Abstract: A process for removing H2S from a gaseous stream, wherein the gaseous stream is flowed through an absorber vessel where the stream is contacted with a sorbing liquor comprising a nonaqueous solvent containing dissolved sulfur, a tertiary amine base having sufficient strength and concentration to drive the reaction between H2S sorbed by the liquor and the dissolved sulfur to form a nonvolatile polysulfide which is soluble in the sorbing liquor, and a solubilizing agent for maintaining the solubility of polysulfide intermediates which may otherwise separate. The dissolved nonvolatile polysulfide in the sorbing liquor is converted to sulfur which remains dissolved in the liquor by contacting the liquor with oxidizing sulfur dioxide. The sorbing liquor following the oxidation of the polysulfide is cooled to a temperature at which the liquor is at or above saturation with respect to the dissolved sulfur.

Abstract: A process is provided for the removal of hydrogen sulfide out of a gaseous stream (22), such as a natural gas, by contacting the hydrogen sulfide containing gas with a sorbing liquid (26) containing a tertiary amine so that the hydrogen sulfide is sorbed into the liquid in absorber (11) and transferring the sorbing liquid/hydrogen sulfide mixture to a reactor (15) where the tertiary amine promotes the conversion of the hydrogen sulfide into polysulfide via reaction with sulfur; transferring the polysulfide solution from the reactor (15) to a regenerator (10) where polysulfide is converted into elemental sulfur via reaction with air (9); transferring at least a portion of the solution (25) containing elemental sulfur, as well as sulfate and thiosulfate species, into a mixture (36) where it is contacted with gaseous ammonia which reacts with the sulfate and thiosulfate species to produce ammonium sulfate and ammonium thiosulfate which are removed from the solution while the remaining portion of solution (25) is

Abstract: In a known process and system wherein hydrogen sulfide is removed from a gaseous stream, using a non-aqueous scrubbing liquor which can be an organic solvent for elemental sulfur such as a phenylxylyl ethane in which are dissolved sulfur and a reaction-promoting amine base such as a tertiary amine, sulfur dioxide is added to the sulfur-amine nonaqueous sorbent (or advantage is taken of SO2 which may already be present in the gas stream) to obtain better H2S removal, lower chemical degradation rates, and lower rates of formation of byproduct sulfur salts such as sulfates.