116results about "Nitric acid" patented technology

The invention discloses a conjugated polymer photocatalyst, a preparation method thereof and application of the conjugated polymer photocatalyst in photocatalytic synthesis of nitric acid, and belongs to the technical field of polymer materials and photocatalysis. The preparation method of the catalyst mainly comprises the following steps: synthesizing an intermediate 2CzTPN-Br through a nucleophilic substitution reaction, then synthesizing an intermediate TBBA through an esterification reaction, and finally copolymerizing the intermediate 2CzTPN-Br and the intermediate TBBA through a coupling polymerization reaction to obtain the target catalyst. The preparation method disclosed by the invention is controllable in process, and the obtained catalyst does not need to participate in noble metal and has wide light absorption, high specific surface area and excellent carrier separation efficiency; when being applied to photocatalytic synthesis of nitric acid, nitrogen in air can be directly and efficiently converted into nitric acid under the mild conditions of room temperature, air atmosphere and water serving as a solvent, excellent durability is shown, the yield of nitric acid can reach 4466.2 mol g <-1 > cat after 324-hour continuous illumination, and wide application prospects are achieved in the field of green synthesis.

A burner basket assembly of an ammonia oxidation reactor, wherein the burner basket assembly comprises a burner basket inner side wall, a gas-permeable bottom plate, wherein between the burner basket inner side wall and the bottom plate a circumferential radial clearance is present, an L-shaped clearance cover profile which comprises a horizontal clearance cover plate and a vertical clearance cover plate which has a certain length, wherein the horizontal and the vertical clearance cover plate are mechanically fixed to each other, and wherein the L-shaped cover profile during operation is displaceable in a vertical direction in view of the burner basket inner side wall, a support ring which is mechanically fixed to the burner basket inner side wall, an upside-down positioned L-shaped locking profile, comprising a horizontal locking plate and a vertical locking plate which are mechanically fixed to each other, wherein the horizontal locking plate is mechanically fixed to the support ring, wherein the L-shaped locking profile, the support ring and the respective part of the burner basket inner side wall limit a ring-shaped gap into which at least a top part of the vertical clearance cover plate is located, and wherein between the support ring and the vertical clearance cover plate a distance is arranged which is such that the vertical displacement of the vertical clearance cover plate in view of the burner basket inner side wall is limited by the support ring and at all times during the operation of the burner basket, collision between the L-shaped clearance cover profile and the L-shaped locking profile is avoided.

This utility model discloses an energy-saving device for nitric acid recovery, including a demineralized water preheater. The outlet of the demineralized water preheater is connected to the inlet of a second demineralized water heater, and the outlet of the second demineralized water heater is connected to the inlet of a nitrogen oxide cooler. It also includes a nitrogen oxide compressor, the outlet of which is connected to the inlet of a first demineralized water heater, and the outlet of the first demineralized water heater is connected to the inlet of a rapid cooler. Furthermore, it includes a demineralized water boiler feed pump, the outlet of which is also connected to the inlet of the first demineralized water heater, the outlet of the first demineralized water heater, and the outlet of the second demineralized water heater, which is also connected to the inlet of the demineralized water preheater. Compared to existing technologies, this utility model adds two demineralized water heaters, recovering heat from nitrogen oxides through demineralized water, reducing the amount of circulating water used, and simultaneously reducing the amount of steam used in the steam drum.

