Air separation sorbents: Mixed-cation zeolites with minimum lithium and silver. (28th April 2019)

• Record Type: Journal Article
• Authors: Epiepang, Franklin E.; Yang, Xiong; Li, Jianbo; Wei, Yuwei; Liu, Yingshu; Yang, Ralph T.
• Is Part Of: Chemical engineering science. Volume 198(2019)
• Page Start: 43
• Page End: 51
• Publication Date: 2019-04-28
• Subjects: Air separation -- Li-LSX -- Mixed-cation zeolites -- LiSr-LSX -- AgCa-LSX; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2018.12.048
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: LSX containing minimum Li and Ag were prepared and evaluated for air separation. ion exchange procedures were designed to miniemize Li + on inaccessible sites. The mixed-cation LSX were compared against pure Li-LSX for air separation by PSA. The mixed cation zeolites show promising performance for replacing Li-LSX. Abstract: Mixed-cation LiSr-LSX, AgCa-LSX and AgSr-LSX containing minimum lithium and silver were prepared by exchanging small fractions of Li + into Sr-LSX and Ag + into Sr-LSX and Ca-LSX. To avoid diffusion of the Li + into the inaccessible sites, the LiSr-LSX sample was exposed to a specifically derived dehydration condition. Similarly, the mixed-silver cation samples were treated to the selected condition post-ion-exchange to allow the Ag + to migrate into SII*. Strong evidences were provided that significant fractions of the exchanged Li + and Ag + remained in SIII and SII* respectively after comparisons of the N2 /O2 adsorption isotherms and isosteric heats of adsorption of the mixed-cation and single-cation samples. Furthermore, the mixed-cation LiSr-LSX, AgCa-LSX and AgSr-LSX samples were compared against the single-cation Li-LSX sample based on their O2 productivity performance via a PSA simulation model.