85 results about "Space velocity" patented technology

The invention discloses a catalytic method for converting alpha-olefin in an alkane-olefin mixture into internal olefin and application, raw materials and a solid acid catalyst are carried out in a fixed bed or a reaction kettle, the reaction temperature is 50-150 DEG C, the reaction pressure is 15-400 psi, and the reaction environment is an inert gas atmosphere; when the reaction is carried out on the fixed bed, the mass space velocity of the solid acid catalyst is 1h <-1 >-20h <-1 >; when the reaction is carried out in the reaction kettle, the conversion frequency of the raw materials is 5000 mol substrate mol acid site density <-1 > h <-1 > to 50000 mol substrate mol acid site density <-1 > h <-1 >; wherein the raw material is an alkane-alkene mixture; the solid acid catalyst comprises an active component and a carrier, wherein the carrier contains at least one inorganic oxide; the active component has a structure as shown in a formula (1) and / or a formula (2), in the formula (1) and the formula (2), R is alkyl or phenyl, and n is greater than or equal to 1. According to the catalysis method provided by the invention, the conversion rate of alpha-olefin can be increased, and the proportion of skeleton isomerization products and oligomers in internal olefin products can be reduced.

The invention discloses application of a supported heterogeneous catalyst of oxide and copper-manganese spinel in preparation of acetaldehyde by anaerobic dehydrogenation of ethanol, and belongs to the technical field of heterogeneous catalysis for preparation of acetaldehyde and hydrogen by anaerobic dehydrogenation of ethanol. The reaction is carried out in a fixed bed reactor, under the conditions that the reaction atmosphere is nitrogen, the reaction temperature is 280 DEG C and the mass space velocity is 66.1 h <-1 >, the ethanol conversion rate is 72.5%, the acetaldehyde selectivity is 95.0%, and the space time yield of acetaldehyde based on the copper-manganese composite oxide is 43.5 h <-1 >, so that high-selectivity preparation of acetaldehyde and hydrogen under relatively mild conditions is realized; the system has the remarkable advantages of simple catalyst preparation, high catalytic activity under the condition of high mass airspeed, high space-time yield of acetaldehyde, high atom utilization rate of the system, good stability and the like. The CuMnTi-1 catalyst can be stabilized for more than 70 hours, the CuMnTi-1 improves the utilization rate of copper and manganese, improves the catalytic performance, reduces the demand quantity of copper-manganese spinel in the reaction, and reduces the overall cost of catalyst preparation.

The invention relates to a non-sulfur-tolerant wide-temperature shift regulation and control process based on a coal natural gas methanation process, and belongs to the technical field of coal chemical industry. The process comprises the following specific steps: carrying out non-sulfur-tolerant wide-temperature shift reaction on purified raw materials for methanation reaction, namely carrying out adiabatic and / or isothermal CO shift reaction under the conditions that the temperature is 200-360 DEG C, the pressure is 1-10 MPa, the molar ratio of H2O to CO is 0.7-2 and the air speed is 3000-40000h <-1 >, reducing the CO concentration at the inlet of a methanation reactor by 30-70%, and then carrying out high-temperature reaction on the methanation reaction to obtain the high-sulfur-tolerant methanation reaction. The CO disproportionation reaction in the methanation reactor is avoided while the circulating gas is effectively reduced, the service life of the existing methanation catalyst is prolonged by more than 50%, and the shutdown frequency and the maintenance time are greatly reduced.

This invention discloses a low-space-velocity (SCR) catalyst and its preparation method. The catalyst includes a coating and a support layer. The coating comprises a coating material consisting of a mixture of tungsten-doped (5%) anatase nano-titanium dioxide, titanium dioxide, and SSZ-13 molecular sieve, with a content of 56.1 wt% to 75.6 wt% of the total loading. The method includes the following steps: preparing a support layer solution and a coating material; preparing a catalyst slurry; drying a catalyst support with a support layer solution; coating the catalyst support with the catalyst slurry; and calcining and drying to obtain the catalyst. This invention improves the coating uniformity and efficiency by coating the support layer solution and the catalyst slurry, thereby improving the NO content of the catalyst under low space velocity conditions. x Conversion efficiency.

