918 results about "Selective catalytic reduction" patented technology

The invention discloses an intelligent denitration control method and system based on PID (Proportion Integration Differentiation) and Transform. The method comprises the following steps: acquiring an operation parameter sequence of an SCR (Selective Catalytic Reduction) denitration system in real time; a time sequence input into the Transform model and the feature dimension are exchanged to form a reverse Transform model, the predicted outlet NOx concentration is obtained, an ammonia injection amount adjusting value is calculated according to the deviation between the predicted outlet NOx concentration and the target outlet NOx concentration, the opening degree of an ammonia injection valve is adjusted in real time, and the reverse Transform model is adjusted on line based on the deviation between the actual outlet NOx concentration and the predicted outlet NOx concentration. The method is applied to the field of denitration control, the change trend of the NOx concentration in a period of time in the future can be predicted more accurately, so that the injection amount of ammonia is adjusted in advance, and the lag defect of an original PID controller is effectively overcome.

The invention relates to an SSZ-39 molecular sieve and preparation and application thereof.The preparation method comprises the following steps that 1, after water, an alkali source and a template agent are mixed, mesoporous Y zeolite and a silicon source are added, the mixture is stirred to be uniform, and the mixture is aged to be in a white gel shape; (2) transferring the obtained white gel into a reaction kettle, carrying out crystallization treatment, and filtering, washing, drying and calcining a crystallized product to obtain a Na-SSZ-39 molecular sieve; (3) carrying out ammonium ion exchange on the Na-SSZ-39 molecular sieve, filtering, washing, drying and calcining to obtain an H-SSZ-39 molecular sieve; and (4) carrying out copper ion exchange on the H-SSZ-39 molecular sieve, filtering, washing, drying and calcining to obtain the Cu-SSZ-39 catalyst. Aluminum used in the method is provided by mesoporous Y zeolite, the pure-phase SSZ-39 molecular sieve can be synthesized in a wide gel range, the crystallization time is shortened to 24 h, and after copper ion exchange, the pure-phase SSZ-39 molecular sieve shows high denitration activity in the selective catalytic reduction reaction of nitrogen oxide ammonia.

The invention discloses a modeling method for single channels of a selective catalytic reduction reactor, a plurality of SCR single channels are arranged in the reactor, a main channel is surrounded by a catalytic coating, a plurality of pore channels are formed in the catalytic coating, ammonia molecules are adsorbed on active sites of a catalyst, and a selective catalytic reduction reaction is carried out on the active sites of the catalyst. The modeling method comprises the steps that S1, an SCR single-channel mathematical model is established, wherein the SCR single-channel mathematical model comprises a component balance equation, a momentum balance equation and an enthalpy balance equation of a gas phase substance in a main channel, a gas phase component balance equation, an enthalpy balance equation, an NH3 coverage balance equation, a component balance equation of a gas phase-coating interface and a gas enthalpy balance equation; s2, giving an initial condition and a boundary condition, limiting part of unknown parameters, and substituting the parameters into each equation to obtain a closed equation set; the model established by the invention can obtain the nitrogen oxide conversion rate, so that the emission reduction performance of the reactor is evaluated. And the influence of mass transfer limitation and mild aging degree of the catalyst is considered, so that the evaluation is more accurate.

The invention discloses a preparation method of a low-temperature SCR (Selective Catalytic Reduction) catalyst with coke loaded with transition metal oxide. The preparation method comprises the following steps: preparing superfine coal powder; removing mineral substances from the superfine coal powder to obtain ash-removed coal powder; chemically activating the deashed coal powder into an activated coal base; coking the activated coal base to form a coal coke carrier; and preparing a single Fe oxide catalyst and an Fe-Mn composite oxide catalyst which take the coal coke as a carrier. The catalyst is prepared from the coal, so that the utilization value of the coal can be improved, the conversion of the coal from fuel to raw materials can be accelerated, and the pollution of the coal to the environment is reduced. Meanwhile, compared with a noble metal catalyst and coke, the catalyst with the coke carrier prepared by the method disclosed by the invention is lower in price and wide in source, so that the preparation cost of the catalyst can be reduced, and compared with other matrix materials, the coke carrier prepared by the method disclosed by the invention takes superfine pulverized coal coke as a matrix, so that the cost of the catalyst is reduced. The preparation cost is lower, and the pore structure is richer.

