CN114605252A

CN114605252A - Method for preparing methacrylic acid and methyl ester thereof

Info

Publication number: CN114605252A
Application number: CN202011449410.6A
Authority: CN
Inventors: 王峰; 张志鑫; 王业红; 李书双; 雷丽军; 张健
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2022-06-10
Anticipated expiration: 2040-12-09
Also published as: CN114605252B

Abstract

The invention relates to a method for synthesizing methacrylic acid and methyl methacrylate thereof, in particular to a method for synthesizing methacrylic acid or methyl methacrylate by catalyzing propionic acid or propionic anhydride or condensing methyl propionate and formaldehyde. The catalytic reaction is carried out in a fixed bed reactor, acetic acid or acetic anhydride or methyl propionate and formaldehyde are gasified and diluted in inert atmosphere to pass through a rod-shaped VPO catalyst, and aldol condensation is carried out to prepare methacrylic acid or methyl methacrylate.

Description

Method for preparing methacrylic acid and methyl ester thereof

Technical Field

The invention relates to a method for synthesizing methacrylic acid or methyl ester thereof, in particular to a method for preparing methacrylic acid or methyl methacrylate by condensing propionic acid or propionic anhydride or methyl propionate with formaldehyde.

Background

Methacrylic acid is an important intermediate of a polymer and an organic chemical raw material, is easy to polymerize into a water-soluble polymer, is a monomer for manufacturing acrylate solvent type and emulsion type adhesives, is used for improving the bonding strength and stability of the adhesives, and is used for manufacturing thermosetting coatings, synthetic rubbers, fabric treating agents, insulating materials, adhesives, ion exchange resins and the like.

The methyl methacrylate which is the most important derivative product of methacrylic acid is a raw material for producing organic glass, can be used for windows of airplanes and civil buildings, and can also be processed into buttons, solar filters, automobile lamp lenses and the like; the coatings produced have superior suspension, rheological and durability characteristics; the prepared adhesive can be used for bonding metal, leather, plastic and building materials; methacrylate polymer emulsions are used as fabric finishing agents and antistatic agents.

At present, the main production methods of methacrylic acid and methyl ester thereof include an ethylene carbonylation method, an isobutylene oxidation method, an acetone cyanohydrin method and the like.

The ethylene carbonylation process comprises: ethylene with CO, H₂The carbonyl is synthesized into propionaldehyde, the propionaldehyde is condensed with formaldehyde to generate methacrolein, methacrylic acid is obtained by oxidation, and methyl methacrylate is generated by esterification. Ethylene, CO and methanol can also be subjected to one-step carbonylation to prepare methyl propionate, and the methyl propionate is condensed with formaldehyde to directly generate methyl methacrylate.

The isobutene oxidation method comprises the following steps: isobutene is oxidized into methacrolein, and then is oxidized into methacrylic acid, and methyl methacrylate can be generated through esterification. The route has the advantages of long process flow, complex equipment, high investment, expensive raw material high-purity isobutene, low total selectivity and high production cost.

The process for preparing Methyl Methacrylate (MMA) by the acetone cyanohydrin method (ACH method) has poor economic benefit and large environmental pollution. The proportion of MMA produced annually by the ACH process has fallen dramatically, with the falling portion being largely replaced by the ethylene and isobutylene processes.

In comparison, the process route for preparing methyl propionate by one step from ethylene, CO and methanol and then condensing methyl methacrylate with formaldehyde is short, highly toxic intermediate species are not generated, the process condition is mild, and the process is safe and environment-friendly. Wherein the condensation of methyl propionate with formaldehyde is one of the keys to the process.

Lucite corporation, uk (now mitsubishi chemist) catalyzes the reaction using a Cs-based catalyst. In 1976 Schlacfer et al prepared Zr/SiO by impregnation₂A catalyst and applying it to the reaction. Then Wolfgang et Al as K/Al₂O₃/SiO₂The catalyst catalyzes the reaction of propionic acid and formaldehyde, the conversion rate is only 33%, and the selectivity is 49%. In 1988, Mamoru Ai reported that a P-V catalyst was used for the condensation reaction of propionic acid and formaldehyde, and found that: at a molar ratio of propionic acid to formaldehyde of 2, the yield of methacrylic acid was 39 mol%. By using the V-Si-P catalyst, the yield of the methacrylic acid under the optimized reaction condition can reach 53 mol%, and the selectivity is 82%. In 2003, Mamoru Ai reported that the yield of methacrylic acid on the Sn-Si-P catalyst could reach 58%.

