A comprehensive investigation was conducted to explore the adsorption behaviors of CH over N on ultra-microporous Al/Zr-FDCA frameworks, which were synthesized specifically using the eco-friendly and bio-sourced 2,5-furandicarboxylic acid (FDCA). Characterization results revealed that both Al-FDCA and Zr-FDCA exhibited similar specific surface area and surface groups, leading to comparable methane uptake per-unit mass at atmospheric pressure. However, the presence of Zr nodes generated ultra-micropores around 0.43 nm in size, leading to a pronounced affinity for CH. Zr-FDCA demonstrated a higher CH/N selectivity (8.90) calculated from the isotherms compared to Al-FDCA (3.86). Furthermore, breakthrough experiments indicated that under the same dynamic conditions, Zr-FDCA exhibited 1.5 times higher CH uptake per unit volume and 2.5 times higher CH/N selectivity when compared to Al-FDCA. Initially, a four-step VPSA process was simulated to investigate the separation of CH/N mixture, in which the effects of feed-gas flow rate, adsorption time, adsorption pressure, and desorption pressure in VPSA cycle were extensively evaluated to enhance the purity and recovery of methane. Subsequently, a six-step process was employed for further optimization, achieving a purity of 95.9 % and a recovery of 99.1 %. The obtained results demonstrated the reliability of the established model and highlighted the significant potential of Zr-FDCA for CH/N separation.

中文翻译：

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使用实验和数值方法评估超微孔 FDCA 基 MOF 的 CH4/N2 分离性能

进行了全面的研究，以探索超微孔 Al/Zr-FDCA 框架上 CH 对 N 的吸附行为，该框架是使用环保且生物来源的 2,5-呋喃二甲酸（FDCA）专门合成的。表征结果表明，Al-FDCA 和 Zr-FDCA 均表现出相似的比表面积和表面基团，导致在大气压下每单位质量的甲烷吸收量相当。然而，Zr 节点的存在产生了尺寸约为 0.43 nm 的超微孔，导致对 CH 具有明显的亲和力。根据等温线计算，Zr-FDCA 表现出比 Al-FDCA (3.86) 更高的 CH/N 选择性 (8.90)。此外，突破性实验表明，在相同的动态条件下，与 Al-FDCA 相比，Zr-FDCA 单位体积的 CH 吸收量高出 1.5 倍，CH/N 选择性高出 2.5 倍。最初，模拟了四步 VPSA 工艺来研究 CH/N 混合物的分离，其中广泛评估了 VPSA 循环中原料气流量、吸附时间、吸附压力和解吸压力的影响，以提高纯度和甲烷的回收。随后，采用六步工艺进一步优化，纯度达到95.9%，回收率达到99.1%。所得结果证明了所建立模型的可靠性，并突显了 Zr-FDCA 在 CH/N 分离方面的巨大潜力。