Journal of Oil, Gas and Petrochemical Technology

Journal of Oil, Gas and Petrochemical Technology

Optimal solvent definition for gas treatment units with the aim of acid gas enrichment

Document Type : Research Paper

Authors
Mohammad Amin Tarokh 1
Mehdi Karimi 1
Ali Garmroudi Asil 2
1 Department of Chemical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran
2 Department of Chemical Engineering, Faculty of Engineering, Bojnord University, Bojnord, Iran
10.22034/jogpt.2025.513545.1137
Abstract
Increasing the concentration of H2S in the acid gas entering the sulfur recovery unit is one of the key parameters for enhancing the sulfur recovery efficiency. This research aims to determine the optimal solvent for a gas treatment unit with a focus on enriching hydrogen sulfide gas in the feed of the sulfur recovery unit. The data from the design of an industrial-scale gas-treating unit was utilized to achieve the research objectives. For simulation, analysis of results, and plotting graphs, ASPEN-HYSYS V11 and DESIGN EXPERT V10 software were employed, respectively. The solvents available in the GPSA handbook were utilized for the solvent and additives selection. In the formulation of a composite solvent, DEA and MDEA solvents were considered as the base solvents, considering the weight percentage range used in the gas processing industry, and other solvents were considered as additives to the composite solvent. Simulation results were analyzed by comparing them with the standards of the Iranian National Gas Company. The results indicated that the combination of MDEA with 42.5wt% as the base solvent and Sulfolane with 7.5wt% as an additive will be the optimum solvent. The reason for this selection is that there will be the maximum H2S concentration in the acid gas while adhering to the mentioned standards. The optimum solvent can increase the concentration of H2S from 33.6 mol% to 41.84 mol% in the acidic gas to the Sulphur recovery unit.
Keywords
Gas treatment
Optimal solvent
Solvent mixture
Acid gas enrichment
Sulfur recovery unit
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Journal of Oil, Gas and Petrochemical Technology
Volume 12, Issue 2
October 2025
Pages 67-79