Natural gas reservoirs are the most abundant source of helium, despite helium being present only in trace amounts. Membrane technology represents an appealing and potentially cost-effective approach to recover helium from natural gas, consisting mainly of methane. Herein, we demonstrate that chabazite zeolite SAPO-34 membranes can effectively separate equimolar helium/methane mixtures. SAPO-34 membranes displayed helium permeance as high as 2.28 × 10^–7 mol/(m² s Pa) and separation selectivity as high as 13.8 for He/CH₄ mixtures. The separation of this binary mixture was favored through molecular sieving and diffusivity differences. The best SAPO-34 membrane surpassed the Robeson limit upper bound, making these membranes appealing for helium recovery from natural gas.

中文翻译：

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用于He / CH ₄分离的菱沸石沸石SAPO-34膜

尽管氦仅以痕量存在，但天然气储层是氦的最丰富来源。膜技术代表了一种从天然气（主要由甲烷组成）中回收氦气的有吸引力且具有潜在成本效益的方法。在这里，我们证明菱沸石沸石SAPO-34膜可以有效地分离等摩尔氦/甲烷混合物。SAPO-34膜的氦气透过率高达2.28×10 ^–7 mol /（m ² s Pa），对He / CH _4的分离选择性高达13.8混合物。通过分子筛和扩散率差异促进了这种二元混合物的分离。最好的SAPO-34膜超过了Robeson上限，使这些膜对从天然气中回收氦具有吸引力。