310 results about "Ammoxidation" patented technology

The invention discloses an amorphous PtNi self-supporting catalytic electrode, a preparation method thereof and a direct ammonia fuel cell, and belongs to the technical field of electrode materials. According to the technical scheme, the catalytic electrode adopts foamed nickel as a conductive framework substrate, and an amorphous PtNi alloy wall-shaped array structure grows on the foamed nickel in situ; the preparation method of the catalytic electrode comprises the following steps: pretreating the foamed nickel substrate; the preparation method comprises the following steps: adding platinum diacetylacetonate, potassium hydroxide, N, N-dimethylformamide and diethylenetriamine into ethylene glycol to prepare a precursor solution; and immersing foamed nickel into the precursor solution, and carrying out in-situ growth reaction under high-temperature and high-pressure conditions to obtain the amorphous PtNi self-supporting catalytic electrode. The catalytic electrode has the beneficial effects that the catalytic electrode shows high specific activity and extremely low apparent activation energy in ammoxidation reaction, still keeps 90% of current density after continuously working for 1000 hours, and shows excellent long-term stability and durability.

A process method for preparing acrylonitrile through propylene ammoxidation belongs to the field of chemical engineering, and is characterized in that in a corresponding device and a reaction system of the method, propylene, ammonia gas and air (in terms of O2) enter a fluidized bed reactor at 400-450 DEG C and 0.01-0.15 MPa for reaction according to a ratio of 1: (1-1.5): (2-10) at a weight hourly space velocity of 0.04-0.1 h <-1 >; the micro-sphere catalyst with the particle size of 40-60 microns in the dense-phase section and the dilute-phase section has alpha-phase bismuth molybdate, gamma-phase bismuth molybdate and lattice oxygen active centers and meets the chemical formula MoaBibNicWdTleVfPgSixOy, the atomic ratio a in the formula is 21-22, the atomic ratio b in the formula is 1.5-2, the atomic ratio c in the formula is 4-5, the atomic ratio d in the formula is 0.8-1, the atomic ratio e in the formula is 0.09-0.1, the atomic ratio f in the formula is 0.15-0.2, the atomic ratio g in the formula is 0.8-1, the atomic ratio x in the formula is 70-71, and y is the number of oxygen atoms needed by the atomic valence of all elements; a product enters a quench tower and a water absorption tower to be neutralized and cooled, and then passes through a recovery tower, an acetonitrile tower, a decyanation tower, a layering device and a finished product tower to realize separation of a water phase and an organic phase, so that crude acetonitrile, hydrocyanic acid and refined acrylonitrile are further obtained. The process is good in conversion degree and product selectivity, stable and reliable in operation, energy-saving and environment-friendly.

This invention discloses a composite sponge carrier for anaerobic ammonia oxidation, its preparation method, and its application, belonging to the field of wastewater treatment technology. The composite sponge carrier comprises: a porous polyurethane sponge and a composite component loaded on the surface and internal pores of the porous polyurethane sponge; wherein the composite component includes chitosan-modified biochar as a microbial affinity functional component and zeolite powder as a component for ammonia nitrogen adsorption and ion exchange regulation. This invention introduces more active functional groups and hydrophilic interfaces conducive to microbial attachment through chitosan modification, and then co-impregnates and loads it with zeolite powder onto the surface and pores of the polyurethane sponge. This improves the composite sponge carrier's retention and enrichment capacity for anaerobic ammonia oxidizing bacteria, improves the local substrate environment during the start-up phase, promotes rapid biofilm establishment, and enhances the system's operational stability.

