Olefin/paraffin separation using task-specific materials based on ionic liquids

• Main Author: Goh, Tee Yong
• Published: Queen's University Belfast 2017
• Subjects: 660
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.726635

The separation of light olefins/paraffins, which is one important process in industry, is usually carried out using cryogenic distillation that heavily depends on the difference of the various components’ boiling points and volatilities. Nevertheless, the close boiling point between an olefin and its corresponding paraffin is an absolute challenge for this process, and hence low temperature (e.g. -13 to -30 °C) and high pressure (e.g. 20-25 bar) are required. It is therefore energy intensive, resulting high cost for the separation processes (e.g. more than $500 million for ethylene unit). Thus, the aims of this project are not only to discover alternative methods to separate light olefin and paraffin mixtures, but also to substitute the conventional energy and cost intensive separation process.The selected alternatives must have the ability to achieve high selectivity in the olefin/paraffin separation, and, more importantly, consume less energy and have lower costs compared to the traditional methods used in industry (e.g. distillations). As a result, in this project ionic liquids are studied in order to improve the separation process of olefin/paraffin thanks to their ability to selectively solubilise olefins. Transition metals such as silver, which is able to form electron donor/acceptor complexes with olefins have also been chosen to be investigated, with the intention of improving the selectivity of the separation. It is important that an alternative technology will focus on solving present existing dilemma of separation processes; which are the issues of operating temperature and pressure, solvent losses as well as the stability of the chosen transition metal.