B.2 Modelling and simulation of membrane-based separation processes

In recent years membrane-based separation systems have been employed successfully for a number of gas and liquid separation tasks. Besides end-of-pipe installations, membrane systems are more and more used as part of a complex flowsheet in combination with other unit operations. If the boundary conditions are in favour of a membrane system, a membrane plant offers several advantages because of its modular structure, low energy consumption and ease of operation. Membrane modules are generally not included in commercial process simulators as standard unit operations. The objective of this project is to develop mathematical models for membrane-based separation processes. Two separation processes have been considered: gas separation and liquid separation by membrane distillation.
A mathematical model for membrane gas separators operated in co-, counter- or crosscurrent flow mode has been developed. The model consists of differential material balance equations and optionally differential pressure drop equations on both sides of the membrane. Furthermore, the non-ideality of the gas phases can be taken into account via an equation of state. For membrane distillation, a rate-based model has been developed for the co-current flow mode.
Current and future work includes testing of the developed algorithm against industrial problems (gas separation) and against known case studies (liquid separation by membrane distillation).
Professor Michael L. Michelsen, KT-DTU and Professor Gunnar Johnson, KT-DTU are collaborating partners in this project.