Search

• 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]

• The absorption mechanism of SRSG absorbent for H 2 S and MM is physical absorption, and COS is chemical absorption. • RPB has been introduced for the simultaneous removal of organic and inorganic sulfur from gases. • The absorption efficiencies of H 2 S, MM and COS can simultaneously reach 99.99%, ∼100%, and ∼100%, respectively. In industries, many gases are required to remove hydrogen sulfide (H 2 S) and organic sulfur. However, it is still a huge challenge to achieve the efficient and simultaneous removal using a single process. Herein, a novel simultaneous removal sulfide gas (SRSG) absorbent is developed to simultaneously absorb H 2 S, methyl mercaptan (MM) and carbonyl sulfide (COS). The absorption mechanism between the SRSG absorbent and H 2 S, MM, COS is explored by quantum chemistry calculations (QCC) and controlled experiments in a rotating packed bed (RPB). Results indicate that the interaction between SRSG and H 2 S, MM belongs to physical absorption while COS absorption in SRSG obeys two molecule reaction mechanism. Furthermore, the effect of different operating conditions, including rotating speed (N), liquid flow rate (L), gas–liquid ratio (G / L) and temperature (T), on the absorption efficiencies (η) and gas volumetric mass transfer coefficient (K G a) of H 2 S, MM and COS is systematically investigated. It can be found that both η and K G a are dependent on those operating conditions. The optimal η value for H 2 S, MM and COS is up to 99.99%, 100%, 100%, respectively. Moreover, nondimensional equations for Sherwood number (Sh) are established, and the calculated and experimental values of Sh (H2S) , Sh (MM) and Sh (COS) are in agreement with a deviation within ±13%, ±13%, and ±20%, respectively. These results will provide a valuable potential technique for simultaneously removing acidic gas components from industrial gases. [ABSTRACT FROM AUTHOR]