Perturbation solution of hollow-fiber membrane module for pure gas permeation

This study presents an analytic solution for permeation of a pure gas in a hollow-fiber module, based on regular perturbation method. It is assumed that pressure drop due to frictional loss should be proportional to velocity, and that mass transfer be mainly convective with the permeation through the fiber membrane. Four governing equations are characterized by five parameters depending on the design specifications and operating conditions of the module. When the parameter characterizing pressure drop is small, regular perturbation method is capable of providing the analytic solution. Compared with numerical simulation, the analytic solution is found to be sufficiently precise when the parameter is far less than the other parameters characterizing the mass transfer and pressure difference between permeate and reject streams. (C) 1998 Elsevier Science B.V.