The invention relates to a method of producing at least one alkene from at least one ketone, the method comprising the step of: (a) contacting at least one gaseous ketone with at least one ketonization catalyst in the presence of at least one hydrogen releasing agent or hydrogen at a temperature of at least 350°C to produce a corresponding alkene, wherein the gases have a gas hourly space velocity (GHSV) of 1 to 1000 m 3 / (m 3 x h), and wherein the ketonization catalyst is a metal oxide catalyst or mixtures thereof.

The invention provides a reaction system for preparing aromatic hydrocarbon through hydrogenation of carbon dioxide. The reaction system comprises an injection loop reactor, a rectification device and a recycle gas separation device, the injection loop reactor comprises a reaction kettle, a circulating pump, a reaction heat exchanger, a cross-flow filter and a Venturi injector which are communicated in sequence; part of the Venturi ejector is arranged in the reaction kettle, and the circulating gas separation device comprises a primary condenser, a secondary condenser, an absorption tower and a desorption tower which are communicated in sequence; the device further comprises a circulating gas heater. The jet loop reactor is adopted as key process equipment to perform carbon dioxide hydrogenation reaction to continuously prepare aromatic hydrocarbon, reaction fluid circulates in a loop in a large flow manner and is jetted at a high speed by the Venturi jet, and negative pressure is formed at a working nozzle, so that process gas is sucked into the jet to form micron-sized bubbles with large specific surface area, and the aromatic hydrocarbon is continuously prepared. Gas-liquid-solid contact is increased, the gas-liquid-solid multi-phase reaction speed can be increased, the reaction efficiency is improved, and therefore the air speed is increased under the condition that the yield is guaranteed.

The invention belongs to the technical field of CO2 catalytic conversion, and discloses an in-situ reduction efficient CO2 methanation catalyst as well as a preparation method and application thereof. The efficient CO2 methanation catalyst NiA (CO3) xRe is formed by in-situ reduction of Ni and A coupled carbonate NiA (CO3) x, wherein A is selected from one of Mg, Ce and Al. NiA (CO3) xRe is prepared by a coprecipitation method. According to the present invention, the reaction equilibrium conversion is achieved at 300 DEG C in the reaction atmosphere with the CO2: H2: N2 volume ratio of 1: 4: 5 and the air speed of 150000 mL.gcat <-1 >. H <-1 >, the methane selectivity reaches 100%, the methane yield reaches 677.8 mmol.gcat <-1 >. H <-1 >, and the methane selectivity is still not reduced after the operation is performed for 100 h under the condition; compared with the prior art, the prepared catalyst greatly improves the high efficiency and stability of methanation catalytic reaction, the preparation process is simple, large-scale production is easy to achieve, the catalyst is matched with the temperature of coal-fired flue gas, energy does not need to be input again, efficient conversion can be completed, carbon emission is effectively reduced, and high-value products are obtained for use; and a favorable way is provided for realizing a carbon neutralization target.

A catalytic cracking process for producing light olefins and aromatic gasoline includes contacting a petroleum-based feedstock with a catalyst in a single riser reactor, where the catalyst includes 0 wt % to about 15 wt % of a Y-type zeolite and greater than 30 wt % of a pentasil zeolite, a weight ratio of pentasil zeolite to Y-type zeolite greater than 3; and a weight hourly space velocity (WHSV) is about 40 h−1 to about 120 h−1.

