Title: Simulation and optimisation for DMR natural gas liquefaction unit

Authors: Ahmed S. Fathalla; Mohammed Hefny; Monica Toderas; Moustapha Salem Mansour; Fathy Shokry

Addresses: Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria, Egypt ' Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria, Egypt ' Department of Physics, Faculty of Informatics and Sciences, University of Oradea, Oradea, Romania ' Chemical Engineering Department, Faculty of Engineering, Alexandria University, Alexandria, Egypt ' Chemical Engineering Department, Faculty of Engineering, Port Said University, Port Fuad, Egypt

Abstract: Dual mixed refrigerants natural gas liquefaction technology (DMR) has been simulated to determine the optimal operational parameters in terms of flowrate ratios for the mixed refrigerants utilised to maintain main cryogenic heat exchangers' stability and prevent temperature profile distortion as result of insufficient heat transfer throughout the main cryogenic heat exchangers that logically will occur if the cooling medium (refrigerants) flowrates will vary. This study examines specific ratios between two mixed refrigerants (MR1, MR2 vapour, MR2 liquid) and liquefied natural gas (LNG) produced, particularly during operations at varying feed gas flowrates. The study resulted in optimal operating zones, which are indicated by ratios such as LNG to MR2L (0.199 to 1.79), MR2V to MR2L (0.49), and MR1/MR2L (1.24 to 2.031) and those ratios showed resulted high production rate without compromising the integrity of the machinery or the operational procedures employing specific flow rate ratios. [Received: January 17, 2025; Accepted: April 22, 2025]

Keywords: simulation; Aspen HYSYS; liquefied natural gas; LNG; optimisation; dual mixed refrigerant unit.

DOI: 10.1504/IJOGCT.2026.153021

International Journal of Oil, Gas and Coal Technology, 2026 Vol.39 No.3, pp.300 - 321

Received: 15 Dec 2024
Accepted: 22 Apr 2025
Published online: 20 Apr 2026 *

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