The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

A dynamically adjustable rate sulfur recovery process continuously calculates and adjusts sour gas stream operating pressure and/or flow rate to maximize sweet gas output, thereby improving efficiency. A corresponding desulfurization system may include a fixed-sized pressure vessel, a flow control valve that controls the rate of flow of a sour gas stream into the pressure vessel, a sensor that measures sulfur concentration in the sour gas stream, a reagent tank, an oxidizer tank, and a phase separator that separates sweet gas as a gaseous phase after hydrogen sulfide in the sour gas stream in the pressure vessel is converted to elemental sulfur, sulfur species, or both by contact with reagent from the reagent tank and oxidizer from the oxidizer tank. A PLC (programmable logic controller) continuously calculates updated flow rates based on sulfur concentration measurements from the sensor to achieve maximum sweet gas production.

A dynamically adjustable rate sulfur recovery process continuously calculates and adjusts sour gas stream operating pressure and/or flow rate to maximize sweet gas output, thereby improving efficiency. A corresponding desulfurization system may include a fixed-sized pressure vessel, a flow control valve that controls the rate of flow of a sour gas stream into the pressure vessel, a sensor that measures sulfur concentration in the sour gas stream, a reagent tank, an oxidizer tank, and a phase separator that separates sweet gas as a gaseous phase after hydrogen sulfide in the sour gas stream in the pressure vessel is converted to elemental sulfur, sulfur species, or both by contact with reagent from the reagent tank and oxidizer from the oxidizer tank. A PLC (programmable logic controller) continuously calculates updated flow rates based on sulfur concentration measurements from the sensor to achieve maximum sweet gas production.

A method for recovering sulfur within a gas processing system is described herein. The method includes contacting a natural gas stream including an acid gas with a solvent stream within a co-current contacting system to produce a sweetened natural gas stream and a rich solvent stream including an absorbed acid gas. The method also includes removing the absorbed acid gas from the rich solvent stream within a regenerator to produce a concentrated acid gas stream and a lean solvent stream. The method further includes recovering elemental sulfur from hydrogen sulfide (H.sub.2S) within the concentrated acid gas stream via a sulfur recovery unit.

A method for recovering sulfur within a gas processing system is described herein. The method includes contacting a natural gas stream including an acid gas with a solvent stream within a co-current contacting system to produce a sweetened natural gas stream and a rich solvent stream including an absorbed acid gas. The method also includes removing the absorbed acid gas from the rich solvent stream within a regenerator to produce a concentrated acid gas stream and a lean solvent stream. The method further includes recovering elemental sulfur from hydrogen sulfide (H.sub.2S) within the concentrated acid gas stream via a sulfur recovery unit.

A method for removing sulfides from an aqueous liquid, wherein the aqueous liquid is contacted with an oxidizer in the presence of fibrous material dyed with at least one sulfur dye or sulfurized vat dye, to convert the sulfides in the aqueous liquid to a non-toxic product.

A method for removing sulfides from an aqueous liquid, wherein the aqueous liquid is contacted with an oxidizer in the presence of fibrous material dyed with at least one sulfur dye or sulfurized vat dye, to convert the sulfides in the aqueous liquid to a non-toxic product.