Search results for "IMPIANTI"
showing 10 items of 797 documents
A multi-physics modelling tool for Reverse Electrodialysis
2015
In this work, a multi-physics modelling approach has been developed for the RED process.
Numerical simulations supporting process models of chemical engineering: applications for membrane systems
2019
This work presents computational fluid dynamics simulations aimed at characterizing flow and mass/heat transport mechanisms in spacer-filled channels for membrane processes, with particular reference to (reverse) electrodyalisis and membrane distillation.
CFD simulation of Electrodialysis channels equipped with profiled membranes
Electrodialysis (ED) is a membrane-based electrochemical process that remove ions from a solution. The main use of ED is for the production of drinking water by brackish water desalination, but there are several other applications. ED is characterized by the coexistence and the interaction of different physical phenomena that affect the stack performance. Among them, fluid dynamics and mass transport are crucial: concentration polarization affects the limiting current density and the non-Ohmic voltage drop due to the chemical potential difference between the two solutions; pressure drop affects the pumping power consumption. Moreover, the total energy consumption depends also on the Ohmic v…
Experimental assessment of the mixing quality in a circular cross-sectional t-shaped mixer for the precipitation of sparingly soluble compounds
2021
Precipitation processes have been successfully proved to be a feasible route to extract high-value products from wastes. However, reactive crystallization is characterized by fast kinetics, especially when highly concentrated solutions are used or sparingly soluble compounds precipitate, thus requiring a fast mixing of the reactants. In this context, T-shaped mixers have been extensively investigated both experimentally and numerically as a mean to achieve a rapid reactants homogenization. Many research efforts have been focused on the analysis of rectangular cross-sectional T-shaped mixers, while less attention has been devoted to the study of circular cross-sectional ones. In the present …
Modelling hybrid systems for seawater desalination: electromembrane processes (RED, ARED and ED) coupled with RO
2018
The need to reduce energy consumption in seawater reverse osmosis processes has pushed research towards the development of new hybrid systems in which, for example, other membrane processes can be used to pre-treat seawater. Electrodialysis and reverse electrodialysis can act as a dilution step before seawater enters the RO unit, thus leading to an important energy saving in RO. In this work, two coupled models are proposed for the RED-RO and ED-RO system. Each process model was validated before being used for a sensitivity analysis in which the effect of the integration on the cost saving in the overall process was assessed. The analysis was performed by changing (R)ED voltage and RO press…
Process modelling of a novel acid-base flow battery based on bipolar-membranes
2021
The storage of electrical energy is crucial for a deeper penetration of renewable energies with intermittent nature, e.g. solar and wind energy. The Acid/Base Flow Battery (AB-FB) is a novel, sustainable, environmental-friendly storage technology with high energy density of the electrolyte solutions. The process is based on reversible electrodialytic techniques with bipolar membranes, which convert the electrical energy in the chemical energy associated to pH gradients and vice versa. The charge phase is a bipolar membrane electrodialysis process, while the discharge phase is a bipolar membrane reverse electrodialysis process. The stack consists of several repetitive units, called triplets,…
Reverse electrodialysis: Applications
2016
Reverse electrodialysis (RED) technology has grown significantly in the last decade, gaining a fast increase in its technology readiness level and presenting some interesting examples of RED pilot systems operating under very different real environments. In this chapter, an overview of technological developments and piloting examples are reported. In particular, a short introduction is given on the historical trend of RED technology growth, followed by a careful analysis of which feed solutions can be adopted and how these can affect the process performance, potentials, and applications. Most prominent fluid dynamics aspects for the RED process are presented, highlighting how these can infl…
Particle distribution in unbaffled stirred vessels
2017
The present work is devoted to providing an insight into the solid-particle distribution within top-covered unbaffled stirred tanks via purposely collected local experimental data. Experiments were carried out on a lab- scale unbaffled stirred tank by making use of a recently introduced technique named Laser Sheet Image Analysis (LSIA). In its original formulation, the technique includes an image post-processing procedure to delete reflection effects on results. In the framework of the present work, a method combining the use of purposely produced fluorescent particles and a suitable camera high pass filter was devised and presented. Results collected with (new method) and without (old fash…
ASSESSMENT OF THE MINIMUM POWER REQUIREMENTS FOR COMPLETE SUSPENSION IN TOP-COVERED UNBAFFLED STIRRED TANKS
2012
A parametric CFD study of hollow fiber membrane modules for hemodialysis
2022
Hemodialysis is a membrane-based process in which solute transport from the patient’s blood to a rinsing solution (dialysate) occurs by diffusion and ultrafiltration. Devices used in hemodialysis are cylindrical modules filled with hollow-fiber membranes which allow the removal of toxic substances and metabolic wastes from the blood, but inhibit the passage of proteins and cells to the dialysate. A predictive porous-media model of hemodialysis was developed and validated against experimental data. Unlike previous literature models, it requires only basic membrane properties (hydraulic and diffusive permeabilities and reflection coefficients) instead of relying on empirically adjusted global…