摘要
测定了两种5A分子筛(5A-1和5A-2)对正己烷的吸附性能,并对它们的结构进行了表征,分析了5A分子筛的微观特性与吸附性能的关系。实验结果表明,与5A-2相比,5A-1的结晶度更高,且5A-1晶粒规整、大小均匀,n(SiO2)∶n(Al2O3)为1.99,具有适度的表面酸性,在30℃下对正己烷的平衡吸附量达到0.16kg/kg,比5A-2提高了约24%。在5A分子筛成型制备中,扩孔剂焙烧以及黏结剂转晶过程中形成的二次孔有利于减小对正己烷吸附的扩散阻力;5A-1具有较小的中孔平均孔径(3.59nm)、较大的中孔比表面积(484.98m2/g)以及适度的中孔和大孔分布,使其对正己烷的吸附速率较快;5A-1对正己烷的吸附平衡时间近似为5A-2的1/12。
Adsorption performances of 5A molecular sieves （5A-land 5A-2 ） for n-hexane were determined and their structures were characterized. Relationships between adsorption performance of the 5A molecular sieves for n-hexane and their microstructures were investigated. Results showed that relative crystallinity of the self-made 5A-1 with regular crystal grain, n（ SiO2 ） ： n（ Al2O3 ） 1.99 and appropriate surficial acidity was higher than that of 5A-2, which was from Nanjing Inorganic Chemical Plant, and its equilibrium adsorption capacity for n-hexane could reach 0.16 kg/kg at 30 ℃, which increased 24% more than that of 5A-2. The mesopores formed through expanding agent calcination and binder crystal transformation in preparation process of the 5A molecular sieves were beneficial to n- hexane adsorption due to decrease of the diffusion resistance. 5A-1 possessed minor average mesoporous diameter（3.59 nm）, superior specific surface area（484.98 m/g） and appropriate mesomacropore distributions. So adsorption rate of 5A-1 for n-hexane was faster and its equilibrium adsorption time was almost 1/12 of 5A-2.
出处
《石油化工》
CAS
CSCD
北大核心
2010年第7期757-761,共5页
Petrochemical Technology
基金
国家自然科学基金项目(20876074)
关键词
5A分子筛
正己烷
平衡吸附量
孔结构
吸附速率
5A molecular sieve
n-hexane
equilibrium adsorption capacity
pore structure
adsorption rate
