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

To high efficiently remove HS from low partial pressure coke oven gas (COG), a novel activator (tetramethylammonium arginine, [N][Arg]) was used to blend with N-methyldiethanolamine (MDEA) for the absorption of HS. High concentrated [N][Arg]-MDEA aqueous solution was used as absorbent. Thermodynamic properties including absorption amount and HS 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 HS in simulated COG was verified in tray towers. Compared with monoethanolamine (MEA)-MDEA and tetramethylammonium glycinate ([N][Gly])-MDEA aqueous solutions, [N][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 HS in the tray tower containing only 4 sieve plates under high concentrated condition (water content < 45%), which may significantly decrease the energy consumption.