TCPSD Process Control for Separation of Acetonitrile/Benzene/Methanol Mixture

Authors

DOI:

https://doi.org/10.33448/rsd-v11i1.25105

Keywords:

TCPSD; Plantwide Control; Control by inference.

Abstract

Aiming for greater saving on operating costs, the inclusion of recycle streams and thermal integrations are routine in chemical processes, generating need for more robust control structures capable of preventing losses due to routine disturbances and providing operational safety. The Triple-Column-Pressure-Swing-Distillation (TCPSD) separation can be used to separate different solvents from the fine chemical industry, and due to the large number of variables involved, together with thermal integrations and recycle streams, the definition of an effective control structure becomes a complex problem. At this context, this paper has as main objective the development and evaluation of plantwide control structures for a TCPSD process used to separate the acetonitrile/benzene/methanol mixture. Using the Aspen Plus© and Aspen Plus Dynamics© software, two control structures were evaluated, in which the product compositions are controlled by inference, by controlling the temperature of sensitive plates. The main difference between the two structures is that Control Structure 1 has a dual sum control loop of temperature sensitive plates in the low-pressure column, manipulating the reflux ratio. When evaluating the results of compositions of products when reaching steady state and ISE values, it was concluded that both structures are capable of controlling step-type disturbances in flow and composition at feed stream of the process. However, the better results were observed in Control Structure 1.

References

Halvorsen, I. J.; Skogestad, S.; Morud, J. C.; Alstad, V. (2003). Optimal selection of controlled variables. Industrial & Engineering Chemistry Research, Trondheim, 42, 3273-3284.

Hori, E. S. (2005). Contribuição ao Estudo de Controle “Plantwide”: Controle Indireto e Coordenação de Controladores Descentralizados. Tese de Doutorado apresentado a Universidade Federal de São Carlos - UFSCar.

Knapp, J. P., Doherty, M. F. (1992). A New Pressure-Swing-Distillation Process for Separating Homogeneous Azeotropic Mixtures. Industrial & Engineering Chemistry Research, 31(1), 346–357.

Luyben, W. L.; Tyréus, B. D.; Luyben, M. L. (1998). Plantwide process control. 1ª ed. New York: McGraw-Hill.

Luyben, W. L. (2006). Evaluation of criteria for selecting temperature control trays in distillation columns. Journal of Process Control, 16(2), 115–134.

Luyben, W. L., Chien, I. L. (2010). Design and Control of Distillation Systems for Separating Azeotropes. 1 ed. New York: John Wiley & Sons.

Luyben, W. L. (2012). Pressure-Swing Distillation for Minimum- and Maximum-Boiling Homogeneous Azeotropes. Industrial & Engeniering Chemical Research, vol. 51, 10881-10886.

Luyben, W. L. (2013). Distillation, Design and Control Using Aspen Simulation. 2 ed. New York: John Wiley & Sons.

Luyben, W. L. (2017). Control of a Triple-Column Pressure-Swing Distillation Process. Sep. Purif. Technol., p. 232-244.

Seader, J. D., Henley, E. J., Roper, D. K. (2011). Separation Process Principles: Chemical and Biochemical Operations. 3ed. New York: John Wiley & Sons.

Seborg, D. E.; Edgar, T. F.; Mellichamp, D. A. (2004). Process dynamics and control. 2nd edition, New York: John Wiley & Sons.

Silva, S. K. da. (2013). Utilização de uma Ferramenta para Seleção Automática de Estruturas de Controle para Plantas de Processos. Tese de Doutorado apresentado a Universidade Federal de Campina Grande - UFCG.

Skogestad, S. (2000). Plantwide Control: the search for the self-optmizing control structure. Journal of Process Control, Trondheim, 10(5), 487-507.

Skogestad, S. (2004). Control structure design for complete chemical plants. Computers & Chemical Engineering, Trondheim, 28(1), 219-234.

Skogestad, S. (2006). The Dos and Don’ts of Distillation Column Control. Chemical Engineering Research and Design, 85, 13-23.

Yang, A., Shen, W., Wei, S., Dong, L., Li, J., Gerbaud, V. (2019). Design and Control of Pressure-Swing Distillation for Separating Ternary Systems with Three Binary Minimum Azeotropes. AIChE Journal, 65, 1281-1293.

Zhang, Q., Liu, M. Li, W., Li, C., Zeng, A. (2019). Heat-integrated triple-column pressure-swing distillation process with multi-recycle streams for the separation of ternary azeotropic mixture of acetonitrile/methanol/benzene, Sep. Purif. Technol, 211, 40–53.

Zhu, Z.; Xu, D.; Liu, X.; Zhang, Z.; Wang, Y. (2016). Separation of acetonitrile/methanol/benzene ternary azeotrope via triple column pressure-swing distillation. Sep. Purif. Technol, 169, 66-77.

Zhu, Z., Xu, D., Jia, H., Zhao, Y., Wang, Y. (2017a). Heat Integration and Control of a Triple-Column Pressure-Swing Distillation Process. Industrial & Engeniering Chemical Research, 56, 2150-2167.

Zhu, Z., Xu, D., Wang, Y., Geng, X., Wang, Y. (2017b). Effect of multi-recycle streams on triple-column pressure-swing distillation optimization. Chemical Engineering Research and Design, 127, 215-222.

Published

09/01/2022

How to Cite

GUIMARÃES, L. de M. J.; RAMOS, W. B. . TCPSD Process Control for Separation of Acetonitrile/Benzene/Methanol Mixture. Research, Society and Development, [S. l.], v. 11, n. 1, p. e39811125105, 2022. DOI: 10.33448/rsd-v11i1.25105. Disponível em: https://rsdjournal.org/index.php/rsd/article/view/25105. Acesso em: 24 apr. 2024.

Issue

Section

Engineerings