1 Membrane Operations for Process Intensification
Process Intensification is an innovative strategy aiming to develop new concepts for redesigning chemical and technological processes, with the aim to reduce production costs, equipment size/productivity ratio, energy consumption and waste generation. The research activity focuses on the design and development of membrane operations potentially of interest in the logic of Process Intensification, on the optimization of materials and operating parameters, and on the implementation of advanced systems for remote control.
2 Integrated Membrane Processes for a Sustainable Growth of Agro-food, Pharmaceutical and Biotechnological industry
The possibility to redesign important production cycles by integrating different membrane operations (already well assessed or still under development), both as separation and reaction units, represents an interesting opportunity because of the synergic effects that can be reached. The research activity concerns the development of innovative membrane contactors units, the energy and exergy evaluation of the integrated schemes, the optimization of the operating conditions, and the evaluation of the process sustainability.
3 Membrane Crystallization and Membrane Emulsification
Membrane crystallizers and membrane emulsifiers represent two of the most recent and promising units in the framework of membrane contactors technology. The goal of the research effort on membrane crystallization is: to prototypize the innovative device for targeted applications, to study the kinetics of nucleation and growth of the crystalline phases, to investigate the influence of fluid-dynamics on the crystal size distribution, shape and purity of the product. Studies on membrane emulsifiers are related to the modelling aspects of the process, the optimization of the morphology and physico-chemical properties of the membranes, the identification of operating parameters allowing to produce stable, micro- and nano-sized monodisperse emulsions.
4. Catalytic membranes and catalytic membrane reactors
Catalysts heterogenization inside membranes constitutes one of the most interesting topics in today’s research, both from industrial and environmental point of view. On this basis, the research activity is focused on the individualization of the optimal conditions for the catalysts heterogenization inside polymeric membranes. These membranes can be employed in catalytic membrane reactors for selective oxidation of organic substrate and for the complete mineralization of pollutants contained in industrial and agricultural effluents. The research study includes: determination of the chemical-physical properties of the catalysts in the new configuration, optimization of the operating parameters for the processes of interest and their modelling.
5. Photocatalytic membrane processes.
Employment of membranes for continuous separation of one or more components from solutions, coupled with the photocatalytic technique method allows to take advantage of the synergy of these two techniques in the photodegradation of various pollutants contained in aqueous solutions. This study concerns: optimization of the chemical-physical properties of the membrane reactors by considering particular model reagents or real effluents; the choice and preparation of photocatalyst (various types of TiO2 polycrystalline catalysts than can contain also photo-sensitizers and additives to increase the photoactivity); test and choice of appropriate polymeric materials stable under irradiations; modelling and construction of laboratory membrane photoreactors; preparation of photocatalytic membranes by using different techniques for the photocatalyst immobilization (in/on various commercial membranes, immobilization in organic and inorganic TiO2 based membranes prepared with different techniques); test and performance optimization of membrane photoreactors under UV-vis radiations with high and medium pressure lamps and/or solar light.
6. Treatment and transformation of gas and liquid streams by polymer based membranes.
The development of membrane processes is hampered today by the modest thermal and chemical resistance of polymers and by their modest intrinsic perm-selectivity. On the other hand, inorganic membranes are poorly reproducible and very expensive.
In order to improve their properties, the best available polymers (permeable, selective, resistant, e.g. polyetherketones, amorphous perfluoropolymers) are mixed with suitable inorganic fillers (e.g. inert or catalytic zeolites). The hybrid membranes are at the same time more permeable and more selective, tolerate solvents and medium-high temperatures. Some examples of the several potential applications are in gas separation (O2/N2, H2/N2, He/H2, etc.), in the treatment of natural gas (dew-pointing, separation of CO2 and H2S, recovery of He), in alkanes/alkenes separations, in the CO2 sequestering from combustion fumes, in the recovery of organic vapours from air, in the separation of water/organic and organic/organic solutions.
7. Membrane processes combined with specifc interactions (Supported Liquid Membranes, Complexation-Ultrafiltration) in treatment of waters.
Use of organic phase soluble complexants (that constitute the key for the transport in liquid membranes, supported of other types) and aqueous phase soluble complexants (mainly macromolecules with specific groups) able to bind ions, permit to facilitate the removal of this last ones by means of membranes with high permeability. Both processes permit to realize the separation, purification and concentration of chemical species (metal ions from wastewaters, some types of biological molecules such as amino acids from fermentation broths, etc.) of wide interest in the chemical and pharmaceutical industries and environmental sector. Aim of the research is the study of the chemical conditions (type of organic solvents and/or their mixtures, pH, concentrations, etc.) that influence the extraction equilibrium; the chemical conditions that determine the separation of the species (extraction and successive release); type of extractant; type of the chemical species that generate the concentration gradient; type of membranes (hydrophobic degree, pore size, membrane configuration, etc.); dependence of the mass flux from the temperature; regeneration techniques and/or membrane stabilization; chemical-physical conditions that give operative stability and maximize the transport velocity; ratio between complexant and various types of diluent; separation factors; transport competition with respect to other species. Other than the experimental part, the mechanisms that control the transport in membranes are studied.
• EU Specific Targeted Research Project (2006-2009) “MEDINA – Membrane-Based Desalination: an Integrated Approach” (6° Programma Quadro - Contratto n. 036997)
• Progetto di Cofinanziamento dei CENTRI DI ECCELLENZA (2003-2007) “CEMIF.CAL – Preparazione e trattamento di materiali a struttura organizzata su scala nanometrica per applicazioni in fotonica, in optoelettronica, in trasformazioni e separazioni (prot. CLAB01TYEF)
• Progetto FIRB (2005-2009) “CAMERE – Nuove membrane catalitiche e reattori catalitici a membrana per reazioni selettive come sistemi avanzati per uno sviluppo industriale sostenibile” (prot. RBNE03JCRS)
• Progetto PRIN (2002-2004) – Area 03, “Studio di membrane e reattori catalitici a membrana in specifici sistemi di interesse” (prot. 2002033184)