Gas adsorption is one of the key physical processes that underlie the numerous industrial uses of porous solids. These include separation processes (adsorption and membrane processes), catalytic reactions, energy storage, and gas recovery from unconventional plays. Using innovative pressure/temperature swing adsorption (P/TSA) processes for gas separation has the potential to provide a reduced fingerprint and energy consumption as compared to conventional thermal processes such as distillation or absorption.
Ethane/ethylene and propane/propylene separation are of particular interest because the production of high-purity alkenes is of primordial importance to our current chemical landscape, and exceeds 200 million tonnes per annum. Conventionally, these separations are carried out by industrially well-established technologies based on cryogenic distillation. However, they are extremely energy intensive due to the very similar volatilities.
Adsorption is believed to be a promising option, although most adsorbents have a stronger affinity towards alkenes, which makes it difficult to design a process that delivers the required 99.5% alkene purity. In recent years, a number of adsorbents that have a stronger affinity towards ethane have been discovered, however, it is not clear if these materials could be incorporated in a process that actually delivers the purity specifications at a lower cost as compared to cryogenic distillation.
One PhD scholarship is available, on a competitive basis, for research to develop novel P/TSA processes for the separation of olefin/paraffin mixtures. Thereby, the focus will be on rationalising the trade-off between material and process complexity. Indeed, for conventional materials that are selective to the alkene, more complex process schemes are requires as compared to the case of advanced materials that show a selectivity towards the alkane.
The work will be mostly modelling based, using and further developing in-house detailed mechanistic models to simulate cyclic adsorption processes (Pressure/Temperature Swing Adsorption). The modelling work will be complemented by a small experimental contribution aimed at calibrating and validating the mathematical models. The obtained process solution will be benchmarked in terms of costs against the conventional cryogenic distillation process.
The research will be supervised by Dr Lisa Joss at the School of Chemical Engineering and Analytical Science at the University of Manchester. The project is part of a larger research initiative within the BP-ICAM Kathleen Lonsdale research fellowship of Dr Joss, and it builds on her experience of adsorption separation process modelling and design, and on the novel adsorption imaging technique she has developed.
The successful candidate will learn the fundamentals of adsorption, gain experience in the design of optimal adsorption processes for gas separation, in approaching problems from a systems perspective, and gain experience in the experimental characterisation of gas adsorption systems with conventional and novel techniques. Applicants should have or expect to achieve at least a 2.1 honours degree in Chemical Engineering, Materials Science and Engineering, Mechanical Engineering, or a closely related subject.