The invention provides an ammonia-hydrogen engine aftertreatment device and a control method. The post-treatment device comprises an electric heater, an N2O decomposition catalyst, a selective catalytic reducer, an ammonia trapping catalyst, a sensor and a controller, the electric heater is arranged at the exhaust end of the ammonia-hydrogen engine, is powered and controlled by the controller and is used for heating exhaust of the ammonia-hydrogen engine. An N2O decomposition catalyst, a selective catalytic reducer and an ammonia trapping catalyst are sequentially arranged at the rear end of the electric heater; the sensors comprise three temperature sensors, one NOx sensor and one NH3 sensor; the controller receives a temperature signal of the temperature sensor and controls the working state of the electric heater according to the received temperature signal; and the controller receives the concentration signal of NOx and the concentration signal of NH3, and controls the working state of the electric heater according to the concentration signals. According to the invention, the decomposition efficiency of N2O can be improved, and the conversion efficiency of NOx can be improved.

The invention discloses an improved SCR (Selective Catalytic Reduction) denitration pretreatment device and an SCR denitration system, aiming at solving the technical problems that a pretreatment catalyst adopted at present is high in cost and is damaged. The system comprises a pretreatment reactor, a pretreatment catalyst in the pretreatment reactor forms a first pretreatment catalyst bed layer and a second pretreatment catalyst bed layer, the first pretreatment catalyst bed layer and the second pretreatment catalyst bed layer are sequentially arranged in the flue gas flowing direction, the first pretreatment catalyst bed layer is formed by stacking activated carbon particles, and the second pretreatment catalyst bed layer is formed by stacking activated carbon particles. The second pretreatment catalyst bed layer is formed by stacking porous ceramics. The adsorption performance of the activated carbon particles and the high-temperature-resistant and corrosion-resistant characteristics of the porous ceramic can be effectively utilized, the activated carbon particles and the porous ceramic have a synergistic effect to further remove sulfur dioxide in the flue gas, and dust in the to-be-denitrified flue gas is adsorbed and removed through the pretreatment catalyst. The interception capability on SO2 and dust is improved, and the problems of high use cost, easiness in damage and the like caused by independent use of an activated carbon-based desulfurization catalyst are solved.

The invention relates to a preparation method of a molecular sieve type SCR (Selective Catalytic Reduction) catalytic membrane, which comprises the following steps: taking an alpha-Al2O3 ceramic membrane tube as a carrier, carrying out alkali washing and acid washing on the ceramic membrane tube, and then drying to remove impurities in the ceramic membrane tube. Meanwhile, preparing a membrane preparation solution, firstly mixing a molecular sieve with a metal compound with an SCR effect, adding deionized water to prepare a mixed solution with the catalytic metal content of 0.1-0.3 mol / L, adjusting the pH value, heating and ultrasonically carrying out an ion exchange reaction, and adding a binder to prepare the membrane preparation solution; and loading the molecular sieve catalyst to the inner side of the alpha-Al2O3 ceramic membrane tube in a dip coating manner. And drying and roasting the membrane tube, and carrying out surface hydrophobic modification on the outer side of the ceramic membrane tube to obtain the molecular sieve SCR catalytic membrane. The efficient molecular sieve SCR catalytic membrane is obtained through one-time roasting, waste gas water and dust removal and SCR catalysis can be achieved at the same time, the conversion rate of NOx in the low-temperature environment is high, and the whole process is safe and environmentally friendly.

