MOFs for Deep Dehydration of Ethylene: Screening, Design and Process Simulation

Abstract

Ethylene (C₂H₄) purification is a critical step in various industrial processes. In particular, during the ethanol dehydration process to produce ethylene, efficient removal of water is essential to prevent blockages in the low-temperature distillation systems used for ethylene separation. In this study, we utilized the Grand Canonical Monte Carlo (GCMC) method to calculate the adsorption and separation behaviors of ethylene/water in 508 types of MOFs from the CoRE MOFs database. Among them, the LEGGIO was identified as a promising adsorbent due to its simple synthesis process and high water adsorption capacity, which was found to be 16.19 mol/kg. Based on LEGGIO, we explored the impact of functional group modification on the water adsorption performance. The results show that the introduction of hydrophilic N sites enhances the interaction between water and the material, thereby leading to an increase in the saturated water adsorption capacity of the modified LEGGIO-N. The temperature and pressure swing adsorption process with LEGGIO-N as adsorbent was further built. Under the optimal process conditions, the H₂O concentration at the outlet is less than 1 ppm, which satisfies the purity requirements for industrial ethylene production.