Comparative Study of Ag⁺-Based Adsorbents Performance in Ethylene/Ethane Separation

Abstract

Four kinds of π-complexation adsorbents are synthesized via ion exchange method or incipient wetness impregnation method with Amberlyst 35, SBA-15, TUD-1, and KIT-6 as supports, and AgNO 3 as active ingredient. The samples are characterized by N 2 adsorption/desorption. Fourier transformed infrared spectroscopies, transmission electron microscopy, X-ray diffraction spectrum analysis, and coupled plasma optical emission spectrometry are also used as adsorbents for ethylene/ethane adsorptive separation. The results show that the specific surface area and the dispersion of silver ions affect the separation performance of the adsorbent. Ag−Amberlyst 35 has the highest ethylene/ethane selectivity among these adorbents while the adsorbed amounts of ethylene of the three mesoporous silica complexation adsorbents are higher. Adsorption thermodynamics analysis suggests that the interaction of ethylene with adsorbent is a mild chemical adsorption. An adsorption kinetics study indicates that the adsorption of ethylene on silver-supported mesoporous materials is not a simple diffusion-control process. The adsorption behavior of ethylene on the π-complexation adsorbent has an energy barrier in the range of 24−33 kJ/mol. Among the adsorbents in this work, the KIT-6-based adsorbent has the best mass kinetic performance due to its three-dimensional regular interconnected mesoporous structure.

A computational study of the interaction of C2 hydrocarbons with CuBTC

“…This leads to a strongly preferred adsorption of the alkene over the alkane. Cation-impregnated amorphous silica materials [7,8] and mesoporous silicas [9,10] as well as zeolites [11,12] have been investigated in this context. Metal-organic frameworks (MOFs) are crystalline hybrid materials that have attracted considerable scientific interest in the last 20 years.…”

Experimental Measurement for Adsorption of Ethylene and Ethane Gases on Copper-Exchanged Zeolites 13X and 5A

“…After the cation exchange process, Na + is replaced by Cu 2+ and this cation binds ethylene molecules by a π-complexation bond, which is related to the main group transition metals. 20,32 According to the data reported in Table 3, the total pore volume and the peak of pore radius are the highest for the CuA sample and this sample has a higher BET surface area than zeolite 5A. Therefore, CuA shows the highest ethane and ethylene uptake.…”

“…Furthermore, the observed better performance of CuA and CuX samples in ethylene adsorption is because of the π-complexation reaction of ethylene and transition-metal ions of Cu. After the cation exchange process, Na + is replaced by Cu 2+ and this cation binds ethylene molecules by a π-complexation bond, which is related to the main group transition metals. , …”

A Thermodynamic Model for Pure and Binary Adsorption Equilibria of N2 and O2 on Lithium-Exchanged Low Silicon-to-Aluminum Ratio X Zeolite

“…Equilibrium measurements of pure and binary adsorption of N 2 and O 2 on LiLSX were performed in a static volumetric apparatus. Details of the pure gas adsorption apparatus appear in the previous publications of Wu et al 45 The pressure was measured with a pressure transmitter (HSTL-800A, precision of 0.02% FS). The temperature difference between the adsorption cell and the reference cell was controlled within ±0.5 K.…”