The application belongs to the technical field of nitric acid decolorization, and particularly relates to a microelectronic nitric acid decolorization device, which comprises a decolorization barrel, a corrugated barrel is fixedly connected to the inner side of the decolorization barrel, a cavity is arranged between the decolorization barrel and the corrugated barrel, the cavity is divided into left and right cavities by two front and back partitions, an air outlet disc is fixedly connected to the bottom end of the corrugated barrel, the top end of the air outlet disc is fixedly connected to the bottom end of the decolorization barrel, a feed pipe is fixedly connected to the front left side of the top end of the decolorization barrel, an activated carbon pipe is fixedly connected to the left side of the top end of the feed pipe, an air inlet pipe one is fixedly connected to the rear left side of the top end of the decolorization barrel, a transmission box is fixedly connected to the middle side of the top end of the decolorization barrel, and transmission assemblies symmetrically arranged on the left and right sides of the transmission box are arranged on the outer side of the transmission box. The microelectronic nitric acid decolorization device provided by the application can solve the problem that the contact area is affected by the synchronous rotation of gas and liquid, and can also perform secondary reaction on the gas which is not completely reacted in the reaction process.

There is provided a method for the synthesis of nitrogen oxides (NOx) comprising the steps of providing a gas mixture comprising oxygen and nitrogen; and heating the gas mixture to a temperature of at least 2300 K at a pressure of 10-100 bar in a thermal reactor forming a gas mixture comprising NOx. There is also provided a method for the production of HNO3.

The utility model discloses a nitric acid preparation device for simulating an early atmospheric photochemical reaction of the earth. The nitric acid preparation device comprises an ultraviolet photochemical reaction system, a reaction gas source feeding system, a water vapor generator and a nitric acid freezing collector, the ultraviolet photochemical reaction system comprises an ultraviolet light source and a reaction chamber, and the ultraviolet light source is used for providing ultraviolet light required by reaction into the reaction chamber; the reaction gas source supply system is communicated with the reaction chamber and is used for supplying gas required for generating nitric acid through ultraviolet light chemical reaction into the reaction chamber; the water vapor generator is used for providing water vapor for the reaction chamber; the water vapor generator is connected with the reaction chamber; the nitric acid freezing collector is connected with the reaction chamber and is used for collecting nitric acid generated by photochemical reaction in the reaction chamber. The utility model realizes the preparation of nitric acid by simulating the early atmospheric photochemical reaction of the earth.

The invention provides a heat pipe enhanced heat exchange reducing absorption tower for nitric acid preparation, which comprises a tower body and a heat pipe exchanger, nitric oxide gas enters from the tower bottom, absorption liquid enters from the tower top, and the nitric oxide gas and the absorption liquid contact and react in the tower body to generate nitric acid, and is characterized in that the tower body is divided into a plurality of sections from top to bottom, the diameters of the sections are different, and the diameters of the sections are different in the direction from top to bottom; the diameter of the tower body is gradually increased; a plurality of heat pipe heat exchangers are arranged, an inclined angle is formed between the heat pipe heat exchangers and the tower body, an evaporation section of each heat pipe is arranged in the tower body, and a condensation end of each heat pipe extends out of the tower body. The design of the reducing absorption tower is matched with the concentration of nitrogen oxide, so that the absorption efficiency can be remarkably improved.

The present disclosure provides systems and methods for effecting chemical conversion using a plasma generating device. Advantageously, the plasma generating device is configured to directly deliver a plasma to fluid within a reservoir in a manner sufficient to create supersonic flow within the fluid. Such systems and methods can enhance reaction efficiency and convenience. A method of providing a point-of-use fertilizer composition is disclosed; the method comprising: introducing a gas feed stream comprising air into a plasma generating device; operating the plasma generating device to produce a plasma output comprising NOx compounds; injecting the plasma output through an outlet component into a reservoir having a fluid contained therein in a manner sufficient to create 5 supersonic flow within the fluid, wherein the outlet component is submerged within the fluid and wherein the fluid comprises water; withdrawing a liquid product stream from the reservoir; and optionally adjusting the pH of the liquid product stream for use as a point-of-use fertilizer composition.

