Alma Mater Studiorum University of Bologna (UNIBO) contributes to MERLIN with the effort of researchers belonging to the Department of Chemistry “G. Ciamician”, operating mainly in the Ravenna Campus in the Environmental Sciences Lab “R. Sartori” (https://site.unibo.it/greenchemistry/en). The team is composed of organic chemists and environmental scientists with strong expertise in Green and Sustainable chemistry, with a special focus on the valorization of biomass and waste with alternative solvents and innovative protocols.
In the MERLIN project, UNIBO has the leadership of Task 2.3, thus the goal of developing processes to recover both high-quality polymer and aluminium from metalized multilayer flexible packaging.
Multilayer packaging systems are highly versatile materials largely exploited in the food industry as aseptic packaging for various goods. With the increase in the number of their everyday-life applications, the volume and typology of these laminated products in municipal solid waste have continuously increased and their recyclability has become an environmental and socio-economical issue. These composite materials are made of several laminated layers that can include paper, aluminium and polymers of different compositions (olefins and/or PET) for making the packaging impermeable and for preventing the contact of food with the aluminium layer. Their recycling is thus a big challenge in the circular economy vision.
The separation of layers in multi-layer metalized packaging materials is being developed in mild conditions by UNIBO through a process based on three fundamental steps: 1) dissolution or delamination of polymeric layers; 2) separation and recovery of aluminium and polymers; 3) recycling of the solvents and additives. UNIBO is investigating the use of lipophilic biobased solvents together with the use of innovative Switchable Hydrophilic Solvents and Surfactants (SHS and SAS), compounds that exploit the use of CO2 as a trigger to reversibly switch their properties, facilitate the separations, and bypass some energy-intensive steps that characterize many syntheses and processes. In comparison to traditional solvents or additives applied so far in the separation of layers in multi-layer materials on a lab-scale, the switchable ones offer undeniable advantages, since the recycled polymer and the solvent can be separated by applying CO2 as a polarity-modifier instead of by solvent evaporation. In this first year of the MERLIN project, UNIBO researchers have developed and optimized the methods, collecting samples and characterizing the recycled materials. The next steps will be the scale-up of the process and the strong interaction with partners dealing with upstream (waste material sorting) and downstream (monomers and polymers recycling) processes.
UNIBO: the MERLIN Research Team
Since its origins in 1088, Alma Mater has been research and student-centred hosting prominent figures from science and the arts. Based in five campuses (Bologna, Cesena, Forli, Ravenna, and Rimini) it offers a teaching catalogue diversified and tailored to the needs of present-day society: over 200 degree programmes among its 32 Departments and 11 Schools are offered to over 81,000 students. As a comprehensive research university, Alma Mater invests in the multidisciplinary cross-cultural approach and in the inseparable connection between research and teaching.
The Department of Chemistry “Giacomo Ciamician” is within the University a community of over 100 researchers who, thanks to their high skills in all areas of chemistry, have the mission of creating scientific culture through basic and applied research, its promotion and diffusion both through didactic activities and with a strong relationship of comparison and exchange with society and the business world. The Department has a long tradition of excellence in teaching, research and technology transfer in all sectors of the Chemical Sciences.
The Green Chemistry Lab is located in the Ravenna Campus. The research group deals with sustainable chemistry, the main activity is the characterization and synthesis of organic molecules, using more sustainable methods and technologies. The focus is on the use of renewable starting products or waste from a circular economy perspective, using alternative solvents and sustainable processes also from an energy point of view. The added value is to carry out these researches within the Environmental Sciences Laboratories, thus managing to combine the specialized synthesis and characterization techniques typical of organic chemistry with a multi and interdisciplinary approach more aimed at assessing the impact of products and processes on the environment.
