290 results about "Methyl acetate" patented technology

The invention discloses a wear-resistant vehicle body film and a preparation method thereof, and relates to the technical field of films. The wear-resistant automobile body film prepared by the invention is prepared from polytetrahydrofuran ether glycol, isophorone diisocyanate, a catalyst, dihydric alcohol quaternary ammonium salt, a functional aid, modified silicon dioxide and a chain extender. The dihydric alcohol quaternary ammonium salt is obtained by reacting N, N '-dihexyl-N, N'-dimethyl propane-1, 3-diamine with monochloroacetone and then condensing with glycerol; the functional additive is obtained by reacting 2-boric acid thiophene-4-methyl acetate with 2, 7-dibromofluorene and then carrying out bromination hydrolysis; the modified silicon dioxide is obtained by reacting pretreated silicon dioxide with melamine and then reacting with sodium hypophosphite. The wear-resistant vehicle body film prepared by the invention has good anti-aging, wear-resistant, antibacterial and flame-retardant properties.

The invention discloses a short c-axis flaky mordenite molecular sieve as well as a preparation method and application thereof, and belongs to the technical field of molecular sieves. The chemical composition of the short c-axis flaky mordenite molecular sieve is Ra.Mb. (SixAly) O2, r is a template agent tetraethylammonium ion; a is the mole number of R in each mole of (SixAly) O2, and a is more than or equal to 0.02 and less than or equal to 0.04; m is an alkali metal ion; b is the mole number of M in each mole of (SixAly) O2, and b is more than or equal to 0.02 and less than or equal to 0.06; x is the mole fraction of Si in each mole of (SixAly) O2, and x is more than or equal to 0.9 and less than or equal to 0.97; y is the mole fraction of Al in each mole of (SixAly) O2, y is more than or equal to 0.03 and less than or equal to 0.1, and x + y is equal to 1; and the dimension thickness of the stone molecular sieve in the c-axis direction is 20-80 nanometers. The molecular sieve shows excellent catalytic performance in a catalytic reaction for preparing methyl acetate through dimethyl ether carbonylation.

The invention relates to a multifunctional tandem catalytic process for directly preparing methyl acetate / ethanol from synthesis gas. According to the process, a novel catalyst for preparing dimethyl ether from synthesis gas is prepared by adopting an impregnation method, and after the catalyst is sequentially connected with a dimethyl ether carbonylation catalyst and a hydrogenation catalyst in series, efficient directional synthesis of methyl acetate and ethanol is realized in a double-bed or three-bed sequential filling form. According to the invention, high CO conversion per pass, high methyl acetate selectivity and low acetic acid selectivity can be realized, and the problems of corrosion and difficult conversion of a subsequent hydrogenation system are effectively avoided; the multifunctional catalytic system provided by the invention is simple in preparation method and easy to realize industrial large-scale production.

The invention discloses a benzene-free environment-friendly plastic printing ink diluent and a preparation method thereof, and relates to the field of chemical engineering. The environment-friendly flame retardant is prepared from the following components in parts by weight: 10 to 25 parts of ethyl acetate, 8 to 15 parts of refined methyl acetate, 5 to 10 parts of butyl acetate, 10 to 30 parts of dimethyl carbonate, 6 to 15 parts of methylal, 10 to 20 parts of propyl acetate, 2 to 7 parts of dibasic acid ester, 3 to 10 parts of propylene glycol monomethyl ether, 7 to 15 parts of isopropanol and 3 to 9 parts of propylene carbonate. According to the present invention, the ethyl acetate, the dimethyl carbonate and other benzene-free solvents are adopted to replace the traditional benzene-series solvent, such that the benzene-free environmental protection target is achieved, the environmental residue and the human health risk are substantially reduced, in addition, the propylene carbonate, the dibasic acid ester and the like in the formula further have the biodegradability, the environmental protection performance of the diluent is further improved, and the environmental protection performance of the diluent is further improved. The cost of the prepared benzene-free environment-friendly plastic printing ink diluent is remarkably reduced compared with that of an imported diluent.

