abstract
The separation of ethylene from ethane is one of the most energy-intensive single distillations practiced. This separation could be alternatively made by an adsorption process if the adsorbent would preferentially adsorb ethane over ethylene. Materials that exhibit this feature are scarce. Here, we report the case of a metal-organic framework, the IRMOF-8, for which the adsorption isotherms of ethane and ethylene were measured at 298 and 318 K up to pressures of 1000 kPa. Separation of ethane/ethylene mixtures was achieved in flow experiments using a IRMOF-8 filled column. The interaction of gas molecules with the surface of IRMOF-8 was explored using density functional theory (DFT) methods. We show both experimentally and computationally that, as a result of the difference in the interaction energies of ethane and ethylene in IRMOF-8, this material presents the preferential adsorption of ethane over ethylene. The results obtained in this study suggest that MOFs with ligands exhibiting high aromaticity character are prone to adsorb ethane preferably over ethylene.
keywords
METAL-ORGANIC FRAMEWORKS; POROUS MATERIALS; CARBON-BLACK; MIXTURES; SIMULATION; STORAGE; CLAYS; ZIF-7; GAS
subject category
Science & Technology - Other Topics; Materials Science
authors
Pires, J; Pinto, ML; Saini, VK
our authors
Groups
acknowledgements
We acknowledge the financial help from Fundacao para a Ciencia e Technologia (FCT; Portugal) to CQB and strategic project PEst-OE/QUI/UI0612/2013. M.L.P. acknowledges the IF contract IF/00993/2012/CP0172/CT0013 and FEDER, QREN, COMPETE for funding PEst-C/CTM/LA0011/2013.