The invention relates to the technical field of catalyst preparation, in particular to a catalyst for preparing 2, 4-dichlorobenzonitrile and a preparation process of the catalyst. The prepared catalyst overcomes the problems that a traditional catalyst for synthesizing 2, 4-dichlorobenzonitrile is poor in catalytic property and poor in catalytic cycle stability. The catalyst is composed of main active metals containing vanadium / molybdenum / tungsten and the like, rare earth metals, acid and alkali metals and other active components and a molecular sieve carrier, and the conversion rate and selectivity of ammoxidation reaction are significantly improved through the synergistic effect of the multi-metal components and through the mechanisms of redox cycle, electron transfer regulation and control, acid site optimization and the like. The carrier adopts a hydrothermal synthesis process, and is subjected to pre-crystallization, crystallization, calcination, ammonium chloride exchange and other steps to form a regular pore channel structure, so that the metal-carrier interaction is enhanced, and the activity stability in recycling is guaranteed; according to the mixing process, through two-stage calcination and accurate proportion regulation and control, uniform loading of active metal is achieved, and the finally prepared catalyst is excellent in catalytic performance and high in stability.

A catalyst for preparing acrylonitrile by propylene ammoxidation, a preparation method therefor, and a use thereof. The catalyst comprises an active component and a carrier, and the active component comprises Mo, Bi, Fe, at least one rare earth element, at least one alkali metal element, and at least one alkaline earth metal element. The catalyst has a molybdate crystal plane distribution index RQ of 0.65-0.98, where RQ = (R'+Q') / (R+Q).

The present invention discloses an ammonia oxidation process and a method for recovering Rh from a gas phase comprising volatile precious metals, comprising the steps of: a) generating or providing volatile precious metals, particularly by operating a catalytic system comprising a catalyst, wherein the catalyst contains precious metals, wherein the precious metals at least comprise Rh, wherein the volatile precious metals comprise at least volatile Rh; b) contacting volatile Rh generated in step a) with a recovery system comprising a compound of formula Co3-xMxO4, where M is Fe or Al and x = 0-2; and c) forming a solid composition comprising the compound of formula Co3-xMxO4 and Rh, wherein the compound of formula Co3-xMxO4 is bonded with Rh, particularly as determined by SEM-EDS and TEM analysis. The present invention further relates to the use of the compound of formula Co3-xMxO4, where M is Fe or Al and x = 0-2, or the use of the recovery system, for recovering at least volatile Rh.

The application provides an ammonia oxidation catalyst, a preparation method and application thereof, and a method for synthesizing acrylonitrile by propylene ammonia oxidation, and the general formula of the active component of the catalyst is Mo 12 Bi a B b C c D d O x ; wherein B is selected from at least one of group VIII metal elements; C is selected from at least one of alkaline earth metal elements; D is selected from at least one of alkali metal elements; and the hollow rate of the catalyst is 0-5%. The catalyst has the advantages of good sphericity, few hollow particles, uniform particle size distribution, good fluidization state in a fluidized bed reactor, less catalyst loss after long-term operation, high acrylonitrile yield, low content of by-products two-carbon and propylene aldehyde, and better long-term operation stability.

The invention discloses a vanadium-chromium composite oxide material. The composition of the composite oxide is VCrxMyOz, wherein M is one of Ti, Mo, W, B, Fe, Co, Ni, Cu, Zn, Sb, Bi, alkali metal or alkaline earth metal; x is equal to 0.1-3 and is the atom molar ratio of chromium to vanadium; y is equal to 0-1.5 and is the atom molar ratio of M to vanadium; z is determined according to the valence state of atoms; the composite oxide material is a porous hollow microsphere formed by assembling blocky or flaky nanoparticles, and the diameter of the composite oxide material is 1-100 [mu] m. The invention also discloses a preparation method and application of the material. Vanadium and chromium compounds and compounds of other elements are used as raw materials, amino acid compounds are used as auxiliary reagents, the prepared vanadium and chromium composite oxide can be self-assembled to form a porous hollow micron spherical structure, and the microsphere material is uniform in particle size distribution and large in specific surface area; the vanadium-chromium composite oxide with the structure can be used for preparing aromatic nitrile through ammoxidation reaction of methyl aromatic hydrocarbon, the ammoxidation reaction temperature is low, the reaction activity and the product yield are high, and the selectivity is good.

