A process for recovering sulfur from a tail gas stream comprising the steps of providing a tail gas stream to a chemical looping combustion (CLC) unit, the tail gas stream comprising a sulfide component, providing an oxygen carrier to the CLC unit, the oxygen carrier comprising a calcium carbonate, providing an air stream to the CLC unit, the air stream comprising oxygen, and reacting the sulfide component in the CLC unit with the calcium compound and the air to produce a product effluent, the product effluent comprising calcium sulfate.