摘要
利用比表面积为2 955 m2·g-1、平均孔径为2.84 nm、汽油蒸气吸附容量为0.71 g·g-1的高性能粉末活性炭涂敷在50 nm孔径的陶瓷膜上,制备出活性炭/陶瓷复合膜.建立一套膜渗透分离测试装置,用来评价其渗透分离性能.实验结果表明涂炭处理是有效的.该复合膜在标准状态下对N2的透气率JN2达5.0×10-9m3·m-2·s-1·Pa-1,远大于传统的聚合物膜,且JN2随膜两侧压差的线性变化明显比未涂炭膜小.该复合膜对于易凝性气体-N2的分离,是以'表面吸附+毛细管凝聚'为主,从而体现出其优良的分离性能,如随膜两侧压差从50～130 kPa变化,汽油蒸气-N2、正辛烷-N2的分离因子分别达15.2～30.7和147.0～150.0.实验结果还表明,涂炭次数对膜的透气分离性能影响不大,建议涂炭1～3次.
A powdery activated carbon with specific surface area of 2955 m2·g-1 and average pore diameter of 2.84 nm and adsorption capacity to gasoline vapor of 0.71 g·g-1 was coated on the surface of the ceramic membrane with pore diameter of 50 nm, and an activated carbon/ceramic composite membrane was prepared. A lab-size appraisement system for VOC-N2 permeability and selectivity by membrane was set up. The results show that preparation of the composite membrane is successful and well effective. The composite membrane has high N2 permeability of 5.0 × 10-9 m3·m-2· s-1·Pa-1, which is higher than that of traditional polymer membrane. And linear variation of JN2 as pressure differential between two sides of the membrane is lower than that of noncoated membrane. Being based on surface adsorption and capillary condensation mechanisms, this composite membrane has more effective permeation and separation capacity, the membrane performs well selectivity to remove various condensative VOC from VOC-N2 streams. The separation factor of gasoline vapor-N2 increases from 15.2 to 30.7 and that of n-octane vapor-N2 from 147.0 to 150.0 on a rise with the pressure differential between two sides of the membrane from 50 kPa to 130 kPa. The results show that optimal number of coated carbon is from 1 to 3 because it has influence slightly on permeation and separation of the composite membrane.
出处
《石油化工高等学校学报》
EI
CAS
2005年第3期1-5,共5页
Journal of Petrochemical Universities
基金
国家自然科学基金资助项目(20406007)
江苏省社会发展科技基金资助项目(BS2001038)。
关键词
活性炭
陶瓷
复合膜
制备
渗透
分离
Activated carbon
Ceramic
Composite membrane
Preparation
Permeation
Separation
