In a paper just published in Nature Communications, an international team of researchers present a convenient and energy-efficient method for separating propyne/propadiene mixtures. They take a physisorptive approach using microporous metal-organic frameworks (MOFs). Professor Rajamani Krishna of the Van 't Hoff Institute for Molecular Sciences contributed to the research with his expertise on modelling and simulation of the separation performance.
Selective separation of propyne/propadiene mixture to obtain pure propadiene (allene), an essential feedstock for organic synthesis, remains an unsolved challenge in the petrochemical industry, thanks mainly to their similar physicochemical properties. We herein introduce a convenient and energy-efficient physisorptive approach to achieve propyne/propadiene separation using microporous metal-organic frameworks (MOFs). Specifically, HKUST-1, one of the most widely studied high surface area MOFs that is available commercially, is found to exhibit benchmark performance (propadiene production up to 69.6 cm3/g, purity > 99.5%) as verified by dynamic breakthrough experiments. Experimental and modelling studies provide insight into the performance of HKUST-1 and indicate that it can be attributed to a synergy between thermodynamics and kinetics that arises from abundant open metal sites and cage-based molecular traps in HKUST-1.
Yun-Lei Peng, Ting Wang, Chaonan Jin, Cheng-Hua Deng, Yanming Zhao, Wansheng Liu, Katherine A. Forrest, Rajamani Krishna, Yao Chen, Tony Pham, Brian Space, Peng Cheng, Michael J. Zaworotko & Zhenjie Zhang: Efficient propyne/propadiene separation by microporous crystalline physiadsorbents. Nat Commun 12, 5768 (2021). DOI: 10.1038/s41467-021-25980-y