大学化工学院,天津300350 [2]中国船舶重工集团公司第七一八研究所,邯郸056027 [3]洁海瑞泉膜技术(天津)有限公司,天津300350

出　　处：《膜科学与技术》2023年第4期136-144,共9页Membrane Science and Technology

摘　　要：研究了以氢溴酸为吸收剂的气态膜法料液脱氨过程。该过程通过使用聚四氟乙烯(PTFE)或聚丙烯(PP)中空纤维微孔疏水膜制作的膜接触器,从含氨水溶液中脱除/回收氨并相应获得溴化铵副产品.研究了料液中氨浓度、料液中电解质浓度、料液表面张力和吸收液pH等操作条件对传质性能的影响,检验了低表面张力料液对PTFE和PP膜组件性能稳定性的影响.实验结果表明,在提供了最大传质系数的吸收液低pH下氢溴酸的挥发性并没有影响PTFE和PP膜组件的操作稳定性.基于传质机理的数学模型可以描述料液浓度、流速、吸收液pH对总传质系数的影响;料液中的高浓电解质减弱了渗透蒸馏效应,例如当料液中溴化钠质量分数为15%时,氨在吸收完成液中的富集倍数高达41.25.在连续运行的6个月内,PTFE膜组件对使用挥发性氢溴酸作为吸收剂来处理低表面张力的料液表现出了良好的性能稳定性,而PP膜组件的总传质系数在10 d内下降了65%.本研究为气态膜技术处理低表面张力的含氨料液或废水并副产溴化铵的工业化应用提供了基本实验数据和基础理论分析.The supported-gas-membrane process was investigated for the removal/enrichment of ammonia from aqueous solution,by using membrane contactor made of microporous hydrophobic PTFE or PP hollow fibers and using dilute hydrobromic acid as the stripping solution,in order to obtain ammonium bromide as the by-product correspondingly.The influence of the operation conditions such as feed concentration,other electrolyte concentration in feed,surface tension of feed and pH of the stripping solution on mass transfer performance were investigated,and the effects of feed with low surface tension on the performance stability of PTFE or PP membrane module were also tested.The experimental results showed that the volatility of hydrobromic acid did not affect the operational stability of PTFE and PP membrane modules at the low pH that the stripping solution provided the maximum mass transfer coefficient.The mathematical model based on mass transfer mechanism can describe well the influence of feed concentration,feed flow rate and pH value of the stripping solution on mass transfer.The highly concentrated electrolyte in the feed weakens the osmotic distillation phenomenon,for example,when the mass fraction of sodium bromide in the feed solution was as high as 15%,the enrichment ratio of ammonia in the final stripping solution was 41.25.In a long-term test of continuous operation for 6 months,PTFE membrane modules had shown good performance stability in dealing with the feed of low surface tension.However the mass transfer coefficient of PP modules decreased significantly within 10 days,with the mass transfer coefficient decreased by 65%.This study lays a theoretical foundation for the industrial application of supported gas membrane and provides experimental data to remove/recover ammonia from feed of low surface tension and to obtain ammonium bromide as a by-product.

关 键 词：气态膜 PTFE中空纤维 低表面张力 脱氨 氢溴酸 

分 类 号：TQ028.8[化学工程]