聚酰亚胺膜制备船载医用高纯氧过程研究

Investigation on the process of shipborne medical purity oxygen production with polyimide membrane

分别采用商业用聚醚酰亚胺和实验室自制的聚酰亚胺为原材料制备中空纤维膜,以体积分数为95%、96.5%、98%、98.5%4种氧浓度的O_(2)/Ar混合气为原料气,在室温下系统考察了膜材料、分离系数、进气压力、原料气浓度、放空比和膜分离器长度等参数对制备高纯氧效果的影响,并设计了二级膜循环系统进行模拟对比.实验结果证明,膜的分离系数从根本上决定着富氧效果;增大进气压力会在一定范围内提升膜的富氧性能,同时还会增加混合气处理量;对于不同浓度的原料气,原料气中氧气浓度越高,膜的渗透速率越大;增大放空比有利于提高渗透侧富氧气的浓度;膜分离器长度的优化也对促进膜富氧性能有一定影响,这些结果揭示了相关参数对氧气与氩气分离过程影响的规律,并验证了采用聚酰亚胺中空纤维膜制备符合国家标准医用高纯氧的可行性.

Hollow fiber membranes were prepared by using laboratory-made polyimide and commercial polyetherimide as raw materials.O_(2)/Ar mixtures with four variable oxygen concentrations of 95%,96.5%,98%and 98.5%were used as feed gas to test the oxygen-enrichment process.The effects of parameters such as membrane separation factor,inlet pressure,feed gas concentration,vent flow ratio and membrane separator length on the separation effect of high-purity oxygen production were systematically investigated at room temperature and a two-stage membrane circulation system for simulation comparison was designed based on the test results.The experimental results show that the separation factor of the membrane fundamentally determines the oxygen-enriching effect;increasing the intake pressure will improve the oxygen-enriching performance of the membrane within a certain range,and at the same time increase the treatment capacity of the mixed gas;for the feed gas with different oxygen concentrations,higher the oxygen concentration in the feed gas is,greater the permeation rate of the membrane will be;increasing the vent flow ratio is beneficial to increase the concentration of oxygen-enriched gas on the permeate side;the optimization of the length of the membrane separator also has a certain impact on the membrane separation performance.These results reveal the influence of relevant parameters on the separation process of oxygen and argon,and verify the feasibility of using polyimide hollow fiber membranes to prepare medical high-purity oxygen that meets national medical standards.