Preparation Of Hollow Fiber Oxygen Permeation Membrane And Partial Oxidation Of Methane To Syngas

In this paper,the influence conditions of Sm0.6Sr0.4Al0.3Fe0.7O3-?-Ce0.85Sm0.15O1.925(SSAF-SDC)hollow fiber membrane oxygen permeability performance and the influence conditions of LCF-Ag hollow fiber membrane for partial oxidation of methane to syngas are studied.SSAF-SDC and La0.8Ca0.2Fe0.95Ag0.05O3-?(LCF-Ag)powders were prepared by solid-phase reaction method and solgel method respectively,and then SSAF-SDC and LCF-Ag hollow fiber membranes were prepared by phase inversion sintering technique.The XRD,SEM,TEM and other detection methods were used to test the prepared material,which proved that the crystal composition and structure of the material met the requirements for subsequent oxygen permeability detection.First,SSAF-SDC hollow fiber membranes for oxygen permeation were prepared.The changes of oxygen permeability with temperature,sweep gas flow rate and air flow rate were studied.The maximum oxygen permeability was 1.88 m L min-1 cm-2 at 950 ?.After changing the oxygen partial pressure between the two sides of the membrane,the maximum oxygen permeability is 2.6 m L min-1 cm-2 at an oxygen partial pressure difference of 1/0.02 atm(feed/permeate side).Next,the SSAF-SDC hollow fiber membrane oxygen permeability and CO2 resistance were tested.The stability test was carried out under He and CO2 gas purging conditions at 950 ? for 100 hours.The oxygen permeability during He as sweep gas was stable at 1.03 m L min-1 cm-2,the oxygen permeability was stable at 0.94 m L min-1 cm-2 during CO2 as sweep gas.The difference in oxygen partial pressure between the two sides of the hollow fiber oxygen-permeable membrane has an important influence on the oxygen permeability.In order to achieve complete separation of oxygen and nitrogen in the air,it is necessary to further increase the oxygen partial pressure across the membrane to increase the oxygen permeability.After that,a silver-doped LCF-Ag dual-phase hollow fiber membrane was prepared,and the catalyst(Ni/La Ni O3/?-Al2O3)was evenly supported on the inner surface of the hollow fiber membrane by injection to test the partial oxidation reaction of methane.At 925 ?,the methane conversion rate is 99%,the CO selectivity is 95%,H2/CO is close to 2,and the N2 concentration on the air side reaches 99.9%.After 200 hours of continuous testing,its reaction performance remains stable.Based on the study of a single membrane,the parallel three membrane reactors were tested for 100 h at the same time,and their performance was consistent with the performance of the single membrane and remained stable.These results indicate that the use of LCF-Ag hollow fiber membrane reactor can simultaneously achieve synthesis gas preparation and nitrogen purification.