Neutralization of acid and base solutions by Reverse Electrodialysis with Bipolar Membranes: a sustainable way to recover energy

The large amount of acidic wastewaters produced in various industrial processes can have a large economic and environmental impact. Companies producing waste acid solutions have to send them to specific sites for the neutralization with alkaline solutions. However, efforts have been devoted so far to promote the acid recovery or its reuse. In the perspective of a more circular manufacturing approach, the present work proposes for the first time the use of the novel Bipolar Membrane Reverse Electrodialysis technology as a viable on-site way to convert the chemical energy associated to the pH gradient of waste acid/base solutions into electrical energy. Bipolar Membrane Reverse Electrodialysi…

Bipolar membrane (reverse) electrodialysis acid/base flow battery for energy storage: a multi-scale model for increased efficiency

The renewable energy market is rapidly increasing. Most of renewable energy sources are intermittent, e.g. wind and solar among them. This has led to the need for new large scale energy storage systems. In this regard, the Acid/Base Flow Battery (AB-FB) represents an innovative, safe and sustainable way to store energy with high performances [1]. The energy density accumulated in an AB-FB, in the form of pH and salinity gradients, can theoretically reach 7 kWh/m8 which is higher than the values relevant to the most used technologies (e.g. pumped hydropower and compressed air). The core of the battery is the stack where two membrane separation processes are carried out: bipolar membrane elec…

Electrochemically Prepared High-k Thin Films for Resistive Switching Devices

A validated multi-scale model of a novel electrodialytic acid-base flow battery

Electrical energy storage is crucial for a deeper penetration of intermittent renewable energies, e.g. solar and wind. The Acid/Base Flow Battery (AB-FB) is a novel, sustainable, environmental-friendly storage technology with high energy density1. The process is based on reversible electrodialytic techniques that convert the electrical energy in the chemical energy associated to pH gradients and vice versa. The bipolar membrane electrodialysis process operates in the charge phase, while the bipolar membrane reverse electrodialysis in the discharge phase. The stack consists of repetitive units, called triplets, made up of an anion-exchange membrane, a bipolar membrane, and a cation-exchange …

Process modelling of a novel acid-base flow battery based on bipolar-membranes

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,…

Polymeric C3N4 and O-doped C3N4: Photoelectrochemical and EPR Features for Selective Photocatalytic Oxidation of Alcohols to Aldehydes

Polymeric C3N4 and O-doped C3N4: Photoelectrochemical and EPR Features for Selective Photocatalytic Oxidation of Alcohols to Aldehydes

The Effect of Electronic Properties of Anodized and Hard Anodized Ti and Ti6Al4V on Their Reactivity in Simulated Body Fluid

The electronic properties of barrier and porous layers on Ti and Ti6Al4V were studied. Barrier anodic oxides grown to 40 V on Ti and on Ti6Al4V are both n-type semiconductors with a band gap of 3.3 eV and 3.4 eV respectively, in agreement with the formation of amorphous TiO2. Anodizing to 200 V at 20 mA cm−2 in calcium acetate and β-glycerol phosphate disodium pentahydrate leads to the formation of Ca and P containing porous films with a photoelectrochemical behaviour dependent on the metallic substrate. A band gap of 3.2 eV and the flat band potential of −0.5 V vs Ag/AgCl were measured for the porous oxide on Ti, while optical transitions at 2.15 eV and a significantly more positive flat b…

Lab-scale experiments on a novel acid/base electrodialytic flow battery with bipolar membranes

Electrical energy storage has a key role in the development and diffusion of renewable energy technologies. The Acid/Base Flow Battery is an innovative process to store electrical energy in the form of pH and salinity gradients via electrodialytic reversible techniques based on the use of bipolar membranes. During the charge phase, the unit produces acid and alkaline solutions by applying an electric field, during the discharge phase, converts the pH gradient into electrical energy. In this work, several experimental tests were performed in a 10×10 cm2 laboratory-scale unit fed with HCl, NaOH and NaCl solutions, in order to characterize the battery and assess its performance. The effect of …