Double H-bonds multimer absorbent design for H2S absorption.

• DBU-2EG multimer absorbent with double H-bonds was designed by intermolecular self-assembly using DBU and EG. • The concentrated electron density around O in EG of DBU-2EG is in favor of the absorption of H 2 S by DBU-2EG. • A method for developing a high-efficiency absorbent for H 2 S was constructed by designing H-bonds in an absorbent molecule. • DBU-2EG multimer absorbent has a high absorption solubility of 5.8 mol/kg (25 °C, 1 atm) for H 2 S. A double H-bonds multimer absorbent for hydrogen sulfide (H 2 S) absorption was designed via intermolecular self-assembly using 1,8-Diazabicyclo-[5.4.0]-undec-7-ene (DBU) and ethylene glycol (EG) under the guidance of quantum chemical calculation (QCC). The formation mechanisms of multimer absorbents and the absorption mechanisms between those absorbents and H 2 S were explored by QCC and experiments. It was found that the formed multimer absorbent at the DBU/EG molar ratio of 1:2 has two intermolecular H-bonds with different strengths between DBU and EG, which can combine with H 2 S via strong intermolecular forces. Furthermore, the characteristics analysis of multimer absorbents and complexes confirmed the above mechanisms. Experimental results indicated that the DBU-2EG has a higher H 2 S solubility of 5.8 mol/kg multimer absorbent with a low viscosity value of 15.12 mPa·s at 25 °C and better regeneration performance. The multimer absorbent exhibits great potential in the H 2 S capture process. [ABSTRACT FROM AUTHOR]