z-logo
Premium
Rational Synthesis of Chabazite (CHA) Zeolites with Controlled Si/Al Ratio and Their CO 2 /CH 4 /N 2 Adsorptive Separation Performances
Author(s) -
Guo Ya,
Sun Tianjun,
Gu Yiming,
Liu Xiaowei,
Ke Quanli,
Wei Xiaoli,
Wang Shudong
Publication year - 2018
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201800930
Subject(s) - chabazite , zeolite , selectivity , adsorption , chemistry , crystallization , equilibrium constant , molecular sieve , inorganic chemistry , catalysis , organic chemistry
Separation of CO 2 from CH 4 and N 2 is of great significance from the perspectives of energy production and environment protection. In this work, we report the rational synthesis of chabazite (CHA) zeolites with controlled Si/Al ratio by using N , N , N ‐trimethyl‐1‐adamantammonium hydroxide (TMAdaOH) as an organic structure‐directing agent, wherein the dependence of TMAdaOH consumption on the initial Si/Al ratio was investigated systematically. More TMAdaOH is required to direct the crystallization of CHA with higher Si/Al ratio. Once the product Si/Al ratio is larger than 24, the amount of TMAdaOH consumption remains nearly constant. CHA zeolites with different Si/Al ratios and charge‐compensating cations were then applied for the separation of CO 2 /CH 4 /N 2 mixtures. The equilibrium selectivities predicted by ideal adsorbed solution theory (IAST) and ideal selectivities calculated from the ratio of Henry's constants for both CO 2 /CH 4 and CO 2 /N 2 decrease with the zeolite Si/Al ratio increasing, whereas the percentage regenerability of CO 2 presents the opposite trend. Therefore, there is a trade‐off between adsorption selectivity and regenerability for the adsorbents. There is a weaker interaction between CO 2 molecules and the H‐type zeolites than that on the Na‐type ones, thus a higher regenerability can be achieved. This study indicates that it is possible to design CHA zeolites with different physicochemical properties to meet various adsorptive separation requirements.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here