摘要
为开发多级逆流微萃取系统,实现稳定逆流操作,研究液-液两相在此系统中的传质规律,以及探索传质性能的最优化操作条件。以双向四缸往复泵和四个缓冲室通过单向阀与料液罐相连,构成脉冲进料出料系统,以单向阀控制两相单向流动,实现微萃取系统的逆流操作;以30%(v/v)TBP-煤油/水体系为研究对象,选择硝酸为待萃取物,以平行并列微通道为微萃取设备,进行单级微萃取实验,研究脉冲频率、脉冲体积、浓度等操作条件对传质性能的影响;在此基础上,进行四级逆流微萃取的研究,总结出最优化操作条件。结果表明,在两相脉冲冲程均为80μL,脉冲频率为0.13 Hz时,单级微萃取的萃取级效率达到最大;在四级逆流微萃取系统中,总萃取效率超过90%。
The purpose of this work is to develop a multi-stage countercurrent micro-extraction system to achieve stable operation of countercurrent flow, and investigate liquid-liquid mass transfer performance. The countercurrent flow was achieved by using a pulse feeding discharging system and a one-way control system. The pulse feeding discharging system was composed of a reciprocating pump with four pistons moving at opposite directions, and four chambers connected with the material vessels by check valves. The single-stage extraction performance was first investigated in a multi-channel micro-extraction device with 30%TBP-kerosene / water- nitric acid as the liquid-liquid extraction system. The effect of operation conditions including pulse frequency, pulse volume and concentration on the mass transfer performance was investigated, and then the extraction performance of the four-stage micro-extraction system was tested. Optimal operation conditions were finally obtained. The highest extraction efficiency of the single-stage extraction is achieved when the pulse frequency is at 0.13Hz, with the pulse stroke of both phases at 80μL. The total extraction efficiency of the four-stage micro-extraction system is higher than 90%in all experiments.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2014年第3期524-529,共6页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金(21106077)
北京市自然科学基金(2113047)
关键词
多级逆流
微萃取
萃取效率
单向流控制
脉冲进出料
multi-stage countercurrent
micro-extraction
extraction efficiency
one-way flow control
pulse feeding and discharging
