Enhanced H2S capture using sterically hindered amine-based non-aqueous solvents: experimental and computational simulation

To overcome high regeneration energy in conventional H 2 S capture processes, a novel non-aqueous solvent comprising sterically hindered tertiary-butylaminoethoxyethanol (TBEE) and triethylene glycol (TEG) was developed. At 30 wt% TBEE loading, exceptional H 2 S absorption capacity of 0.982 mol/mol was achieved under 0.6 bar and 293 K. Experimental characterizations combined with theoretical calculations analyses revealed that strong hydrogen-bonding networks between TBEE and TEG significantly enhanced thermal stability. Kinetic studies showed that the rate constants exhibited temperature- and pressure-dependent variations. Thermodynamic analysis using the Reaction Equilibrium Thermodynamic Model with physical absorption (RETM1-P) and van't Hoff equation obtained enthalpy (Δ H ) and entropy (Δ S ) values of −66.76 kJ/mol and −211.85 J/mol·K, respectively. Furthermore, the optimal absorption / desorption temperatures and theoretical desulfurization rate were determined. Moreover, the TBEE/TEG system show excellent recyclability with almost no significant decline in absorption capacity over ten consecutive absorption-desorption cycles, demonstrating its potential for long-term industrial application.