Gas transport through intrinsic defects and tears is a critical yet poorly understood phenomenon in graphene membranes for gas separation. We report that independent stacking of graphene layers on a porous support exponentially decreases flow through defects. On the basis of experimental results, we develop a gas transport model that elucidates the separate contributions of tears and intrinsic ...

An efficient membrane for helium separation from natural gas is quite crucial for cryogenic industries. However, most experimentally available membranes fail in separating helium from small molecules in natural gas, such as H2, as well as in 3He/4He isotopes separation. Using first-principles calculations, we theoretically demonstrated that the already-synthesized graphitic carbon nitride (g-C3...

Natural gas produced at high pressure (50-70 bar) is the only industrial source of helium (He). A membrane separation process may offer a more efficient production system with smaller footprint and lower operational cost than conventional cryogenic system. Inorganic membranes with high mechanical strength are known to exhibit good stability at high pressure. In this work, two inorganic membrane...

Membrane gas separation has potential for the recovery and purification of helium, because the majority of membranes have selectivity for helium. This review reports on the current state of the research and patent literature for membranes undertaking helium separation. This includes direct recovery from natural gas, as an ancillary stage in natural gas processing, as well as niche applications ...

This study investigates the separation based on adsorption of the binary gas mixture of hydrogen withbiogas (gases: CO2, CH4, O2, N2) and inert gases (gases: He, Ne, and Ar) using single-walled ((7,7), (15,15),(29,29), (44,44), (58,58) and (73,73) SWBNNTs), double-walled ((11,11)@(15,15), (7,7)@(22,22) DWBNNTs)and triple walled ((8,8)@(11,11)@(15,15) and (7,7)@(15,15)@(22,22) ...

in recent years there has been considerable interest in the synthesis and separation of enantiomers of organic compounds especially because of their importance in the biochemistry and pharmaceutical industry. high-performance liquid chromatography is a very useful method for the direct separation of enantiomers. however, about 30−40 years ago, commercially available chiral stationary phases wer...

a r t i c l e i n f o

For the investigation of the plasticizing effect of carbon dioxide on polymers used for gas separation membranes new experimental methods have been developed that measure the sorption kinetics as well as the dilation kinetics. Comparing dilation and sorption kinetics at low and elevated pressures gives information about different types of swelling behaviour depending on the pressure level. Volu...

Membrane technology applied to the separation of gaseous mixtures competes with conventional unit operations (e.g., distillation, absorption, adsorption) on the basis of overall economics, safety, environmental and technical aspects. Since the first industrial installations for hydrogen separation in the early eighties, significant improvements in membrane quality have been achieved in air sepa...