Potential of microporous metal-organic frameworks for separation of hydrocarbon mixtures

In the process industries, the separation of mixtures of hydrocarbons is important both for the preparation of feedstocks and for use as end products. The constituents, hydrocarbons, are either aliphatic or aromatic, saturated or unsaturated, with a large variation in the number of carbon atoms. Using microporous metal-organic frameworks (MOFs), a number of different separation strategies can be employed to achieve the desired separation performance. The strategies include selective binding with the metal atoms of the framework, exploiting differences in molecular packing efficiencies within the ordered pore structures, utilizing selectivities based on the framework flexibility and gate-opening mechanisms, and molecular sieving. Various strategies are discussed in this article, along with perspectives for future research and development for improving the separation performance.