物理化学学报 >> 2002, Vol. 18 >> Issue (11): 998-1004.doi: 10.3866/PKU.WHXB20021108

研究论文 上一篇    下一篇

Ca2+交换的几种分子筛的氮氩分离性能

关莉莉;段连运;谢有畅   

  1. 北京大学化学与分子工程学院,物理化学研究所,北京 100871
  • 收稿日期:2002-03-12 修回日期:2002-05-10 发布日期:2002-11-15
  • 通讯作者: 谢有畅 E-mail:yxie@pku.edu.cn

Adsorptive Separation of N2 and Ar by some Zeolites Exchanged with Ca2+

Guan Li-Li;Duan Lian-Yun;Xie You-Chang   

  1. Institute of Physical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871
  • Received:2002-03-12 Revised:2002-05-10 Published:2002-11-15
  • Contact: Xie You-Chang E-mail:yxie@pku.edu.cn

摘要: 采用水溶液离子交换法制备了Ca2+交换的4A、13X和LSX分子筛,并在25 ℃下测定了它们的静态吸附等温线和动态穿透曲线.研究发现, Ca2+交换的4A、13X和LSX分子筛对氮的吸附性能都明显优于其相应的钠型分子筛,而它们对氩的吸附量变化不大,说明Ca2+交换的这三种分子筛是较好的氮氩分离吸附剂.从动态吸附的结果来看,所研究的各种分子筛都有一个最优的吸附分离压力,在本论文研究的压力范围内,这个最优压力在0.6 MPa附近.由穿透曲线可推算出混合气体的吸附量,通过氮和氩在混合气体中的吸附量和相应纯气体吸附量的对比可以得出,对于氮氩吸附选择性较高的分子筛,氮的存在对氩的吸附量有较大的影响.

关键词: 4A分子筛, 13X分子筛, LSX分子筛, 吸附等温线, 穿透曲线

Abstract: The 4A, 13X and LSX were ion exchanged by Ca2+ in water solution, and the adsorption isotherms and breakthrough curves of these zeolites were measured at 25 ℃. The data demonstrate that the 4A, 13X and LSX ion-exchanged by Ca2+ have higher adsorption capacity of N2 than the original ones, but the adsorption capacity of Ar for Ca2+ exchanged zeolites is almost the same as that of the original ones. It is clear that these Ca2+ exchanged zeolites have better adsorption selectivity for N2 than for Ar. From breakthrough curves it is known that the zeolites have a suitable pressure for adsorption separation of N2 and Ar. In the pressure range we studied, the best pressure is about 0.6 MPa. The adsorption capacities of N2 and Ar for the gas mixtures can be obtained from the breakthrough curves. Compared with the adsorption capacity of pure N2 and Ar, it can be found that nitrogen in the mixtures has a large effect on the argon adsorption capacity of the zeolites, which have higher adsorption separation selectivity for N2 and Ar.

Key words: Zeolite 4A, Zeolite 13X, Zeolite LSX, Adsorption isotherm, Breakthrough curve