A plant for the production of sulfur trioxide from a feed stream containing sulfur-containing compounds and dissolved metals and alkali metals by a process, which involves gas quenching, comprises an incineration furnace, a mixing device and/or a dilution air heater, a dust removal device and an SO.sub.2 converter. The plant may further comprise a condenser for the purpose of producing sulfuric acid.

Sulfur trioxide is produced from a feed stream comprising sulfur-containing compounds and dissolved metals, such as alkali metals, in a plant comprising an incineration furnace, a waste heat boiler, a dilution air heater, a dust removal absorber and an SO.sub.2 converter. The plant may further comprise a sulfuric acid condenser for the production of sulfuric acid.

Methods and systems for recovering sulfur dioxide from a Claus unit process emissions stream are provided. The method comprises the steps of generating a process emissions stream from a thermal oxidizer or other combustion device, introducing the emissions stream to an SO.sub.2 removal system, introducing the SO.sub.2 rich stream from the SO.sub.2 removal system to a CO.sub.2 removal system, and introducing an enriched SO.sub.2 stream back to the Claus unit. The SO.sub.2 removal system can include one or more SO.sub.2 selective membranes. The CO.sub.2 removal system can include one or more CO.sub.2 selective membranes.

A process for recovering sulfur in a sulfur recovery unit comprising the steps of reacting hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent; reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants; reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent; reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream; reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream comprises sulfur dioxide; and separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, the recycle stream comprises sulfur dioxide.

A process for recovering sulfur in a sulfur recovery unit comprising the steps of reacting hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent; reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants; reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent; reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream; reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream comprises sulfur dioxide; and separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, the recycle stream comprises sulfur dioxide.

Thermoneutral systems and methods for producing carbon monoxide (CO) and sulfur dioxide (SO.sub.2) are disclosed. The systems can include a first reaction zone and a second reaction zone, where heat generated in the first reaction zone is sufficient to drive a carbon dioxide gas (CO.sub.2(g)) and elemental sulfur gas (S(g)) reaction to produce a product stream that includes CO(g) and SO.sub.2(g).

Disclosed is a method of producing carbon monoxide (CO) and sulfur dioxide (SO.sub.2), the method comprising obtaining a reaction mixture comprising carbon dioxide gas (CO.sub.2(g)) and elemental sulfur gas (S(g)), and subjecting the reaction mixture to conditions sufficient to produce a product stream comprising CO(g) and SO.sub.2(g).

The present invention concerns a method for oxidizing reactant sulfur(S) and/or reactant sulfur dioxide (SO2) by means of carbon dioxide (CO2), comprising the steps of: a) decomposing CO2 to form carbonyl (CO) radicals and oxygen (O) radicals by igniting a plasma in a plasma process fluid stream comprising said CO2: b) contacting reactant sulfur and/or reactant sulfur dioxide with said oxygen radicals, thereby: oxidizing said reactant sulfur to product sulfur dioxide and/or product sulfur trioxide (SO3), and/or oxidizing said reactant sulfur dioxide to product sulfur trioxide, thereby obtaining an outlet fluid stream comprising said product sulfur dioxide and/or said product sulfur trioxide.

Methods and systems for producing sulfuric acid and/or sulfur trioxide, which may include contacting a first stream that includes oxygen and a second stream that includes sulfur to produce a third stream that includes sulfur dioxide, and subjecting the third stream to an oxidation reaction to produce a fourth stream that includes sulfur trioxide. The contacting of the first and second streams may include contacting a molar amount of oxygen that exceeds a molar amount of sulfur.

Sulfur species may be processed using an ionic liquid, a deep eutectic solvent, or a combination of both. An example of a method of such processing may include: supplying a first reaction medium including an iodine species and a first catalyst, wherein the first catalyst includes a first deep eutectic solvent, a first ionic liquid, or a first mixture of both; contacting the reaction medium with a first sulfur species, wherein the first sulfur species includes hydrogen sulfide, a sulfur-containing hydrocarbon, or any combination thereof; and reacting the first sulfur species with the reaction medium to produce a second sulfur species, hydrogen iodide, or a combination thereof.