In summary, it can be seen that the condensation reaction catalyst is critical in the reaction of propionic acid or propionic anhydride or methyl propionate with formaldehyde to produce methacrylic acid or methyl methacrylate. The catalytic activity of the catalysts reported at present is generally low. Therefore, the development of new catalysts with high activity is key and has important significance.

Disclosure of Invention

The invention aims to provide a method for synthesizing methacrylic acid and methyl methacrylate thereof, which prepares the methacrylic acid or the methyl methacrylate by condensing cheap, easily obtained and stable propionic acid or propionic anhydride or methyl propionate and formaldehyde through a proper catalytic system.

The technical scheme is as follows:

in a fixed bed reactor, propionic acid or propionic anhydride or methyl propionate and formaldehyde are gasified and diluted with inert carrier gas in certain proportion, and then reacted in certain amount of rod-shaped VPO catalyst at certain temperature and pressure to produce methacrylic acid or methyl methacrylate.

The formaldehyde is provided by one or more than two of formalin, trioxymethylene and methylal;

the molar ratio of the propionic acid or the propionic anhydride or the methyl propionate to the formaldehyde is as follows: 10/1-1/10;

the inert atmosphere comprises: n is a radical of₂、Ar、He；

The total volume of the formaldehyde and the propionic acid or the propionic anhydride or the methyl propionate in the gas phase accounts for 5-25% of the total gas volume;

the total mass space velocity of formaldehyde and propionic acid or propionic anhydride or methyl propionate on the catalyst is as follows: 0.5-5h^-1；

The reaction temperature is as follows: 280 ℃ and 480 ℃;

the reaction pressure is as follows: 0.5-30 atm.

Providing a scheme that:

the molar ratio of the propionic acid or the propionic anhydride or the methyl propionate to the formaldehyde is as follows: 10/1-3/1 or 1/3-1/10;

the total mass space velocity of formaldehyde and propionic acid or propionic anhydride or methyl propionate on the catalyst is as follows: 0.5-3h^-1；

The reaction temperature is as follows: 310 ℃ to 430 ℃;

providing a scheme that:

the molar ratio of the propionic acid or the propionic anhydride or the methyl propionate to the formaldehyde is as follows: 10/1-5/1 or 1/5-1/10;

the total mass space velocity of formaldehyde and propionic acid or propionic anhydride or methyl propionate on the catalyst is as follows: 0.5-1h^-1；

The reaction temperature is as follows: 340 ℃ and 390 ℃;

the preparation method of the rod-shaped VPO catalyst comprises the following steps:

dissolving a precursor salt of vanadium and a precursor salt of P in a solvent according to a certain P/V molar ratio, then carrying out crystallization treatment for a period of time at a certain temperature, filtering, washing and drying the obtained solid, and roasting for a period of time at a certain atmosphere and temperature to obtain the rod-shaped VPO catalyst.

Wherein the precursor salt of vanadium is: ammonium metavanadate, sodium pyrovanadate, sodium orthovanadate, vanadyl sulfate, vanadium nitrate, V₂O₅One or more than two of the above;

the precursor salt of P is: NH (NH)₄H₂PO₄Ammonium metaphosphate, sodium pyrophosphate, sodium phosphate, POCl₃85% phosphoric acid, P₂O₅One or more than two of (a);

the molar ratio of P/V is 0.5-2.5;

the solvent is as follows: water, monohydric alcohol or dihydric alcohol or polyhydric alcohol which is liquid at room temperature, water solution of polyhydric alcohol which is solid at room temperature, lactic acid or its water solution (wherein the mass fraction of acid in the water solution is 5-50%), citric acid water solution (wherein the mass fraction of acid in the water solution is 5-50%); the mass of the solvent accounts for 50-95% of the total mass of the materials;

the crystallization temperature is as follows: 120-250; the crystallization time is as follows: 6-48 h;

the roasting atmosphere is as follows: inert atmosphere (including N)₂Ar and He), oxygen-containing atmosphere (wherein the volume fraction of oxygen is 5-99%), butane-containing oxygen-containing atmosphere (wherein the volume fraction of butane is 1-5%, and the integral number of oxygen is 15-19%);

roasting temperature: 350-850 ℃; roasting time: 6-72 h.