The invention discloses a novel process for joint production of concentrated nitric acid and dilute nitric acid. The novel process comprises the procedures of N2O4 separation, absorption, rectification, oxidation and bleaching. The N2O4 separation is to separate liquid N2O4 from the NOX gas produced by a double-pressurization method; the absorption is that NOX which is not completely separated is absorbed to generate dilute nitric acid; in the rectification step, dilute nitric acid generated by absorption is concentrated to obtain a finished product dilute nitric acid; in the oxidation step, dilute nitric acid, liquid N2O4 and oxygen are subjected to a reaction to generate concentrated nitric acid, and in the bleaching step, impurities in the concentrated nitric acid are removed to obtain the finished product concentrated nitric acid. By technically improving the nitric acid device adopting the double-pressurization method, the concentrated nitric acid and the dilute nitric acid can be co-produced, the production cost of the concentrated nitric acid and the dilute nitric acid can be effectively reduced, a new concentrated nitric acid production device is not needed, and the existing production line is improved at low cost. In addition, the yield of concentrated nitric acid and dilute nitric acid can be controlled by controlling the separation amount of N2O4.

This invention discloses a waste acid recovery method based on ion exchange separation technology, belonging to the field of waste acid recovery technology. The method includes the following steps: passing a waste nitric acid solution containing aluminum and chloride ions through a cation exchange resin to adsorb aluminum ions; adding silver nitrate solution to the adsorbed waste liquid to allow silver ions to react with chloride ions to form silver chloride precipitate; filtering out the silver chloride precipitate to obtain a nitric acid solution; removing the silver chloride precipitate, using aluminum foil as a reducing agent, and adding a small amount of hydrochloric acid to reduce the silver chloride to silver powder; washing the reduced silver powder and dissolving it in nitric acid to obtain a silver nitrate solution for recycling. This waste acid recovery method based on ion exchange separation technology solves the problem of excessive total nitrogen in wastewater discharge; it also significantly reduces waste acid treatment costs and improves economic efficiency.

The invention relates to a process for producing nitric acid comprising at least one step for treating a gaseous effluent containing N2O, said process comprising at least the following steps in this order: - a step in which ethanol is added to the gaseous effluent; - a step for treating the gaseous effluent which is a decomposition step of the N2O on a catalytic bed containing at least one catalyst comprising an iron-exchanged ferrierite zeolite, at a temperature below 400°C. The invention also relates to a nitric acid production unit.

The invention provides a production method and production equipment of an aromatic nitro compound, and the production method comprises the following steps: carrying out nitration reaction on fuming nitric acid, a sulfuric acid-nitric acid mixed solution and aromatic hydrocarbon to obtain a nitration product crude product and waste acid; performing first-stage pickling on the nitration product crude product by using first pickling water to obtain a first-stage pickled crude product and first-stage yellow water; performing second-stage pickling on the first-stage pickling crude product by adopting second pickling water to obtain a second-stage pickling crude product and second-stage yellow water; mixing the first-grade yellow water with a nitric acid replenishing solution to obtain a sulfuric acid-nitric acid mixed solution, and returning the sulfuric acid-nitric acid mixed solution to the nitration reaction as a raw material; the second pickling water is concentrated wastewater generated by concentrating a byproduct dilute sulfuric acid in the preparation process of fuming nitric acid to form concentrated sulfuric acid; the first pickling water is a mixed solution formed by mixing secondary yellow water and sulfuric acid. The production method is good in operation stability, simple in technological process and low in cost.

This invention discloses a conjugated polymer photocatalyst, its preparation method, and its application in the photocatalytic synthesis of nitric acid, belonging to the fields of polymer materials and photocatalysis technology. The preparation method mainly includes: firstly, synthesizing the intermediate 2CzTPN-Br via a nucleophilic substitution reaction; subsequently, synthesizing the intermediate TBBA via esterification; and finally, copolymerizing the two via coupling polymerization to obtain the target catalyst. The preparation method of this invention is process-controllable, and the resulting catalyst does not require the participation of noble metals, exhibiting broad light absorption, high specific surface area, and excellent carrier separation efficiency. When applied to the photocatalytic synthesis of nitric acid, it can directly and efficiently convert nitrogen in the air into nitric acid under mild conditions of room temperature, air atmosphere, and water as a solvent, exhibiting excellent durability. After 324 hours of continuous light irradiation, the nitric acid yield can reach 4466.2 µmol g. ‑1 cat It has broad application prospects in the field of green synthesis.

