苯基修饰微孔SiO2膜的氢气分离和水煤气变换反应性能

通过正硅酸乙酯与苯基三乙氧基硅烷共水解缩聚反应制备苯基修饰SiO2膜,研究膜材料的氢气渗透和分离性能,并将其作为膜反应器的关键材料应用于水煤气变换反应.结果表明,氢气在苯基修饰SiO2膜中的渗透率随着温度的升高而增大,遵循活化扩散机理,300℃下H2渗透率达到4.67×10-7 mol/(m2·s·Pa),理想分离系数H2/CO、H2/CO2和H2/SF6分别达到10.54、10.50、21.16.在300℃,反应物H2O/CO摩尔比为2∶1的条件下进行水煤气变换反应,膜反应器的CO的转化率比传统固定床反应的CO的转化率高约12％,其原因是苯基修饰的SiO2膜对H2具有一定的选择性.

Phenyl-modified microporous silica membranes for hydrogen separation and water gas shift reaction

Silica membranes were modified by phenyl groups through an acid-catalyzed co-hydrolysis and condensation of tetraethylorthosilicate(TEOS) and phenyltriethoxysilane(PTES).The hydrogen permeation and separation performance of the phenyl-modified silica membranes and their role in the water gas shift reaction were investigated.The results show that the hydrogen transportation in the modified silica membranes is subjected to an activated diffusion mechanism,as demonstrated by the fact that hydrogen permeance increases with increasing temperatures.The silica membranes possess a hydrogen permeance of 4.67×10-7 mol /(m 2.s.Pa) and a permselectivity of 10.54,10.50and 21.16for H 2 / CO 、 H 2 / CO 2 and H 2 / SF 6 respectively at 300 ℃.The CO conversion of the membrane reactor is 12% higher than that of fixed-bed at a temperature of 300℃and a H 2 O / CO ratio of 2∶1,due to the hydrogen selective property of the modified silica membranes.