Li Xiaoyu, Wu Yue, Wang Shanshan, Zhang Wenxiang, Yang Qing-Yuan, Ma Heping
School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
ACS Appl Mater Interfaces. 2024 Jun 19;16(24):31464-31472. doi: 10.1021/acsami.4c05368. Epub 2024 Jun 5.
One-step He purification from natural gas represents a crucial solution for addressing the global He shortages. The prevailing method to produce high-grade He involves cryogenic distillation and ultralow temperature adsorption processes, which is highly cost- and energy-intensive. Separating and purifying He at ambient temperature is a great challenge because the fundamental limitation lies in the boiling point, polarizability, and kinetic diameters of CH/N/He gases. In this study, we seek to implement a relay adsorption strategy using Ni(ina) and MIL-100(Cr) metal-organic frameworks (MOFs) to produce high-purity He from ternary mixtures (CH, N, and He) at ambient temperature. The CH/He selectivity in Ni(ina) and N/He selectivity in MIL-100(Cr) both reach record 15.39 and 128.49, respectively, making the relay adsorption for helium purification highly efficient. The breakthrough experiments show that the two MOFs can sequentially adsorb CH and N in ternary mixtures, producing He with a purity of up to 99.99% in one step. The remarkable separation performance and stability of these MOFs underscore the industrial potential in purifying He at ambient temperature.
从天然气中一步法提纯氦气是解决全球氦气短缺问题的关键解决方案。生产高纯度氦气的主流方法涉及低温蒸馏和超低温吸附过程，成本和能源消耗都很高。在常温下分离和提纯氦气是一项巨大的挑战，因为根本限制在于CH/N/He气体的沸点、极化率和动力学直径。在本研究中，我们试图采用一种接力吸附策略，使用Ni(ina)和MIL-100(Cr)金属有机框架（MOF）在常温下从三元混合物（CH、N和He）中生产高纯度氦气。Ni(ina)中的CH/He选择性和MIL-100(Cr)中的N/He选择性分别达到创纪录的15.39和128.49，这使得用于氦气提纯的接力吸附非常高效。突破实验表明，这两种MOF可以依次吸附三元混合物中的CH和N，一步法生产出纯度高达99.99%的氦气。这些MOF卓越的分离性能和稳定性凸显了其在常温下提纯氦气的工业潜力。