The invention first relates to a process for the dehydrogenation of a feedstock comprising cycloalkanes having 6 carbon rings to produce an effluent comprising hydrogen and aromatics, using a reaction section comprising at least one multi-tubular reactor comprising at least two tubes comprising a fixed bed of at least one dehydrogenation catalyst and a shell comprising at least one fixed bed of at least one dehydrogenation catalyst, -the feedstock is fed into the tube in gaseous form at an inlet temperature of the feedstock greater than or equal to 300 DEG C, at an inlet pressure of the feedstock between 0.1 and 1 MPa, and at a feedstock weight hourly space velocity (WWH) at an inlet between 1 and 15 h <-1 >,-a heat transfer fluid is circulated in the shell, the heat transfer fluid is introduced in gaseous form at the inlet of the shell, and-the heat transfer fluid is introduced in gaseous form at the inlet of the shell. The heat transfer fluid is introduced into the shell at an inlet temperature of between 320 DEG C and 400 DEG C and at an inlet pressure of between 0.10 MPa and 1.10 MPa at a flow rate such that the ratio of the weight flow rate of the heat transfer fluid at the inlet of the shell to the weight flow rate of the feedstock at the inlet of the tube is greater than or equal to 1.0.

The invention relates to the technical field of diene hydrogenation preparation, in particular to a preparation method of exo-tetrahydrodicyclopentadiene, which comprises the following steps of: performing catalytic hydrogenation on a dicyclopentadiene solution by using a circulating continuous flow bubbling hydrogenation reactor at the normal pressure and the temperature of 70-90 DEG C at the volume space velocity of 5h <-1 > and the hydrogen-oil volume ratio of 750-850 to obtain exo-tetrahydrodicyclopentadiene, automatically separating the hydrogenation catalyst at the tail end of the reactor to obtain a hydrogenation product, stirring and mixing an isomerization catalyst and the hydrogenation product at 90-110 DEG C, and carrying out catalytic isomerization to prepare exo-tetrahydrodicyclopentadiene; and rectifying and separating to obtain hanging tetrahydrodicyclopentadiene. According to the invention, the circulating continuous flow bubbling hydrogenation reactor is adopted for liquid phase hydrogenation, continuous production of exo-tetrahydrodicyclopentadiene is realized by a two-step method, the problem that catalytic hydrogenation and isomerization reaction are not matched is avoided, the conversion rate of exo-tetrahydrodicyclopentadiene is increased, and coking and impurity pollution of non-target products are reduced.

A selective hydrogenation method for ethane cracking to olefins involves selectively hydrogenating the ethylene feedstock from the top of an ethane stripper to remove acetylene. Reaction conditions: inlet temperature 50℃~95℃, pressure 1.5~3.0MPa, space velocity 8000~14000h⁻¹ ‑1 The preferred reaction conditions are: reactor inlet temperature 60℃~90℃, reaction pressure 2.0~2.5MPa, and space velocity 9000~12000h⁻¹. ‑1 The catalyst support is alumina or mainly alumina, and has a bimodal pore structure. The specific surface area of ​​the catalyst is 3–16 m². 2 The catalyst contains at least Pd, Fe, Ni, and Cu, with Pd supported in both microemulsion and solution formats. Ni and Cu are supported in microemulsion, while Fe is supported in solution. The solution-supported Pd and Fe are primarily located in the 56–75 nm micropores, while the microemulsion-supported Ni, Cu, and Pd are mainly distributed in the 300–650 nm macropores of the support. This alkyne removal method exhibits excellent catalytic performance and anti-coking properties, with low "green oil" formation.

The application relates to a preparation method of a high-temperature-resistant high-space-velocity VOCs catalytic combustion catalyst for acid ester waste gas and the catalyst, and belongs to the field of industrial waste gas treatment. The catalyst takes noble metal, transition metal oxide and rare earth oxide as active components, takes honeycomb ceramic or metal honeycomb as a carrier, and is prepared by adopting a coating process. First, Ce x Zr 0.6‑x La y Pr 0.1‑ y O2 is prepared by using lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, cerium nitrate hexahydrate and zirconium nitrate pentahydrate; then, La-Al2O3 is prepared by using lanthanum nitrate hexahydrate and Al2O3 through an equal-volume impregnation method; and finally, the catalyst is prepared by using Ce x Zr 0.6‑x La y Pr 0.1‑ y O2, La-Al2O3 and noble metal. The catalyst has the characteristics of high low-temperature activity, good thermal stability and high purification efficiency for catalytic combustion of volatile organic compounds of acid esters at high space velocity.

