A method and system for cooling sulfuric acid aqueous solutions (H.sub.2SO.sub.4) belonging to the field of chemical processes, which is part of a contact process for production of sulfuric acid with or without energy recovery. The method comprises absorption of SO.sub.3, which produces heated concentrated sulfuric acid and indirectly cooling the hot acid. The method uses a sulfuric acid-inert coolant. A cooling step comprises an intermediate indirect acid-fluid cooling and a second fluid-water or fluid indirect cooling stepthird fluid, wherein when the process is of the type with energy recovery. A third step includes energy recovery, steam generation. A system to perform the method, which works next to the SO.sub.3 absorption tower comprises an acid cooling loop consisting of an intermediate acid-fluid heat exchanger; a second fluid-water heat exchanger, and when the process is of the type with energy recovery, said equipment further includes a steam generation boiler.

Sulfur trioxide is produced from a feed stream comprising sulfur-containing compounds and dissolved metals, such as alkali metals, in a plant comprising an incineration furnace, a waste heat boiler, a dilution air heater, a dust removal absorber and an SO.sub.2 converter. The plant may further comprise a sulfuric acid condenser for the production of sulfuric acid.

A system (100) for producing aqueous sulphuric acid. The system (100) comprises a first heat exchanger (410) configured to cool water and/or aqueous sulphuric for producing cooled water and/or cooled aqueous sulphuric acid; a pre-cooling unit (200) configured to pre-cool some gas containing sulphur trioxide, the pre-cooling unit (200) comprising an inlet or inlets (212, 214) for receiving [i] the gas containing sulphur trioxide and [ii] the cooled water and/or the cooled aqueous sulphuric acid, an outlet (216) for letting out aqueous sulphuric acid and the gas containing sulphur trioxide, and a first nozzle (220) for spraying the cooled water and/or the cooled aqueous sulphuric acid onto the gas containing sulphur trioxide to cool the gas containing sulphur trioxide. The system further comprises a condensation tower (300) comprising a first inlet (302) for receiving the cooled gas containing sulphur trioxide and aqueous sulphuric acid from the pre-cooling unit (200) and means (320) for circulating the aqueous sulphuric acid within the

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 present invention, in general, relates to portable/transportable apparatuses, methods, and systems for generating and delivering sulfur trioxide on-site or near an item to be treated. The present invention also relates to portable/transportable apparatuses, methods, and systems for removing hydrocarbon contaminants including waxes, paraffins, resins, and ashpaltenes from surfaces and treating the surfaces to reduce hydrocarbon contaminant build-up on the surfaces.

The present invention, in general, relates to portable/transportable apparatuses, methods, and systems for generating and delivering sulfur trioxide on-site or near an item to be treated. The present invention also relates to portable/transportable apparatuses, methods, and systems for removing hydrocarbon contaminants including waxes, paraffins, resins, and ashpaltenes from surfaces and treating the surfaces to reduce hydrocarbon contaminant build-up on the surfaces.

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.

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.

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 invention describes a process for producing sulfuric acid by catalytic oxidation of SO.sub.2 to SO.sub.3 and subsequent absorption of the SO.sub.3 in sulfuric acid, wherein the SO.sub.3 is introduced into a first absorption stage (primary absorber) and at least partly absorbed there in concentrated sulfuric acid, wherein the SO.sub.3 not absorbed in the first absorption stage is supplied to a second absorption stage (secondary absorber) for the further absorption in concentrated sulfuric acid, and wherein the sulfuric acid is cooled after passing through the two absorption stages. The cooling of the sulfuric acid is effected in at least two heat exchangers connected in parallel, wherein one of the at least two heat exchangers is operated as partial evaporator and is cooled with boiler feed water/steam and the other one is cooled with cooling water and operated as pure acid cooler.