A new technique presented can offer analytical solutions for the local equilibrium true countercurrent model to study the simulated moving-bed (SMB) separation process. This equilibrium theory could be very useful for predicting both optimal and robust operation conditions for the SMB separation process, if the results can be easily calculated. However, analytical solution was available only in the limiting case of binary separation. With this analytical solution for multicomponent systems, the application of equilibrium theory will be more practical. While developing these solutions, a new way of applying the well-known omega-transformation to nonlinear adsorption system was conceived. This approach may have broader applications than are presented here.