The invention discloses an improved SCR (Selective Catalytic Reduction) denitration device and an SCR denitration system. The technical problem that the denitration efficiency is reduced due to the influence of water vapor in flue gas to be denitrated on a denitration catalyst is solved. The SCR denitration device comprises an SCR denitration reactor, an activated carbon-based denitration catalyst is adopted as a denitration catalyst, and the working temperature of the activated carbon-based denitration catalyst is 120-200 DEG C; the flue gas dehumidification device is connected with the to-be-denitrated flue gas inlet and is used for reducing the content of water vapor in flue gas entering the to-be-denitrated flue gas inlet. The flue gas dehumidification device is arranged, so that the content of water vapor in flue gas entering the SCR denitration reactor is reduced, the influence of the water vapor on an activated carbon-based denitration catalyst can be avoided, the sufficient contact degree of nitrogen oxides and the denitration catalyst is ensured, and the relatively high denitration efficiency is maintained.

A computer system comprising processing circuitry configured to obtain topographic data containing information about the topography of the road along which a heavy-duty vehicle is currently travelling, the topographic data including information about an upcoming downhill slope; acquire prediction data indicative of the braking requirements for the upcoming downhill slope, the braking requirements including how much brake power and / or brake energy that will be needed in the upcoming downhill slope to maintain the speed of the heavy-duty vehicle at or below a selected speed limit of the heavy-duty vehicle throughout the travel in the downhill slope; determine a brake blending combination which allows a Selective Catalytic Reduction System (SCR) of the heavy-duty vehicle to be kept as warm as possible while still fulfilling the braking requirements; and apply the determined brake blending combination to the heavy-duty vehicle while travelling along the downhill slope.

The invention discloses a bimetallic CO-SCR catalyst and a preparation method and application thereof, and belongs to the technical field of catalytic materials. The bimetallic CO-SCR catalyst comprises the following raw materials: an X metal precursor, a Y metal precursor, a ligand and a carrier, x metal in the X metal precursor is precious metal; y metal in the Y metal precursor is non-noble metal. According to the bimetal CO-SCR catalyst, coordination of bimetal X and Y is utilized, high oxygen resistance of the X-Y bimetal catalyst is achieved through the steric hindrance effect by means of the synergistic effect of ligands, the preparation method is simple, and an important reference basis is provided for preparation of the catalyst for CO selective catalytic reduction of NOx (CO-SCR) in the oxygen-containing environment.

The invention discloses an ammonia distillation method for a garbage incinerator SCR (Selective Catalytic Reduction) system. The problems that existing equipment is high in ammonia water steaming energy consumption and inconvenient to control are solved. The method comprises the following steps; the method comprises the following steps: S1, taking a 20-25% concentrated ammonia water solution as a raw material, and filling the concentrated ammonia water solution into a concentrated ammonia water storage tank for storage; s2, conveying 20-25% of concentrated ammonia water solution in a concentrated ammonia water storage tank into an ammonia distillation tower by using a first metering pump; ammonia gas in the concentrated ammonia water solution is separated out by using an ammonia distillation tower and is used for SCR (Selective Catalytic Reduction) denitration reaction; s3, dilute ammonia water generated at the bottom of the ammonia still is pumped out by a second metering pump and conveyed into a dilute ammonia water buffer tank for temporary storage, and the concentration of the dilute ammonia water is below 5%; s4, denitration is completed through a catalyst. The method has the beneficial effects that ammonia for SCR and SNCR in flue gas treatment equipment of the garbage incinerator is combined together, the ammonia still is used for separation and purification, ammonia gas is sprayed into the SCR, and raw materials of a reducing agent, the equipment cost and the operation cost are saved.

The invention discloses a steel tower type container for SCR denitration and an SCR denitration system. The technical problems that an existing SCR denitration pretreatment device / SCR denitration device is complex in structure, the engineering construction period control difficulty is large, and the construction period is long are solved. Comprising a steel outer cylinder and a steel inner supporting system arranged in the steel outer cylinder, and the bottom of the steel outer cylinder and the bottom of the steel inner supporting system are installed on a concrete base; the steel inner supporting system is provided with a center stand column and a plurality of layers of horizontal frames arranged in the axis direction of the center stand column at intervals, and the center stand column, the horizontal frames and the steel outer barrel are connected to form a steel tower. A part of the horizontal frames serve as partition plate supporting frames and are provided with sealing partition plates in a laid mode, the other part of the horizontal frames serve as catalyst supporting frames and are provided with catalyst breathable supporting layers in a laid mode, and the catalyst breathable supporting layers are used for being filled with denitration catalysts / pretreatment catalysts.

