Patent ID: 6495117
Filing Date: 2002-12-17
Classification: B01D,C01B

Abstract:
A process for treating an H2S-containing stream to convert said H2S to elemental sulfur, said process comprising:(a) feeding said H2S-containing stream to a continuous-flow reactor and contacting said H2S-containing stream in said reactor with an SO2-containing stream and an organic liquid solvent under the following conditions: (i) said organic liquid solvent contains a homogeneous catalyst that promotes the liquid phase reaction 2H2S+SO2â†’âˆ’3S+2H2Oâ€ƒâ€ƒ(I) (ii) the temperature in said reactor is maintained above the melting point of sulfur and below the boiling point of said solvent, and (iii) said H2S-containing and SO2-containing streams are fed at relative feed rates such that H2S is fed in excess relative to SO2 in accordance with reaction (I) to convert substantially all of said SO2 to liquid elemental sulfur and to produce reactor discharges containing said liquid elemental sulfur and gaseous unreacted H2S; wherein both said H2S-containing stream and said SO2-containing streams are gas streams, and both H2S and SO2 are absorbed in said reactor by said solvent, said solvent containing said catalyst dissolved therein; (b) combusting said unreacted H2S in said gaseous reactor effluent with an O2-containing gas in accordance with the reaction 2H2S+3O2â†’2SO2+2H2Oâ€ƒâ€ƒ(III) to convert said H2S to SO2, and to produce a combustion gas containing SO2 and H2O; and(c) passing said combustion gas through an SO2 absorber to recover substantially all SO2 from said combustion gas, thereby leaving a tail gas substantially free of H2S and SO2, and recycling SO2 thus recovered to said continuous-flow reactor.