کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6588704 | 1423241 | 2018 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Heats of adsorption on mixed-cation LiNa-LSX: Estimating SIII site occupancy by Li
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
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چکیده انگلیسی
Li-LSX (low silica type-X) zeolite is the sorbent of choice for air separation by adsorption today. Li-LSX is obtained by ion exchange of Na-LSX. The occupancy of Site III (SIII, which is the open site in the supercage) by Li+ is crucially important for N2 adsorption. In this work, mixed-cation LiNa-LSX zeolites were prepared and N2 adsorption isotherms were measured. The isosteric heats of adsorption of N2 were obtained from the temperature dependence. The heats of adsorption remained at approximately 17.7â¯kJ/mol (i.e., that for pure Na-LSX) at Li+ exchange below approximately 70%, and increased upon further increase in Li+ exchange, to 22.6â¯kJ/mol (i.e., that for pure Li-LSX). The increase was not linear (i.e., concave shaped), however, which indicated that one N2 molecule could likely adsorb on two adjacent cation sites. The relationship between heat of adsorption and Li ion occupancy on site SIII was obtained. It is suggested that this relationship may be used to estimate the occupancy by Li+ on SIII of faujasite type of zeolites.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Engineering Science - Volume 178, 16 March 2018, Pages 194-198
Journal: Chemical Engineering Science - Volume 178, 16 March 2018, Pages 194-198
نویسندگان
Xiong Yang, Franklin E. Epiepang, Yingshu Liu, Ralph T. Yang,