The invention relates to the technical field of traction equipment, in particular to an SCR continuous casting copper billet traction clamping and conveying mechanism and traction method.The SCR continuous casting copper billet traction clamping and conveying mechanism comprises a plurality of pressing and conveying units distributed in the circumferential direction around the copper billet conveying axis, and each pressing and conveying unit comprises a conveying assembly and a pressing assembly; the conveying assembly comprises two conveying wheels and a soft belt arranged on the two conveying wheels in a transmission mode. By adopting a surface contact traction mode, the contact area between the mechanism and the surface of the copper billet can be effectively increased, so that the local stress on the surface of the copper billet is reduced, the copper billet is conveniently protected and prevented from being deformed and damaged, and meanwhile, the contact area increasing mode is also beneficial to improving the friction force, avoiding the slipping phenomenon and conveniently enabling the copper billet to be uniformly stressed, so that the service life of the copper billet is prolonged. Therefore, the traction stability of the copper billet is improved; by adopting a rotary traction mode, the traction work can be simpler and more convenient to operate, the structure mode is simplified, and the traction speed is more stable.

The invention relates to the technical field of flue gas denitrification, and discloses a flue gas baffle system for an SCR (Selective Catalytic Reduction) denitrification device and a use method.The flue gas baffle system is provided with a control system and a matrix flowmeter, a baffle assembly is composed of a plurality of baffle units, each flue is uniformly divided into a plurality of subareas, and each subarea corresponds to a group of adjusting units; and each baffle unit correspondingly controls one subarea of the cross section, so that the technical effects of automatically detecting the flow field at the inlet of the reactor and automatically adjusting the angle of the baffle under different loads or different flow field conditions are realized, the uniformity of the flue gas flow field under different loads is improved, the adaptability of the SCR denitration device to the loads is improved, and the service life of the SCR denitration device is prolonged. The ammonia escape amount when the load or the flow field changes is reduced, and the technical problem that in the prior art, an SCR denitration device cannot adjust the flue gas flow field according to the incoming flow characteristics of flue gas and cannot adjust the flue gas flow field when the performance of an existing flow equalizing device is damaged is solved.

The invention discloses a system of a belt type roasting machine for denitration by using return hot air, which comprises a return hot air blower, a first heat exchanger, a second heat exchanger, a second heat exchanger, a third heat exchanger, a third heat exchanger, a fourth heat exchanger, a fourth heat exchanger and a fourth heat exchanger, the first heat exchanger comprises a first heat exchange gas flow path and a second heat exchange gas flow path, the first heat exchanger comprises a first heat exchange gas flow path and a second heat exchange gas flow path, the first heat exchange gas flow path is communicated between an air box of the belt type roasting machine and a backheating fan, an air outlet of the backheating fan is opened towards an upper cover of the belt type roasting machine, the second heat exchanger comprises a third heat exchange gas flow path and a fourth heat exchange gas flow path which exchange heat with each other, and the third heat exchange gas flow path is communicated with the second heat exchange gas flow path; a flue gas outlet of the desulfurization system is communicated with the fourth heat exchange gas flow path, a gas inlet of the selective catalytic reduction reactor is communicated with the fourth heat exchange gas flow path, and a gas inlet of the denitration exhaust fan is communicated with a gas outlet of the selective catalytic reduction reactor. The system for denitration by using the return hot air of the belt type roasting machine can reduce the consumption of coal gas.

