Absorption and oxidation of H2S in triethylamine hydrochloride · ferric chloride ionic liquids

To explore environmentally benign solvents for absorbing and oxidizing H2S, a series of triethylamine hydrochloride · ferric chloride ionic liquids (Et3NHCl · FeCl3 ILs) were synthesized, the absorption and oxidation efficiency of H2S in which were measured. The influence parameters, mole ratios of ILs and temperature, on the sulfur capacity of H2S in the Et3NHCl · FeCl3 ILs were investigated. The sulfur capacity of 1.5 Et3NHCl · FeCl3 ILs at 303.15 K and 101.3 kPa is the highest (2.178 wt.%). The oxidation efficiency of H2S in 1.5 Et3NHCl · FeCl3 IL was up to 87.9%. The absorption and oxidation mechanism of H2S in the ILs was studied. Fe (III) in the ILs was reduced to Fe (II) and H2S was oxidized to sulfur at the same time. After bubbling air through the IL, Et3NHCl · FeCl3 IL was regenerated, allowing the IL to be reused five times without clearly loss of capability.