A high efficient absorbent for the separation of H₂S from low partial pressure coke oven gas

To high efficiently remove H₂S from low partial pressure coke oven gas (COG), a novel activator (tetramethylammonium arginine, [N₁₁₁₁][Arg]) was used to blend with N-methyldiethanolamine (MDEA) for the absorption of H₂S. High concentrated [N₁₁₁₁][Arg]-MDEA aqueous solution was used as absorbent. Thermodynamic properties including absorption amount and H₂S loading values were measured, then the kinetic apparent absorption rate was calculated based on the change of absorption amount with time. The removal efficiency of H₂S in simulated COG was verified in tray towers. Compared with monoethanolamine (MEA)-MDEA and tetramethylammonium glycinate ([N₁₁₁₁][Gly])-MDEA aqueous solutions, [N₁₁₁₁][Arg]-MDEA aqueous solution takes advantages of higher absorption capacity, absorption rate and removal efficiency. Our results showed that the proposed absorbent has good industrial application prospect in coke oven gas desulfurization, because it achieved 100% removal of H₂S in the tray tower containing only 4 sieve plates under high concentrated condition (water content < 45%), which may significantly decrease the energy consumption.