Providing a scheme that:

the molar ratio of P/V is 0.8-2.0;

the solvent is as follows: water, monohydric alcohol of C1-C6, dihydric alcohol of C2-C6, polyhydric alcohol of C3-C6 and a mixed solvent of alcohol and water (wherein the mass fraction of the water is 5-95%);

the crystallization temperature is as follows: 150-220; the crystallization time is as follows: 12-48 h;

the roasting atmosphere is as follows: oxygen-containing atmosphere (wherein the volume fraction of oxygen is 5-99%), butane-containing oxygen-containing atmosphere (wherein the volume fraction of butane is 1-5%, and the integral number of oxygen is 15-19%);

roasting temperature: 450 ℃ and 750 ℃; roasting time: 12-36 h.

Providing a scheme that:

the molar ratio of P/V is 1.0-1.6;

the solvent is as follows: ethanol, ethylene glycol, propylene glycol, butanediol, glycerol or a water solution thereof, a mixed solvent of alcohol and water (wherein the mass fraction of the water is 5-95%), an aqueous solution of erythritol, pentaerythritol, xylitol, glucose and sorbitol (wherein the mass fraction of the alcohol is 5-50%);

the crystallization temperature is as follows: 170-; the crystallization time is as follows: 24-48 h;

the roasting atmosphere is as follows: an atmosphere containing oxygen in butane (wherein the volume fraction of the butane is 1-5%, and the integral number of oxygen is 15-19%);

roasting temperature: 550-650 ℃; roasting time: 15-24 h.

Advantageous technical effects

1. The catalyst used in the invention has cheap and easily available raw materials, the preparation process is controllable and easy to operate, and the condensation reaction of propionic acid or methyl propionate and formaldehyde can be effectively generated;

2. the catalyst has good stability and hydrothermal stability, the reaction process is simple, controllable and easy to operate, and the yield of methacrylic acid or methyl methacrylate can reach 80 percent at most.

Drawings

FIG. 1 is a rod-shaped VPO catalyst prepared in example 12.

Detailed Description

In order to further explain the present invention in detail, several specific embodiments are given below, but the present invention is not limited to these embodiments.

Example 1

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 0.5, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 2.5 mu m, and the radius is 0.09 mu m).

Tabletting the obtained sample to form 20-60 meshes, adding the sample into a fixed bed reactor, gasifying formalin and propionic acid, and reacting the gasified formalin and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 2

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 0.8, stirring the mixture at room temperature for 30min, and then crystallizing the mixture in an oven at 170 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 1.5 mu m, and the radius is 0.10 mu m).

Tabletting and molding the obtained sample to 20-60 meshes, adding the sample into a fixed bed reactor, gasifying formalin and propionic acid, and mixing the gasified formalin and propionic acid with inert atmosphere Ar, wherein the molar ratio of formaldehyde to propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10% of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 3

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1, stirring the mixture at room temperature for 30min, and then crystallizing the mixture in an oven at 170 ℃ for 24 h. And filtering, washing and drying the obtained mixture, and roasting for 24 hours at 550 ℃ in an air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.3 mu m and the radius of 0.10 mu m).

Tabletting and molding the obtained sample to 20-60 meshes, adding the sample into a fixed bed reactor, gasifying formalin and propionic acid, and mixing the gasified formalin and propionic acid with inert atmosphere He, wherein the molar ratio of formaldehyde to propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10% of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1，340℃，1atm, the reaction is carried out under the condition of m, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in the table 1.

Example 4

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1.6, stirring the mixture at room temperature for 30min, and then crystallizing the mixture in an oven at 170 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.5 mu m and the radius of 0.09 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic acid, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 5

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 2, stirring the mixture at room temperature for 30min, and then crystallizing the mixture in an oven at 170 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 2.0 mu m, and the radius is 0.21 mu m).

