Design of Optimal Process Flowsheet for Fractional Crystallization Separation Process

A procedure is presented that synthesizes fractional crystallization separationprocesses to obtain pure solids from multi-component solutions. the method includes a procedureto generate a network flow model to identify alternative process designs for fractionalcrystallization. the main advantage of this systematic procedure with respect to other reportedprocedures is using non-equilibrium solubility values for crystallizers and mixing tanks as processpoints. by employing an approach factor to show the distance from equilibrium, a non-linearprogramming model is obtained. solving the non-linear programming model, optimal processflowsheet and the corresponding non-equilibrium solubility values for process points are presented.the proposed procedure is used to design an optimal flowsheet for production of sodium carbonateand sodium sulfate from burkeite. the results show that when the approach factor goes to unity, themaximum efficiency of separation process is attained which corresponds to the minimum total flowrates and total cost of the process.