A novel integrated simulation approach for natural gas sweetening and dehydration: H2S, CO2, and H2O removal with energy optimization using Aspen HYSYS

• Integrated MDEA sweetening and TEG dehydration in a single Aspen HYSYS flowsheet. • Heat integration and solvent recovery reduce total energy use by 13.78%. • MDEA–TEG absorption achieves ∼97 mol% pure natural sales gas. • Treated gas reaches a high heating value of ∼46 MJ/kg, enhancing market value. • Material balance validation in MATLAB shows < 1% average error. Natural gas has emerged as the predominant energy source globally. However, raw natural gas typically contains impurities such as hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), and water (H 2 O), necessitating treatment prior to pipeline delivery. This work develops and validates an integrated Aspen HYSYS V15 simulation that combines MDEA-based sweetening with TEG-based dehydration in a single, heat-integrated flowsheet. Unlike prior studies that have optimized these units separately, the present model performs co-optimization with energy recovery and closed-loop solvent recycling, achieving compliance with pipeline specifications and 13.78% energy savings. The treated sales gas achieves 96.86 mol% purity while preserving a heating value of 46.08 MJ/kg. Independent MATLAB material-balance validations with average deviation of 0.97% from HYSYS stream results confirms the model’s numerical accuracy. Treating sweetening and dehydration as a single, heat-integrated optimization problem provides an energy-efficient framework suitable for natural gas processing facilities.