NUMERICAL-SIMULATION OF A PARALLEL-PASSAGE PISTON-DRIVEN PSA UNIT

A theoretical model has been developed to simulate the operation of a dual-piston pressure swing adsorption (PSA) system. In contrast to pre vious models for this type of system, the pressure variation is calcul ated directly from the specified movement of the pistons. The predicti ons of the simulation are compared with experimentally observed pressu re profiles under various operating conditions. The model provides a g ood qualitative prediction of the system behaviour, although the exper imental pressure profiles are generally somewhat attenuated relative t o the predicted profiles. At slow speeds there is little phase differe nce between the experimental profiles and the theoretical profiles cal culated assuming local equilibrium, but for faster cycles (>10 rpm) ph ase lags become increasingly evident, suggesting the progressive intru sion of mass transfer resistance. (C) 1998 Elsevier Science B.V.