The present application provides a catalyst for preparing acrylonitrile, which comprises a carrier and an active component, wherein the active component is a metal oxide having the general formula (I) A a B b C c Fe d Ni e Bi f Mo 12 O x (I). The present application also provides a method for preparing the catalyst for preparing acrylonitrile of the present application. The present application also provides the use of the catalyst for preparing acrylonitrile of the present application or the catalyst for preparing acrylonitrile prepared according to the method of the present application in the preparation of acrylonitrile by propylene ammoxidation. The catalyst for preparing acrylonitrile of the present application still has a high acrylonitrile yield under a high propylene load. The catalyst not only has a high acrylonitrile yield under a high propylene load, but also has a low acrolein yield, so that the acrylonitrile recovery rate of the device is high to improve the production efficiency and economic benefit of the device.

The application provides a method for synthesizing adiponitrile by selective ammoxidation of epoxycyclohexane. The purpose of the application is to simulate and optimize the process of synthesizing adiponitrile by one-step direct ammoxidation of epoxycyclohexane, and to develop a new type of multiphase composite metal vanadium-based oxide catalyst, which is composed of Co a V b P c Mo d MNOx / TiO2, the active elements of which include vanadium element V, cobalt element Co, phosphorus element P and molybdenum element Mo, M is an auxiliary metal element (Mn, Cr, Fe or Ni), N is an alkali metal (Na, K or Cs); the value range of a is 0.2-1.2; the value range of b is 0.8-1.5; the value range of c is 0.1-0.23; the value range of d is 0.07-0.35; x is the proportion of oxygen atoms required to meet the oxidation state of metal. The catalyst has the advantages of simple preparation, good cycle stability, high yield and the like. The yield and product purity of adiponitrile are improved, the energy consumption in the production process of adiponitrile is reduced, and a breakthrough is realized in the production technology of adiponitrile.

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.

The invention relates to the field of catalysts, in particular to an ammoxidation catalyst, a preparation method and application thereof and a preparation method of acrylonitrile. The catalyst comprises a carrier and an active component, the active component comprises a composite oxide of molybdenum, bismuth and iron, and the carrier contains an inert oxide and an MFI molecular sieve. Through research, the inventor finds that by optimizing the components of the catalyst and adding the MFI molecular sieve into the carrier, the adsorption and migration speed of raw material molecules on the surface of the catalyst can be increased, and the adsorption activation rate is increased, so that the catalytic performance and stability of the catalyst under a high-load condition are improved.

The invention discloses a preparation method of a superfine PtIr nanowire catalyst for ammoxidation. The preparation method comprises the following steps: firstly, fully dissolving platinum acetylacetonate, iridium acetylacetonate, tungsten hexacarbonyl and dodecyl trimethyl ammonium bromide in oleylamine to obtain a light yellow solution; carrying out ultrasonic treatment on the obtained light yellow solution until the solution is fully dissolved; and heating the obtained uniform light yellow solution to 190 DEG C in an oil bath, keeping the temperature for 5 hours, centrifuging, washing and drying to obtain the superfine PtIr nanowire catalyst. The nanowire structure has a high specific surface area and abundant active sites, and is beneficial to effective quality and electron transmission. Through alloying of Ir and Pt, the electronic structure on the surface of the catalyst is changed, and the poisoning probability is effectively reduced. Meanwhile, the adsorption and activation process of ammonia molecules is optimized through the synergistic effect between Pt and Ir, the reaction activation energy is reduced, and the reaction rate is remarkably increased. The catalyst not only has remarkable ammonia oxidation catalytic performance, but also is good in stability and simple in preparation process.

The present invention relates to an ammonia slip catalyst article comprising a substrate, a first catalyst coating, and a second catalyst coating. The first catalyst coating comprises an ammonia oxidation catalyst. The second catalyst coating comprises a selective catalytic reduction catalyst and is formed by calcining a second catalyst washcoat comprising polysaccharide particles.

