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

Abstract To explore environmentally benign solvents for absorbing and oxidizing H 2 S, a series of triethylamine hydrochloride · ferric chloride ionic liquids (Et 3 NHCl · FeCl 3 ILs) were synthesized, the absorption and oxidation efficiency of H 2 S in which were measured. The influence parameters, mole ratios of ILs and temperature, on the sulfur capacity of H 2 S in the Et 3 NHCl · FeCl 3 ILs were investigated. The sulfur capacity of 1.5 Et 3 NHCl · FeCl 3 ILs at 303.15 K and 101.3 kPa is the highest (2.178 wt.%). The oxidation efficiency of H 2 S in 1.5 Et 3 NHCl · FeCl 3 IL was up to 87.9%. The absorption and oxidation mechanism of H 2 S in the ILs was studied. Fe (III) in the ILs was reduced to Fe (II) and H 2 S was oxidized to sulfur at the same time. After bubbling air through the IL, Et 3 NHCl · FeCl 3 IL was regenerated, allowing the IL to be reused five times without clearly loss of capability.