Search results for "Ion-exchange membranes"
showing 4 items of 4 documents
Optimization of net power density in Reverse Electrodialysis
2019
Abstract Reverse Electrodialysis (RED) extracts electrical energy from the salinity difference between two solutions using selective ion exchange membranes. In RED, conditions yielding a large net power density (NPD) are generally desired, due to the still large cost of the membranes. NPD depends on a large number of physical and geometric parameters. Some of these, for example the inlet concentrations of concentrate and diluate, can be regarded as “scenario” variables, imposed by external constraints (e.g., availability) or chosen by different criteria than NPD maximization. Others, namely the thicknesses HCONC, HDIL and the velocities UCONC, UDIL in the concentrate and diluate channels, c…
Electrostatic phenomena in ion exchange membranes
1971
Abstract Specific and transport properties of a cation and an anion exchange membrane in Na + and Cl - form respectively have been measured in water and dioxane water mixtures. A greater electrolyte absorption and a lesser specific conductivity and counterion transport number in solvents at higher dioxane content indicate strong electrostatic interactions between fixed groups in the membrane and counterions.
Design of a novel membrane-integrated waste acid recovery process from pickling solution
2019
Abstract Hydrochloric acid pickling is a common practice in steel manufacturing industry. During the process, acid is consumed to dissolve surface oxides and metals ions are accumulated in the solution, which becomes less effective with time. In addition, the costly and risky waste acid disposal is another issue affecting the hot-dip galvanizing industry. In this work, a novel sustainable waste acid recovery process from pickling solutions based on circular approach is proposed to tackle these issues. The innovative system allows (i) the continuous regeneration of pickling solutions to enhance process rate and performance and (ii) minimise the highly expensive and environmentally risky wast…
Thermal potential of ion-exchange membranes and its application to thermoelectric power generation
2016
The low efficiency and high price of thermoelectric semiconductors has generated interest in unconventional forms of thermoelectric materials. In this article, ionic thermoelectricity has been studied with commercial ion-exchange membranes for different aqueous 1:1 electrolytes. The theory of thermal membrane potential has been derived taking into account the ionic heats of transport, the non-isothermal Donnan potentials, the temperature polarization, and the thermally-induced concentration polarization of the electrolyte. Also the generated thermoelectric power has been experimentally studied. The experiments show good agreement with the theory, and suggest ways for systematic improvement …