Efficient separation of ethane and ethylene using an electrically neutral aluminum phosphate zeolite with ultra-microporous structures

Developing ethane (C 2 H 6 )-selective adsorbents is crucial for energy-efficient separation and the direct production of high-purity ethylene (C 2 H 4 ). While pure-silica zeolites show promise, their limited selectivity necessitates the exploration of alternative materials. Herein, we present AlPO 4 -17, an electrically neutral aluminum phosphate (AlPO) zeolite and isostructural analog of pure-silica zeolites. Featuring ultra-microporous structures and low-polarity surfaces, AlPO 4 -17 exhibits denser and stronger C−H···O interactions with C 2 H 6 than with C 2 H 4 . This results in the highest experimentally confirmed C 2 H 6 /C 2 H 4 selectivity (2.27) and C 2 H 6 adsorption heat (36.05 kJ/mol) among all reported C 2 H 6 -selective zeolites. Breakthrough experiments validate its superior C 2 H 6 /C 2 H 4 separation performance. Vacuum pressure swing adsorption (PSA) experiments demonstrate its practical efficiency under real-world conditions, while PSA simulations highlight its potential for enhanced recovery. As the first AlPO zeolite developed for C 2 H 6 /C 2 H 4 separation, AlPO 4 -17 offers valuable insights into the design of advanced C 2 H 6 -selective adsorbents, paving the way for more efficient industrial C 2 H 4 purification processes.