This desulfurization device is for desulfurizing a discharge gas which contains sulfur oxides and which was discharged from a device for sulfuric acid production that includes a concentrated-sulfuric-acid production step in which sulfur trioxide gas obtained by oxidizing sulfur dioxide gas is absorbed in an aqueous sulfuric acid solution while supplying water thereto to thereby produce sulfuric acid having a concentration as high as 90 wt % or more but less than 99 wt %, the desulfurization device comprising: a desulfurization tower in which the sulfur oxides are removed from the discharge gas and, simultaneously therewith, dilute sulfuric acid is formed from the sulfur oxides; and a dilute sulfuric acid mixer which, in the concentrated-sulfuric-acid production step, mixes the dilute sulfuric acid with the aqueous sulfuric acid solution.

Commercial production of sulfuric acid is almost entirely accomplished nowadays using the contact process. And the trend is to increase conversion efficiency and reduce emissions of unconverted sulfur dioxide. By using a special combination of contact catalyst beds, a single contact single absorption (SCSA) system can be engineered to achieve the conversion and emission capabilities of conventional double contact double absorption systems. Thus, the complexity and cost of incorporating a second absorption tower and associated heat exchanger in the system can be omitted. In the SCSA system, the initial catalyst bed or beds comprise vanadium oxide catalyst and the last catalyst bed or beds comprise platinum catalyst operating at a much lower temperature than the initial beds.

The present disclosure relates to a process for purification of an aqueous solution comprising hydrogen sulfide comprising the steps of a. directing an amount of recycle gas to contact the aqueous solution comprising hydrogen sulfide, to separate a gas comprising hydrogen sulfide from the aqueous solution, b. heating said gas comprising hydrogen sulfide optionally after addition of a source of oxygen to provide a process feed gas, c. in a hydrogen sulfide oxidation step directing said process feed gas to oxidation of hydrogen sulfide to sulfur dioxide, d. in a sulfur dioxide oxidation step directing said sulfur dioxide rich gas to contact a material catalytically active in oxidation of sulfur dioxide to sulfur trioxide, to provide a sulfur trioxide rich gas e. in a condensation step cooling said sulfur trioxide rich gas, to enable hydration of sulfur trioxide and condensation of sulfuric acid to provide a stream of concentration sulfuric acid and a purified process gas, and in a recycling step, directing at least a part of the purified process gas as said recycle gas.

The present disclosure relates to a process for purification of an aqueous solution comprising hydrogen sulfide comprising the steps of a. directing an amount of recycle gas to contact the aqueous solution comprising hydrogen sulfide, to separate a gas comprising hydrogen sulfide from the aqueous solution, b. heating said gas comprising hydrogen sulfide optionally after addition of a source of oxygen to provide a process feed gas, c. in a hydrogen sulfide oxidation step directing said process feed gas to oxidation of hydrogen sulfide to sulfur dioxide, d. in a sulfur dioxide oxidation step directing said sulfur dioxide rich gas to contact a material catalytically active in oxidation of sulfur dioxide to sulfur trioxide, to provide a sulfur trioxide rich gas e. in a condensation step cooling said sulfur trioxide rich gas, to enable hydration of sulfur trioxide and condensation of sulfuric acid to provide a stream of concentration sulfuric acid and a purified process gas, and in a recycling step, directing at least a part of the purified process gas as said recycle gas.

Improved systems and methods are disclosed for treating tail gas in a sulfuric acid production plant. A tail gas treatment system is employed which comprises a product stripper and a purge gas scrubber. The inventive arrangement provides an advantageous economical way to remove high levels of SO.sub.2 from the tail gas stream.

Improved systems and methods are disclosed for treating tail gas in a sulfuric acid production plant. A tail gas treatment system is employed which comprises a product stripper and a purge gas scrubber. The inventive arrangement provides an advantageous economical way to remove high levels of SO.sub.2 from the tail gas stream.

A novel integrated system utilizing sulfur as alternative carbon-free fuel in an ammonia primary reformer combustion zone, with co-production of sulfuric acid from concentrated SO.sub.2 off-gas stream. Such integration shall reduce hydrocarbon fuel consumption, minimize CO.sub.2 emissions, and optimize overall energy utilization.

A method for manufacturing electronic-grade sulfuric acid includes following steps: providing sulfur-containing material; burning the sulfur-containing material with pure oxygen to obtain sulfur dioxide gas; converting the sulfur dioxide gas into sulfur trioxide gas; and processing the sulfur trioxide gas to obtain the electronic-grade sulfuric acid.

Provided herein are methods and systems for treating a sulfur dioxide-containing gaseous stream. The method includes combusting a tail gas in an excess of oxygen gas to yield a thermal oxidizer effluent containing sulfur dioxide and oxygen. The thermal oxidizer effluent is introduced to an oxidative catalytic converter to convert sulfur dioxide to sulfur trioxide, thereby forming an oxidized gas stream. The oxidized gas stream is routed to a quench tower and contacted with a dilute aqueous acid quench stream to yield sulfurous acid, hydrated sulfur dioxide, or both. The sulfurous acid or hydrated sulfur dioxide is oxidized with the excess of oxygen from the thermal oxidizer effluent to yield sulfuric acid.

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.