The process for configuring or reconfiguring a sulfur removal plant having a plurality of Claus units that is greater than the number of downstream tail gas treating units (TGTUs) is disclosed. The process allows for the regeneration of one of the Claus units without shutting down any of the downstream TGTUs or the other Claus units. Specifically, the regeneration tail gas can be diverted to the reaction furnace of an in-service Claus unit, thereby allowing excess oxygen to be used to regenerate the Claus unit more efficiently, and without exceeding environmental SO2 emission requirements.

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.

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.

The process for configuring or reconfiguring a sulfur removal plant having a plurality of Claus units that is greater than the number of downstream tail gas treating units (TGTUs) allows for the regeneration of one of the Claus units without shutting down any of the downstream TGTUs or the other Claus units. Specifically, the regeneration tail gas can be diverted to the reaction furnace of an in-service Claus unit, thereby allowing excess oxygen to be used to regenerate the Claus unit more efficiently, and without exceeding environmental SO2 emission requirements.

The present invention is directed to a process for the removal of aromatic hydrocarbons from a lean acid gas containing less than 20 mol. % of H.sub.2S, comprising:

a) contacting the lean acid gas stream (1) with a H.sub.2S-selective liquid absorbent solution (29) in a first absorption zone (2) to produce a gas stream depleted in H.sub.2S (3) and an absorbent solution enriched in H.sub.2S (4),

b) introducing the absorbent solution (4) into a non-thermic stripping zone (8) where it is contacted with a stripping gas stream (7) to obtain an absorbent solution depleted in C.sub.4.sup.+ aliphatic and aromatic hydrocarbons (9) and a stripping gas stream enriched in aromatic and C.sub.4.sup.+ aliphatic hydrocarbons (10),

c) contacting the stripping gas stream (10) obtained in step b) with a H.sub.2S-selective liquid absorbent solution (28) in a second absorption zone (12) to obtain a stripping gas stream depleted in H.sub.2S (13), and an absorbent solution enriched in H.sub.2S (14)

d) introducing the absorbent solution (9) obtained in step b) into a desorption zone (16) wherein the H.sub.2S-selective liquid absorbent solution (17) is recovered and a lean acid gas is produced.

Systems and methods for minimizing fuel consumption in an incinerator system in a sulfur recovery unit (SRU), including obtaining input gas flow data for streams entering the incinerator system of the SRU. Systems and methods also include making a determination of whether the SRU is operated with a tail gas treatment unit (TGTU), selecting a first relationship in response to the determination that the SRU is not operated with the TGTU and otherwise selecting a second relationship. Systems and methods further include determining an optimal incinerator system temperature based on the input gas flow data and using the first or the second relationship, determining, based on the optimal incinerator system temperature, an optimal flow rate of a fuel gas used in the incinerator system, and adjusting a fuel gas flow rate to the optimal flow rate of the fuel gas.