The present application relates to a stainless steel pickling waste mixed acid treatment system and a method for recovering nitric acid and hydrofluoric acid, the stainless steel pickling waste mixed acid treatment system comprising a waste acid storage tank, an electrolytic cell, an air extraction device, a spraying device, a filtering device, a cathode acid storage tank and an anode acid storage tank, wherein the electrolytic cell is provided with a cation membrane, separating the electrolytic cell into a cathode chamber and an anode chamber, the cathode chamber being connected to the cathode acid storage tank through the corresponding air extraction device and spraying device, for guiding the hydrogen fluoride gas volatilized from the cathode chamber into the cathode acid storage tank, the anode chamber being connected to the anode acid storage tank through the corresponding air extraction device and spraying device, for guiding the nitric acid gas volatilized from the anode chamber into the anode acid storage tank, the cathode chamber and the filtering device being connected into a circulating loop, for circulating and filtering the cathode liquid to remove the precipitate in the cathode liquid, the filtering device also being connected to the cathode acid storage tank, and the anode chamber being connected to the anode acid storage tank. The above-mentioned waste mixed acid treatment system can realize the recovery of nitric acid and hydrofluoric acid in the waste mixed acid.

The invention discloses an efficient nitric acid concentration device in adipic acid production. The efficient nitric acid concentration device comprises a first concentration tower, a second concentration tower, a reboiler, a heater, a first preheater, a second preheater, a first cooler, a second cooler, a first condensate tank and a second condensate tank which are sequentially arranged, in the production process of nitric acid double-effect thermal coupling rectification concentration, by balancing the thermal coupling matching degree of the two concentration towers and recycling the heat of secondary gas and liquid, the efficiency of the concentration towers and the secondary gas-thermal coupling utilization rate are improved, the operation flexibility and stability of the concentration towers are improved, and the production cost is reduced. The nitric acid concentration quality is improved, steam is saved, and the production cost is reduced.

The invention relates to the technical field of radioactive waste liquid treatment, in particular to a method for recycling nitric acid in uranium purification raffinate by adopting a heat pump rectification technology. According to the method, the nitric acid in the uranium purification raffinate is recovered by adopting a vacuum distillation technology, and the steam at the top of the rectifying tower is pressurized and heated by a heat pump compressor to serve as a heat source of a tower bottom reboiler and a feed preheater, so that the energy of the steam at the top of the rectifying tower is recycled, and the energy consumption of production operation is reduced. Meanwhile, the blockage of the reboiler is reduced through the arrangement of a pretreatment system, a forced circulation system and the like; and through the arrangement of the steam washing tower, the heat pump compressor is prevented from being damaged by acid steam, so that the operation stability of the whole system is improved, and the overhaul frequency is reduced.

The invention provides an ultra-clean high-purity nitric acid production process, and belongs to the field of nitric acid production.The ultra-clean high-purity nitric acid production process comprises the specific steps that raw materials are prepared; carrying out primary processing on nitric acid, controlling the room temperature, filtering the nitric acid, and collecting ultrapure nitric acid; distilling nitric acid, distilling diluted nitric acid, mixing ultra-pure nitric acid with high-purity water, diluting, filtering the nitric acid again, and performing secondary distillation on the filtered nitric acid; the nitric acid is cooled, the nitric acid is placed in a refrigerating chamber to be cooled, and airflow is increased to cool the nitric acid; filling and storing the cooled nitric acid; and the storage tank is taken out of the refrigerating chamber and then sealed. According to the invention, distilled nitric acid can be rapidly cooled, so that the time between distillation and filling can be shortened, the production efficiency can be greatly improved, and the quality of a product produced by the technical process reaches the SEMI G5 level for integrated circuit manufacturing.

