چكيده لاتين
In this study, aimed at improving the performance of the sulfur recovery unit at Ilam Petrochemical Company, the effect of solvent change in the process of absorbing acidic gases was investigated and analyzed. Given the importance of removing sulfur compounds from natural gas streams and its role in reducing equipment corrosion, enhancing product quality, and meeting environmental requirements, a precise simulation of various units was conducted using HYSYS software. In this regard, different units, including hydrotreating reactors and the Merox unit (for the absorption and oxidation of mercaptans and carbonyl sulfide), were comprehensively simulated and analyzed. Subsequently, by changing the solvent type from diethanolamine to methyl diethanolamine and examining different compositions and concentrations of the solvent, the effect of this change on the removal efficiency of hydrogen sulfide, carbon dioxide, and carbonyl sulfide gases, energy consumption, thermal load of the regeneration tower, and operational stability of the system was evaluated. The simulation results showed that in Unit 30, the use of methyl diethanolamine improved the selectivity for hydrogen sulfide absorption over carbon dioxide and reduced steam consumption in the regeneration tower. Additionally, a kinetic model for carbonyl sulfide absorption in the Merox unit was developed and validated with experimental data. Overall, the results indicate that in Unit 20, substituting MDEA with DEA is not recommended due to the low reaction rate constant during the design phase of this unit, which can lead to the formation of sodium sulfide salts in the caustic loop, reduced extraction tower efficiency, potential tray flooding in the extraction tower, and increased maintenance and mechanical costs. This research can serve as a foundation for future studies on the design and optimization of gas sweetening and sulfur recovery units from a kinetic and thermodynamic perspective.
