A catalytic reactor may have at least one reactor module and a shell that extends about a reactor center axis. The reactor module may include a gas distribution chamber, a gas collection chamber, and a catalyst. The gas distribution chamber may be connected to a shell-side gas feed. The gas collection chamber may be connected to a shell-side gas discharge. A catalyst bed between the distribution and collection chambers may extend transversely to the reactor center axis. The gas distribution and collection chambers are bounded by the catalyst bed and reactor walls. The gas feed either opens into the gas distribution chamber on the shell side or is connected to a pipe length that extends towards the reactor center axis and opens into the gas distribution chamber in the region of the reactor center axis. A height parallel to the reactor center axis of the gas distribution chamber reduces towards the reactor center axis starting from a mouth of the gas feed in the case of a shell-side connection.

The above mentioned invention describes a process for cooling a gas mixture of SO.sub.2 and/or SO.sub.3 and water, wherein the gas mixture is cooled by means of a first heat exchanger carrying a coolant. The temperature of the coolant lies above the dew point of the gas or gas mixture.

A process for the catalytic conversion of sulfur dioxide to sulfur trioxide to increase sulfuric acid regeneration from a spent sulfuric acid stream or other sulfur-containing stream includes replacing at least a portion of the atmospheric air typically used to oxidize sulfur dioxide to sulfur trioxide with oxygen by introducing oxygen-enriched air and/or pure oxygen feed streams into the process. A related apparatus for use in the process is also provided for catalytic conversion of sulfur dioxide to sulfur trioxide.

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.

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.

A process and a process plant for conversion of SO.sub.2 to H.sub.2SO.sub.4 including a. directing a process gas stream including at least 15 vol % SO.sub.2, and an amount of O.sub.2 originating from a source of purified O.sub.2 or O.sub.2 enriched air to contact a first material catalytically active in oxidation of SO.sub.2 to SO.sub.3 under oxidation conditions involving a maximum steady state temperature of the catalytically active material above 700 C., to provide an oxidized process gas stream, wherein the material catalytically active in oxidation of SO.sub.2 to SO.sub.3 includes an active phase in which the weight ration of vanadium to other metals is at least 2:1 supported on a porous carrier comprising at least 25 wt % crystalline silica, b. absorbing at least an amount of the produced SO.sub.3 in a stream of lean sulfuric acid to provide a stream of liquid sulfuric acid.

A process and a process plant for conversion of SO.sub.2 to H.sub.2SO.sub.4 including a. directing a process gas stream including at least 15 vol % SO.sub.2, and an amount of O.sub.2 originating from a source of purified O.sub.2 or O.sub.2 enriched air to contact a first material catalytically active in oxidation of SO.sub.2 to SO.sub.3 under oxidation conditions involving a maximum steady state temperature of the catalytically active material above 700 C., to provide an oxidized process gas stream, wherein the material catalytically active in oxidation of SO.sub.2 to SO.sub.3 includes an active phase in which the weight ration of vanadium to other metals is at least 2:1 supported on a porous carrier comprising at least 25 wt % crystalline silica, b. absorbing at least an amount of the produced SO.sub.3 in a stream of lean sulfuric acid to provide a stream of liquid sulfuric acid.

Improved systems and methods are disclosed for producing sulfuric acid or for producing liquefied sulfur dioxide. The systems comprise a reactor for the combustion of sulfur to sulfur dioxide, a reactor gases heat exchanger, and either a contact apparatus and absorption apparatus combination or an absorption subsystem and liquefaction apparatus combination for producing either sulfuric acid or liquid sulfur dioxide respectively. By appropriately incorporating two recycle circuits, the first after the reactor gases heat exchanger and the second after the absorption apparatus or liquefaction apparatus, several advantages can be obtained. These include reductions in equipment size, complexity, power consumption energy losses, and suppression of NOx.

A process for the production of liquid acid, comprising the steps of: feeding liquid acid with a first concentration into a gas purification; passing a gas through the gas purification such that a second concentration of the liquid acid is reached; withdrawing the liquid acid from the sump of the gas purification, where in the gas purification sump is divided by a partition wall into a first and a second section. The concentration of the liquid acid collected in the first section is adjusted to the first concentration. The liquid acid with the first concentration from the first section is at least partially fed back into step and the liquid acid with the second concentration collected in the second section is at least partially withdrawn as product.

A process for the production of liquid acid, comprising the steps of: feeding liquid acid with a first concentration into a gas purification; passing a gas through the gas purification such that a second concentration of the liquid acid is reached; withdrawing the liquid acid from the sump of the gas purification, where in the gas purification sump is divided by a partition wall into a first and a second section. The concentration of the liquid acid collected in the first section is adjusted to the first concentration. The liquid acid with the first concentration from the first section is at least partially fed back into step and the liquid acid with the second concentration collected in the second section is at least partially withdrawn as product.