The application discloses a catalyst for preparing methyl acetate or ethanol by hydrogenation of dimethyl oxalate and a preparation method thereof. The catalyst comprises an active component, an auxiliary component and a carrier. The active component is a single substance or an oxide of Cu, the auxiliary component is a single substance or an oxide of W, the high active site is a Cu-W alloy interface and single Cu and W metals, and the carrier is one or more than two of silicon dioxide, aluminum oxide, zirconium oxide, zinc oxide, magnesium oxide and cerium oxide. The copper-tungsten alloy catalyst provided by the application has the advantages of structural stability, high mechanical strength, good heat conduction performance, high substrate conversion rate and high product selectivity. The preparation method is simple in steps, easy in raw material acquisition, low in cost, green in pollution, good in preparation repeatability and easy in scale production. The catalyst has extremely high stability and catalytic activity in the reaction of preparing methyl acetate or ethanol by hydrogenation of dimethyl oxalate, high ethanol or methyl acetate yield and high active component utilization rate.

The invention relates to the technical field of household fabrics, and particularly discloses a polypropylene elastic non-woven fabric and a preparation method thereof. The polypropylene elastic non-woven fabric is mainly prepared from the following raw materials in parts by weight: 100 parts of polypropylene, 10-20 parts of an ethylene-octylene copolymer, 2-4 parts of maleic anhydride grafted polypropylene, 1-3 parts of modified nano silicon dioxide and 0.5-2 parts of an antioxidant. The modified nano silicon dioxide is obtained by treating nano silicon dioxide with 3-trimethoxy silane propyl acrylate, oleamide and 2-(4-vinyl phenyl) methyl acetate. Through mutual cooperation of the raw materials, the non-woven fabric has the characteristics of high breaking strength, high elongation at break and high wear resistance, shows excellent comprehensive performance, and can meet the requirements of the non-woven fabric as spring wrapping cloth.

The invention belongs to the technical field of lithium batteries, and relates to a lithium ion battery, in particular to a phosphate battery with both battery rate capability and safety performance. The lithium ion battery comprises a positive plate, a negative plate, a diaphragm and a non-aqueous electrolyte, the positive plate comprises a positive electrode material layer containing a phosphate material; the organic solvent comprises a first solvent, and the first solvent is selected from at least one of methyl acetate, ethyl acetate and methyl propionate; the lithium salt comprises LiPF6 and LiFSI; the first additive comprises a compound as shown in a structural formula 1; the lithium ion battery satisfies 0.02 < = 10c / a + e < = 1.8, 40 < = a < = 60, 1.1 < = b < = 1.5, 0 < e < = 1.5, and 0.05 < = c < = 2. According to the lithium ion battery provided by the invention, high-concentration LiPF6, low-content LiFSI and high-content carboxylic ester are matched with one another, so that the compatibility of rate capability and safety performance of a phosphate battery is realized.

The invention provides a polymer framework ink, a polymer framework and cell-loaded gel collaborative 3D printing method and a structural body. The polymer framework ink contains a high-molecular polymer, an organic solvent and organic modified synthetic flaky silicate, wherein the organic solvent comprises a first solvent and a second solvent, the first solvent is an ethanol aqueous solution and / or absolute ethyl alcohol, and the second solvent is methyl acetate and / or isoflurane. The polymer framework ink provided by the invention is rapidly cured through direct volatilization of the organic solvent; the flake silicate is synthesized through organic modification, so that higher fidelity is obtained, and the effect of rapid shaping is achieved while curing is carried out; different sizes of pores in the polymer filaments can be obtained by controlling the temperature difference between the polymer frame ink and the environment; finally, collaborative printing of the polymer framework and the cell-carrying gel can be realized under mild conditions, and the activity of cells is ensured.

