Numerical algorithm for modelling multicomponent multipermeator systems

The presented algorithm allows calculation of multicomponent gas separation in hollow-fibre membrane modules in co-current, counter-current and cross-flow configurations. The permeators can be combined in any system with recycles. The algorithm is based on the finite difference Gauß–Seidel method. The solution of the system can be stabilised by means of adaptation of the relaxation factor in case of difficulties with convergence. The performance of the algorithm was evaluated in terms of the required number of iterations and computational time for a number of single permeator and multipermeator separation problems. The counter-current configuration with component gases having high selectivities required the most computational time.

The permeation of a biogas-like gas mixture consisting of three components: methane, carbon dioxide and oxygen was modelled and compared with an experiment. The results of the modelled gas separation were found to be in good agreement with the measured values. The highest performance was achieved by the counter-current configuration.