Energy, exergy, economic, environment, exergo-environment based assessment of amine-based hybrid solvents for natural gas sweetening

Natural gas is the cleanest form of fossil fuel that needs to be purified from CO2 and H2S to diminish harmful emissions and provide feasible processing. The conventional chemical and physical solvents used for this purpose have many drawbacks, including corrosion, solvent loss, high energy requirement, and the formation of toxic compounds, which ultimately disrupt the process and affect the environment. Hybrid solvents have lately been researched to cater to these liabilities and enhance process economics. This study screened eight solvents based on CO2 selectivity viscosity, absorption enthalpy, corrosivity, working capacity, specific heat, and vapor pres-sure. From the screened solvents, ten cases of hybrid solvents are simulated and optimized on Aspen HYSYS (R). Furthermore, 5Es (Energy, Exergy, Economic, Environmental, and Exergy-environmental) analyses were per-formed on optimized cases, and results were compared with the base case, MEA (30 wt%). The hybrid blend of Sulfolane and MDEA with weight percentages of 6% and 24%, respectively, showed the highest energy savings of 20% concerning the base case. In addition, it offered 93% savings in exergy destruction and 17.26% in the total operating cost of the process. It is also promising to the environment due to reduced entropy sent to the ecosystem and controlled CO2 emissions. Therefore, the blend of Sulfolane and MDEA is proposed to Supersede the conventional solvent MEA for the natural gas sweetening process.

Automated summary

This study explores the use of hybrid solvents in the natural gas sweetening process to overcome the drawbacks of conventional solvents. Through screening and optimization, a blend of Sulfolane and MDEA was found to significantly reduce energy consumption, environmental impact, and operating costs while improving process efficiency. The findings suggest that this hybrid solvent can be a viable alternative to the traditional MEA solvent.