Patent ID: 6096280
Filing Date: 2000-08-01
Classification: B01D,C01B,C10L

Abstract:
A process for the removal of hydrogen sulfide from a first gas stream comprising a concentrated hydrogen sulfide gas stream from a natural gas sweetening process, which comprises:partially oxidizing said concentrated hydrogen sulfide gas stream to form a second gas stream containing hydrogen sulfide and sulfur dioxide having a proportion of sulfur dioxide which is either stoichiometric or a slight stoichiometric excess of that required by the equation (1):H.sub.2 S+SO.sub.2 .fwdarw.H.sub.2 O+3S (1)said second gas stream comprising carbonyl sulfide and/or carbon disulfide,contacting said second gas stream with an autogenously-formed aqueous acid medium having a pH of about -0.5 to about 4 at a temperature of about 0.degree. to about 155.degree. C. and a pressure of above atmospheric to about 1000 kPa absolute to effect reaction of hydrogen sulfide and sulfur dioxide in accordance with said equation (1) to form sulfur and to hydrolyze a proportion of said carbonyl sulfide and/or carbon disulfide in said autogenously-formed acid aqueous medium in accordance with equations (2) and (3):CS.sub.2 +H.sub.2 O.fwdarw.COS+H.sub.2 S (2)COS+H.sub.2 O.fwdarw.H.sub.2 S+CO.sub.2 ( 3)to form a third gas stream containing unreacted carbonyl sulfide and/or carbon disulfide,recovering the sulfur from the aqueous medium,hydrolyzing unreacted carbonyl disulfide and/or carbon disulfide in said third gas stream in the presence of quinoline to form hydrogen sulfide in accordance with the reactions of equations (2) and (3),reacting the hydrogen sulfide so formed with a stoichiometric excess of sulfur dioxide present in said quinoline in accordance with equation (1) to form sulfur.