The invention provides a white flower salvia miltiorrhiza composition and application thereof in medicines for preventing and treating atherosclerosis, and belongs to the technical field of traditional Chinese medicines. According to the technical scheme, the composition is characterized by comprising 3-5 parts of white flower salvia miltiorrhiza root slices, 1-2 parts of white flower salvia miltiorrhiza dried leaves and 1-2 parts of white flower salvia miltiorrhiza extract. Mixing the white flower salvia miltiorrhiza leaf powder with a malic acid aqueous solution, carrying out ultrasonic treatment, filtering, and carrying out alcohol precipitation on filtrate to obtain an alcohol precipitate; extracting the white flower salvia miltiorrhiza root powder by using supercritical carbon dioxide to obtain a supercritical extract; mixing the alcohol precipitate and the supercritical extract according to the weight ratio of (7-9): (1-3) to obtain a white flower salvia miltiorrhiza extract; the alcohol used in the alcohol precipitation is methanol; methyl acetate is used as an entrainer in the supercritical carbon dioxide extraction. The white flower salvia miltiorrhiza composition provided by the invention has the beneficial technical effect of remarkably improving atherosclerosis.

The invention discloses a machine learning assisted acetic acid reaction rate prediction model training method and device and a prediction method. The machine learning assisted acetic acid reaction rate prediction model training method comprises the following steps: acquiring an enhanced data training set; extracting a training feature vector of the enhanced data training set; obtaining a classification promotion regression model for the acetic acid reaction rate; and training the classification lifting regression model for the acetic acid reaction rate through the feature vectors for training so as to obtain the trained classification lifting regression model for the acetic acid reaction rate. According to the method, a model relationship between input characteristics and acetic acid reaction rates (including reactant mass, catalyst mass, methyl acetate concentration and the like) is established through training set learning. A user can directly obtain the prediction result of the acetic acid reaction rate by inputting the characteristic variables.

This invention provides a flavoring agent for enhancing the honey-sweet aroma of tobacco, comprising the following raw materials and their mass percentages: 0.2-0.3% 2,3-pentanedione, 0.45-0.55% phenylacetic acid, 0.45-0.55% phenethyl acetate, 0.25-0.4% phenylethanol, 0.45-0.6% methyl phenylacetate, 0.45-0.6% ethyl phenylacetate, 0.5-0.6% menthyl acetate, 0.15-0.25% geraniol, and the balance being propylene glycol. This invention belongs to the field of tobacco flavoring technology. By combining 2,3-pentanedione, phenylacetic acid, and phenethyl acetate in a specific mass ratio and conducting testing and evaluation, a flavoring agent suitable for enhancing the honey-sweet aroma of tobacco has been successfully developed. The composition is clearly defined, significantly improving the honey-sweet aroma of tobacco products, with a rich and long-lasting aroma, and good taste harmony.

The invention discloses a dual stimulus-responsive supramolecular gel temporary plugging agent and a preparation method thereof, and relates to the technical field of oil-gas field development. The supramolecular gel temporary plugging agent comprises the following components in percentage by mass: 5wt%-10wt% of a tertiary amine surfactant; the temperature response authigenic acid accounts for 0.2 wt%-2wt%; and the balance of water. Wherein the tertiary amine surfactant is prepared by reacting fatty acid and N, N-dimethyl-1, 3-diaminopropane according to the molar ratio of 1: 1, and the temperature response authigenic acid is composed of methyl formate, ethyl formate, methyl acetate, ethyl acetate and the like; the dual-stimulus-responsive supramolecular gel temporary plugging agent disclosed by the invention has the plugging strength of 4.3 MPa, takes water as a solvent, and is simple in process, high in yield, strong in environmental protection property, stable in performance and low in cost.

The utility model discloses a front mixing device of dimethyl ether and CO for methyl acetate processing, and belongs to the field of mixing tanks. The problems that the mixing efficiency of materials is low, and bottom liquid materials are difficult to fully contact and mix with gas materials are solved. The top of the fixed tank is fixedly provided with a liquid inlet pipe, the bottom of the fixed tank is fixedly provided with a liquid outlet pipe, the fixed tank is fixedly provided with a plurality of air inlet pipes, the air inlet pipes are fixedly provided with a plurality of nozzles, and the fixed tank is internally and fixedly provided with a mixing assembly; liquid materials are dispersed through the dispersing plate, dispersed liquid collides with CO gas, the contact area of the liquid materials and the CO gas is effectively increased, the mixing efficiency of gas materials and the liquid materials is effectively improved, a solution at the bottom of the fixed tank is sprayed through the shell and the transverse pipe, and the mixing efficiency of the gas materials and the liquid materials is improved. The gas material and the liquid material are further mixed, and meanwhile, the liquid material and the gas material at the bottom of the fixed tank are fully contacted and mixed.

