Because of some disadvantages of conventional tubular reactors (CTRs), the concept of spherical membrane reactors is proposed as an alternative. In this study, it is suggested to apply hydrogen perm-selective membrane in the axial-flow spherical packed-bed naphtha reformers. The axial flow spherical packed-bed membrane reactor (AF-SPBMR) consists of two concentric spheres. The inner sphere is supposed to be a composite wall coated by a thin Pd-Ag membrane layer. Set of coupled partial differential equations are developed for the AF-SPBMR model considering the catalyst deactivation, which are solved by using orthogonal collocation method. Differential evolution optimization technique identifies some decision variables which can manipulate the input parameters to obtain the desired results. In addition to lower pressure drop, the enhancement of aromatics yield by the membrane layer in AF-SPBMR adds additional superiority to the spherical reactor performance in comparison with CTR. (C) 2011 American Institute of Chemical Engineers AIChE J, 57: 3182-3198, 2011