Hydrolytically stable fluorinated metal-organic frameworks for energy-efficient dehydration

Natural gas must be dehydrated before it can be transported and used, but conventional drying agents such as activated alumina or inorganic molecular sieves require an energy-intensive desiccant-regeneration step. We report a hydrolytically stable fluorinated metal-organic framework, AlFFIVE-1-Ni (KAUST-8), with a periodic array of open metal coordination sites and fluorine moieties within the contracted square-shaped one-dimensional channel. This material selectively removed water vapor from gas streams containing CO2, N-2, CH4, and higher hydrocarbons typical of natural gas, as well as selectively removed both H2O and CO2 in N-2-containing streams. The complete desorption of the adsorbed water molecules contained by the AlFFIVE-1-Ni sorbent requires relatively moderate temperature (similar to 105 degrees C) and about half the energy input for commonly used desiccants.