The invention belongs to the field of pharmaceutical chemical engineering and fine chemical engineering, and relates to a method for recovering 2-cyano-2-methylvaleric acid as shown in a chemical structural formula I. The method comprises the following steps: selecting methyl 2-cyanoacetate and 1-chloropropane, and carrying out catalytic dipropylation under the action of potassium carbonate to prepare methyl 2-cyano-2-valproate; hydrolyzing the latter to obtain 2-cyano-2-valproic acid (crude product) as shown in a formula III; adding water, alcohol and other polar solvents into the 2-cyano-2-valproic acid crude product, pulping, carrying out gradient crystallization, filtering, and carrying out low-temperature vacuum drying to obtain 2-cyano-2-valproic acid monohydrate and 2-cyano-2-methylvalproic acid monohydrate; the 2-cyano-2-valproic acid monohydrate is subjected to high-temperature decarboxylation hydrolysis through sulfuric acid, and valproic acid is prepared; and carrying out high-temperature decarboxylation hydrolysis on the 2-cyano-2-methylpentanoic acid monohydrate by using sulfuric acid to obtain the essence 2-methylpentanoic acid.

This application discloses a method for producing acetonitrile by amination of acetate, comprising the following steps: in a reactor, acetate, ammonia, and a catalyst are contacted and reacted to obtain acetonitrile; wherein the acetate is selected from at least one of methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and cyclohexyl acetate; the catalyst is composed of a support and alkaline earth metal oxides and alkali metal oxides supported on the surface of the support; wherein the support is selected from at least one of silicon oxide, aluminum oxide, titanium oxide, and zirconium oxide; wherein the alkaline earth metal oxide is selected from at least one of magnesium oxide, calcium oxide, strontium oxide, and barium oxide; wherein the alkali metal oxide is selected from at least one of lithium oxide, sodium oxide, and potassium oxide; wherein the loading of alkaline earth metal oxide in the catalyst is 0.01–10 wt%, the loading of alkali metal oxide is 0.05–5 wt%, and the remainder is the support.

The invention discloses a methyl acetate purification device and process, and relates to the technical field of chemical purification. The following scheme is proposed, comprising a machine body and a stirring barrel fixedly connected to the inside of the machine body, a driving mechanism, wherein the driving mechanism is installed on the top of the machine body, and a stirring mechanism, wherein the stirring mechanism is installed inside the stirring barrel and one end is connected to the driving mechanism. The stirring mechanism comprises a connecting rod rotatably connected to the inside of the machine body and a stirring rod fixedly connected below the connecting rod. The driving mechanism drives the connecting rod to rotate, and the rotation of the connecting rod drives the stirring rod to rotate synchronously. The invention can not only blow the heat of the electric heating wire to the stirring barrel through the rotation of the fan blades to quickly heat the methyl acetate processing raw materials, but also can quickly and evenly stir the methyl acetate through the stirring rod and the flip rod, thereby effectively improving the effect and efficiency of methyl acetate purification.

The invention discloses a catalyst for preparing methyl acetate through carbonylation of dimethyl ether as well as a preparation method and application of the catalyst, and belongs to the technical field of industrial catalysis. A preparation method of a catalyst for preparation of methyl acetate through carbonylation of dimethyl ether comprises the following steps: placing a template agent-containing sodium mordenite molecular sieve in low-temperature plasma, and carrying out modification treatment under a first preset condition to obtain a modified sodium mordenite molecular sieve; performing ammonium ion exchange treatment on the modified sodium-type mordenite molecular sieve to obtain an ammonium-type mordenite molecular sieve; and placing the ammonium type mordenite molecular sieve in low-temperature plasma, and carrying out modification treatment under a second preset condition to obtain the catalyst, wherein the first preset condition comprises that modification treatment is carried out under gradient voltage; the second preset condition comprises modification treatment under a constant voltage. According to the preparation method disclosed by the invention, the acid density, the micropore specific surface area and the micropore volume of the mordenite can be improved, and the mordenite shows higher catalytic activity and stability in a reaction for preparing methyl acetate through dimethyl ether carbonylation.