The invention discloses a method for preserving heat of a urea NaOH and Mg (OH) 2 storage cabin, and aims at a ship which is provided with an SCR (Selective Catalytic Reduction) system, an EGR (Exhaust Gas Recirculation) system, an iCER (Initial Continuous Emission Reduction) system and a desulfurization system and needs to store urea, NaOH or Mg (OH) 2. Condensed water of the air conditioning unit is collected and then introduced into the storage cabin in a gravity mode, and the condensed water generation amount and the condensed water temperature of the air conditioning unit are analyzed and calculated. On the premise that the cabin capacity meets the condition, condensate water is used for cooling the urea cabin and then discharged into the clean cabin bottom water cabin, and the cooling capacity of the condensate water is utilized to the maximum extent. In winter or in a cold area, when the air conditioning unit does not need to operate, in order to avoid too low temperature of the solution cabin, the storage cabin can be heated by using the discharged water in the clean cabin bottom water cabin before discharging, so that the storage temperature of the urea, NaOH or Mg (OH) 2 solution is ensured to be 10-35 DEG C.

The invention discloses an integrated treatment method and system suitable for multi-component industrial waste gas, and relates to the technical field of industrial waste gas treatment, and the method comprises the steps of S1, waste gas pretreatment, S2, pre-oxidation and sulfur fixation, S3, thermal oxidation, S4, non-quenching temperature self-adaptive adjustment, S5, selective catalytic reduction denitration, S6, emission and monitoring, and S7, intelligent dynamic system control. The gradient temperature field of the heat storage ceramic body is used for providing accurate and stable air inlet temperature for the SCR reaction, an independent quenching device is omitted, and therefore the comprehensive energy consumption and the operation cost of the system are greatly reduced, and by additionally arranging the pre-oxidation layer and adopting the dual-function SCR catalyst, the heat storage effect of the system is greatly improved. The system effectively realizes advanced fixation of organic sulfur and efficient removal of nitrogen oxides, dynamically adjusts the ammonia injection amount and combustion intensity, ensures that the system can still maintain extremely high treatment efficiency and stability under flow fluctuation and complex working conditions, reduces ammonia escape to the greatest extent, and is convenient to use.

An exhaust aftertreatment system (10) in the exhaust stream of an internal combustion engine (12) that is at least partially powered by an alcohol fuel is permeable to an exhaust stream containing nitrogen oxides as well as an alcohol and / or formaldehyde. The exhaust aftertreatment system (10) comprises a metering device (14) for metering ammonia into the exhaust stream, a first SCR catalyst (16), and a second SCR catalyst (18), wherein the first SCR catalyst (16) is arranged in the exhaust stream downstream of the metering device (14) and is configured to generate a treated exhaust stream from the exhaust stream of the internal combustion engine (12) that contains nitrogen oxides and at least one nitrogen-containing hydrocarbon compound.The second SCR catalyst (18) is arranged in the exhaust stream downstream of the first SCR catalyst (16) and is designed to reduce the nitrogen oxides contained in the generated treated exhaust stream by consuming the nitrogen-containing hydrocarbon compound contained in the generated treated exhaust stream. Furthermore, a method for exhaust aftertreatment and the use of an exhaust aftertreatment system (10) are specified.

An exhaust aftertreatment system (10) in the exhaust stream of an internal combustion engine (12) that is at least partially powered by an alcohol fuel is permeable to an exhaust stream from the internal combustion engine (12) containing nitrogen oxides as well as an alcohol and / or formaldehyde. The exhaust aftertreatment system (10) comprises an oxidation catalyst (14) for removing methanol and formaldehyde from the exhaust stream, an SCR catalyst (18), and a metering device (16) for metering ammonia into the exhaust stream, wherein the oxidation catalyst (14) is arranged in the exhaust stream upstream of the SCR catalyst (18). The metering device (16) is arranged in the exhaust stream upstream of the SCR catalyst (18) and upstream or downstream of the oxidation catalyst (14). Furthermore, a method for exhaust aftertreatment and the use of the exhaust aftertreatment system (10) are specified.

