A process and a process plant for production of elemental sulfur from a feedstock gas including from 15 vol % to 100 vol % H2S and a stream of sulfuric acid, the process including a) providing a Claus reaction furnace feed stream with a substoichiometric amount of oxygen, b) directing s to a reaction furnace operating at elevated temperature, c) cooling, d) directing to contact a material catalytically active in the Claus reaction, e) withdrawing a Claus tail gas and elemental sulfur, f) directing to a means for sulfur oxidation, g) directing to contact a material catalytically active in SO2 oxidation to SO3, h) converting to concentrated sulfuric acid, i) recycling to the Claus reaction furnace, wherein an amount of combustibles, in the Claus tail gas, is oxidized in the presence of a material catalytically active in sulfur oxidation, at an inlet temperature below 400° C.

Systems and methods use bimetallic alloy particles for converting hydrogen sulfide (H.sub.2S) to hydrogen (H.sub.2) and sulfur (S), typically during multiple operations. In a first operation, metal alloy composite particles can be converted to a composite metal sulfide. In a second operation, composite metal sulfide from the first operation can be regenerated back to the metal alloy composite particle using an inert gas stream. Pure, or substantially pure, sulfur can also be generated during the second operation.

Methods and systems are provided for treating the tail gas stream of a sulfur recovery plant. The methods including generating a tail gas stream from a sulfur recovery plant, treating the tail gas stream with a hydrogen sulfide removal unit and a hydrogen selective membrane unit, generating a stream low in hydrogen sulfide and a stream rich in hydrogen. The hydrogen sulfide rich stream is recycled to the sulfur recovery unit. The hydrogen selective membrane unit includes a glassy polymer membrane selective for hydrogen over hydrogen sulfide and carbon dioxide.

A revamp process for modifying a sulfur abatement plant including a Claus process plant, the Claus process plant including a Claus reaction furnace and one or more Claus conversion stages, each Claus conversion stage including a conversion reactor and a means for elemental sulfur condensation, and a means of Claus tail gas oxidation configured for receiving a Claus tail gas from said Claus process plant and configured for providing an oxidized Claus tail gas, the process revamp including: a) providing a sulfuric acid producing tail gas treatment plant producing sulfuric acid, and b) providing a means for transferring an amount or all of the sulfuric acid produced in said sulfuric acid producing tail gas treatment plant to said Claus reaction furnace, wherein the moles of sulfur in the transferred sulfuric acid relative to the moles of elemental sulfur withdrawn from the Claus process plant is from 3% to 25%.

In a method for capturing carbon, sulfur, and/or nitrogen from a target source, a matrix including activated metal dispersed in a metal activating agent is provided. The target source may be or include a carbon, sulfur, and/or nitrogen target compound. The target source is contacted with the matrix, wherein the activated metal reacts with the target source to produce elemental carbon, elemental sulfur, elemental nitrogen, and/or one or more compounds transformed from the target compound(s). The matrix may be produced by contacting a metal with the metal activating agent, and maintaining contact between the metal and the metal activating agent for a period of time sufficient for metal atoms from the solid metal to disperse in the metal activating agent. The reaction may also produce a metal compound. The activated metal may also be utilized in alkylation and other synthesis processes.

In a method for capturing carbon, sulfur, and/or nitrogen from a target source, a matrix including activated metal dispersed in a metal activating agent is provided. The target source may be or include a carbon, sulfur, and/or nitrogen target compound. The target source is contacted with the matrix, wherein the activated metal reacts with the target source to produce elemental carbon, elemental sulfur, elemental nitrogen, and/or one or more compounds transformed from the target compound(s). The matrix may be produced by contacting a metal with the metal activating agent, and maintaining contact between the metal and the metal activating agent for a period of time sufficient for metal atoms from the solid metal to disperse in the metal activating agent. The reaction may also produce a metal compound. The activated metal may also be utilized in alkylation and other synthesis processes.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S- containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.

A system and method for recovering sulfur in a copper smelting process includes removing fine dust from high-concentration SO.sub.2 flue gas from a matte smelting furnace, introducing the flue gas into a fluidized bed carbothermic reduction tower to be reduced by a carbon-based reducing agent to obtain reducing gas, passing the reducing gas through a high temperature separator to separate down unsaturated powder coke contained in the reducing gas, and condensing the reducing gas to obtain sulfur. The saturated powder coke entrained in the reducing gas enters a desorption tower to desorb SO.sub.2 gas therein, and the desorbed powder coke enters a fluidized bed sulfur reduction tower to continue to participate in the reduction reaction. Part of the SO.sub.2 gas discharged from the desorption tower is discharged to the fluidized bed carbothermic reduction tower to produce sulfur, and the other part enters a desulfurization tower.

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.

Disclosed is a catalyst suitable for the catalytic oxidative cracking of a H.sub.2S-containing gas stream. The catalyst comprises at least one or more active metals selected from the group consisting of iron, cobalt, and nickel, supported by a carrier comprising ceria and alumina. The active metal is preferably in the form of its sulphide. Also disclosed is a method for the production of hydrogen from a H.sub.2S-containing gas stream, comprising subjecting the gas stream to catalytic oxidative cracking so as to form H.sub.2 and S.sub.2, using a catalyst in accordance with any one of the composition claims.