Design of Optimal Process Flowsheet for Fractional Crystallization Separation Process

Document Type: Research Article

Author

School of Chemical, Gas and Petroleum Engineering, Semnan University, Semnan, I.R. IRAN

Abstract

A procedure is presented that synthesizes fractional crystallization separation processes to obtain pure solids from multi-component solutions. The method includes a procedure to generate a network flow model to identify alternative process designs for fractional crystallization. The main advantage of this systematic procedure with respect to other reported procedures is using non-equilibrium solubility values for crystallizers and mixing tanks as process points. By employing an approach factor to show the distance from equilibrium, a non-linear programming model is obtained. Solving the non-linear programming model, optimal process flowsheet 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 carbonate and sodium sulfate from Burkeite. The results show that when the approach factor goes to unity, the maximum efficiency of separation process is attained which corresponds to the minimum total flow rates and total cost of the process.  

Keywords

Main Subjects


[1] Fitch, B., How to Design Fractional Crystallization Processes, Ind. Eng. Chem. Res., 62, 6 (1970).

[2] Cisternas, L.A., Rudd, D.F., Process Design for Fractional Crystallization from Solution, Ind. Eng. Chem. Res., 32, 1993 (1993).

[3] Chang, Liu, Yuanhui, Ji, Yang, Bai, Fangqin Cheng, Xiaohua Lu, Fluid Phase Equilibria, 216, 300(2007).

[4] Rajagopal, S., Ng, K.M., Douglas, J.M., Design of Solids Processes: Production of Potash, Ind. Eng. Chem. Res., 27, 2071 (1988).

[5] Rajagopal, S., Ng, K.M., Douglas, J.M., A Hierarchical Procedure for the Conceptual Design
of Solids Processes, Comput. Chem. Eng., 16, 675 (1992).

[6] Rajagopal, S., Ng, K.M., Douglas, J.M., Design and Economic Trade-Offs of Extractive Crystallization Processes, AIChE J., 37, 437 (1991).

[7] Dye, S.R., and Ng, K.M., Bypassing Eutectics with Extractive Crystallization: Design Alternatives and Tradeoffs, AIChE J., 41, 1456 (1995).

[8] Dye, S.R. and Ng, K. M., Fractional Crystallization: Design Alternatives and Tradeoffs, AIChE J., 41, 2427 (1995).

[9] Ng, K.M., Systematic Separation of a Multi-Component Mixture of Solids Base on Selective Crystallization and Dissolution, Sep. Technol., 1, 108 (1991).

[10]  Sze, W. Lin, NgK.M., Christianto Wibowo, Synthesis of  Crystallization  Processes  for  Systems Involving Solid Solutions, Computers and Chemical Engineering, 32, 956 (2008).

[11] Berry, D.A., Dye, S.R. and Ng, K.M., Synthesis of Drowning-Out Crystallization-Based Separations, AIChE J., 43, 91 (1997).

[12] Berry, D.A., and Ng, K.M., Separation of Quaternary Conjugate Salt Systems by Fractional Crystallization, AIChE J., 42, 2162 (1996).

[13] Takano, K., Gani, R., Ishikawa, T., Kolar P., Conceptual Design Andanalysis Methodology for Crystallization Processes with Electrolytesystems, Fluid Phase Equilib., 194, 783 (2002).

[14] Wibowo, C. and Ng, K.M., Unified Approach for Synthesizing Crystallization - Based Separation Processes, AIChE J., 46, 1400 (2000).

[15] Thomsen, K., Rasmussen, P., Gani, R., Simulation and Optimization Offractional Crystallization Processes, Chem. Eng. Sci., 53,1551 (1998).

[16] Thomsen, K., Gani, G., Rasmussen, P., Synthesis and Analysis of Processes with Electrolyte Mixtures, Comput. Chem. Eng., 19,27 (1995).

[17] Cisternas, L.A., Swaney, R.E., Separation System Synthesis for Fractional Crystallization from Solution Using a Network Flow Model, Ind. Eng. Chem. Res., 37,2761 (1998).

[18] Cisternas, L.A., Optimal Design of Crystallization-Based Separation Schemes, AIChE J., 45, 1477 (1999).

[19] Cisternas,  L. A.,  Cueto,  J.,  Swaney , R., Flowsheet Synthesis  of   Fractional   Crystallization Processes with Cake Washing, ComputersandChemical Engineering, 28,613 (2004).

[20] Perry  Robert H.,  Don  Green,  “Perry’s Chemical Engineering Handbook”, McGraw-Hill Inc., (1984).

[21] Silcock, H. L., “Solubilities of Norganic and Organic Compound”, Pergamon Press, Oxford, (1979).