Provided herein are systems and methods for producing renewable nitrogen products.

The invention discloses an adipic acid crystallizer vacuum system and method capable of realizing zero liquid discharge of nitrogen-containing wastewater, which adopts a multi-stage Roots vacuum unit to realize pressure control on the adipic acid crystallizer vacuum system and a nitric acid concentration tower through a front buffer tank of the multi-stage Roots vacuum unit. Most condensable gas of the nitrite-containing steam generated by the adipic acid crystallizer is condensed and recovered to a condensate tank by using a gas condenser; uncondensed nitrogen-containing gas and a gas phase of the nitric acid concentration tower enter a buffer tank through pressure control, then are extruded by a multi-stage vacuum unit and are subjected to deep condensation treatment, condensed liquid enters a liquid storage tank through potential difference, and liquid in the liquid storage tank is sent to the nitric acid concentration tower through liquid level control to serve as reflux absorption liquid to absorb nitrite gas volatilized by the concentration tower; the adipic acid crystallizer vacuum system technology replaces a traditional steam injection pressurization vacuum system technology, consumption of medium-pressure steam and circulating water is reduced, zero liquid discharge of nitrogen-containing wastewater is achieved, and the adipic acid crystallizer vacuum system technology has remarkable environmental protection benefits and economic benefits.

A catalyst support system (1) for an ammonia oxidation burner (2), comprising a catalytic gauze for oxidation of ammonia; a basket (14) connected to a supporting ring (10) for containing an inert and / or a catalyst for removing N2O from a gaseous effluent of said catalytic gauze (9); said basket (14) has a modular structure including a plurality of modules, wherein each module includes a gas-permeable surface (16) and a supporting frame (15), wherein each module is connected to adjacent modules by connections adapted to allow a limited displacement between modules, wherein only outer modules forming the periphery of the basket are connected to said supporting ring (10).

The application belongs to the field of chemical raw material recovery, and discloses a mixed acid waste liquid recovery and refining system and method. The system comprises a nitric acid pyrolysis kettle, an absorption tower, an extraction tower, a backwashing tower, a rectifying tower and a drying tower. The pyrolysis gas phase outlet of the nitric acid pyrolysis kettle is connected with the inlet of the kettle top condenser, and the outlet of the kettle top condenser is connected with a non-condensable gas output pipeline, which is connected with the non-condensable gas inlet of the absorption tower. The absorption liquid outlet of the absorption tower is connected with the absorption liquid heavy phase inlet of the extraction tower. The extraction liquid outlet of the extraction tower is connected with the extraction liquid light phase inlet of the backwashing tower. The non-nitric acid waste liquid outlet of the nitric acid pyrolysis kettle and the raffinate outlet of the extraction tower are connected with the feed inlet of the rectifying tower. The tower liquid outlet of the rectifying tower is connected with the inlet of the tower kettle circulating production pump, and one of the outlets of the tower kettle circulating production pump is connected with the feed inlet of the drying tower. The application can recover nitric acid, hydrochloric acid and sulfuric acid in the mixed acid waste liquid containing metal cations.

The present disclosure relates to a nitric acid production process and apparatus in which the off-gas is recycled to a burner and O2 is fed to an absorption section in a molar ratio to the ammonia feed.

The invention discloses a circulating evaporation nitric acid recovery system in adipic acid production, which is provided with a gas-liquid separation circulating tank, a heater, a falling film evaporator and a vacuum system connected with the upper part of the gas-liquid separation circulating tank through a pipeline, and a flash plate with flash holes is laid in the gas-liquid separation circulating tank; the heaters comprise the first heater and the second heater which are arranged in parallel, forced circulation is adopted for the heaters and the gas-liquid separation circulation tank, materials are pushed to flow under the action of the circulation pump, the tube pass turbulence degree is improved, scaling is reduced, and the problems that a traditional evaporator is high in energy consumption, prone to scaling and the like are solved. In addition, a falling-film evaporator is adopted, a falling-film distributor, namely an overflow weir, is arranged above a tube bundle, materials uniformly enter a heating tube through the falling-film distributor, and a uniform thin liquid film is formed, so that turbulent flow is remarkably enhanced, a thermal boundary layer is destroyed, and strong shearing and scouring effects are generated.

