间二甲苯在KX和CaX上的吸附平衡和动态吸附性能.pdf

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2012年第31卷第10期
CHEMICAL INDUSTRY AND ENGINEERING PROGRESS
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研究开发
对二甲苯/间二甲苯在KX和CaX上的吸附平衡和动态吸附性能
陈乐,张致慧,陈群,何明阳
(常州大学石油化工学院,江苏省精细石油化工重点实验室,江苏常州213164
摘要:通过静态吸附实验,测定了对二甲苯、间二甲苯在分子筛KX和CaX上的吸附速率曲线及吸附等温线
动态吸附穿透实验测定了对二甲苯/间二甲苯混合液在固定床中的连续流出曲线。结果表明,对二甲苯、间二甲
苯在CaX上的静态饱和吸附量和动态穿透吸附量均高于KX,但CaX对对二甲苯的吸附选择性不及KX; Langmuir
吸附等温绒方程可以很好地拟合对二甲苯、间二甲苯在CaX上的等温线;二级吸附速率方程可以较好地描述对
二甲苯、间二甲苯的吸附动力学行为
关键词:对二甲萃;间二甲苯;KX;CaX;吸附平衡;动态吸附
中图分类号:TQ028
文献标志码:A文章编号:1000-6613(2012)10-2167-06
Adsorption equilibrium and dynamic adsorption of xylene isomers on KX
and Cax zeolites
CHEN Le, ZIANG Zhihui, CHEN Oun, HE Mingyang
(Key Laboratory of Fine Petrochemical Engineering, School of Petrochemical Engineering, Changzhou University
Changzhou 213164, Jiangsu, China)
Abstract: Adsorption rate curves and isotherms of p-xylene, m-xylene on K X and Cax zeolites were
obtained by conducting static adsorption experiments. The breakthrough curves of p-xylene/m-xylene
mixture adsorption on zeolites were obtained by conductin dynamic adsorption experiment. The results
showed that static and dynamic adsorption capacities of the xylene isomers on Cax were higher
compared to the adsorption capacities on KX. And the separation factor of the xylene isomers on Cax
were lower than that on KX. The results indicated that the isotherms of xylene isomers on Cax were
consistent with Langmuir isotherm equation and the adsorption kinetic data of zeolites adsorption fitted
well with the pseudo-second-order rate equation
Key words: p-xylene m-xylene KX; Cax; adsorption equilibrium; dynamic adsorption
エ业中混合二甲苯的来源主要集中于从石油催化前常用的分离对二甲苯与间二甲苯的方法,根据
重整中抽提、煤焦油中以及甲苯催化岐化制取。这3混合二甲苯分子尺寸的差异(对二甲苯尺寸5.9A,
种异构体对二甲苯(PX)、间二甲苯(MX)和邻二甲间二甲苯尺寸6.8A,1A=10-10m),选择合适孔径
苯(OX)均是重要的化工基础原料,可以进一步合成的分子筛吸附剂,利用分子筛的空间位阻效应,实
下游产品,如对二甲苯是最大用量的C8芳烃,是聚酯现二甲苯异构体的分离。具有代表性的PX吸附工
T业的重要原料リ,因此分离提纯二甲本异构体具有重艺为美国UOP公司的 Parex工艺,所选吸附剂Ba
要意义。目前主要的分离方法有吸附法2的、膜分离或K、Ba交换的X或Y分子筛,该工艺生产PX
法?、冷冻结晶法、吸附结晶集成分离法?等
占全球市场份额的90%以上0tリ
混合二甲苯中3种异构体密度接近、沸点相差
很小,特别是对二甲苯与间二甲苯的沸点仅相差
收稿日期:2012-04-09;修改稿日期:2012-05-29。
第一作者及联系人:陈乐(1981ー),女,博士,讲师。 E-mail
0.75℃,用传统的精馏方法很难分离,吸附法是目 henle_199o163,com