The invention belongs to the technical field of sewage treatment, and particularly relates to a lateral flow anaerobic ammonia oxidation effluent deep nitrogen and phosphorus resource recycling method which comprises the following steps: mixing treated anaerobic sludge digestion liquid and untreated anaerobic sludge digestion liquid in an intermediate water tank to form mixed inlet water; adding a magnesium source into the mixed inlet water in the middle water tank to form a middle mixed solution; transferring the intermediate mixed solution into a short-cut denitrification-anaerobic ammonia oxidation coupled struvite reactor, adjusting the pH value of the intermediate mixed solution, and adding a carbon source into the pH-adjusted intermediate mixed solution to form a reaction solution; and carrying out solid-liquid separation on a product obtained after the reaction of the reaction liquid, and discharging the separated liquid or systematically recycling the separated liquid. According to the invention, deep nitrogen removal and phosphorus resource recovery under the condition of low carbon source can be realized, and a new way is provided for subsequent deep treatment of a short-cut nitrification-anaerobic ammonia oxidation process.

The utility model discloses waste heat recovery complete equipment for a small ammoxidation furnace, and belongs to the technical field of ammoxidation furnaces. The waste heat recovery complete equipment comprises a furnace end and a furnace body, the furnace end comprises a maneuvering device, a catalyst basket, an ignition device and a rotating device; the catalyst basket comprises four identical right-angle sectors, the linear edge of each right-angle sector wraps an L-shaped steel plate, the right-angle sectors are connected through bolts, welding bolts for lifting lugs are reserved in each right-angle sector, and the lifting lugs and the furnace end are of a bolt detachable structure. The catalyst basket is composed of four identical right-angle sectors, the length of each L-shaped plate is reduced, bending deformation in the later high-temperature using process due to the too long length is avoided, meanwhile, parts are conveniently maintained and replaced in a split mode, and resources are saved; a lifting lug of the catalyst basket adopts a bolt detachable structure, so that the catalyst net is convenient to mount and use; meanwhile, the catalyst baskets are connected through bolts, and welding bolts are reserved for lifting lugs of the catalyst baskets, so that later maintenance, replacement and lifting are facilitated.

The invention relates to a high-stability catalyst for preparing acrylonitrile through propylene ammoxidation as well as a preparation method and application of the high-stability catalyst. The catalyst comprises an active component and a carrier, the carrier is silicon dioxide, and the active component is composed of Mo, Bi, Fe, a rare earth element, an alkali metal element, an alkaline earth metal element and an element A; (R '+ Q') / (R + Q) of the catalyst is 0.65-0.98, preferably 0.70-0.98, R and Q are respectively peak areas when 2 theta is near 23 degrees + / -0.2 and 25.5 degrees + / -0.2 in X-ray diffraction of the catalyst, and R'and Q 'are respectively peak areas when 2 theta is near 23 degrees + / -0.2 and 25.5 degrees + / -0.2 in X-ray diffraction of the reduced catalyst.

The present invention discloses an ammonia oxidation catalyst, a preparation method thereof and an application thereof. The active components of the catalyst include molybdenum and bismuth, and the carrier includes silica. The change in the average pore diameter of the catalyst after heat treatment conforms to Y = (P2 - P1) / P1, where the value of Y is less than or equal to 4.5, and P1 and P2 are the average pore diameters of the catalyst under different heat treatment conditions respectively. This catalyst exhibits better long-term stability in the application of ammoxidation of propylene to acrylonitrile.

Provided are a catalyst for an ammoxidation reaction, a method for producing the catalyst for an ammoxidation reaction, and a method for ammoxidation.

A catalytic article for treating an exhaust stream, which comprises -a substrate, -a coating layer, comprising a first catalyst containing a precious metal component and a second catalyst containing a molecular sieve component, in a first coating configuration; or -a substrate, -a first coating layer, which comprises a first catalyst containing a precious metal component, and -a second coating layer, which covers at least part of the first coating layer and comprises a second catalyst containing a molecular sieve component, in a second coating configuration; wherein the coating layer in the first coating configuration or the second coating layer in the second coating configuration has inter-particle pores at a pore ratio of 5.7% or more respectively. It also relates to a process for preparing the catalytic article by using a pore-forming agent in the slurry for depositing a coaing layer, and to a system for treating an exhaust stream comprising the catalytic article.

