Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
10.24200/sci.2026.66683.10184
Abstract
Nitrogen rejection from high-nitrogen natural gas (NG) streams is energy-intensive and reduces the economic viability of such resources. Various nitrogen rejection technologies have been developed to address this issue. This study presents a comprehensive economic evaluation of two cryogenic nitrogen rejection unit (NRU) configurations: single-column and double-column. The research introduces an economic enhancement by incorporating the rejected nitrogen into the value chain, proposing its use in enhanced oil recovery (EOR) instead of atmospheric venting. For this purpose, a compression-injection unit is integrated into the process. The evaluation considers four scenarios (two NRU configurations and two nitrogen utilization options) and uses net present value (NPV) as the optimization objective. Simulation and optimization results show that the double-column configuration is the most profitable when nitrogen is vented, with NPVs of $894 million and $1,073 million for single- and double-column configurations, respectively. However, when nitrogen is utilized for EOR, NPVs increase significantly to $4,787 million and $4,861 million, respectively. The economic advantage of the double-column configuration diminishes in the EOR case due to higher compression costs, highlighting that the optimal choice is context-dependent, as the single-column configuration becomes more profitable at increased EOR throughputs.
Mostafavi, M. , Eini, S. and Farhadi, F. (2026). Optimization of cryogenic nitrogen rejection process with rejected nitrogen utilization. Scientia Iranica, (), -. doi: 10.24200/sci.2026.66683.10184
MLA
Mostafavi, M. , , Eini, S. , and Farhadi, F. . "Optimization of cryogenic nitrogen rejection process with rejected nitrogen utilization", Scientia Iranica, , , 2026, -. doi: 10.24200/sci.2026.66683.10184
HARVARD
Mostafavi, M., Eini, S., Farhadi, F. (2026). 'Optimization of cryogenic nitrogen rejection process with rejected nitrogen utilization', Scientia Iranica, (), pp. -. doi: 10.24200/sci.2026.66683.10184
CHICAGO
M. Mostafavi , S. Eini and F. Farhadi, "Optimization of cryogenic nitrogen rejection process with rejected nitrogen utilization," Scientia Iranica, (2026): -, doi: 10.24200/sci.2026.66683.10184
VANCOUVER
Mostafavi, M., Eini, S., Farhadi, F. Optimization of cryogenic nitrogen rejection process with rejected nitrogen utilization. Scientia Iranica, 2026; (): -. doi: 10.24200/sci.2026.66683.10184
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