Modelling of Pressure-Driven Membrane Separation of Electrolytes: 'High Temperature' Approximation
Journal of Membrane Science
, E-ISSN: 1873-3123
||Electrolyte separation, Mathematical modelling, Membrane process
Maryasov Alexander G.
Semin George L.
Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
Boreskov Institute of Catalysis, Russian Academy of Sciences, Novosibirsk 630090, Russian Federation
A model of pressure-driven membrane process of electrolyte separation is presented. The electric field potential assumed as being known, exact solution for permeate composition is readily obtained. All species are assumed to have the same convection velocity. Local electroneutrality condition is not used. The electric potential has been taken into account under high temperature approximation, thus reducing the problem to algebraic equation in exp(Ψ), where Ψ is dimensionless flow potential, and making it possible to calculate concentrations of ions in permeate. Negative retention is shown to be possible for one-component electrolyte solution. For electrolyte mixtures, concentration of ion with high charge is shown to “govern” the membrane selectivity in respect to low-charge ions. Results obtained are in qualitative accordance with the earlier experimental data on membrane separation of reaction mixtures in homogeneous catalysis.