The invention relates to a process for converting CO2 into methane, wherein hydrogen is contacted with a gaseous feed comprising CO2 in at least one methanation reactor comprising a catalyst bed at a catalyst bed temperature of 160°C to 550°C at a pressure of 0.1 MPa to 1 MPa, wherein the gas hourly space velocity is 10 m 3 / kg / hour to 50 m 3 / kg / hour, and wherein the H2 / CO2 molar ratio is 1 to 8, and wherein the catalyst comprises Ni metal deposited on a substrate made of uranium oxide having the formula UO 2+x , wherein x is 0.01 to 0.6, and wherein the mass content of nickel is 5% to 40% of nickel metal relative to the total mass of the catalyst.

The invention relates to a process condition simulation method and simulation device for regulating and controlling the burn-out rate of dry quenching. The method comprises the following steps: setting the temperature rise time in a simulation reaction to be equal to the cooling time of coke in a dry quenching furnace in industrial production; the initial temperature is equal to the coke discharge temperature of a dry quenching furnace in industrial production; the volume flow rate of the mixed gas is determined by the volume space velocity of cooled circulating gas reacted with coke in the fixed bed in industrial production and the accumulation volume of a coke material in the simulated reaction; the concentration of reaction gas is equal to that of circulating gas in industrial production; the method comprises the following steps: placing a coke material in a constant-temperature area of a reaction section, heating to an initial temperature, recording the mass, then introducing a mixed gas of a reaction gas and an inert gas, heating to a red coke temperature from the initial temperature within the heating time, and recording the mass; and calculating the dry quenching burn-out rate. Compared with the prior art, the method provided by the invention has the advantages that the integrating degree of conditions and actual working conditions is high, and the influence of the actual working condition change on the dry quenching burn-out rate can be accurately reflected.

This invention belongs to the field of chemical product synthesis technology and discloses a method for isomerization of methylphenolic compounds. Under certain reaction temperature and pressure conditions, methylphenolic compounds are vaporized and mixed with a carrier gas. The mixture passes through a fixed-bed reactor containing a bilayer modified ZSM-5 catalyst at a certain space velocity, where it undergoes an isomerization reaction to generate its isomer products. The ZSM-5 catalyst contains Si, Al, Fe, and Ge elements. This invention, by introducing metal heteroatom components into the ZSM-5 molecular sieve framework, effectively improves the pore structure and active sites of the molecular sieve, enhances the catalyst's resistance to carbon deposition, strengthens its activity and stability, and significantly extends its lifespan. Furthermore, it exhibits excellent catalytic effects on the isomerization of various methylphenolic compounds.

The application provides a low-temperature high-activity supported Ru-based catalyst, a preparation method and application, the method is characterized in that a manganese oxide carrier is synthesized by a precipitation method, the manganese oxide carrier is loaded by a deposition precipitation method, and a supported Ru-based catalyst is obtained. ‑1 ·h ‑1 Under high space velocity conditions, a CO2 conversion rate of 94.9% and a selectivity of 100% are achieved, the bottleneck of insufficient low-temperature activity of existing catalysts is broken through; meanwhile, the catalyst exhibits excellent long-term stability, after continuous operation for 100 hours at 180 DEG C, the CO2 conversion rate attenuation is less than 0.5%, and the selectivity is always kept at 100%, laying a solid durability foundation for industrial application.

