氢气分离提纯技术研究进展

Research Progress in Hydrogen Separation and Purification Technologies

低温分离法(深冷法)、选择吸附法、膜分离法是比较常见的氢气分离提纯技术。低温分离法在气体分离过程中涉及压缩和冷却过程,需要很高的能耗,适用于大规模气体分离过程。选择吸附法可分为变压吸附法、低温吸附法和低温吸收法,其中变压吸附工艺应用范围广,能够处理多种杂质,吸附剂是该工艺的基础和核心;低温吸附法操作较复杂,能耗较高,投资成本高,仅适用于大规模生产;低温吸收法适用于工业化生产,但也存在设备投资大、能耗较高等缺点。膜分离法是一种很有前途的生产超纯氢气的技术,按照制膜材料的不同,又可分为无机膜、有机膜和混合基质膜。就氢气纯度而言选择吸附法的效果最好,深冷分离法和膜分离法的氢气回收率比变压吸附法高,膜分离法的成本较其他两种低。实际应用中可选用两种或多种氢气分离法联合使用,以获得更好的氢气分离性能和经济性。目前氢分离的研究热点主要集中在新型无机膜及其复合膜的研制,以及多种分离过程集成方法的研究。

Low temperature separation method(cryogenic method),selective adsorption method and membrane separation method are common hydrogen separation and purification technologies.For the low temperature separation method,its gas separation involves compression and cooling,which requires high energy consumption,so it is suitable for large-scale gas separation process.The selective adsorption method can be divided into pressure swing adsorption method,low temperature adsorption method and low temperature absorption method.The pressure swing adsorption process has a wide application range and can deal with various impurities.The adsorbent is the basis and core of the process.The low temperature adsorption method has complicated operation,high energy consumption and high investment cost,so it is only suitable for large-scale production.The low temperature absorption method is suitable for industrial production,but it also has the disadvantages of high equipment investment and high energy consumption.Membrane separation is a promising technology for producing ultra-pure hydrogen.According to the different membrane materials,it can be divided into inorganic membrane,organic membrane and mixed matrix membrane.In terms of hydrogen purity,the adsorption method has the best effect.The hydrogen recovery rate of cryogenic separation method and membrane separation method is higher than that of pressure swing adsorption method,and the cost of membrane separation method is lower than that of the other two methods.In practical applications,two or more hydrogen separation methods can be used in combination to obtain better hydrogen separation performance and economy.At present,the research of hydrogen separation mainly focuses on the development of new inorganic membranes and their composite membranes,as well as the integration methods for various separation processes.