Example 6

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 2.5, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 2.3 mu m, and the radius is 0.24 mu m).

Example 7

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into water according to the P/V molar ratio of 1.6, wherein the sum of the mass of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass, stirring at room temperature for 30min, and then placing in an oven at 170 ℃ for crystallization for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 5.0 mu m and the radius of 0.56 mu m).

Example 8

Ammonium metavanadate and NH₄H₂PO₄Adding into ethanol at a molar ratio of P/V of 1.6, stirring at room temperature for 30min, and crystallizing in oven at 170 deg.CAnd (5) melting for 48 hours. And filtering, washing and drying the obtained mixture, and roasting for 24 hours at 550 ℃ in an air atmosphere to obtain the rod-shaped VPO catalyst (the length is 2.4 mu m, and the radius is 0.25 mu m).

Example 9

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into glycerol according to the P/V molar ratio of 1.6, wherein the sum of the mass of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass, stirring at room temperature for 30min, and then placing in an oven at 170 ℃ for crystallization for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.3 mu m and the radius of 0.12 mu m).

Example 10

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 5%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 0.95 mu m, and the radius is 0.09 mu m).

Tabletting the obtained sample to 20-60 meshesThen adding the mixture into a fixed bed reactor, gasifying formalin and propionic acid, and reacting the gasified formalin and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 11

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 0.9 mu m and the radius of 0.08 mu m).

Example 12

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 95%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 1.1 mu m, and the radius is 0.09 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic acid, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of formaldehyde to propionic acid is 1/5, and the gasified formaldehyde and propionic acidThe volume of the catalyst accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 13

Ammonium metavanadate and NH₄H₂PO₄Adding the mixed solution of erythritol and water according to the molar ratio of P/V of 1.6, wherein the mass of the alcohols accounts for 5%, the mass sum of precursor salts of vanadium and phosphorus accounts for 30% of the total mass, stirring at room temperature for 30min, and then placing in an oven at 170 ℃ for crystallization for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 1.1 mu m, and the radius is 0.1 mu m).

Example 14

Ammonium metavanadate and NH₄H₂PO₄Adding the mixed solution of xylitol and water (wherein the mass of the alcohol accounts for 25%) according to the molar ratio of P/V of 1.6, stirring the mixed solution at room temperature for 30min, and crystallizing the mixed solution in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 1.0 mu m, and the radius is 0.096 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic acid, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1Reaction at 340 deg.C under 1atm, gas chromatography on-line monitoring, and reactionThe product yields and selectivities after 6h are shown in table 1.

Example 15

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of pentaerythritol and water (wherein the mass of alcohols accounts for 25%) according to the molar ratio of P/V of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 1.1 mu m, and the radius is 0.093 mu m).

Example 16

Ammonium metavanadate and NH₄H₂PO₄Adding the mixed solution of xylitol and water according to the molar ratio of P/V of 1.6, wherein the mass of the alcohol accounts for 35%, the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass, stirring at room temperature for 30min, and then placing in an oven at 170 ℃ for crystallization for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.2 mu m and the radius of 0.091 mu m).

Example 17

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of grape alcohol and water (wherein the mass of the alcohol accounts for 50%) according to the molar ratio of P/V, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. And filtering, washing and drying the obtained mixture, and roasting for 24 hours at 550 ℃ in an air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.4 mu m and the radius of 0.12 mu m).

Example 18

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of sorbitol and water (wherein the mass of alcohols accounts for 50%) according to the molar ratio of P/V of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.3 mu m and the radius of 0.11 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic acid, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6h of reaction are shown in Table 1.

Example 19

Ammonium metavanadate and NH₄H₂PO₄Adding into a mixed solution of lactic acid and water (wherein the mass of the alcohol accounts for 50%) according to a P/V molar ratio of 1.6, wherein the sum of the mass of the precursor salts of vanadium and phosphorus accounts for the total mass30 percent of the amount, stirring the mixture for 30min at room temperature, and then placing the mixture in an oven at 170 ℃ for crystallization for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.6 mu m and the radius of 0.11 mu m).