The invention relates to a preparation method of a trifloxystrobin intermediate (E)-2-(2-bromomethyl phenyl)-2-methoxyimino methyl acetate, and belongs to the technical field of organic chemistry. The method comprises the following steps: by taking a trifloxystrobin intermediate (E)-2-(2-bromomethyl phenyl)-2-methoxyimino methyl acetate containing dibromo impurities as a raw material and an organic solvent I as a reaction medium, carrying out debromination reaction at 5-60 DEG C by using phosphite, desolventizing and extracting a reaction solution, and crystallizing to obtain the high-purity (E)-2-(2-bromomethyl phenyl)-2-methoxyimino methyl acetate. According to the method disclosed by the invention, the dibromo impurity of the trifloxystrobin intermediate is subjected to debromination treatment by adopting the phosphite, so that the dibromo impurity is converted into the trifloxystrobin intermediate. By adopting the method provided by the invention, the conversion time of the dibromo impurity can be obviously shortened, the content and the yield of the trifloxystrobin intermediate obtained by conversion are both higher than 95%, and the reaction efficiency and the quality of the intermediate are greatly improved.

The invention discloses a method for purifying methyl isobutyrylacetate, which comprises the following steps of: introducing a concentrated material obtained at the front end into the middle part of a continuous rectifying tower T1 for rectifying to obtain light components at the top of the tower, and removing dichloromethane, methanol and 3-methyl-2-butanone; a tower kettle substrate of the continuous rectifying tower T1 enters the middle part of a continuous rectifying tower T2 to be rectified, and diethyl methyl ester with the purity of 90% is obtained at the tower top; a tower kettle substrate of the continuous rectifying tower T2 enters the middle part of a continuous rectifying tower T3 to be rectified, and an isobutyryl methyl acetate product is produced at the tower top; the method has the advantages that the methyl isobutyrylacetate is purified by adopting a continuous rectification method, and rectification parameters are optimized, so that the yield of the methyl isobutyrylacetate can reach 85% or above under the condition that the purity of the methyl isobutyrylacetate is not lower than 99%; and the continuous rectification is continuous feeding and continuous extraction, the retention time is short, and the energy consumption is low.

The application discloses a refining device and method and application of a nitrogen-containing solvent precursor. The refining method takes liquid-phase material obtained through cryogenic separation of a gas-phase mixture obtained through an ammoniation reaction as raw material, and obtains acetonitrile main product, acetamide by-product and recycled unreacted raw material through the steps of side-line rectification, component rough separation, three-waste separation and differential pressure separation, and avoids the discharge of polluting gas by dissolving trace impurities and non-condensable gas at low temperature through self-produced wastewater. The application can be used for the separation and refining of liquid-phase reaction product of methyl acetate ammoniation acetonitrile, and is simple in process, friendly to environment, easy to operate and suitable for industrialized large-scale continuous production.

This invention provides a method for preparing and purifying methyl isoglycyrrhizate. The preparation method includes reacting isoglycyrrhizic acid (of formula I) or its salt in a mixed solvent of methanol and methyl acetate in the presence of acetyl chloride. The purification method involves adding crude methyl isoglycyrrhizate to a mixed solvent of organic solvent and water after the reaction, heating and stirring to dissolve; then adding water dropwise, cooling to allow crystallization, and filtering to obtain a solid. This invention, by adding a certain amount of methyl acetate during the reaction, can ensure the conversion rate, control the acidity of the reaction environment, reduce the degradation of methyl isoglycyrrhizate, and greatly improve the product yield and material utilization. The purification method for methyl isoglycyrrhizate provided by this invention can efficiently remove impurity A from the product, is simple to operate, uses little solvent, has a high yield, and is environmentally friendly.

