Tail gas treatment by two stage adsorption with intermediate cooling

A tail gas treatment system comprising:

• a hydrogenation reactor configured to receive a tail gas stream, wherein sulfur-containing gases in the tail gas stream are converted into hydrogen sulfide (H2S), resulting in a gas mixture comprising H2S;
• a quench tower, fluidically coupled to the hydrogenation reactor, configured to receive the gas mixture, wherein water is condensed from the gas mixture;
• a chiller, fluidically coupled to the quench tower, configured to reduce the temperature of the gas mixture to further condense water from the gas mixture;
• an oxidation reactor, fluidically coupled to the chiller and placed downstream of the chiller, to oxidize H2S in the gas mixture to sulfur dioxide (SO2), resulting in a oxidized gas mixture;
• a first stage adsorption bed fluidically coupled to the oxidation reactor to adsorb water from the oxidized gas mixture;
• and
• a second stage adsorption bed, placed downstream of the first stage adsorption bed to selectively adsorb SO2 from the oxidized gas mixture.

A method for sulfur dioxide (SO2) recovery, the method comprising:

• receiving a tail gas stream from a Claus unit, wherein the tail gas stream comprises sulfur-containing gases;
• reducing or hydrolyzing the sulfur-containing gases in the tail gas stream to hydrogen sulfide (H2S), resulting in an effluent gas stream;
• removing moisture from the effluent gas stream by a quench tower;
• after removing moisture from the effluent gas stream, condensing water from the effluent gas stream in an intermediate chiller;
• after condensing water from the effluent gas stream, oxidizing the effluent gas stream using a catalyst to form an oxidized gas stream;
• adsorbing, by a first adsorption bed, water vapor from the oxidized gas stream;
• adsorbing, by a second adsorption bed, SO2 from the oxidized gas stream;
• regenerating the first adsorption bed and the second adsorption bed to desorb water vapor and SO2, respectively;
• and
• after regenerating, recycling the SO2 to a Claus feed chamber.