The present invention relates to a method for the catalytic removal of sulfur dioxide from waste gases in two reactors, wherein the first reactor is charged with an activated carbon catalyst. The method comprises: a. provision of a waste gas with a water content of less than 1 g H.sub.2O/Nm.sup.3 and an SO.sub.2 content of at least 5 ppm, b. introduction of the waste gases into a first reactor, c. catalytic conversion of the SO.sub.2 into gaseous SO.sub.3 in the first reactor by the activated carbon catalyst, wherein catalytic conversion on the activated carbon catalyst proceeds at a temperature of below 100° C., d. introduction of the prepurified waste gases from the first reactor into a second reactor, e. conversion of the SO.sub.3 with water into H.sub.2SO.sub.4 in the second reactor.

The present invention relates to a method for the catalytic removal of sulfur dioxide from waste gases in two reactors, wherein the first reactor is charged with an activated carbon catalyst. The method comprises: a. provision of a waste gas with a water content of less than 1 g H.sub.2O/Nm.sup.3 and an SO.sub.2 content of at least 5 ppm, b. introduction of the waste gases into a first reactor, c. catalytic conversion of the SO.sub.2 into gaseous SO.sub.3 in the first reactor by the activated carbon catalyst, wherein catalytic conversion on the activated carbon catalyst proceeds at a temperature of below 100° C., d. introduction of the prepurified waste gases from the first reactor into a second reactor, e. conversion of the SO.sub.3 with water into H.sub.2SO.sub.4 in the second reactor.

The invention relates to a method for manufacturing sulphuric acid, which involves converting sulphur dioxide SO.sub.2 into sulphur trioxide S0.sub.3, by injecting gaseous sulphur dioxide into a converter (1) inside which at least one mass (2) of a catalyst for the conversion is present, and according to which, during phases in which the injection of the gaseous sulphur dioxide is stopped, the space inside the converter (1) is heated in such a way as to maintain a minimum temperature of 200° C., and preferably 250° C., within each catalyst mass (2), characterized by the fact that the stopping of the injection of the sulphur dioxide is slaved to the starting of the heating, and vice versa.

A method of removing hydrogen peroxide from sulfuric acid includes the following steps: First step of pouring the sulfuric acid having 0.1 wt % to 10 wt % of hydrogen peroxide into a vessel. Second step of adding a catalyst containing copper and a copper compound to the vessel to undergo a reaction with the sulfuric acid to remove the hydrogen peroxide from the sulfuric acid, to generate heat, and to generate metal ions in the sulfuric acid. Third step of activating a cooling device to cool the vessel to a predetermined temperature range. Fourth step of adding hydrogen sulfide to the vessel to undergo a reaction with the metal ions to generate metallic sulfide and metal free sulfuric acid. Fifth step of purifying the metallic sulfide and the metal free sulfuric acid to obtain purified metallic sulfide and purified sulfuric acid as products.

A method of removing hydrogen peroxide from sulfuric acid includes the following steps: First step of pouring the sulfuric acid having 0.1 wt % to 10 wt % of hydrogen peroxide into a vessel. Second step of adding a catalyst containing copper and a copper compound to the vessel to undergo a reaction with the sulfuric acid to remove the hydrogen peroxide from the sulfuric acid, to generate heat, and to generate metal ions in the sulfuric acid. Third step of activating a cooling device to cool the vessel to a predetermined temperature range. Fourth step of adding hydrogen sulfide to the vessel to undergo a reaction with the metal ions to generate metallic sulfide and metal free sulfuric acid. Fifth step of purifying the metallic sulfide and the metal free sulfuric acid to obtain purified metallic sulfide and purified sulfuric acid as products.

H2 production, sulfuric acid and SO2 production process refers to an innovative process VIA the phenomena of the Sulfur-Iodine (S-I) thermochemical cycle. The process consist of the acid gas burner to burn all the acid gases with air, enriched air or oxygen and without using any fuel gas to produce SO2. The acid gases are normally processed in the prior arts of the sulfur recovery units. Iodine is used to produce the hydrogen.

A portion or all of the acid gases are sent to the acid gas burner in accordance with the present invention.

The present innovation not only produces hydrogen but also reduces the SO2 and CO2 emissions.

The produced SO2 is sent to other units to produce other fertilizer products and the produced CO2 is sent to CO2 removal or CO2 Liquefaction process.

The hydrogen is produced is used to supply the needs within the facility like hydrotreaters to reduce external import and to reduce the operating costs.

H2 production, sulfuric acid and SO2 production process refers to an innovative process VIA the phenomena of the Sulfur-Iodine (S-I) thermochemical cycle. The process consist of the acid gas burner to burn all the acid gases with air, enriched air or oxygen and without using any fuel gas to produce SO2. The acid gases are normally processed in the prior arts of the sulfur recovery units. Iodine is used to produce the hydrogen.

A portion or all of the acid gases are sent to the acid gas burner in accordance with the present invention.

The present innovation not only produces hydrogen but also reduces the SO2 and CO2 emissions.

The produced SO2 is sent to other units to produce other fertilizer products and the produced CO2 is sent to CO2 removal or CO2 Liquefaction process.

The hydrogen is produced is used to supply the needs within the facility like hydrotreaters to reduce external import and to reduce the operating costs.

A process plant for production of sulfuric acid from a process gas comprising SO2, including a process gas inlet, a first SO2 converter having an inlet and an outlet, a first condenser having a gas inlet, a gas outlet and a liquid outlet, a gas mixing device having a first inlet, a second inlet and an outlet, a process gas heater having an inlet and an outlet, a second SO2 converter having an inlet and an outlet, a second condenser having a gas inlet, a gas outlet and a liquid outlet, one or more means for cooling and storage of sulfuric acid and a purified process gas outlet.

A process plant for production of sulfuric acid from a process gas comprising SO2, including a process gas inlet, a first SO2 converter having an inlet and an outlet, a first condenser having a gas inlet, a gas outlet and a liquid outlet, a gas mixing device having a first inlet, a second inlet and an outlet, a process gas heater having an inlet and an outlet, a second SO2 converter having an inlet and an outlet, a second condenser having a gas inlet, a gas outlet and a liquid outlet, one or more means for cooling and storage of sulfuric acid and a purified process gas outlet.

The invention is a method and a sulfuric acid plant design for reduction of start-up SO.sub.2, SO.sub.3 and H.sub.2SO.sub.4 emissions in sulfuric acid production, in which SO2 is converted to SO.sub.3 in n successive catalyst beds, where n is an integer >1. The final catalytic beds are used as absorbents for SO.sub.2 to SO3 during the start-up procedure, and one or more of the m beds downstream the first bed are purged, either separately or simultaneously, with hot gas, where m is an integer >1 and m<n, during the previous shut-down. Also, one separate purge with hot gas is used on the final bed.