Solvent-Based Simulation and Techno-Economic Evaluation of CO2/H2S Separation at Shurtan Gas Complex

Building on the chemical absorption modeling of CO2 and H2S separation, this study further evaluates the feasibility of integrating the simulated process within Uzbekistan’s industrial carbon management strategy. The Aspen Plus rate-based simulations indicated that MEA and MDEA solvents offer distinct trade-offs between absorption capacity and regeneration energy demand. MDEA, for instance, showed lower reboiler duty (2.1 GJ/ton CO2) compared to MEA (2.5 GJ/ton), while maintaining comparable CO2 removal efficiency at elevated lean solvent loadings. Sensitivity analysis revealed that increasing the gas flow beyond 30 t/h led to marginal reductions in CO2 capture rate due to mass transfer limitations, suggesting the need for optimization of column internals in scaling scenarios. Additionally, integrating heat recovery between the absorber and regenerator units was estimated to lower total energy consumption by up to 14%. From a utilization perspective, the captured CO2 is intended for downstream conversion into calcined soda (Na2CO3) via the Solvay-like process implemented at the Dehkanabad plant. A mass balance indicates that 20 t/h of CO2 with 99.5% purity can yield ~37.1 t/h of soda, supporting annual outputs exceeding 290,000 tons. This valorization pathway not only offsets fossil-based soda production but also promotes circular carbon practices. Overall, the study reinforces the techno-economic potential of CCU in the Shurtan Gas Chemical Complex and advocates for pilot-scale demonstration to validate long-term operational stability and cost competitiveness.