The application discloses a device capable of switching production of refined methyl acetate or acetate and methyl alcohol products, which comprises a fourth rectifying tower capable of switching for separating an aqueous solution of acetate or for rectifying and extracting crude methyl acetate, an eighth rectifying tower capable of switching for removing low-boiling impurities or for evaporating and purifying an extractant and a first rectifying tower capable of switching for extractive rectification of methyl acetate or for removing light components; the fourth rectifying tower is connected with the first rectifying tower, a fifth rectifying tower for refining acetate and a decomposition tower for hydrolyzing methyl acetate respectively; the first rectifying tower is connected with a second rectifying tower for purifying methyl alcohol and a third rectifying tower for removing light components again respectively, and the third rectifying tower is connected with a seventh rectifying tower for removing light components for the third time. The device has two functions, i.e. production of acetate, methyl alcohol and refined methyl acetate can be adjusted in time according to market conditions.

The invention relates to the technical field of methyl chloroacetate synthesis, in particular to a methyl chloroacetate synthesis method which comprises the following specific steps: S1, raw material preparation; s2, performing an electrochemical carboxylation reaction to obtain a reaction solution containing products such as methyl chloroacetate; s3, copolymerization reaction of epoxypropane: transferring the electrochemical carboxylation reaction liquid to a high-pressure reactor, and adding a bifunctional organic tin initiator for reaction; and S4, product separation and treatment. In the synthesis process, toxic and harmful dehydrating agents and purification reagents are not used in the raw material preparation link, so that the safety and environmental risks caused by strong corrosivity of concentrated sulfuric acid and hypertoxicity of phosgene in the traditional method are avoided. In the reaction process, the used electrolyte, the catalyst and the like are relatively environment-friendly, and in the product separation stage, by-products are effectively separated through reasonable process design, the emission of wastes is reduced, so that the method integrally conforms to the concept of green chemistry, and the pollution to the environment is greatly reduced.

A kind of polyvinylidene fluoride and poly (methyl methacrylate) gradient composite fiber membrane and its preparation method and application, poly (methyl methacrylate) and polyvinylidene fluoride are respectively dissolved in the mixed solution of N, N dimethylformamide and methyl acetate, oil bath stirring, obtain homogeneous transparent spinning solution;The above two kinds of spinning solution are added in needle tube respectively, fixed on microfluidic spinning advance pump, connect infusion hose;Temperature and humidity in spinning bin are controlled, install nylon net on receiver to carry out gradient composite fiber membrane collection, by microfluidic control system, polyvinylidene fluoride and poly (methyl methacrylate) spinning solution pumping is carried out at different change rate, open air valve, and carry out spinning;Gradient composite fiber membrane is taken off from nylon net, and dried to obtain two-component air-blowing poly (methyl methacrylate) and polyvinylidene fluoride gradient composite membrane.

The utility model relates to the technical field of chemical equipment, in particular to a purification device for preparing methyl 4-chloroacetoacetate. By means of the steam absorption pipe in the purification box, most of generated steam can be conveniently absorbed when an evaporation product is heated, the steam absorption pipe is driven by the electric push rod to move, and the telescopic corrugated pipe is connected to the top end of the steam absorption pipe, so that the steam absorption pipe can move in the purification box, and then steam at different positions in the purification box can be conveniently absorbed; the top end of a moving rod penetrates through a box cover and is slidably inserted into a limiting sleeve, a guide rod is slidably sleeved with a guide block, a steam absorption pipe is conveniently limited, the steam absorption pipe is not prone to inclining, a valve body can be opened through an auxiliary absorption pipe at one end of an auxiliary pipe, and steam at the top of the steam absorption pipe can be absorbed; all generated steam can be conveniently discharged out of the purification box through the connecting pipe, so that a small amount of steam is not easy to remain in the purification box, and the preparation purity of a product is not influenced.

