Simulation of breakthrough curves and a pressure swing adsorption process of air separation

For pressure swing adsorption (PSA) processes, the sharp concentration wavefront is beneficial to the separation of gas mixtures, yet such a phenomenon is difficult to simulate. In this study, a method of lines with cubic spline approximating functions is used to simulate breakthrough curves and a nonisothermoal PSA process with 5A zeolite for separating air, which can bring up a sharp concentration wavefront. In the region the estimated value of the second spatial derivative of approximating function becomes large, extra grid points will be specified to insure enough grid points around concentration wavefront. This method is combined with the integration program LSODE of DSS/2 package. The simulation is compared with experimental data. The results show that this method can reasonably simulate such a PSA system with nonlinear isotherm. (from Authors)