23 results about "Methacrolein" patented technology

The invention belongs to the technical field of catalysts, and discloses a nanorod-like Keggin type heteropolyacid catalyst and a preparation method and application thereof, the nanorod-like Keggin type heteropolyacid catalyst has a double rod-like structure, and the double rod-like structure is a rod-like structure with the length of 50-150 nm and a rod-like structure with the length of 3-10 [mu] m. The heteropolyacid catalyst has the characteristics of large specific surface area, double rodlike structure and the like, and the reaction performance of the catalyst for preparing methacrylic acid by oxidizing methylacrolein can be optimized.

The invention belongs to the technical field of catalytic materials, and particularly discloses an ionic liquid catalyst for preparing methylacrolein and a preparation method of the ionic liquid catalyst. According to the preparation method, ionic liquid (protonated morpholine hydrochloride or 1-butyl-3-methylimidazole chloride salt) and metal chloride are subjected to a reaction, metal chelating ionic liquid is obtained, and the ionic liquid catalyst is obtained. The ionic liquid catalyst disclosed by the invention is simple in synthesis operation and mild in reaction condition, and has good industrial amplification potential; compared with the traditional supported or single metal salt catalyst, the catalyst provided by the invention has the advantages that the metal ion loss or agglomeration phenomenon is not easy to occur in the use process, the service life of the catalyst is effectively prolonged, and the problem that the existing catalyst is easy to inactivate is solved; the catalyst is adjustable in active center, high in selectivity and excellent in catalytic performance.

The catalyst for the oxidative esterification of methacrolein to methyl methacrylate comprises a support having an average diameter of at least 0.8 mm. The support is selected from oxides of silicon, carbides of silicon, metal oxides, and metal carbides. The catalyst further comprises nickel oxide and gold particles disposed on the support. The gold particles have an average diameter of less than 12 nm and a standard deviation of + / - 4 nm. A process for preparing methyl methacrylate from methacrolein and methanol using the catalyst is also disclosed.

The invention provides a methacrylic acid catalyst, the chemical general formula of which is PxMoyVzOw [-COOH] n, P, Mo and V are active components, and the molar ratio of x: y: z: w: n is (0.8-2.0): (10.0-12.0): (0.5-2.5): (30.0-50.0): (1.0-6.0). When the methacrylic acid catalyst is used for selectively oxidizing methylacrolein, the methylacrolein conversion rate and the methacrylic acid selectivity are high, and the stability is excellent. And the preparation method of the methacrylic acid catalyst is simple, convenient and low in cost.

The application relates to a method for co-producing methacrylate and methallyl alcohol, comprising the following steps: mixing methacrolein, a first catalyst and an aprotic nonpolar solvent to carry out a Chichibabin reaction to obtain a first reaction solution; the first catalyst comprises an aluminum alcoholate catalyst; mixing a fatty alcohol, a second catalyst and the first reaction solution to carry out an ester exchange reaction to prepare methacrylate and methallyl alcohol; the second catalyst comprises at least one of a titanate and an organotin. The method can co-produce methacrylate and methallyl alcohol in one pot, the yield is relatively high, by-products are relatively few, and the purity of the methacrylate and the methallyl alcohol is relatively high.

The application provides a method for preparing lilial. The method is that lilial is synthesized from t-butylbenzene and alpha-methylacrolein under the catalysis of a Ti-K(Na) / F-Meso-SiO2 heterogeneous catalyst. The catalyst used in the application is modified by F element on the carrier, further enhancing the B acid acidity of the catalyst, and the doping of K and / or Na on the Ti metal effectively improves the catalytic activity of the Ti metal. The catalyst used in the application has both B acid and L acid sites, and the two acid active centers synergistically catalyze, so that the process conditions are mild, the reaction time is short, the catalyst is easy to recycle, and the problem of a large amount of waste acid and solid waste generated after the use of traditional catalysts is solved.

A process for preparing a catalyst for the oxidative esterification of methacrolein to methyl methacrylate includes providing a support selected from an oxide of silicon, a carbide of silicon, a metal oxide, and a metal carbide. Particles of at least one oxide of a metal are provided on the support. The support is contacted with a gold salt and heated at a temperature ranging from 50°C to 600°C for a time ranging from at least 0.1 hours to 48 hours to convert the gold salt into gold nanoparticles having an average diameter of less than 12 nm and a standard deviation of + / - 4 nm, with at least 75% by number of the gold nanoparticles located within 20 nm of the metal oxide particle.

The application discloses a preparation method of a supported Ag metal catalyst and application thereof, and the preparation method comprises the following steps: after a molecular sieve is impregnated with an alkali solution and a silver source solution, the molecular sieve is dried and calcined to obtain the supported Ag metal catalyst. The application is matched with a continuous reactor-fixed bed, and the production efficiency of 2-methylpropenol is greatly improved. Under the condition that hydrogen is used as a reducing agent and without a solvent, the conversion rate of methacrolein on the Ag metal catalyst reaches 90%, the selectivity of 2-methylpropenol is 89%, and the catalyst can be stably operated for a relatively long time.