The present invention relates to a process for preparing and processing of synthesis gas, the process particularly comprising the steps of preparing a first gas stream comprises H2 and CO2; feeding said gas stream into a first reactor comprising a reverse water gas shift catalyst, wherein said gas stream is fed into the first reactor at a gas hourly space velocity (GHSV) in the range of from 1,000 to 100,000 h-1, wherein the reverse water gas shift reaction is conducted at a temperature in the range of from 650 to 1,000 °C, wherein in a time interval Δt, wherein Δt is in the range of from 1 to 60 minutes, the GHSV of said gas stream displays a gradient in the range of from 2,000 to 60,000 h-1, obtaining a second gas stream; feeding the second gas stream into a second reactor, wherein the second reactor comprises one or more of a methanol synthesis catalyst, a dimethyl ether synthesis catalyst, an oxo synthesis or hydroformylation catalyst, a Fischer-Tropsch synthesis catalyst, a formic acid synthesis catalyst, and a phosgene synthesis catalyst, obtaining a product stream.

The invention discloses a method for preparing a carbon nano tube through H2 in-situ regulation and control of a Ni-CeO2 / Al2O3 nano island catalytic material, and relates to the field of chemical catalysis. The reaction is carried out in a vertical quartz tube of a high-temperature furnace of the fixed bed reactor, the catalyst is Ni-CeO2 / Al2O3-X with nano island morphology and is fixed on the upper section, and the lower section is connected with a detachable collection bottle; the volume ratio of raw material gas CH4 to CO2 is 1: 1, the reaction is carried out under the conditions that the temperature is 750 DEG C, the pressure is normal and the mass space velocity is 160000 mL gcat-h, and the carbon nano tube and the synthesis gas are co-produced. According to the process, three synchronization of high yield of CNTs, stable yield of synthesis gas and long service life of the catalyst is realized for the first time, and a low-cost, green and scalable industrial route is provided for large-scale preparation of high-purity carbon nanotubes from CO2-CH4.

The present invention is a method for producing a catalyst-free olefin by continuous operation in a fixed-bed reactor at a temperature of 80 to 250°C, a total pressure of 10 to 200 barg, and a liquid hourly space velocity (LHSV) of 0.1 to 6 h -1 and a method for hydrotreating a nitrogen-enriched liquid oil stream by reacting said nitrogen-enriched liquid oil stream with hydrogen, thereby producing a stabilized liquid oil stream.

The invention discloses a method for producing hexafluoropropylene from vinylidene fluoride, which comprises the following steps: mixing VDF and diluent gas (nitrogen / argon) according to a ratio of 1: (3-8), preheating, introducing into a fixed bed reactor filled with a CrO-MnO / gamma-AlO catalyst, reacting under the conditions of 350-450 DEG C, 0.1-0.5 MPa and air speed of 1000-3000h <-1 >, and separating the product to obtain high-purity hexafluoropropylene. Through collaborative optimization of catalyst components and design of a mild reaction system, 88% of VDF conversion rate, 90% of HFP selectivity and 99.8% of product purity are achieved, energy consumption and equipment cost are remarkably reduced, and the method is suitable for industrial continuous production.

The present application relates to the technical field of 1-butene oligomer preparation, and more particularly to a process for producing 1-butene trimer, i.e., dodecene. The present application provides a process for producing 1-butene trimer, which comprises: subjecting initial raw materials containing butane and 1-butene to catalytic reaction in a fixed-bed tubular reactor under the conditions of 50-100 DEG C, 1-2 MPa pressure, raw material space velocity 0.5-2 h ‑1 -1 of the fixed-bed tubular reactor containing a solid acid catalyst. The catalyst of the present application is simple to prepare, has high 1-butene trimerization selectivity, and can maintain high activity after long-time operation.

The invention discloses a method for preparing formic acid through water carbonylation, and belongs to the technical field of catalytic chemistry. The method comprises the following steps: heating and vaporizing water, mixing with carbon monoxide to form feed gas, and reacting under the action of a catalyst at certain temperature, pressure and space velocity to generate formic acid. The catalyst is selected from at least one of mordenite, ZSM-5, ZSM-23, a Na-type Y molecular sieve and an H-type Y molecular sieve, and can be subjected to gas activation before use. According to the method, cheap and easily available raw materials are adopted, the reaction condition is mild, the technological process is simple, and a new way with potential application value is provided for green synthesis of formic acid.

