Erlangen Catalysis Resource Center (ECRC), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstr. 3, 91058 Erlangen, Germany.
Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstrasse 3A, 30167 Hannover, Germany.
Molecules. 2018 Apr 11;23(4):889. doi: 10.3390/molecules23040889.
In this study, two zeolitic imidazolate frameworks (ZIFs) called ZIF-4 and ZIF-zni (zni is the network topology) were characterized by sorption studies regarding their paraffin/olefin separation potential. In particular, equilibrated pure and mixed gas adsorption isotherms of ethane and ethene were recorded at 293 K up to 3 MPa. ZIF-4 exhibits selectivities for ethane in the range of 1.5-3, which is promising for continuous pressure swing adsorption (PSA). ZIF-4 shows high cycle stability with promising separation potential regarding ethane, which results in purification of the more industrial desired olefin. Furthermore, both ZIF materials were implemented in Matrimid to prepare a mixed matrix membrane (MMM) and were used in the continuous separation of a propane/propene mixture. The separation performance of the neat polymer is drastically increased after embedding porous ZIF-4 crystals in the Matrimid matrix, especially at higher feed pressures (3-5 barg). Due to the smaller kinetic diameter of the olefin, the permeability is higher compared to the paraffin.
在这项研究中，我们通过吸附研究来表征两种沸石咪唑酯骨架（ZIF），即 ZIF-4 和 ZIF-zni（zni 是网络拓扑结构），以评估它们在烷烃/烯烃分离方面的潜力。具体来说，我们在 293 K 下记录了乙烷和乙烯的平衡纯气和混合气吸附等温线，最高压力可达 3 MPa。ZIF-4 对乙烷的选择性在 1.5-3 范围内，这对于连续压力变换吸附（PSA）来说是很有前景的。ZIF-4 表现出了很高的循环稳定性，对于乙烷具有很好的分离潜力，这可以实现更具工业价值的烯烃的提纯。此外，我们将这两种 ZIF 材料都嵌入到了 Matrimid 中，制备了混合基质膜（MMM），并用于连续分离丙烷/丙烯混合物。在 Matrimid 基质中嵌入多孔 ZIF-4 晶体后，纯聚合物的分离性能大大提高，尤其是在较高的进料压力（3-5 barg）下。由于烯烃的动力学直径较小，其渗透性比烷烃高。