Example 20

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of citric acid and water (wherein the mass of alcohols accounts for 50%) according to the molar ratio of P/V of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 170 ℃ for 48 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 1.8 mu m, and the radius is 0.15 mu m).

Example 21

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 200 ℃ for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 20% of the total mass. Filtering, washing and drying the obtained mixture, and roasting the mixture for 24 hours at 550 ℃ in air atmosphere to obtain the rod-shaped VPO catalystReagent (0.9 μm long and 0.09 μm radius).

Example 22

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 220 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.3 mu m and the radius of 0.14 mu m).

Example 23

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 250 ℃ for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 20% of the total mass. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (the length is 2.3 mu m, and the radius is 0.16 mu m).

Tabletting the obtained sample to 20-60 meshes, adding into a fixed bed reactor, and passing formalin and propionic acid throughAfter gasification, reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 24

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 150 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in the air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.0 mu m and the radius of 0.09 mu m).

Example 25

Ammonium metavanadate and NH₄H₂PO₄Adding the mixture into a mixed solution of glycerol and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.6, stirring the mixture at room temperature for 30min, and crystallizing the mixture in an oven at 120 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 24 hours at 550 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.3 mu m and the radius of 0.18 mu m).

Tabletting the obtained sample to form 20-60 meshes, adding the sample into a fixed bed reactor, gasifying formalin and propionic acid, and reacting the gasified formalin and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of formaldehyde to propionic acid is 1/5, the gasified volume of formaldehyde and propionic acid is 10% of the total gas volume, and formaldehyde and propionic acid are added on the catalystThe mass space velocity of the acid is 3h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 26

Adding sodium metavanadate and ammonium metaphosphate into a mixed solution of glucose and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass. The resulting mixture is filtered, washed and dried in N₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.4 mu m and the radius of 0.12 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and propionic acid, and reacting the gasified trioxymethylene and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the formaldehyde and the propionic acid accounts for 20 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 280 ℃ and 0.5atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 27

Adding sodium metavanadate and ammonium metaphosphate into a mixed solution of glucose and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass. The resulting mixture is filtered, washed and dried in O₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.4 mu m and the radius of 0.12 mu m).

Example 28

Adding sodium metavanadate and ammonium metaphosphate into a mixed solution of glucose and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass. The resulting mixture was filtered, washed and dried to 5 vol% O₂N of (A)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.4 mu m and the radius of 0.12 mu m).

Example 29

Adding sodium metavanadate and ammonium metaphosphate into a mixed solution of glucose and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass. The resulting mixture was filtered, washed and dried in 60 vol% O₂N of (A)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.4 mu m and the radius of 0.12 mu m).

Example 30

Adding sodium metavanadate and ammonium metaphosphate into mixed solution of glucose and water (wherein the mass of water is 50%) according to the P/V molar ratio of 1.2And the sum of the mass of the precursor salts of vanadium and phosphorus accounts for 30 percent of the total mass, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (2)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst. (Length 1.4 μm and radius 0.12 μm)

Example 31

Adding sodium metavanadate and ammonium metaphosphate into a mixed solution of glucose and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting at 750 deg.c for 36 hr to obtain rod-shaped VPO catalyst with length of 0.9 micron and radius of 0.12 micron.

Example 32

Adding sodium metavanadate and ammonium metaphosphate into mixed solution of glucose and water (wherein the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring at room temperature for 30min, and crystallizing in oven at 200 deg.CAnd (5) 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (2)₂Roasting for 72h at 850 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 0.8 mu m and the radius of 0.12 mu m).

Example 33

Adding sodium metavanadate and ammonium metaphosphate into a mixed solution of glucose and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring the mixture at room temperature for 30min, and then placing the mixture in an oven at 200 ℃ for crystallization for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 30% of the total mass. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting for 6h at 350 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.5 mu m and the radius of 0.12 mu m).

