Robust Multicriteria Selection of Process-Air Redistribution Strategies in A Medium-Pressure Nitric Acid Plant: An Ak-72m Case Study
DOI:
https://doi.org/10.37547/Keywords:
Nitric acid, process integration, airflow redistributionAbstract
Air compression, ammonia oxidation, heat recovery, nitrogen-oxide absorption and product-acid bleaching are strongly coupled in medium-pressure nitric acid plants. This study formulates the redistribution of process air in an AK-72M unit as a multicriteria retrofit-selection problem. Five alternatives were compared against seven criteria covering production potential, energy performance, capital demand, implementability, process safety, environmental performance and controllability. A normalized weighted-sum model identified partial replacement of the T-5–K-47 bleaching-air stream by filtered ambient air, with the released M-10A compressor air redirected to the R-12/1,2 contact section, as the leading concept (score 7.49/9). Control-only optimization ranked second (7.18/9). Robustness was evaluated by 200,000 Monte Carlo samples in which all criterion weights were perturbed independently by ±20% and renormalized. The preferred concept ranked first in 99.9895% of samples; its 95% score interval was 7.444–7.535 and the 95% score gap over the second-ranked alternative was 0.102–0.515. The result is robust to the stated weight uncertainty but remains conditional on the expert ratings and on hard technical constraints. A front-end engineering and validation framework is therefore proposed instead of claiming an implemented industrial improvement.
References
1. European Commission. Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic Chemicals—Ammonia, Acids and Fertilisers. European IPPC Bureau, Brussels, 2007.
2. Fertilizers Europe. Best Available Techniques for Pollution Prevention and Control in the European Fertilizer Industry. Booklet No. 2: Production of Nitric Acid. Brussels, 2000/2014.
3. Thiemann, M.; Scheibler, E.; Wiegand, K.W. Nitric Acid, Nitrous Acid, and Nitrogen Oxides. Ullmann’s Encyclopedia of Industrial Chemistry, 2000. https://doi.org/10.1002/14356007.a17_293.
4. Haas, M.; Nien, T.-W.; Fadic, A.; et al. N2O selectivity in industrial NH3 oxidation on Pt gauze is determined by interaction of local flow and surface chemistry. Chemical Engineering Science 260 (2022) 117832. https://doi.org/10.1016/j.ces.2022.117832.
5. Pradhan, M.P.; Suchak, N.J.; Walse, P.R.; Joshi, J.B. Multicomponent gas absorption with multiple reactions: modelling and simulation of NOx absorption in nitric acid manufacture. Chemical Engineering Science 52 (1997) 4569–4591. https://doi.org/10.1016/S0009-2509(97)00300-X.
6. Belghaieb, J.; Dkhil, O.; Elhajbelgacem, A.; Hajji, N.; Labidi, J. Energy optimization of a network of exchangers-reactors in a nitric acid production plant. Chemical Engineering Transactions 21 (2010) 271–276. https://doi.org/10.3303/CET1021046.
7. Mabitsela, L.; Telukdarie, A.; Munsamy, M. Modelling for Cleaner Production & Optimization. Procedia Computer Science 217 (2023) 679–688. https://doi.org/10.1016/j.procs.2022.12.264.
8. Sitoh, Y.; Tan, V.W.G.; Tapia, J.F.D.; Tan, R.R.; Foo, D.C.Y. Optimal pathways for nitric acid synthesis using P-Graph attainable region technique. Processes 11 (2023) 2684. https://doi.org/10.3390/pr11092684.
9. Hwang, C.L.; Yoon, K. Multiple Attribute Decision Making: Methods and Applications. Springer-Verlag, Berlin, 1981.
10. Saaty, T.L. The Analytic Hierarchy Process. McGraw-Hill, New York, 1980.
11. Chakraborty, S. TOPSIS and modified TOPSIS: a comparative analysis. Decision Analytics Journal 2 (2022) 100021.
12. Montgomery, D.C. Design and Analysis of Experiments, 10th ed. Wiley, Hoboken, 2019.
13. AK-72M. Permanent technological regulation for weak nitric acid production, sheets 2–36. Internal plant technical document.
14. AK-72M unit. Material-flow diagram 5.1. Internal plant material-balance document.
15. Bird, R.B.; Stewart, W.E.; Lightfoot, E.N. Transport Phenomena, 2nd ed. Wiley, New York, 2002.
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Copyright (c) 2026 Anvarkhon Madaminovich Nabiyev, Qobil Odilovich Nazirov, Rustam Rasulovich Tojiyev, Azizjon Salomiddinovich Isomidinov
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