Multiscale screening of metal-organic frameworks for one-step ethylene purification in pressure-swing adsorption processes

Abstract

Purification of polymer-grade (99.9%) C₂H₄ from C₂ hydrocarbon mixture is industrially important but challenging. Cryogenic distillation is energy intensive. Recently, pressure/vacuum swing adsorption (P/VSA) processes using metal-organic frameworks (MOFs) as adsorbents have been attracting increasing attention as an alternative technology. A multiscale hierarchical framework is proposed to select promising MOFs and design suitable P/VSA processes by combining property-based material screening and model-based process optimization. Using this framework, we successfully identified seven promising one-step C₂H₄ purification MOFs that outperformed the benchmark TJT-100 in both C₂H₄ purity and recovery for the 5/90/5 C₂H₂/C₂H₄/C₂H₆ feed mixture. Among them, OFUCAV exhibited the highest C₂H₄ productivity of 0.158 mol/m³/s while JAVTAC demonstrated the lowest energy consumption of 42.76 kWh/tonne. The latter can potentially save 80% of the energy consumption compared to cryogenic distillation. Moreover, these two P/VSA processes show very high robustness in response to composition fluctuations in the feed stream.