C4 olefins including 1,3-butadiene (C4H6), 1-butene (n-C4H8), and isobutene (iso-C4H8) are basic organic raw materials for the production of a variety of synthetic rubbers and chemicals. However, the separation of C4 olefins presents one of the great challenges in hydrocarbon purifications owing to their similar structures and physical properties. It is urgent and desirable to design efficient method to separate C4 olefins. In this talk, we will introduce our recent work on C4 separations with anion-functionalized ionic liquids and metal-organic frameworks. These ionic materials with basic anions as binding sites exhibit different recognition ability for C4 olefin molecules, thus leading to high separation selectivities for C4 olefins. The results present that the basicity and free volume of ionic liquids were positively correlated with the 1,3-C4H6 solubility. Thus, rationally tuning the kinds of anions and cations enabled the highly selective separation of C4H6 and n-C4H8 with a high C4H6 mass solubility. For anion-pillared metal-organic frameworks, altering the kinds of anion pillars and organic linkers endows the materials with different pore size and electronegative properties, resulting in the materials with selective recognition and size-sieving for different C4 olefins. The binding sites of C4 olefins in ionic materials are explored using DFT calculations. This work indicates that the anions are highly selective sites to recognize hydrocarbon molecules with different shape, size and polarity.

Selective Separation of C4 Olefins with ionic materials

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.