Management of Energy Conversion Processes in Membrane Systems

The internal energy ( U -energy) conversion to free energy ( F -energy) and energy dissipation ( S -energy) is a basic process that enables the continuity of life on Earth. Here, we present a novel method of evaluating F -energy in a membrane system containing ternary solutions of non-electrolytes based on the K r version of the Kedem–Katchalsky–Peusner (K–K–P) formalism for concentration polarization conditions. The use of this formalism allows the determination of F -energy based on the production of S -energy and coefficient of the energy conversion efficiency. The K–K–P formalism requires the calculation of the Peusner coefficients K i j r and K d e t r ( i , j ∈ {1, 2, 3}, r = A, B), which are necessary to calculate S -energy, the degree of coupling and coefficients of energy conversion efficiency. In turn, the equations for S -energy and coefficients of energy conversion efficiency are used in the F -energy calculations. The K r form of the Kedem–Katchalsky–Peusner model equations, containing the Peusner coefficients K i j r and K d e t r , enables the analysis of energy conversion in membrane systems and is a useful tool for studying the transport properties of membranes. We showed that osmotic pressure dependences of indicated Peusner coefficients, energy conversion efficiency coefficient, entropy and energy production are nonlinear. These nonlinearities were caused by pseudophase transitions from non-convective to convective states or vice versa. The method presented in the paper can be used to assess F -energy resources. The results can be adapted to various membrane systems used in chemical engineering, environmental engineering or medical applications. It can be used in designing new technologies as a part of process management.