Sustainable membrane fabrication: contribution of biobased and/or biodegradable polymers

Separation stages in industrial processes account for 10-15% of global energy consumption and 60-80% of the costs of chemical and biotechnological industrial processes . It is therefore of the utmost importance to develop more energy- and cost-efficient separation processes.

Membrane processes have emerged as promising solutions for process intensification, and have already demonstrated their ability to achieve cleaner, more energy-efficient separations than conventional technologies (e.g. distillation or evaporation). These technologies have made their mark in the water treatment sector (potabilization, wastewater treatment and seawater desalination), in the medical (kidney dialysis) and biopharmaceutical (vaccine production) sectors, and in the agri-food sector (dairy industry in particular).

The term "membrane process" covers all separation techniques based on the use of a "membrane". This can be defined as a thin layer of material (usually a polymer), semi-permeable or selectively permeable, capable of separating different compounds according to their chemical and/or physical properties under the action of a driving force.

Although considered sustainable, almost all of these techniques require the use of membranes produced from non-biodegradable petrosourced polymers. In a context of transition to the use of renewable resources and a desire for better end-of-life management of materials, numerous initiatives are emerging to offer an alternative to these polymers for membrane manufacture.

The aim of this article is to provide an overview of the different biobased or biodegradable polymers that can be used to manufacture membranes for liquid phase separations. After a brief introduction to membrane processes and manufacturing, the different polymer families that can be used will be presented with regard to their applications in membrane manufacture. Their advantages and disadvantages will be highlighted and discussed in relation to these applications. In particular, the potential and limitations of biobased or biodegradable polymers for industrial-scale membrane production will be discussed where possible. Finally, in a concluding section, the main efforts still to be made towards more sustainable...