For decades, mankind has been living in a ‘make, take, dispose’ economic model. Fortunately, awareness rises all over the world that serious steps towards more sustainability are a must to guarantee decent life for all. Thanks to this, energy efficiency, electrification, carbon circularity, and minimal liquid discharge have become important chemical industry drivers. Thanks to their inherently energy- and chemical-lean character, as well as flexibility and scalability, membrane processes are fully aligned with these goals. Therefore, membranes are considered a powerful tool, even key enabling technology, for tackling tomorrow’s separation challenges in chemical related industries.

This keynote zooms in on separation challenges related to the recycling of textile, plastics and used lubricant oil, and to the re-use and valorization of lignin-based side streams and kitchen-related waste oils. Nowadays, textile, plastics, used lubricant oils, Kraft lignin, as well as cooking oil or grease trap waste are recycled/valorized only to a limited extent, and, if done, often not in the most energy-efficient way. To motivate more sustainability, and mitigate greenhouse gas emissions, recent legislation calls for far higher recovery and recycling rates of all these types of materials at the end of their service life.

To recover solvents used in textile recycling, virgin polymers from solvent-based plastics mixtures, base lubricant from used lubricating oils, or to purify oxidized Kraft lignin to be used as plasticizer, or kitchen oil/fat usable as non-toxic substrate for fermentation, robust membranes that can cope with high viscosities and work at elevated temperatures near or above 100°C, are required. To address these challenges, tubular polymeric or ceramic membranes, if needed with tailored surface chemistries, are/were deployed, with positive results. This research fits in the EU projects INNOMEM, CUMERI and LigniOx, and the Belgian projects RENOVATE and LIPTYDA. Piloting is/was possible with the latest mobile solvent filtration pilot of VITO, specifically designed to work at high temperatures.