Advances in Separation of Ethylene and Ethane With Molecular Sieve and Metal-Organic Frameworks

In the petroleum industry, there is a great challenge in the ethylene/ethane separation because of their similarities in molecular size and physicochemical properties. Compared with the energy-intensive cryogenic distillation, the adsorptive separation using porous materials (such as molecular sieves) as adsorbents can complete the separation of ethylene and ethane at a normal temperature with a low cost and energy consumption, which is found to be a promising energy-saving alternative. In the past 30 years, molecular sieves and MOFs were widely studied in the adsorptive separation of ethylene/ethane. In this review, the crystal and pore structure, modification methods, main separation mechanism, adsorption and separation properties of ethylene and ethane by molecular sieves and MOFs are summarized. The research shows that the molecular sieve-based adsorbents have high separation selectivity and excellent stability for ethylene and ethane, but their adsorption capacities are not that high. MOFs exhibit excellent adsorption and separation properties for ethylene and ethane owing to their well-defined framework and abundant pore structure. However, there is still much room for improvement in structural stability and separation selectivity of MOFs. According to the advantages of molecular sieves and MOFs in the adsorptive separation of ethylene/ethane, the research trends and development directions in the adsorptive separation of ethylene/ethane are proposed. © 2020, Editorial Office of Acta Petrolei Sinica(Petroleum Processing Section). All right reserved.