5A分子筛吸附正己烷的性能及其表征-学兔兔 www.xuetutu.com.pdf

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油化工
2010年第39卷第7期
PETROCHEMICAL TECHNOLOGY
5A分子筛吸附正己烷的性能及其表征
姚小利,杜旭东,刘宗健,崔群,王海燕,姚虎卿
(南京工业大学化学化工学院,江苏南京210009
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(Al2O
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
(3.59m)、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。
关键词]5A分子筛;正已烷;平衡吸附量;孔结构;吸附速率
文章编号]1000-8144(2010)07-0757-05
中图分类号]TQ028.15
文献标识码
Adsorption Performance for n-hexane and Characterization of 5A Molecular Sieves
Yao Xiaoli, Du Xudong, Liu Zongjian, Cui Qun, Wang Haiyan, Yao Huging
College of hemistry and Chemical Engineering, Nanjing University of Technology, Nanjing Jiangsu 210009, China)
Abstract] Adsorption performances of 5A molecular sieves(5a-1 and 5A-2 for n-hexane were
determined and their structures were characterized. Relationships between adsorption performance of
the 5 A 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(Sio,): n(A1,O ) 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 k/k at 30 C, 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 A 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(484.8 m/g)and appropriate meso
macropore distributions. So adsorption rate of 5A-L for n-hexane was faster and its equilibrium
Adsorption time was almost 1/12 of 5A-2
Keywords 5.A molecular sieve; n-hexane; equilibrium adsorption capacity; pore structure
adsorption rate
高纯度正己烷(纯度大于98.5%)是用于化工、烷?,但至今未见有大规模工业化应用。吸附分离
医药和食品等领域的优质溶剂,在制药行业的需求正/异构烷烃技术在提高汽油辛烷值、分子筛脱蜡
量趋增。工业上生产正己烷主要采用精密精馏提供生产烷基苯的直链烃原料8-等方面已得到广
或特殊精馏方法从C。馏分中提取,能粍较高,且较泛应用。中国石化扬子石油化工有限公司开发了
难得到高纯度正己烷。我国目前高纯度正己烷从工业正己烷或C。馏分中通过吸附分离提取高纯
主要依赖进口。
度正己烷的工艺,并研究了相关的吸附剂及其性能。
根据择形吸附原理,利用孔径适宜的吸附剂从
C馏分中选择性吸附正己烷,解吸后可获得高纯度收稿日期】20-01-15:[修改稿日期]200-04-28。
正己烷,该技术具有能耗低、正己烷纯度高等优『作者简介」姚小利(953-),男,陕西省风期县人,博土生,教授级
高级工程帅,电话025-57785755,电邮yaoxi(@ypc.com,cn。联系
点?。20世纪80年代初,美国 Richfield公司报道
人:崔群,电话025-83587188,电邮cuique@njut.edu.cn。
过用吸附法分离C。馏分生产纯度为98%的正已『基金项目』国家自然科学基金项日(098010