High-performance Pebax/UiO-66 thin-film nanocomposite (TFN) membranes for natural gas dehydration

Thin-film nanocomposite (TFN) membranes incorporating metal-organic frameworks have attracted considerable interest in natural gas (NG) dehydration. However, fabricating high-performance TFN membranes remains a major challenge. In the current study, TFN membranes were produced by combining UiO-66 nanoparticles into a Pebax 1657 matrix supported by porous polyacrylonitrile (PAN). Even though the pore size of UiO-66 is bigger than both water and methane molecules, the presence of UiO-66 in the Pebax significantly improved the H 2 O/CH 4 separation performances, which is attributed to a combined mechanism involving molecular sieving and selective affinity, including the potential formation of hybrid interfacial channels with narrowed pore sizes, the framework flexibility of UiO-66, and the strong hydrogen bonding between H 2 O and the Zr–OH clusters that enhances water solubility selectivity over CH 4 . At a UiO-66 loading of 30 wt%, the water vapor permeance rose to 56,725 GPU, alongside an outstanding H 2 O/CH 4 selectivity (29,553), representing an 110% increase in water permeance and a 990% enhancement in H 2 O/CH 4 selectivity compared to the pristine Pebax membrane. This performance exceeds most literature-reported values, furthermore, the H 2 O/CH 4 separation performances were also carried out using the produced water from a natural gas field, excellent stability of the TFN membrane was observed over a 7-day continuous test, marking a significant advance toward practical application. The findings demonstrate that strategically incorporating UiO-66 into a Pebax matrix to form TFN membranes holds immense potential for NG dehydration. Graphic abstract Download: Download high-res image (101KB) Download: Download full-size image