Production of membranes using green, safe and sustainable alternative solvents

A major trend in current chemical engineering is the design (or re-design) of processes in ways that are less environmentally harmful. Most of the industrially relevant membrane polymer-solvent systems use organic solvents with inadequate environmental, health and safety (EHS) profiles. Current “solvent workhorses” of the membrane manufacturing industry such as dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), dimethylformamide (DMF) and trichloroethylene (TCE), have been recently classified as substances of very high concern by the European Chemicals Agency. There is thus a pressing need to reduce or eliminate environmentally harmful solvents from membrane production processes. In fact, the negative environmental impact of the synthesis may even offset eventual environmental gains that arise from using membrane technology. This research project aims to develop polymer membranes produced via “green” polymer solutions. The selection of acceptable alternative solvents will follow a “holistic” approach that will take into consideration both experimental data and molecular simulations.

In a first stage, a pre-screening of available “green” solvents will be performed by comparing their physical properties to those of the original solvents that must be replaced. A reduced number of solvents coming from the pre-screening will be tested using molecular simulations of the precursor polymer materials (used to synthesize the membrane) in each candidate solvent, with the aim of identifying the best systems under more realistic conditions. Finally, the chosen replacement solvents will be tested in the laboratory in real membrane synthesis processes. The aim is to propose replacement formulations for the most widely produced membrane materials, so as to obtain products that perform as well (or even better) than commercial ones made using environmentally harmful compounds. As a final step of the project, a full life-cycle analysis (LCA) will be carried out on a selected membrane application (e.g. carbon capture, production of drinking water or protein concentration), taking into account not only the separation process, but also the membrane production itself.

In addition to undertaking cutting edge research, students are also registered for the Postgraduate Certificate in Researcher Development (PGCert), which is a supplementary qualification that develops a student’s skills, networks and career prospects.

Information about the host department can be found by visiting:

www.strath.ac.uk/engineering/chemicalprocessengineering

www.strath.ac.uk/courses/research/chemicalprocessengineering/