Abstract: A mono-pressure plant for the production of nitric acid, comprising an ammonia convertor configured for operating at a working pressure ranging between 2 bar and 16 bar, for oxidizing ammonia, thereby producing a gaseous NOx gas/steam mixture; an air compressor in fluid communication with the ammonia convertor, for pressurizing air to the working pressure; an absorber unit, wherein the nitrogen oxides contained in a gaseous NOx stream react with water, thereby producing nitric acid; a first bleacher unit for stripping the dissolved nitrogen oxides from the output product stream, thereby producing a first NOx-loaded stripping gas; and a means for directing the first NOx-loaded stripping gas to an inlet of the absorber unit.

Abstract: A dual pressure plant for the production of nitric acid, comprising: an air compressor; a converter, operating at a low pressure (LP), operable to be fed with a stream of an ammonia/pressurized air mixture to produce an LP gaseous NOx gas/steam mixture, comprising water, NO, NO2 and N2O4; a NOx gas compressor; an absorber unit (6); and a bleacher unit; wherein the plant comprises means for directing the NOx-loaded stripping gas to the downstream side of the NOx gas compressor; the plant being characterized in that it further comprises a high-pressure (HP) water electrolyser, in fluid communication with the bleacher unit.

Abstract: A vertical absorption column comprising a liquid distributor comprising a feed box having a serrated weir for distribution of a liquid through upward-pointing serrations of the serrated weir into perforated trays of the liquid distributor and located directly above a structured packing, a structured packing, a plate packing comprising a plurality of horizontal plates, provided with cooling means, an inlet for the addition of oxygen to the lower part of the vertical absorption column, an inlet for the process gas comprising nitrogen oxides from an ammonia oxidation process at the lower part of the vertical absorption column, an inlet for an aqueous solution at the upper part of the vertical absorption column, at least one nitric acid outlet at the bottom of the vertical absorption column and an outlet for tail gas comprising nitrogen oxides at the top of the vertical absorption column.

Abstract: A vertical bleaching tower for removing dissolved nitrogen oxides from an aqueous nitric acid solution using a stripping gas such as air, nitrogen, oxygen or combinations thereof in a process for producing nitric acid, comprising a structured packing; a liquid distributor comprising a feed box having a serrated weir for distribution of the aqueous nitric acid solution comprising the dissolved nitrogen oxides through upward-pointing serrations of the serrated weir into perforated trays of the liquid distributor and located above the structured packing for distributing the aqueous nitric acid solution comprising the dissolved nitrogen oxides to the structured packing; an inlet and outlet, both suitable for aqueous nitric acid solution; and an inlet and outlet, both suitable for the stripping gas.

Abstract: A support system for catalyst gauzes in an ammonia oxidation burner and a method of reducing movement of particulate ceramic material due to thermal dilatation includes the catalyst gauzes (1) and possibly support screens (2) being supported by ceramic fillings contained in a burner basket with metal walls and a perforated bottom plate. A “wave breaker” (9, 11) is fixed to the metal wall (4) and/or the outer part/periphery of the bottom plate (5).

Abstract: The invention comprise a support system for catalyst gauzes in an ammonia oxidation burner and a method of reducing movement of particulate ceramic material due to thermal dilatation. The catalyst gauzes (1) and possibly support screens (2) are being supported by ceramic fillings contained in a burner basket with metal walls and a perforated bottom plate. A “wave breaker” (9, 11) is fixed to the metal wall (4) and/or the outer part/periphery of the bottom plate (5).