The invention discloses a modeling method of an SCR (Selective Catalytic Reduction) denitration system mechanism hybrid prediction model based on Transform. Feature extraction is carried out on the collected data, a reaction kinetic equation is constructed, an Euler method is adopted for solving, and unknown model parameters are reserved; a section of working condition stable data is selected from the collected data and imported into a mechanism model, optimal model parameters are found, the mechanism model of the SCR denitration reaction is obtained, and the A side outlet flue concentration and the B side outlet flue concentration are calculated through the model; a Transform model is trained to compensate the SCR system mechanism model, and the compensated SCR system mechanism model serves as real-time soft measurement values output by the A side and the B side; input variable selection is carried out on all-condition data, A-side and B-side outlet flue concentrations obtained by the mechanism model in real time and outputs at the first two moments are included into an input variable set, and time delay processing is carried out on input variables; and the mechanism models of the A-side flue and the B-side flue are connected in series with a Transform model, the Transform model needs to be imported into the output of the mechanism models in real time, and finally the SCR denitration system hybrid prediction model is obtained.

A non-transitory computer-readable media having computer-readable instructions stored thereon that, when executed by at least one controller, cause the at least one controller to cause a first doser to cease dosing a first reductant portion of a reductant to a first exhaust portion of exhaust upstream of a first catalyst member disposed in a first leg of a selective catalytic reduction (SCR) system. The instructions can cause the at least one controller to cause a second doser to dose a second reductant portion of the reductant to a second exhaust portion of the exhaust upstream of a second catalyst member disposed in a second leg of the SCR system. The instructions can cause the at least one controller to determine a first conversion efficiency of the first leg while the first doser is not dosing the first reductant portion and the second doser is dosing the second reductant portion.

A system, method, and apparatus for detecting sensor tampering are provided. An aftertreatment system includes a first train having a first selective catalytic reduction (SCR) system, a first doser, and a first NOx sensor; a second train having a second SCR system, a second doser, and a second NOx sensor; and a controller. The controller determines satisfaction of activation conditions. The controller doses reductant to the first and second SCR systems. The controller determines the NOx levels of the first SCR system and the second SCR system. The controller adjusts the dosing of the first SCR system for a period of time. The controller measures the NOx levels of the first SCR system and the second SCR system. The controller determines a difference between the third and first NOx levels and a difference between the fourth and second NOx levels.The control generates an indication as to whether the first NOx sensor is displaced.

The invention provides a corrugated SCR (Selective Catalytic Reduction) catalyst as well as a preparation method and application thereof. The preparation method of the corrugated SCR catalyst comprises the following steps: uniformly mixing a molecular sieve, a copper source and water, heating and stirring for ion exchange, and then adding a binder, a dispersant, an auxiliary agent and water to prepare catalyst coating slurry; respectively carrying out first coating on fiber paper and corrugation by adopting the obtained catalyst coating slurry, and then compounding the fiber paper and the corrugation which are subjected to the first coating, so as to prepare the corrugated paper; the preparation of the corrugations comprises the following steps: pressing fiber paper into the corrugations through corrugating rollers which are arranged in pairs; and carrying out second coating on the prepared corrugated paper by using the obtained catalyst coating slurry, and then drying and roasting to obtain the corrugated paper. The corrugated SCR catalyst is prepared by the preparation method, and is suitable for national sixth diesel engines. The SCR catalyst is prepared by adopting a one-step forming process, and the obtained catalyst is low in density, high in catalytic activity, low in cost and suitable for industrial popularization.

The invention discloses a gas turbine SCR denitration ammonia injection automatic adjusting system and method, and relates to the technical field of gas turbine flue gas denitration, and the method comprises the following steps: periodically obtaining first difference value data and second difference value data; wherein the first difference value data is obtained by calculating the difference value between the outlet NOx concentration data and a preset NOx concentration target value; the second difference value data is obtained by calculating the difference value between the NOx concentration data before denitration and a preset NOx concentration target value; and performing double-component decomposition including a baseline component and a transient component on the first difference data, and recombining a double-component decomposition result to obtain unit area ammonia gas amount data. According to the scheme, the steady-state deviation and the dynamic disturbance are separated through error decomposition and variance correction, the problem of ammonia spraying amount calculation errors caused by the fact that the steady-state deviation and the transient deviation are not distinguished in the prior art is solved, the weight of the transient component is dynamically adjusted through variance correction, and the ammonia spraying amount calculation accuracy is improved. And the generation process of the unit area ammonia gas amount data can respond to the long-term operation requirement of the system.

