The Preparation Of Novel Hollow Fiber Membranes For Methane And Carbon Dioxide Separation

Compared with other separation processes membranes have advantages of high selectivity,low energy consumption, high efficiency, small volume and less occupation of land area,simple manipulation, none pollution, easy to integrate with other technique. The separation ofmethane and carbon dioxide has a large market and bright future in oil and gas industry.Nowadays, the separation of methane and carbon dioxide in membrane processes is a researchhotspot. PPESK showed both excellent comprehensive performances and highheat-resistances (Tg263～305℃), better than other dissoluble engineering plastics. A kind ofhollow fiber composite membrane for methane and carbon dioxide separation has beenprepared by using PPESK as the membrane material and PDMS as the coating material.First, structure and performance of the PPESK hollow fiber membranes prepared basedon the phase separation behavior has been systemically researched. The influences ofthermodynamics and dynamic factors to the performance of membranes were studied. Such astypes of solvent, the theta-composition of NMP/EtOH mixture, air gap of the dry/wetspinning process, temperature of casting solution, temperature of coagulant media, types ofinner coagulant media and shear rate. The structure research and character analysis are madewith SEM, gas permeability and separation coefficient. Summary from research, thepreparation technology of membranes for methane and carbon dioxide separation is got.Second, with the dip-coating method, the hollow fiber composite membrane has beenprepared using PDMS as the coating material. The resistance model of composite membraneis established. The influences of basement membrane, silicon rubber's contents, and thetemperature of the operation have been systemically studied. At the same time, the resistanceto high temperature of composite membranes has been studied. Summary from research, themethod of coating is found.Finally, thy drying treatment of basement membrane has been studied. Such as air drying,ethanol three degrees dehydrate and surfactants treatment. The best drying treatment is gotafter the research of influences on membrane and coating.