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.

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.

A sulfuric acid recovery device includes a first recovery tank configured to recover sulfuric acid; a concentration meter configured to measure a concentration of hydrogen peroxide in the sulfuric acid; a discharge pipe configured to discharge the sulfuric acid from the first recovery tank to a second recovery tank; a circulation pipe with a maximum installation height position equal to or lower than a maximum installation height position of the discharge pipe and with a flow path formed, causing the sulfuric acid to return to the first recovery tank; a first valve configured to open and close a flow path of the discharge pipe; a pump configured to feed the sulfuric acid discharged to at least the circulation pipe of the circulation pipe and the discharge pipe; and a control circuit configured to control opening and closing of the first valve in accordance with the concentration of the hydrogen peroxide.

A sulfuric acid recovery device includes a first recovery tank configured to recover sulfuric acid; a concentration meter configured to measure a concentration of hydrogen peroxide in the sulfuric acid; a discharge pipe configured to discharge the sulfuric acid from the first recovery tank to a second recovery tank; a circulation pipe with a maximum installation height position equal to or lower than a maximum installation height position of the discharge pipe and with a flow path formed, causing the sulfuric acid to return to the first recovery tank; a first valve configured to open and close a flow path of the discharge pipe; a pump configured to feed the sulfuric acid discharged to at least the circulation pipe of the circulation pipe and the discharge pipe; and a control circuit configured to control opening and closing of the first valve in accordance with the concentration of the hydrogen peroxide.

A recycling system and method for treating waste sulfuric acid solution containing hydrogen peroxide are provided. The recycling system includes a preheat subsystem, a reaction cycle control subsystem, and a cooling subsystem. The preheat subsystem heats the waste sulfuric acid solution to a target temperature through a cyclic heat exchange method and then further raises the temperature using an acid-resistant heater. The reaction cycle control subsystem monitors the sulfuric acid concentration, hydrogen peroxide content, reaction temperature, and nitrate compound content of the waste sulfuric acid solution to determine the amount and mode of addition of a nitrate-containing promoter. The cooling subsystem includes a first cooling heat exchanger to transfer waste heat to the initial waste sulfuric acid solution and a second cooling heat exchanger to reduce the sulfuric acid to a safe temperature, thereby avoiding overheating.

A recycling system and method for treating waste sulfuric acid solution containing hydrogen peroxide are provided. The recycling system includes a preheat subsystem, a reaction cycle control subsystem, and a cooling subsystem. The preheat subsystem heats the waste sulfuric acid solution to a target temperature through a cyclic heat exchange method and then further raises the temperature using an acid-resistant heater. The reaction cycle control subsystem monitors the sulfuric acid concentration, hydrogen peroxide content, reaction temperature, and nitrate compound content of the waste sulfuric acid solution to determine the amount and mode of addition of a nitrate-containing promoter. The cooling subsystem includes a first cooling heat exchanger to transfer waste heat to the initial waste sulfuric acid solution and a second cooling heat exchanger to reduce the sulfuric acid to a safe temperature, thereby avoiding overheating.

A method for separating arsenic and heavy metals in an acidic washing solution which contains both arsenic and heavy metal, more particularly in a washing solution which is formed in copper smelting and contains sulphuric acid, comprises a separation process section, in which arsenic and at least one primary heavy metal are separated from one another. The separation process section comprises a processing step, in which hydrogen peroxide H2O2 is added to the washing solution, and the separation process section comprises a precipitation stage, in which the washing solution is admixed with a sulphide precipitation reagent, causing the at least one primary heavy metal to precipitate in the form of a metal sulphide. The processing step in this system is carried out before the precipitation stage.

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.

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.

Disclosed is a methanol and sulfuric acid co-production system capable of producing methanol and sulfuric acid in equal equivalents. Specifically, the system includes an oxidation reaction unit configured to produce methyl bisulfate (CH.sub.3OSO.sub.3H) by reacting methane gas with an acid solution in the presence of a catalyst, a reactive distillation unit disposed downstream of the oxidation reaction unit and configured to esterify methyl bisulfate (CH.sub.3OSO.sub.3H) supplied from the oxidation reaction unit with trifluoroacetic acid (CF.sub.3COOH) to obtain a product and to separate the product into methyl trifluoroacetate (CF.sub.3COOCH.sub.3) and sulfuric acid (H.sub.2SO.sub.4) through thermal distillation, and a hydrolysis reaction unit disposed downstream of the reactive distillation unit and configured to produce methanol by hydrolyzing methyl trifluoroacetate (CF.sub.3COOCH.sub.3) supplied from the reactive distillation unit, in which the reactive distillation unit recirculates the sulfuric acid resulting from separation to the oxidation reaction unit.