高效分离同碳数烃的先进微孔膜:现状与挑战

Advanced microporous membranes for efficient separation of same-carbon-number hydrocarbon mixtures:State-of-the-art and challenges

热法精馏分离同碳数烃混合物是当前石油化工行业中最耗能的过程之一。膜分离技术具有投资成本和操作费用低、节能降耗和集成度高等优点,可实现低能耗的膜法流程再造。以沸石分子筛和金属有机骨架材料(MOF)为代表的先进微孔膜较传统聚合物膜,具有更高的分离性能;渗透性和分离选择性可提升一至两个数量级,展现出优异的应用前景。本文综述了先进微孔膜在提升渗透性、分离选择性与分离过程稳定性3个方面的研究进展,深入探讨了膜层厚度、孔道取向、骨架柔性和晶间缺陷等微结构调控与同碳数烃分离性能间的构效关系。并且分析了面向同碳数烃高效分离应用的几种沸石膜和MOF膜面积放大制备的瓶颈问题,提出了晶种/成核位点均一性分布在先进微孔膜放大制备中的关键作用。最后对进一步加快新型先进微孔膜材料开发进程以应对石化行业多元化分离体系,以及加大膜工艺技术开发力度以匹配石化行业主流程工艺要求进行了展望。

Separation of hydrocarbon mixtures with the same carbon number by thermal distillation is one of the most energy-consuming processes in the petrochemical industry.The membrane separation technology can realize the reconstruction of membrane technology with low energy consumption due to the advantages of low investment and operating costs,high energy saving and high process integration degree.The advanced microporous membranes represented by zeolite and metal-organic framework materials have better separation performance than traditional polymers membrane,which can improve the permeability and selectivity by one or two orders of magnitude,and show excellent application prospects.This paper reviewed the progress of advanced microporous membranes in improving permeability,separation selectivity and separation process stability.The structure-activity relationship between the separation performance of hydrocarbon with the same carbon number and the microstructure regulation of membrane thickness,pore orientation,framework flexibility and intergranular defects was discussed in detail.The bottleneck problem of area scaling preparation of several zeolite films and MOF films for efficient separation of hydrocarbon with the same carbon number was analyzed,and the key role of homogeneity distributionof crystal seed/nucleation site in advanced microporous film scaling was proposed.Finally,it was expected to further accelerate the development of new advanced microporous membrane materials to cope with the diversified separation system in the petrochemical industry,and to increase the development of membrane technology to match the main process requirements in the petrochemical industry.