Abstract: A process for removing sulfur dioxide from a mixture of gases and recovery of sulfur dioxide. The sulfur dioxide is first contacted in a scrubbing zone with an aqueous solution of a salt, M.sub.2 B, where M is a alkali metal cation, and B is a divalent anion derived a weak acid which has an ionization constant (pKa) value of at least 3.0. The pregnant scrubbing solution is then contacted with an amine acid salt, AHB, where A is an amine cationic group containing a hydrophobic subgroup of 8-45 carbons, and HB is a monovalent proton containing anion of a weak acid, to form by ion exchange, an amine hydrogen sulfite and an aqueous solution of alkali metal salt containing the anion HB. The sulfur bearing amine is heated to decompose the sulfite, releasing sulfur dioxide and a reduce sulfur content amine phase. The reduced sulfur content amine phase is contacted with the aqueous solution of alkali metal HB salt to regenerate the scrubbing salt solution of M.sub.2 B and the amine acid salt AHB.

Abstract: A process for removing sulfur dioxide from a mixture of gases and converting the removed SO.sub.2 to elemental sulfur. The sulfur dioxide is first contacted in a scrubbing zone with a scrubbing agent which is an aqueous solution of an alkali metal salt of a weak acid which has an ionization constant (pKa) value of at least 3.5. The pregnant scrubbing solution is then contacted with an organic transfer reactant which is a water immiscible, water insoluble amine salt to effect a transfer reaction by which the sulfite ions are transferred to the non-aqueous phase by way of an ion exchange reaction. The sulfur bearing, non-aqueous phase is next heated to decompose the sulfite, releasing sulfur dioxide and a water immiscible, water insoluble amine-bearing compound. The amine-bearing compound is next contacted with the alkali metal salt scrubbing solution from the transfer step.

Abstract: A process for removing sulfur dioxide from a mixture of gases and converting the removed sulfur dioxide to elemental sulfur. The sulfur dioxide is first contacted in a scrubbing zone with a scrubbing agent which is an aqueous solution of an alkali metal sulfite. The pregnant scrubbing solution is then contacted with an organic transfer reactant which is a water-immiscible long chain aliphatic amine to effect a transfer reaction in which the amine combines with sulfite ions to form organic amine sulfite, and regenerate the alkali metal sulfite scrubbing agent. In the final step of the process, the long chain aliphatic amine sulfite is heated to decompose the sulfite, releasing sulfur dioxide and regenerating the amine. The regenerated amine, as well as the regenerated alkali metal sulfite scrubbing agent, are recycled in the process, and the sulfur dioxide product can be optionally further reduced to elemental sulfur.