The present invention relates to a method for recovery of NOx, said method comprising: producing a flue gas stream comprising NOx in a gas turbine, cooling said flue gas stream, and feeding the cooled flue gas stream to a NOx recovery unit to obtain a purified NOx flue gas stream. The invention further relates a system configured to carry out said method and to the use of said system.

The present invention relates to a method and system for preparing a metal oxide precursor for a battery by means of the spray pyrolysis of a nitrate. The method comprises: preparing a metal nitrate mixed solution; atomizing the metal nitrate mixed solution and spraying same into a reaction furnace, and then pyrolyzing same in different heating zones in the reaction furnace, so as to obtain a metal oxide mixture and high-temperature flue gas; subjecting the high-temperature flue gas to a waste heat recovery treatment, and then conveying same to a regeneration device for recovery, so as to obtain regenerated nitric acid; and subjecting the metal oxide mixture to secondary heating at the bottom of the reaction furnace. In the present invention, the metal oxide precursor is prepared by means of spray pyrolysis, and compared with a traditional coprecipitation and calcination process, the method is more economical and has lower operation costs; moreover, since different heating zones are used for pyrolysis, the method has a wider range of application, and can be used for metal nitrates having different pyrolysis temperatures.

The invention relates to the technical field of chemical engineering, and discloses a nitric acid production process and a nitric acid production system. According to the nitric acid production process, a nitric oxide supercharger is additionally arranged on the downstream of a nitric oxide compressor in a traditional four-in-one unit, the pressure of an outlet of the nitric oxide compressor can be reduced, and insufficient pressure is supplemented by the nitric oxide supercharger; in the reaction process of nitric oxide and water, the rotating speed N of a nitric oxide supercharger and / or the water supplementing amount Q of the top of the absorption tower are / is adjusted by monitoring the mass concentration C1 of nitric acid at the bottom of the absorption tower and the content C2 of NOX in tail gas at the top of the absorption tower in real time, so that the mass concentration of nitric acid is controlled to be 66% or above.

An integrated process for the synthesis of ammonia and nitric acid, comprising the production of hydrogen from water electrolysis, controlled by selective switching between a first mode of operation and a second mode of operation, wherein in the first mode of operation, an excess of ammonia is produced and stored in a suitable ammonia reservoir; in the second mode of operation, ammonia from the ammonia reservoir is used to provide an additional input amount of ammonia for the production of nitric acid; the switching between the first and second modes is based on the amount of power delivered to the water electrolysis.

The invention discloses a nitric acid absorption tower and an absorption process thereof, and belongs to the technical field of nitric acid production. The nitric acid absorption tower comprises an absorption unit, a washing unit and a recovery unit, a plurality of absorption structures are arranged in an absorption box of the absorption unit in a linear array mode, and the absorption structures are used for spraying and absorbing nitric oxide to form nitric acid; the washing unit is located above the absorption unit, a plurality of gas mixing structures distributed in a linear array mode are arranged in the washing box, and the gas mixing structures are used for mixing air and nitric acid and washing the nitric acid; the recycling unit is arranged between the washing unit and the absorption unit, the washing unit is connected with the recycling unit through an exhaust pipe arranged on the upper portion of the washing unit, and the recycling unit is connected with the absorption box through a gas return pipe and sends recycled gas into the absorption box. By adopting the nitric acid absorption tower and the absorption process thereof, the problems of low nitric oxide conversion rate and low nitric acid concentration of the existing absorption tower can be solved.