Preparation Of Polymeric Microspheres Modified Pebax Membrane And Application For CO₂ Capture

CO₂ is one of the main greenhouse gas,but also a kind of important carbon resources.Thus developing energy-efficient and environment-friendly CO₂ capture technology is imperative.Compared to the traditional CO₂ separation methods,membrane technology has incomparable advantages.Development of high performance CO₂ separation membrane materials has important theory value and practical significance.Because of the Reboson upper limitation,the commercially available polymeric membranes often have either high permeability or high selectivity,but not two together.Therefore requires modification of polymeric membrane is studied,in order to improve the membrane separation performance properties.In this paper choose Pebax as matrix,synthesized three functional groups of the polymer microspheres as fillers,composite membrane was prepared by Pebax mixed with polymer microsphere,research the membrane structure and properties,and separate CO₂ / CH4 mixed gas.The research content is as follows:In alkaline water and ethanol mixed solution,the PDA microspheres was synthesized,through FTIR and SEM to analysis the result,PDA microspheres loaded with hydroxyl and amine group.Then Pebax/PDA microsphere composite membrane was prepared and studied the structure and properties of this series of membranes,and separate CO₂ / CH4 mixed gas.The operating pressure at 0.2 Mpa and operating temperature at 25 ?,PDA microspheres add to 5 wt%,CO₂ permeability is 408 Barrer,CO₂/CH4 selectivity of 48;In the influence of operating pressure on the membrane separation performance test result shows that CO₂ permeability and CO₂/CH4 selectivity were reduced with the increase of test pressure,shows that in the preparation of synthetic PDA microspheres plays a promoting in themembrane.According to the conclusion of the previous chapter,the PDA microspheres can promote the effect of CO₂,on the basis of PDA microspheres,hope to be able to get a higher performance of membrane materials.Therefore,using PDA catechol groups on the surface of the microspheres as active site grafted polyethyleneimine,PDA-PEI microsphere was prepared.Then prepared Pebax/PDA-PEI composite membrane,the membrane,the structure and properties of the membranes were studied,and separate CO₂/CH4.The results show that the PDA-PEI content of 8 wt%,the membrane CO₂ permeability is 423 Barrer,CO₂/CH4 selectivity of 48.There is affinity function between carboxyl and CO₂,so using the soap-free emulsion polymerization method prepared carboxyl polystyrene microspheres,Pebax/CPS composite membrane was prepared,and study the structure and properties of the membrane,and separate CO₂/CH4.The Pebax/CPS-5% membrane on the separation of CO₂/CH4 results showed that membrane CO₂ permeability and CO₂/CH4 selectivity were respectively on the basis of pure Pebax membrane increased by about 137% and 161%.