The invention relates to a Ru / CeO2 passive nitrogen oxide adsorbent as well as a preparation method and application thereof. The Ru / CeO2 passive nitrogen oxide adsorbent comprises the following components in percentage by weight: 0.1 to 5.0 percent of Ru and 95.0 to 99.9 percent of CeO2. The Ru / CeO2 adsorbent is prepared by adopting an excessive impregnation method, and the specific method is as follows: adding the prepared CeO2 carrier into a ruthenium nitrate solution, adding deionized water for dilution, stirring for 10-15 hours at normal temperature, then carrying out rotary evaporation on the mixed solution at 60-80 DEG C, drying for 6-12 hours in a drying oven at 60-120 DEG C, and finally roasting for 2-6 hours in an air atmosphere at 400-600 DEG C. The adsorbent is used for treating NOx-containing tail gas. Compared with the prior art, the adsorbent disclosed by the invention has the advantages that the adsorption capacity at 80 DEG C is up to 299 mu mol / g, the adsorbent is efficiently desorbed at 200-500 DEG C, the desorption capacity is up to 285 mu mol / g, and the adsorbent has excellent water-resistant and CO-resistant performance and cycling stability. The desorption temperature window of the Ru / CeO2 adsorbent is highly matched with the subsequent selective catalytic reduction (SCR) of nitrogen oxides, and the Ru / CeO2 adsorbent is matched with the subsequent SCR to realize efficient degradation of the nitrogen oxides, so that the Ru / CeO2 adsorbent has a wide application prospect.

The utility model discloses an anti-blocking device for a high-temperature SCR (Selective Catalytic Reduction) denitration catalyst of boiler flue gas, which belongs to the technical field of boiler flue gas treatment and comprises an anti-ash-blocking component correspondingly arranged at the top of a boiler flue, and the anti-ash-blocking component is positioned above the SCR catalyst and is provided with a plurality of layers of SCR catalysts arranged along the boiler flue from bottom to top. And the anti-ash-blocking assembly is of a herringbone structure. Flue gas is purified and removed before passing through an SCR catalyst, efficient and stable operation of the SCR catalyst and up-to-standard emission of boiler flue gas are guaranteed, power consumption of a boiler system is reduced, and the operation period of a boiler is prolonged; the anti-clogging assembly does not need to be provided with a catalyst dust removal pretreatment device, and investment cost increase caused by high-temperature dust removal is avoided; a herringbone ash blocking prevention assembly and a mechanical ash blowing device are arranged above an SCR catalyst, large-particle fly ash in boiler flue gas can be removed, blocking of the catalyst and a tail air pre-heater is reduced, and power consumption of an induced draft fan is reduced.

The present invention discloses an exhaust gas treatment device and an exhaust gas treatment method for an ammonia diesel engine, and relates to the technical field of exhaust gas treatment for an ammonia diesel engine. A selective catalytic reducer, an ammonia oxidation catalyst, and a particle collector are connected in sequence from front to back. An ammonia nozzle is provided at the front end of the selective catalytic reducer, and the ammonia nozzle is connected to the ammonia source of the ammonia diesel engine. A first temperature sensor and a first nitrogen oxide sensor are provided at the front end of the selective catalytic reducer. A first ammonia sensor is also provided at the front end of the selective catalytic reducer. The first temperature sensor, the first nitrogen oxide sensor, and the first ammonia sensor are electrically connected to the post-processing unit of the ammonia diesel engine, respectively. The present invention adopts DPF passive regeneration to solve the problem of particles in the exhaust gas; the ammonia source of the selective catalytic reducer borrows the ammonia used for combustion of the ammonia diesel engine, eliminates the urea injection system, and solves the problem of urea crystallization.

