Design,preparation And Performance Of CO₂ Mixed Substrate Membrane With High Efficiency

Membrane separation technology has shown good application prospects in the field of CO₂ separation with its advantages of low energy consumption,high efficiency,and environmental protection.In the membrane separation technology,the membrane material is the core part,and the key to the membrane separation performance is the choice of membrane material.Therefore,it is of great significance to develop an efficient CO₂ separation membrane mater ial.According to the difference between CO₂ molecules and CH₄ and N2 molecules,the selection of polymer polyether-polyamide block copolymer?Pebax?as a polymer membrane matrix is based on the advantages of the arrangement and orientation of two-dimensional mater ials in the polymer matrix.Mixed matrix membranes with efficient transfer channels for CO₂ separation systems with the aim of achieving efficient separation of CO₂.The main research contents and research results are as follows:The preparation of Pebax-Ag MMMs and application for CO₂ separation: Preparation of Pebax-Ag MMMs based on two-dimensional plane transfer Pebax wa used as a membrane matrix.Ag sheet prepared by a wet chemical method was used as a filler.The Ag sheet had a smooth surface and provided gas transmission.A fast transmission channel is contructed for the transfer of CO₂.In the CO₂/CH₄ system,the CO₂ permeability coefficient of Pebax-Ag-4 MMMs is 449 Barrer,CO₂/CH₄ selectivity is 43,and CO₂ permeability coefficient of Pebax-Ag-4 MMMs reaches 403 Barrer in CO₂/N2 system.The CO₂/N2 selectivity reaches 67.The preparation of Pebax-PCNs MMMs and application for CO₂ separation: Based on two-dimensional planar and porous transmission,Pebax-PCNs MMMs was designed and prepared.PCNs was synthesized by self-assembly method.CO₂ transport channels were constructed by incorporating PCNs as filler into Pebax matrix.The microporous structure of PCNs shortens the diffusion path of CO₂,thereby increasing the CO₂ permeability coefficient.The staggered stacking of PCNs and the infiltration of polymer chains into the pores of the PCNs resulted in smaller pore diameters,which increased the CO₂/CH₄ selectivity and CO₂/N2 selectivity of the Pebax-PCNs mixed matrix membrane.In the CO₂/CH₄ system,the CO₂ permeability coefficient of Pebax-PCNs-10 mixed matrix membrane is 520 Barrer,CO₂/CH₄ selectivity is 51,and the CO₂ permeability coefficient of Pebax-PCNs-10 mixed matrix membrane is 613 Barrer in CO₂/N2 system.The CO₂/N2 selectivity reaches 61.The preparation of Pebax-ZIF-TCPP MMMs and application for CO₂ separation: Based on two-dimensional planar and interconnected porous transmission,Pebax--ZIF-TCPP MMMs was designed and prepared.ZIF-TCPP was prepared as a filler,and ZIF-TCPP was filled into Pebax matrix to construct CO₂ transport channels.The ZIF-TCPP packing shows good dispersibility in Pebax matrix and has good compatibility with Pebax matrix.The microporous structure of ZIF-TCPP shortens the diffusion path of CO₂ while the interconnected pore size increases the diffusion channel,thereby increasing the CO₂ permeability coefficient.In addition,the basic group contained in ZIF-TCPP increases the reaction site with CO₂.When the filling volume of ZIF-TCPP was 7 wt%,the CO₂ permeability coefficient was 626 Barrer,and the CO₂/CH₄ selectivity was 65.