Title: Exergy analysis and optimisation of nitric acid production plant

Authors: Oludare Johnson Odejobi; Atilade Amos Oladunni; Grace Oluwaseun Gbadebo

Addresses: Applied Thermodynamics and Process Design Research Laboratory, Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria ' Department of Chemical Sciences, Ajayi Crowther University, Oyo, Nigeria ' Applied Thermodynamics and Process Design Research Laboratory, Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria

Abstract: Ostwald process for nitric acid production was simulated using Aspen HYSYS. Effects of input parameters on concentration of nitric acid in the product show increase in mole fraction with increasing ammonia and air flow rates but decrease as feed water flow rate increases. Separator has highest exergetic efficiency of 90.4%. Optimum conversion for absorber, feed water temperature and flow rate are 70%, 25.5°C and 3,000 kg/h, respectively for exergetic efficiency and 69.8%, 25.49°C and 3,500 kg/hr, respectively for irreversibility. Flow rate for economical operation of the plant was 800 and 12,000 kg/h for ammonia and air, respectively.

Keywords: nitric acid plant; exergetic efficiency; irreversibility; optimisation; Aspen HYSYS.

DOI: 10.1504/IJEX.2023.134606

International Journal of Exergy, 2023 Vol.42 No.2, pp.179 - 191

Received: 23 Jul 2022
Received in revised form: 03 Jan 2023
Accepted: 03 Jan 2023
Published online: 30 Oct 2023 *

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