The invention provides a urea injection control method and device and a vehicle. For each stage of SCR in a two-stage SCR aftertreatment system, the urea injection amount matched with the stage of SCR is determined based on the target mode started by an engine, the temperature value of an inlet, the exhaust flow, the nitrogen and oxygen concentration and the degradation factor, and on the premise that the emission standard is met, the urea injection amount matched with the stage of SCR can be controlled. The operation mode requirement of the engine and the actual treatment capacity of the selective catalytic reduction device are matched in time, the aftertreatment cost is reduced, the service life of the aftertreatment system is prolonged, and therefore the comprehensive treatment effect of the two-stage SCR aftertreatment system on nitric oxide is effectively improved.

The invention discloses an anti-alkali metal poisoning SCR (Selective Catalytic Reduction) catalyst and a preparation method and application thereof, and belongs to the field of catalysts for atmospheric governance, the SCR catalyst comprises the following components in percentage by mass: 80%-90% of TiO2, 0.5%-1.5% of V2O5, 3%-5% of WO3 and 3%-10% of a cocatalyst; the cocatalyst comprises one or two of zirconium phosphate and titanium phosphate. The SCR catalyst provided by the invention is high in targeting property and remarkable in alkali metal poisoning resisting effect. TiO2 is used as a main carrier, V2O5 provides a main catalyst active component, WO3 can improve the thermal stability and acidity of the catalyst, a cocatalyst loses activity after capturing alkali metal, and an effective chemical barrier is constructed by sacrificing the cocatalyst; the path that alkali metal ions continue to diffuse into the coating and react with key V-OH acidic sites is blocked, and the alkali poisoning resistance is qualitatively improved, so that the denitration activity of the catalyst is preserved.

The invention relates to a preparation method of a MnSm-LDHs catalyst which is prepared by adopting a coprecipitation method and is derived from MnSm-LDHs as a precursor through roasting activation and application of the MnSm-LDHs catalyst. According to the catalyst, Mn is used as an active metal, doped Sm is used as an auxiliary agent, catalytic active species are inserted between hydrotalcite layers, hydrotalcite is used as a precursor, and the high-dispersion composite metal oxide type catalyst can be prepared through activation. The preparation method comprises the following steps: firstly, weighing Mn (NO3) 2.4 H2O and Sm (NO3) 3.4 H2O according to a stoichiometric ratio, adding a proper amount of deionized water, dissolving the Mn (NO3) 2.4 H2O and the Sm (NO3) 3.4 H2O to obtain a metal salt solution, adding an alkaline stabilizer into the deionized water to prepare a stabilizer solution, weighing Na2CO3 with the same mole number as metal ions, dissolving the Na2CO3 into the deionized water to prepare a precipitant, and adding the precipitant into the deionized water to prepare a precursor solution; dropwise adding the metal salt solution into a precipitant sodium carbonate solution under constant-temperature stirring, and dropwise adding a precipitant in the process to control the pH to be stable; the preparation method comprises the following steps: dropwise adding the Mn1Sm < 0.75 >-LDO-Air-NaOH solution into a reaction kettle, stirring for 12 hours, then dropwise adding the Mn1Sm < 0.75 >-LDO-Air-NaOH solution into the reaction kettle, vigorously stirring and aging the turbid liquid for 12 hours under a constant-temperature condition after dropwise adding, adjusting parameters such as pH, aging time and precipitant types in the process, drying after filtering, roasting and activating in air, nitrogen and other atmospheres after drying, tabletting and grinding into a 20-40-mesh catalyst, namely the Mn1Sm < 0.75 The Mn1Sm < 0.75 >-LDO-Air-NaOH composite metal oxide type catalyst disclosed by the invention has relatively good C3H6-SCR activity in the whole temperature range, and can be used for effectively removing nitrogen oxides and hydrocarbons. Hydrotalcite is used as a precursor, a high-dispersion composite metal oxide catalyst can be prepared through activation, and the catalyst generally has the characteristics of uniform distribution of high-activity sites in transition metal content, small crystal grains, large specific surface area, good stability for inhibiting sintering and the like, so that the catalyst shows excellent catalytic performance; therefore, the catalyst has high C3H6-SCR catalytic activity in the whole temperature range.