Process for reducing the content of NOx and N2O from an input tail gas of a nitric acid process, said input tail gas having a temperature lower than 400 C., the process comprising an abatement stage at least including a deN2O stage and deNOx stage and providing a conditioned tail gas having a temperature greater than the input tail gas, wherein, prior to submission to said abatement stage, said input tail gas is pre-heated to a temperature of at least 400 C. by indirect heat exchange with at least a portion of said conditioned gas.

A system suitable for oxidizing ammonia with oxygen in the presence of catalysts is described. The system includes a reactor equipped with at least one supply line for a reactant gas mixture and at least one discharge line for a process gas; a catalyst comprising at least one transition metal oxide that is not an oxide of a platinum metal; and a device for adjusting a molar ratio of oxygen to ammonia of less than or equal to 1.75 mol/mol in the reactant gas mixture by mixing an oxygen-containing gas stream having an O.sub.2 content of <20% by volume with a chosen amount of ammonia. The oxygen-containing gas stream is produced by a device for: diluting an air stream with a gas stream comprising less than 20% by volume oxygen; or depleting oxygen from an oxygen-containing gas mixture, preferably from air; or by a combination thereof.

A system suitable for oxidizing ammonia with oxygen in the presence of catalysts is described. The system includes a reactor equipped with at least one supply line for a reactant gas mixture and at least one discharge line for a process gas; a catalyst comprising at least one transition metal oxide that is not an oxide of a platinum metal; and a device for adjusting a molar ratio of oxygen to ammonia of less than or equal to 1.75 mol/mol in the reactant gas mixture by mixing an oxygen-containing gas stream having an O.sub.2 content of <20% by volume with a chosen amount of ammonia. The oxygen-containing gas stream is produced by a device for: diluting an air stream with a gas stream comprising less than 20% by volume oxygen; or depleting oxygen from an oxygen-containing gas mixture, preferably from air; or by a combination thereof.

Wire for weaving or knitting a catalyst gauze, said wire being characterized in that it is a stranded wire comprising an assembly of n intertwined filaments, n being an integer with 2n8, wherein each of said filaments comprises Pt or a Pt alloy constituted of at least 50% by 5 weight of Pt, said filaments being twisted together over their length so that each of the filaments is wound to at least one other filament.

A high energy recovery process in nitric acid production process recovers, utilizes and/or stores heat energy in at least four stages. In the first stage, a first heat energy is recovered at the catalytic oxidation of ammonia to nitric oxide to generate high-pressure steam used for a first electrical power generation. A second heat energy is recovered at the catalytic oxidation of nitric oxide to nitrogen dioxide to generate low-pressure steam used for a second electrical power generation in the second stage. The nitrogen dioxide is further cooled in a condenser and a third heat energy is recovered and stored in a thermal storage via a heat pump. The nitrogen gas is absorbed to produce nitric acid in an absorber resulting in a hot tail gas stream. The hot tail gas stream is expanded over a tail gas turbine for a third electrical power generation.

A metal-organic compound containing polymer matrix includes a polymer and a three-dimensional metal-organic framework includes a polydentate organic linker. The metal-organic compound containing polymer matrix is configured to continuously produce nitric oxide when exposed to a physiological fluid including a nitric oxide-releasing compound via a catalytic reaction catalyzed by the three-dimensional metal-organic framework.

A method for the production of nitric acid, comprising a step of oxidation of ammonia in the presence of a catalyst, comprising a step of monitoring the temperature of said catalyst by at least one contactless infrared sensor.

Ammonia oxidation catalyst units comprising a pair of honeycomb-type blocks having interplaced between them a layer of a gas permeable material performing the function of radially mixing the gas flow, said blocks comprising an ammonia oxidation catalysts, and having height of less than 15 cm and the interplaced layer height of 3 to 0.5 cm.

Known catalyst systems for the catalytic combustion of ammonia to form nitrogen oxides consist of a plurality of catalyst gauze layers which are knitted, woven or braided from platinum-based precious metal wire, which form a catalyst package when arranged after one another when viewed in a fresh gas flow direction. In order to provide a catalyst system on this basis for use in a medium-pressure system, with which a yield of the main product NO comparable to the industry standard can be achieved despite the reduced precious metal use, according to the invention, the catalyst package is formed from a front assembly with three catalyst gauzes with a first average mass per unit area and a downstream assembly of catalyst gauze layers arranged after the front assembly and having a second average mass per unit area, wherein the average mass per unit area of the front assembly has a short weight in the region of 1.5% to 29% in relation to the second average mass per unit area, and the first average mass per unit area lies in the regions of 410 to 30 g/m.sup.2 and the second average mass per unit area lies in the region of 540 to 790 g/m.sup.2.

A catalyst gauze and gauze pack comprise a knitted catalyst gauze containing a first layer of a first wire material, wherein the first wire material is made from a platinum-rhodium alloy, and wherein the first layer contains an activator in the form of a second wire material which is knitted among the first wire material, and which is made from un-alloyed platinum.