CNT@Cu₃(BTC)₂ and Metal–Organic Frameworks for Separation of CO₂/CH₄ Mixture

Abstract

Effectively separating CO2 from the natural gas, which is one of alternative “friendly” fuels, is a very important issue. A hybrid material CNT@Cu3(BTC)2 has been prepared to separate CO2 from the CO2/CH4 mixture. For comparison of separation efficiency, a series of representative metal–organic frameworks (MOF-177, UMCM-1, ZIF-8, MIL-53 (Al), and Cu3(BTC)2) have also been synthesized by the solvothermal method. Adsorption isotherms of CO2 and CH4 pure gases are measured by Hiden Isochema Intelligent Gravimetric Analyzer (IGA-003). The dual-site Langmuir–Freundlich (DSLF)-based ideal adsorption solution theory (IAST) is used to predict adsorption of each component in the CO2/CH4 mixture. The IAST-predicted results show that the hybrid material CNT@Cu3(BTC)2 exhibits the greatest selectivity among the six materials, and its selectivity keeps in the range of 5.5 to 7.0 for equimolar CO2/CH4 mixture at 1 < p < 20 bar, which is higher than activated carbons. Moreover, the selectivity of CNT@Cu3(BTC)2 for the CO2/CH4 mixture keeps almost no change with the composition of CH4, which is one of the excellent properties as a promising separation material. In short, this hybrid material CNT@Cu3(BTC)2 shows great potential in separation and purification of CO2 from various CO2/CH4 mixtures by adsorptive processes in important industrial systems.

Two stable 3D porous metal–organic frameworks with high performance for gas adsorption and separation

“…48 At zero loading, Q st of CH 4 , C 2 H 6 and C 3 H 8 adsorption is 18, 25 and 44 kJ mol -1 , respectively, as estimated from the sorption isotherms at 273 and 298 K (Fig. [54][55][56] The potential application for the industrially important small hydrocarbon separation is also explored for JLU-Liu18 by IAST. It indicated that the unique cage structures of JLU-Liu18 with medium pore size induce stronger interaction with larger hydrocarbons than the smaller ones.…”

Hierarchically structured metal–organic framework/vertically-aligned carbon nanotubes hybrids for CO2 capture

“…[13][14][15][16] Yang et al 14 prepared carbon nanotube (CNT)/MOF-5 hybrid composite and found that the surface area and the hydrogen storage capacity were signicantly improved compared to pure MOF-5. Xiang et al 17 synthesized the CNT/ [Cu 3 (BTC) 2 ] hybrid via CNT incorporation. The CO 2 and CH 4 uptakes on this composite increased dramatically compared to the unmodied MOFs.…”

The Role of Multiwall Carbon Nanotubes in Cu‐BTC Metal‐Organic Frameworks for CO2 Adsorption

“…However, dramatic mass losses, indicating the breakdown of the framework, were observed at 310–440°C, as shown in Figure . Xiang et al . reported the thermodynamic stability of Cu‐BTC and CNTs@Cu‐BTC up to 200°C.…”