The invention relates to the technical field of chemical catalysis, and discloses a method for continuously preparing 2-methyl pentamethylene diamine based on a three-phase hydrogenation reactor, which comprises the following steps: (1) mixing 2-methyl pentamethylene dinitrile, a solvent and alkali to form a mixed fluid; (2) in a three-phase hydrogenation reactor, filling the supported catalyst at the lower part of the reactor and above a gas distributor, introducing hydrogen from the gas distributor arranged at the lower part of the reactor under the pressure of 2-12MPa, introducing the mixed fluid from the bottom of the reactor under the mass space velocity of 0.1-4h <-1 >; and then controlling the reaction temperature to be 70-160 DEG C, carrying out hydrogenation reaction, and discharging a product obtained by the reaction from the upper part of the reactor. According to the present invention, the supported catalyst is adopted, and the hydrogenation reaction is performed in the three-phase hydrogenation reactor, such that the 2-methylpentanediamine yield can be effectively improved, the continuous production is achieved, and the production energy consumption is reduced.

The invention relates to the technical field of preparation of 2-vinylpyridine, in particular to a preparation method of 2-vinylpyridine, which comprises the following steps: performing purity control and impurity removal on raw materials, and preparing a composite catalyst with specific loading capacity and pore size by roasting, dipping and drying processes; determining the molar ratio of the raw materials according to the loading capacity of the obtained catalyst, mixing the pretreated raw materials with the catalyst, and controlling the temperature and stirring parameters to activate surface active sites of the raw materials; and introducing the activated mixed material into a reactor filled with a catalyst according to a set volume space velocity. According to the preparation method of the 2-vinylpyridine, high-purity raw materials are selected, isomer impurities are removed, and the composite catalyst with specific loading capacity and pore diameter is matched, so that the reaction selectivity is greatly improved, and side reactions are reduced; a reaction and separation integrated reactive distillation tower is adopted, the thermodynamic equilibrium limitation is broken, and the dehydration reaction efficiency and the product yield are effectively improved.

The application relates to the technical field of catalyst preparation, in particular to a high-selectivity catalyst suitable for high air speed and a preparation method and application thereof. 12 Bi a Fe b Co c Ni d A e Cl f O x , A is one of sodium, potassium, rubidium and cesium; a=0.3-3, b=1-4, c=3-8, d=1-5, e=0.01-0.5, f=0.01-2, and x is a value determined by the total valence of elements in the general formula except oxygen. The catalyst prepared by the preparation method has excellent catalytic performance under high air speed conditions and has a good application prospect.

A kind of method for quickly evaluating sulfur tolerance limit of diesel engine aftertreatment catalyst, the intercepted catalyst sample is arranged in the tubular heating furnace of atmosphere aging platform reactor, polluted gas C3H8, C3H6, CO, NO, NH3, SO2, CO2 etc. are introduced into the heating furnace, the concentration of gas pollutant at the outlet of catalyst is recorded by analyzer, after the SO2 concentration at the outlet of the catalyst to be detected no longer changes, the polluted gas is cut off, the fast heating atmosphere in the process of simulating vehicle oil injection regeneration is introduced into the heating furnace under the condition that the space velocity of analyzer is unchanged, after the SO2 concentration at the outlet of the catalyst to be detected no longer changes, a reaction cycle is ended, the catalyst sample is taken out, the amount of sulfur compound captured by catalyst is detected, and the NOx conversion efficiency is calculated;The above steps are repeated until the NOx conversion efficiency reduces to 0, which is regarded as the sulfur tolerance limit of catalyst.The present application can be close to the actual use of vehicle, and the sulfur resistance and regeneration capacity of aftertreatment catalyst are systematically tested, the sulfur tolerance boundary of catalyst is defined, and calibration support is provided for actual vehicle application.