The utility model provides an anaerobic ammonia oxidation reaction system. The reaction system comprises a wastewater treatment system, the wastewater treatment system comprises: a first reactor for removing nitrate nitrogen in wastewater and producing first treated water; the second reactor is used for removing ammonia nitrogen and nitrite nitrogen in the first treated water and producing second treated water; the third reactor is used for adjusting the nitrogen composition and concentration of the second treated water and producing third treated water; and the fourth reactor is used for reducing nitrate nitrogen in the third treated water into nitrogen so as to reduce the concentration of total nitrogen in the effluent. The utility model solves the technical problems that an anaerobic ammonia oxidation water treatment system adopting a traditional activated sludge process is insufficient in total nitrogen treatment capacity during operation, and particularly cannot effectively remove nitrate nitrogen in an anaerobic ammonia oxidation reaction product; in the prior art, the treated water can still contain a certain amount of nitrogen pollutants and cannot meet the requirements of discharged water quality.

The invention discloses a rapid nitrite nitrogen enrichment method based on flow regime optimization, a wastewater low-carbon denitrification system and application, according to the method, a microenvironment suitable for AOB growth and nitrite nitrogen accumulation is accurately induced to be formed in a reactor through hydrodynamic regulation and control of an MBBR, so that treated water contains rich nitrite nitrogen, and the content of nitrogen in the wastewater is increased. And the water outlet is further connected with a denitrification biological nitrogen removal process or an anaerobic ammonia oxidation biological nitrogen removal process to form a wastewater low-carbon nitrogen removal system. The coupling system realizes a complete denitrification path under the condition of no additional or low carbon source, is suitable for the treatment requirements of urban sewage and industrial wastewater with low C / N ratio, and has the remarkable engineering advantages of low energy consumption, low carbon source requirement, high operation stability and the like.

A device and a method for maintaining the stability of anaerobic ammonium oxidation (anammox) by using a combined zeolite filler to resist water quality fluctuations are provided. The device includes a water inlet tank, an anammox reactor, and a water outlet tank, where the anammox reactor is filled with the combined zeolite filler maintained in a state of suspension, domestic sewage enters the anammox reactor through a water inlet pump, and effluent water enters the water outlet tank through an overflow port. The device combines the physical characteristics of zeolite adsorption of ammonium with the anammox process: when the concentration of ammonium in the influent water is too high, the zeolites will temporarily store the excess ammonium adsorbed; when the concentration of nitrite in the influent water is too high, the zeolites are capable to release the stored ammonium into a liquid phase through balanced adsorption desorption.

The application provides a method for one-step conversion of aromatic alcohol into aromatic nitrile, which comprises the following steps: using a metal salt as a catalyst, a hydroxylamine salt as an ammonia source, air or oxygen as an oxidant, and performing an ammoxidation reaction of the aromatic alcohol under light conditions to convert the aromatic alcohol into the aromatic nitrile in one step. The application does not use any expensive or toxic photocatalyst, material or reagent, the raw material is easy to obtain, the operation is simple, the reaction is carried out at normal temperature and pressure, the conditions are mild, and the application has an industrial amplification prospect; and the safety, environmental protection, economy and social benefit of the application have remarkable advantages.

