A system and method including a sulfur recovery system (SRU) having a Claus system, reacting hydrogen sulfide and oxygen in a furnace to give sulfur dioxide, performing a Claus reaction in the furnace to give elemental sulfur, performing the Claus reaction in a Claus reactor to give elemental sulfur at a temperature greater than a dew point of the elemental sulfur, performing the Claus reaction in a Claus cycling reactor to give elemental sulfur at a temperature less than a solidification temperature of the elemental sulfur, depositing the elemental sulfur as solid elemental sulfur on catalyst in the Claus cycling reactor, and regenerating (heating) the Claus cycling reactor thereby forming elemental sulfur vapor from the solid elemental sulfur.

A system and method including a sulfur recovery system (SRU) having a Claus system, reacting hydrogen sulfide and oxygen in a furnace to give sulfur dioxide, performing a Claus reaction in the furnace to give elemental sulfur, performing the Claus reaction in a Claus reactor to give elemental sulfur at a temperature greater than a dew point of the elemental sulfur, performing the Claus reaction in a Claus cycling reactor to give elemental sulfur at a temperature less than a solidification temperature of the elemental sulfur, depositing the elemental sulfur as solid elemental sulfur on catalyst in the Claus cycling reactor, and regenerating (heating) the Claus cycling reactor thereby forming elemental sulfur vapor from the solid elemental sulfur.

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.

A process for production of elemental sulfur from a feedstock gas including from 15% to 100 vol % H2S and a stream of sulfuric acid, the process including: a) providing a Claus reaction furnace feed stream substoichiometric oxygen with respect to the Claus reaction, b) directing to a reaction furnace zone operating at elevated temperature such as above 900° C., c) directing to a sulfuric acid evaporation zone downstream said reaction furnace zone, d) cooling to provide a cooled Claus converter feed gas, e) directing to contact a material catalytically active in the Claus reaction, f) withdrawing a Claus tail gas and elemental sulfur, g) directing to a Claus tail gas treatment plant, with the associated benefit of a process involving injection of sulfuric acid in a sulfuric acid evaporation zone allowing high temperature combustion of said feedstock gas, including impurities, without cooling from evaporation and decomposition of sulfuric acid.

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.

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%.

Described is related to nano-structured composite materials for removing harmful chemical air pollutants and odors from the air to prevent people from breathing in disease-causing chemicals and provide them with clean indoor air. The nano-structured composite materials comprise nano-catalysts embedded in the pores of nano-structured substrate materials selected from the group consisting of nano-porous carbon, nano-porous rare earth oxide, nano-porous zeolite, nano-porous alumina and nano-porous silica. The nano-scale synergy of nano-catalysts and nano-structured substrate materials provides effective air filtration materials for the complete trapping and elimination of the full spectrum of chemical air pollutants including both organic and inorganic compounds and odors for indoor spaces, which HEPA or activated carbon filters cannot achieve.

A system includes a purification unit configured to process a vapor stream including sulfur dioxide. The purification unit includes an inlet configured to allow the vapor stream to enter the purification unit. The purification unit includes a steam coil configured to circulate steam and provide a source of heat. The purification unit includes a packed bed. The purification unit includes a tray configured to accumulate sulfur. The purification unit includes an absorber section configured to remove at least a portion of the sulfur dioxide from the vapor stream. The purification unit includes an outlet configured to allow an effluent with a lower sulfur dioxide content than the vapor stream to exit the purification unit. The system includes a sulfur tank including a vent line in fluid communication with the inlet. The vent line is configured to allow vapor to flow from the sulfur tank to the purification unit.

Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80 680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.

The methods and systems are disclosed which leverage sulfur abatement resources present at most refineries or other hydrocarbon processing plants, such as natural gas processing plants to capture and treat sulfur-containing byproducts, such as SO.sub.2, generated during the regeneration of spent HDP catalysts. Thus, the disclosed methods and systems allow for converting hazardous waste spent catalyst to a salable product at it source while simultaneously capturing the sulfur oxides removed from the catalyst and converting them to a useful product instead of a resultant waste stream requiring management and/or disposal. Thus, spent sulfur bearing refinery wastes, such as HDP catalyst, can be roasted or regenerated at the refinery site to convert the hazardous sulfur-bearing wastes into one or more salable products.