Ca^(2+)交换的几种分子筛的氮氩分离性能

Adsorptive Separation of N_2 and Ar by some Zeolites Exchanged wit h Ca^(2+)

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0.6MPa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.

The 4A,13X and LSX were ion exchanged by Ca 2+ in water solution,and the adsorptio n isotherms and breakthrough curves of these zeo lites were measured at 25℃.The data d emonstrate that the 4A,1 3X and LSX ion-exchanged by Ca 2+ have higher adsorption capacity of N 2 than the original ones,but the adsor ption capacity of Ar for Ca 2+ exchanged zeolites is almost the sam e as that of the original ones.It is clear that these Ca 2+ exchanged zeolites have better adso rption s electivity for N 2 than for Ar.From breakthrough curves it is known that the zeolites have a suitab le pressure for adsorption separati on of N 2 and Ar.In the pressure range we studied,the best pressure is about 0.6 MPa.The adsorption capacities of N 2 and Ar for the gas mixtures can be obtained from the breakthrough curv es.Compared with the adsorption cap acity of pure N 2 and Ar,it can be found that nitrogen in the mixtures has a l a rge effect on the argon adsorption capacity of the zeolites which have hig her adsorption separation selectivity for N 2 and Ar.