The invention discloses a starting and control method for treating ammonia-nitrogen wastewater by an integrated complete ammoxidation coupling short-cut denitrification anaerobic ammoxidation process, and belongs to the field of wastewater biological treatment. The starting method adopts a step-by-step inoculation strategy, and comprises the following steps: firstly, inoculating complete ammoxidation sludge in the SBR reactor for low-oxygen domestication, and after successful starting, supplementing and inoculating short-cut denitrification coupled anaerobic ammoxidation sludge. The control method adopts a sectional water inlet mode, and comprises the following steps: a first part of ammonia nitrogen wastewater firstly enters an integrated SBR (Sequencing Batch Reactor), and ammonia nitrogen is directly oxidized into nitrate nitrogen through complete ammonia oxidizing bacteria (Comammox) under the condition of low dissolved oxygen; aeration is stopped, a carbon source is added for short-cut denitrification, and nitrate nitrogen is reduced into nitrite nitrogen; and then pumping a second part of ammonia nitrogen wastewater, and converting ammonia nitrogen in the wastewater and accumulated nitrite nitrogen into nitrogen by using anaerobic ammonium oxidation bacteria, so as to remove the ammonia nitrogen in the wastewater. According to the invention, deep denitrification is realized under the condition of saving energy consumption and a carbon source.

The utility model discloses an ammoxidation platinum-saving combined net convenient to assemble, which relates to the technical field of combined nets and comprises an annular cylindrical mounting ring frame, internal threads are arranged in the inner wall of the upper part of the mounting ring frame, a binary platinum-rhodium net is mounted in the upper part of the mounting ring frame, and a high target net is mounted in the mounting ring frame below the binary platinum-rhodium net. A supporting net is mounted in the mounting ring frame below the high target net; by means of the protruding columns outside the mounting ring frames, force application operation in the assembling process is facilitated, assembling convenience is improved, the function of quickly connecting the mounting ring frames can be achieved, firm connection between the mounting ring frames can be conveniently achieved through cooperation of the L-shaped grooves, the clamping blocks, the springs and the pressing plates at the bottoms of the mounting ring frames, and the service life of the mounting ring frames is prolonged. The connection stability is improved, the function of stabilizing the structure of the combined net can be achieved, and finally the problems that a traditional combined net is difficult to assemble, insufficient in stability and long in service life are solved.

The invention belongs to the technical field of material chemistry, and particularly relates to an MOF catalyst containing high-valence copper and a preparation method and application of the MOF catalyst. According to the invention, Ag is doped on a Cu-based metal organic framework material framework through an ion exchange method, then the Ag is mixed with a binder solution to prepare slurry, the slurry is coated on an electrode substrate, the electrode substrate is dried to serve as a working electrode, constant potential or circulating potential is applied to the working electrode in a preset voltage range in an electrochemical system containing an electrolyte, and thus the Cu-based metal organic framework material is obtained. Cu (III) is generated in situ through electrochemical reconstruction, and the MOF catalyst containing high-valence copper is obtained. The MOF catalyst containing high-valence copper has excellent ammoxidation reaction activity and stability, is especially suitable for high-conversion-rate and high-selectivity ammoxidation reaction to prepare nitrite, and is suitable for industrial induced production application.

The invention relates to the technical field of wastewater treatment, and particularly provides a method for improving the anaerobic ammonia oxidation denitrification effect of high-ammonia-nitrogen wastewater. The method is realized by adding one or more enhancer combinations into a reaction system, wherein the enhancer is selected from vitamin B6, siderophore catechin (CAT) and siderophore hydroxyethyl ethylenediamine triacetic acid (HEDTA). By adding the enhancer, the inhibition effect of a high-ammonia-nitrogen environment on anaerobic ammonium oxidation functional flora can be effectively relieved, and the metabolic activity and the proliferation rate of the anaerobic ammonium oxidation flora are remarkably enhanced. The method is simple and convenient to operate and low in cost, can greatly improve the denitrification efficiency and operation stability of the system under high ammonia nitrogen load on the premise of not changing the structure of the existing reaction system, and is suitable for treating high ammonia nitrogen wastewater such as mine leaching tail water, landfill leachate and the like.

The present invention relates to a composition comprising platinum supported on titanium oxide, the platinum particles having an average particle diameter of 50-200 nm. The composition has a surprisingly low light-off temperature for the ammonia oxidation and a high selectivity for oxidation to N2.