The application discloses a kind of for methanol and methyl methacrolein oxidation esterification catalyst and its preparation method and application, belong to catalytic synthesis technical field.The application first prepares silicon-titanium molecular sieve TS-1 carrier, then loads gold nanoparticles, and gold-based catalyst is prepared, TS-1 carrier can not only stabilize gold salt, Ti-O-Au bond can be formed between titanium species in TS-1 carrier and gold nanoparticles, improve the interaction between gold metal and carrier, more effectively limit the size of gold particle, form smaller size nano gold particle and good dispersity, improve the specific surface area of catalyst, to improve catalyst activity and stability.Mass concentration is 45-80% methanol and methyl methacrolein mixed solution and the obtained catalyst are mixed sufficiently, oxygen is input, and oxidation esterification reaction occurs under 70-160 DEG C, 0.5-2MPa, to prepare methyl methacrylate.The gold-based catalyst prepared by the application significantly improves the conversion rate of methyl methacrolein and the selectivity of methyl methacrylate.

A process for concurrently producing methacrylic acid and methyl methacrylate comprising: a) producing methacrolein from propionaldehyde and formaldehyde; b) splitting the methacrolein into a first methacrolein stream and a second methacrolein stream; c) producing methacrylic acid in an oxidative reaction from water and the first methacrolein stream; and d) producing methyl methacrylate in an oxidative esterification reaction from methanol and the second methacrolein stream.

A catalyst for oxidative esterification of methacrolein to methyl methacrylate comprises a support having an average diameter of at least 0.8 mm. The support is selected from an oxide of silicon, a carbide of silicon, a metal oxide, and a metal carbide. The catalyst further comprises nickel oxide and gold particles disposed on the support. The gold particles and have an average diameter of less than 12 nm and a standard deviation of + / −4 nm. A method for preparing methyl methacrylate from methacrolein and methanol using the catalyst is also disclosed.

The invention relates to the technical field of preparation of methyl methacrylate, in particular to a hydrotalcite-based catalyst, preparation of the hydrotalcite-based catalyst and application of the hydrotalcite-based catalyst in production of methyl methacrylate. In the invention, the hydrotalcite-based catalyst comprises a carrier and an active center loaded on the carrier, the carrier is lanthanide series metal modified hydrotalcite (MgO-Al2O3-La2O3), and the catalyst is a catalyst. The active center is gold; wherein the loading capacity of the gold is 0.5-1 wt%. According to the preparation method, the gold particle catalyst with uniform particles and high activity can be obtained, the preparation process is simple, operation is convenient, the loading amount of active components is low, meanwhile, the catalyst has excellent activity and good stability, the preparation cost of the catalyst is low, the conversion rate of methylacrolein and the selectivity of MMA are high, and the catalyst is suitable for industrial production.

This invention provides a method for preparing a catalyst for the oxidation of isobutylene to methacrolein and its application. The preparation method includes the following steps: Step 1: Mixing a molybdenum-containing precursor solution I, a bismuth-containing precursor solution II, and a cobalt- and iron-containing precursor solution III to obtain solution V; Step 2: Adding a hydroxylated polycarboxylic acid to solution V and performing a crystallization reaction to obtain a catalyst precursor; Step 3: Calcining the catalyst precursor to obtain a catalyst for the oxidation of isobutylene to methacrolein; wherein the hydroxylated polycarboxylic acid is selected from one or more combinations of glycolic acid, lactic acid, citric acid, malic acid, and tartaric acid. This invention, through pretreatment with hydroxylated polycarboxylic acids, can block dispersed oxide lattice clusters, inhibit the formation of large particle structures, and fully expose the active defect sites of the catalyst, thereby improving catalytic activity.

The invention provides a composite carrier catalyst as well as a preparation method and application thereof. The composite carrier catalyst comprises a composite carrier and an active component loaded on the composite carrier; the composite carrier comprises Al2O3, SiO2 and a basic oxide; the active component comprises a composition with a chemical formula of AuNiaCubOx in atomic ratio, the value range of a is 0.2-5, the value range of b is 0-5, and x is the total number of oxygen atoms required by valence of each element in the active component. The composite carrier catalyst provided by the invention can be used in a reaction for synthesizing methyl methacrylate through oxidative esterification of methylacrolein, has good catalytic performance, and can have the characteristics of high methylacrolein conversion rate and high methyl methacrylate yield under the condition of relatively low Au content of the catalyst.

This invention belongs to the field of catalytic ammonia oxidation technology, and specifically relates to a Ru / AMn2O4 catalyst for the gas-solid phase synthesis of methacrylonitrile, its preparation method, and its application. The catalyst preparation includes the preparation of an AMn2O4 spinel support, AMn2O4 spinel support pretreatment, and Ru / AMn2O4 catalyst preparation. The catalyst of this invention, prepared by the above method, possesses advantages such as high activity at low temperature, high stability, high conversion rate of methacrolein, high yield of methacrylonitrile, and low yield of the byproduct hydrogen cyanide. It is particularly suitable for use as a catalyst in the gas-solid phase ammonia oxidation of methacrolein to methacrylonitrile.