The invention discloses a hydrogen recovery device and method for PTA (pure terephthalic acid) production, the hydrogen recovery device comprises a first cooler and a first gas-liquid separation tank, the outlet end of the first cooler is connected with the first gas-liquid separation tank, the first gas-liquid separation tank is connected with a hydrogen recovery washing tower through a pipeline, the bottom of the hydrogen recovery washing tower is connected with an acid recovery device through a pipeline, and the acid recovery device is connected with the acid recovery device through a pipeline. The top of the hydrogen recovery washing tower is connected with a second cooler through a pipeline; the hydrogen recovery washing tower is connected with the oxidation device through a conveying pump so as to convey acid into the hydrogen recovery washing tower, and hydrogen-rich steam is sequentially subjected to acid pickling and desalted water spraying from bottom to top in the hydrogen recovery washing tower; the invention aims to provide the hydrogen recovery device and method for PTA (pure terephthalic acid) production, so that the content of methyl acetate and methanol in the hydrogen recovery process is reduced, the purity of hydrogen is improved, and the production cost is reduced.

This invention discloses a method for synthesizing a mordenite molecular sieve-encapsulated metal catalyst for the synthesis of ester compounds, comprising the following steps: 1) mixing a water-soluble metal salt sequentially with an amine ligand and an alkali metal hydroxide to obtain a preliminary mixture solution; 2) mixing the preliminary mixture solution sequentially with an aluminum source and a silicon source to obtain a gel; 3) crystallizing the gel at 160–180 °C, cooling after crystallization, and separating to obtain an initial solid; 4) drying and calcining the obtained initial solid to obtain a preliminary molecular sieve; 5) placing the preliminary molecular sieve in an inorganic ammonium salt solution for ion exchange, separating the reactants after ion exchange to obtain a solid, drying and calcining the solid to obtain a mordenite molecular sieve-encapsulated metal catalyst for the synthesis of ester compounds. The catalyst obtained by this synthesis method can be used for the carbonylation of dimethyl ether to produce methyl acetate, exhibiting a relatively fast reaction rate while maintaining a high conversion rate of dimethyl ether.

The invention discloses a copper-zinc catalyst, a preparation method thereof and application of the copper-zinc catalyst in preparation of ethanol by hydrogenation of methyl acetate. Comprising the following steps: (1) mixing water, a silicon source, an aluminum source and alkali, stirring I, and crystallizing in a closed container to obtain a solution A; (2) mixing the solution A with an alkali solution, and stirring II to obtain a solution B; (3) mixing water, a copper source, a zinc source and an auxiliary agent source to obtain a solution C; and (4) mixing the solution B and the solution C, controlling the pH value to be 6.5-9.5, aging, washing, drying and roasting to obtain the copper-zinc catalyst. And carrying out hydrogen reduction on the copper-zinc catalyst, and carrying out hydrogenation reaction. The specific surface area of the catalyst prepared by the preparation method provided by the invention is increased, the particle size of the active species Cu is relatively small, the thermal stability of the catalyst is favorably improved, the catalytic activity is remarkably improved, and the catalyst has higher methyl acetate conversion rate and ethanol selectivity.

The invention relates to a mycobacterium hydrolase and application thereof in preparation of flavors and fragrances, and belongs to the fields of enzyme engineering and mining and application of new enzyme resources. The hydrolase comes from mycobacteria, and the amino acid sequence of the hydrolase is shown as SEQ ID No: 2; the hydrolase MdHDL disclosed by the invention has relatively high catalytic activity and substrate concentration tolerance, and can efficiently utilize benzyl alcohol or phenethyl alcohol to react with p-nitrophenyl methyl acetate pNPA, p-nitrophenyl methyl butyrate pNPB or p-nitrophenyl methyl caprylate pNPO to synthesize essence and perfume substances with different flavors; the method is suitable for preparing flower fragrance and fruit fragrance type flavors and fragrances such as jasmine flower fragrance, rose fragrance, pineapple fragrance, banana fragrance and apricot fragrance by an enzyme method, has obvious industrial production potential, and provides technical basis and method guidance for preparing the flower fragrance and fruit fragrance type flavors and fragrances by the enzyme method.