The utility model relates to a fixed bed phenol hydrogenation catalyst evaluation device which comprises a reactor, the upper part of the reactor is provided with a feed port, the lower part of the reactor is provided with a discharge port, the discharge port is connected to a condenser through a pipeline, the lower part of the condenser is provided with a gas-liquid two-phase outlet, the gas-liquid two-phase outlet is connected to a gas-liquid separator through a pipeline, and the gas-phase outlet is arranged above the gas-liquid separator. The outlet of the circulating fan is connected to a phenol evaporator through a pipeline, the upper part of the phenol evaporator is provided with a gas phase outlet, the gas phase outlet is connected to a heater through a pipeline, the upper part of the heater is provided with a material outlet, and the material outlet is connected to a material inlet at the upper part of the reactor through a pipeline. The device can accurately adjust the temperature of a reaction hot spot, is suitable for comparison tests of multiple parameters such as system pressure, reaction temperature, hydrogen / phenol feed ratio, air speed and catalyst service life, almost completely fits an industrial device, and greatly improves the accuracy of a catalyst evaluation result.

This invention discloses a method for preparing formaldehyde by oxidizing methylal, belonging to the field of chemical technology. The method uses methylal and oxygen as raw materials, wherein the volume fraction of methylal feed is 2%~6%, the volume ratio of methylal to oxygen feed is 1:1.5~1:5.0, the mass ratio of methylal to water feed is 1:0.09~1:0.24, and the mass ratio of methylal to methanol feed is 1:0.02~1:0.13; the oxidation reaction temperature is 280℃~380℃, and the gas hourly space velocity is 6000~11000 h⁻¹. ‑1 This system regulates reaction selectivity through the synergistic effect of water vapor and oxygen; simultaneously, the staged introduction of methanol not only increases the reaction temperature at the top of the reactor and balances the temperature distribution throughout the reactor, but also achieves efficient control of the heat of reaction, thereby reducing methanol residue in the product. This invention effectively solves the problems of low reaction temperature and high methanol content in the product during the oxidation of methyl acetal, and has the advantages of excellent formaldehyde selectivity and high product purity.

The application relates to the technical field of denitration, and specifically discloses a lime kiln flue gas denitration treatment method. The lime kiln flue gas denitration treatment method specifically comprises the following steps in sequence: SNCR and SCR; the process parameters of the SNCR section are as follows: the flue gas temperature is 900-1200 DEG C, 10-14 wt% urea solution is sprayed, and the target denitration efficiency is 10-30%; the process parameters of the SCR section are as follows: the flue gas temperature is 180-220 DEG C, 17-22 wt% ammonia water is used as a reducing agent, a honeycomb catalyst is used, and the space velocity is 3000-5000 h-1 1 ; the honeycomb catalyst is prepared from the following components: vanadium pentoxide, titanium dioxide, zinc-aluminum hydrotalcite and stearic acid. The technical scheme provided by the application has excellent denitration performance in the denitration treatment of lime kiln flue gas; the denitration system can be operated for a long time, and the denitration efficiency is relatively high after long-time continuous operation.

The present application belongs to the field of chemical catalysis technology, and in particular to a method for preparing acetaldehyde from ethylene glycol with high selectivity using a molecular sieve with MWW topology. The method comprises the following steps: mixing ethylene glycol with an inert carrier gas and vaporizing the mixture, and then feeding the mixture into a fixed bed reactor, and under the conditions of a certain reaction temperature and reaction absolute pressure, the ethylene glycol is dehydrated and converted into acetaldehyde by contacting with a molecular sieve catalyst with MWW topology. The present application uses a molecular sieve with MWW topology as a catalyst for the reaction of preparing acetaldehyde from ethylene glycol with high selectivity. By utilizing the topological pore and acidic characteristics of the molecular sieve, the high selective conversion of ethylene glycol into acetaldehyde is realized under a relatively simplified catalyst system. By adjusting the reaction temperature, space velocity, reaction absolute pressure, and the ratio of ethylene glycol feed to carrier gas, the effective control of the reaction path and product distribution is realized.