@ARTICLE{10.21494/ISTE.OP.2026.1481, 

TITLE={Impact Analysis of Deisohexanizer Fractionation On Isomerate Research Octane Number At The Algiers Refinery}, 
  
AUTHOR={Rima Harche
, Nadia Aicha Laoufi, }, 
	
JOURNAL={Entropy: Thermodynamics – Energy – Environment – Economy }, 
	
VOLUME={7}, 

NUMBER={Special issue CIER}, 
	
YEAR={2026}, 

URL={https://www.openscience.fr/Impact-Analysis-of-Deisohexanizer-Fractionation-On-Isomerate-Research-Octane}, 
	
DOI={10.21494/ISTE.OP.2026.1481}, 
	
ISSN={2634-1476}, 
	
ABSTRACT={This study investigates the optimization of the light naphta isomerization process at the Algiers Refinery, with a focus on the operational efficiency of the Deisohexanizer (DIH) column. Isomerization is a critical refinery process that upgrades low-octane linear alkanes into high-octane branched isomers, thereby enhancing the Research Octane Number (RON) of the gasoline pool. The research methodology employed Aspen HYSYS software to conduct rigorous steady state modeling and performance analysis of the unit. To quantify the added value of the fractionation section, a baseline simulation was first established for a once-through configuration that excluded the DIH. Subsequently, a comprehensive simulation integrated the Deisohexanizer into the process flow to evaluate its impact on the global system efficiency and product quality. The study focused on the sensitivity analysis of key operating parameters, including reflux ratios, feed tray locations, and reboiler duties. These adjustments aimed to maximize the separation of low-octane normal hexane (nC6) from high-octane dimethylbutanes, thereby optimizing recycling cycles and minimizing energy consumption. The final results identify several optimal operating points and provide a set of technical recommendations proposed to Sonatrach. These suggestions aim to enhance the RON of the final isomerate while maintaining cost-effective energy profiles within the Algiers refinery’s current infrastructure.}}