The Optimal Design of Pressure Swing Adsorption Process of Air Oxygen Enrichment Under Uncertainty

The paper formulates and studies the problem of optimal (by the criterion of profits from oxygen production) design of a pressure swing adsorption (PSA) unit for air oxygen enrichment under partial uncertainty of the source data (the air composition, temperature, atmospheric pressure) with limitations on oxygen purity, unit capacity, and resource saving granular adsorbent. A heuristic iterative algorithm was developed for solving an optimal design problem under partial uncertainty of the source data. An auxiliary optimization problem related to the class of nonlinear programming problems (assuming the approximation of continuous control functions at the stages of the adsorption-desorption cycle by step-functions) was formulated and then solved by the sequential quadratic programming method. The problem of optimal design was solved for the range of PSA units with a capacity of 1 to 4 l/min allowing to obtain oxygen with a purity of 40 to 90 vol. According to the findings, we analyze the most promising operational and design parameters ensuring the maximum profit in the operation of the PSA unit, taking into account the saving of the granular adsorbent. It was established that the introduction of limitations on the gas flow rate in the frontal layer of the PSA unit adsorbent allows to increase the reliability of its operation and the adsorbent service life.

Keywords

pressure swing adsorption; zeolite; mathematical modelling; optimization; design; uncertainty.

References

1. Chistyakova T.B., Razygrayev A.S., Polosin A.N., Araztaganova A.M. Joint Innovative IT Projects in the Field of Production of Polymeric Sheet Materials. Proceedings of the 2016 IEEE V Forum "Strategic Partnership of Universities and Enterprises of Hi-Tech Branches (Science. Education. Innovations)". St. Petersburg, Saint Petersburg Electrotechnical University LETI, 2016, pp. 61-64.
2. Chistyakova T.B., Polosin A.N. Computer Modelling System of Industrial Extruders with Adjustable Configuration for Polymeric Film Quality Control. Proceedings of 2017 IEEE II International Conference on Control in Technical Systems (CTS). St. Petersburg, Saint Petersburg Electrotechnical University LETI, 2017, pp. 47-50.
3. Shumyatskii Yu.I. Promyshlennye adsorbtsionnye processy [Industrial Adsorption Processes]. Moscow, KolosS, 2009.
4. Keltsev N.V. Osnovy adsorbtsionnoy tekhniki [Basics of Adsorption Technology]. Moscow, Khimiya, 1984.
5. Ruthven D.M., Farooq S., Knaebel K.S. Pressure Swing Adsorption. New York, Wiley, 1994.
6. Chin-Wen Wu, Vermula R., Kothare M., Sircar S. Experimental Study of a Novel Rapid Pressure-Swing Adsorption Based Medical Oxygen Concentrator: Effect of the Adsorbent Selectivity of N_2 over O_2. Industrial and Engineering Chemistry Research, 2016, vol. 55, no. 16, pp. 4676-4681.
7. Moran A., Talu O. Limitations of Portable Pressure Swing Adsorption Processes for Air Separation. Industrial and Engineering Chemistry Research, 2018, vol. 57, no. 35, pp. 11981-11987. DOI: 10.1021/acs.iecr.8b02237
8. Chai S.W., Kothare M.V., Sircar S. Rapid Pressure Swing Adsorption for Reduction of Bed Size Factor of a Medical Oxygen Concentrator. Industrial and Engineering Chemistry Research, 2011, vol. 50, pp. 8703-8710.
9. Akulinin E.I., Golubyatnikov O.O., Dvoretsky D.S., Dvoretsky S.I. Numerical Study of Cyclic Adsorption Processes of Air Oxygen Enrichment in Dynamics. Journal of Physics: Conference Series, 2019, vol. 1278, article ID: 012005.
10. Akulinin E.I., Golubyatnikov O.O., Dvoretsky D.S., Dvoretsky S.I. Optimizing Pressure-Swing Adsorption Processes and Installations for Gas Mixture Purification and Separation. Chemical Engineering Transactions, 2019, vol. 74, pp. 883-888.
11. Kirillin V.A., Sychev V.V., Sheindlin A.E. Tekhnicheskaya termodinamika [Technical Thermodynamics]. Moscow, MEI, 2016.
12. Dubinin M.M. Adsorbtsiya i Poristost' [Adsorption and Porosity]. Moscow, VAKhZ, 1972.
13. Akulinin E., Golubyatnikov O., Dvoretsky D., Dvoretsky S. Optimization and Analysis of Pressure Swing Adsorption Process for Oxygen Production from Air Under Uncertainty. Chemical Industry and Chemical Engineering Quarterly, 2020, vol. 26, no. 1, pp. 89-104.
14. Rice R.G., Do D.D. Applied Mathematics and Modelling for Chemical Engineers. New Jersey, Wiley, 2012.
15. Cruz P., Magalhaes F.D., Mendes A. On the Optimization of Cyclic Adsorption Separation Processes. AIChE Journal, 2005, vol. 51, pp. 1377-1395.
16. Kheifets L.I., Zelenko V.L., Pavlov Y.V. Elementy teorii protsessov adsorbtsionnogo razdeleniya gazovykh smesey [Elements of the Theory of Processes Adsorption Separation Gas Mixture]. Moscow, MGU, 2004.
17. Skvortsov S.A., Akulinin E.I., Golubyatnikov O.O., Dvoretsky D.S., Dvoretsky S.I. Mathematical Modelling of Cyclic Pressure Swing Adsorption Processes. Journal of Physics: Conference Series, 2018, vol. 1015, article ID: 032002. DOI: 10.1088/1742-6596/1015/3/032002
18. Goldstein A.L. Optimizatsiya v srede MATLAB [Optimization in MATLAB]. Perm, PNIPU, 2015.