Natural Gas Sweetening Technologies: A Technical and Comparative Analysis of Processes and Applications

This article presents a comprehensive and technical analysis of modern natural gas sweetening technologies, including chemical absorption, physical absorption, hybrid processes (such as Sulfinol), direct conversion (e.g., Stretford and iron sponge), and dry bed adsorption. It discusses their thermodynamic principles, removal mechanisms, operational conditions, and associated technical challenges, all supported by up-to-date technical literature and regulatory frameworks. The methodology was based on a systematic review of scientific literature, utilizing well-established databases and rigorous bibliographic selection criteria. The findings indicate that chemical absorption—particularly using MEA and MDEA solutions—remains the most versatile option for gas streams with high compositional variability. However, technologies such as physical absorption (e.g., Selexol and Rectisol) offer energy efficiency advantages in high-pressure environments. Hybrid systems provide a more balanced operational performance in complex scenarios, while direct conversion and dry bed adsorption, although limited in capacity and regeneration potential, are effective for small-scale or targeted applications. In conclusion, the selection of an appropriate sweetening process should take into account technical, economic, and environmental considerations, including energy efficiency, ease of solvent regeneration, selectivity, and overall operational feasibility. Finally, the study highlights future research directions focused on novel regenerable adsorbent materials and integrated carbon capture technologies (CCUS), in alignment with global energy sustainability objectives.