A numerical analysis was performed for a separation process of methane using polysulfone hollow fiber membranes which has an excellent separation efficiency for carbon dioxide from its gas mixture of methane and carbon dioxide. Governing equations of cocurrent were thought to be an initial value problem and the nonlinear ordinary differential equations were simultaneously solved using the Runge-Kutta-Verner fifth-order method. Governing equations of countercurrent were regarded to be two point boundary value problem and the nonlinear ordinary differential equation were simultaneously solved using the finite difference method. A computer program was developed using the Compaq Visual Fortran 6.6 software.
Experimental and numerical analysis were performed for separation of carbon dioxide from methane and carbon dioxide gas mixture using a polysulfone hollow fiber membrane. The experimental results were compared with those obtained as the same operating condition by the numerical analysis. It was observed that there was a big difference between the experimental data because the permeance of methane and its ideal selectivity over carbon dioxide that were obtained from the experiment were applied to the fortran program. Therefore, the permeance of methane and its selectivity were obtained from the separation experimental data and these were expressed in a function of both the carbon dioxide pressure and the mole fraction of methane in the gas mixture. The results of the numerical analysis were in good agreement with those of the experimental.
A numerical analysis was performed for a 3-stage membrane process to concentrate methane from gas mixture using the developed program. The process variables were mole fraction of CH4 in feed stream, pressure, area and so on. The results were expressed in terms of the final CH4 purity, recovery, recycle.
When the methane mole fraction of feed, membrane area, feed pressure were decreased and flow rate was increased, the mole fraction of retentate was increased and recovery of CH4 was decreased.
When the feed pressure were increased the recycle ration of methene was increased. To get more increased methane mole fraction and decreased methane recycle, need preprocessing process.