The invention relates to the technical field of catalysts, and discloses a heteropolyacid catalyst as well as a preparation method and application thereof. The roundness P of the heteropolyacid catalyst is more than or equal to 0 and less than or equal to 0.8, meanwhile, the stacking density rho of the heteropolyacid catalyst is limited, and the relationship between the roundness P and the average radius Ravg is more than or equal to 0 and less than or equal to 0.95, namely (2 * rho * P) / Ravg; the catalyst can be efficiently stacked and arranged in the tube nest of the reactor, so that the catalyst is arranged more tightly, channeling and reverse mixing of feed gas among catalyst particles are effectively reduced, the utilization rate of methylacrolein can be increased in the reaction of producing methacrylic acid by oxidizing methylacrolein, and meanwhile, the occurrence of excessive reaction is reduced; therefore, the catalyst can keep high methylacrolein conversion rate and methacrylic acid selectivity at the same time. Meanwhile, the specific structure of the outer surface of the catalyst can enable the catalyst to obtain good mechanical strength, the cracking and crushing conditions of the catalyst are reduced, and the service life of the catalyst is prolonged.

This utility model relates to a coal-based apparatus for producing methyl methacrylate; it includes a raw coal bunker and an oxygen pipeline, which are respectively connected to the inlet of a gasification unit. The outlet of the gasification unit is connected to both a non-shifted gas scrubbing unit and a shifted gas scrubbing unit. The outlet of the non-shifted gas scrubbing unit is connected to a methanol synthesis unit, which is connected to a methanol-to-olefins unit, which is connected to a propionaldehyde synthesis unit, which is connected to a methacrolein synthesis unit, and finally, the methacrolein synthesis unit is connected to a methyl methacrylate synthesis unit. This apparatus achieves the goal of conforming to my country's energy structure and reducing dependence on foreign oil, while also extending the coal chemical industry chain to increase product added value and enhance the competitiveness of coal chemical enterprises.

Improved processes for the production of methacrylates, especially methacrylic acid and methyl methacrylate (MMA), based on C-4 feedstocks are described. In this case the C4 feedstock is especially isobutene or tertiary butanol. In addition, a wide range of embodiments for the efficient production of these products is provided. The invention especially relates to a process for the production of methacrylic acid and methyl methacrylate by gas phase oxidation of isobutene. In a second gas phase oxidation step, methacrolein is converted to methacrylic acid and unconverted methacrolein is removed from the methacrylic acid. This methacrolein is evaporated in the presence of various gases and vapors in an evaporation device and mixed in gaseous form with the process gas of the first oxidation stage in which the methacrolein was produced. In this way, the recycled methacrolein can be fed back into the process and catalytic partial oxidation.

This is a 3,5,5-trimethylhexanoic acid composition comprising 3,5,5-trimethylhexanoic acid and methacrolein as a trace component, wherein the deuterium-to-toluene concentration of methacrolein, as determined by olfactory gas chromatography / mass spectrometry, is 0.50 ppb by volume or more and 30 ppb by volume or less.

A 3, 5, 5-trimethylhexanoic acid composition containing 3, 5, 5-trimethylhexanoic acid and methacrolein as a trace component, the methacrolein having a concentration in terms of deuterated toluene of 0.50-30 vol ppb (inclusive) as determined by odor-smelling gas chromatography / mass spectrometry.

The present application relates to the technical field of catalyst preparation, in particular to a catalyst for one-step oxidation esterification of methylpropylaldehyde to produce methyl methacrylate and its preparation and application. The catalyst comprises a carrier and active centers loaded on the carrier; the active center is gold, and the loading amount of the active center is 0.1-2 wt%; the carrier is a transition metal oxide carrier modified by lanthanide elements, and the content of the lanthanide elements is 0.1-6 wt%. The catalyst can be applied to one-step oxidation of methylpropylaldehyde and esterification with methanol to produce methyl methacrylate. The catalyst provided by the present application has low Au loading amount, simple preparation process, convenient operation and low raw material price. The catalyst can realize efficient conversion of methylpropylaldehyde to methyl methacrylate at a relatively low noble metal loading amount, and the selectivity can reach 97.16% at most, so the catalyst has a very wide industrial application prospect.

The application discloses a preparation method of a copper-based bimetallic catalyst, the copper-based catalyst and application, and the preparation method comprises the following steps: mixing raw materials containing a molecular sieve, a copper source, a second metal source, an ester compound and an alcohol compound, and then impregnating the raw materials with an alkali solution to obtain the copper-based bimetallic catalyst; and the second metal source is selected from one of zinc nitrate, gallium nitrate, iron nitrate and indium nitrate. The application is matched with a continuous reactor-fixed bed, and the production efficiency of 2-methylpropenol is greatly improved. Under the condition that hydrogen is used as a reducing agent and without a solvent, the conversion rate of methacrolein on the bimetallic catalyst reaches 85%, the selectivity of 2-methylpropenol is 90%, and meanwhile, the catalyst can be stably operated for a long time.