A dynamic nonequilibrium stage model of multicomponent distillation processes is developed in this paper. Mass and energy transfer rate equations are used in describing the transfer processes on real trays and thus the computations of stage efficiencies are entirely avoided. By in-troducinga separation efficiency function

an applicable simulation model of simple structure is presented and the procedure for solving the differential equations using Gears algorithm is depicted as well. The simulation results obtained from two industrial distillation columns show that

comparing with the experimental data

this model can really predict the dynamics on real trays.