Example 34

Adding sodium pyrovanadate and sodium pyrophosphate into a mixed solution of lactic acid and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 ℃ for 6 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting at 550 ℃ for 24h in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.0 mu m and the radius of 0.11 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting the gasified methylal and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the methylal and the propionic acid accounts for 20 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 310 ℃ and 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 35

Sodium pyrovanadate and sodium pyrophosphate are added into a mixed solution of lactic acid and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, the mass sum of the precursor salts of vanadium and phosphorus accounts for 5% of the total mass, the mixed solution is stirred at room temperature for 30min, and then the mixed solution is placed in an oven at 170 ℃ for crystallization for 12 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting at 550 ℃ for 24h in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.2 mu m and the radius of 0.10 mu m).

Example 36

Adding sodium pyrovanadate and sodium pyrophosphate into a mixed solution of lactic acid and water (wherein the mass of the water accounts for 50%) according to the P/V molar ratio of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 ℃ for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting at 550 ℃ for 24h in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.9 mu m and the radius of 0.10 mu m).

Subjecting the obtained product toTabletting and molding a sample to 20-60 meshes, adding the sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic acid is 1/5, the gasified volume of the methylal and the propionic acid accounts for 20 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 310 ℃ and 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 37

Adding sodium orthovanadate and sodium phosphate into a mixed solution of ethylene glycol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1.2, stirring the mixture at room temperature for 30min, and then crystallizing the mixture in an oven at 170 ℃ for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting at 550 ℃ for 24h in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.6 mu m and the radius of 0.09 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic anhydride, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic anhydride is 1/3, the gasified volume of the formaldehyde and the propionic anhydride accounts for 5 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 0.5h^-1The reaction is carried out at 430 ℃ and 30atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the acrylic acid after 8 hours of reaction are shown in Table 1.

Example 38

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, and gasifying formalin and propionic anhydride to be mixed withInert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic anhydride is 1/3, the gasified volume of the formaldehyde and the propionic anhydride accounts for 5 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 1h^-1The reaction is carried out at 430 ℃ and 30atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8h of reaction are shown in Table 1.

Example 39

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic anhydride, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic anhydride is 1/3, the gasified volume of the formaldehyde and the propionic anhydride accounts for 5 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 3h^-1The reaction is carried out at 430 ℃ and 30atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 40

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying formalin and propionic anhydride, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the propionic anhydride is 1/3, and gasifying the formaldehyde and the propionic anhydrideThe volume of (a) is 5% of the total gas volume, and the mass space velocity of formaldehyde and propionic acid on the catalyst is 5h^-1The reaction is carried out at 430 ℃ and 30atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

EXAMPLE 41

Vanadyl sulfate and POCl₃Adding the mixed solution of xylitol and water (wherein the mass of the water accounts for 75%) according to the molar ratio of P/V of 1.2, stirring the mixed solution at room temperature for 30min, and crystallizing the mixed solution in an oven at 170 ℃ for 24h, wherein the mass sum of the precursor salts of vanadium and phosphorus accounts for 20% of the total mass. The obtained mixture is filtered, washed and dried, and is roasted for 15 hours at 650 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.9 mu m and the radius of 0.08 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting the gasified methylal and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the methylal to the propionic acid is 1/5, the volume of the methylal and the propionic acid after gasification accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 1h^-1The reaction is carried out at 280 ℃ and 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 42

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting the gasified methylal and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the methylal to the propionic acid is 1/5, the volume of the methylal and the propionic acid after gasification accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 1h^-1The reaction is carried out at 310 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8h of reaction are shown in the table1。

Example 43

Tabletting the obtained sample to 20-60 meshes, adding the sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting with inert atmosphere N₂Mixing, wherein the molar ratio of the methylal to the propionic acid is 1/5, the volume of the methylal and the propionic acid after gasification accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 1h^-1The reaction is carried out at 340 ℃ under the condition of 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 44

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting the gasified methylal and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the methylal to the propionic acid is 1/5, the volume of the methylal and the propionic acid after gasification accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 1h^-1The reaction is carried out at 480 ℃ and 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 8 hours of reaction are shown in Table 1.

Example 45

Adding vanadium nitrate and 85% phosphoric acid into a mixed solution of xylitol and water (wherein the mass of the water accounts for 75%) according to the molar ratio of P/V of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 ℃ for 24 h. The obtained mixture is filtered, washed and dried, and is roasted for 15h at 650 ℃ in air atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.9 mu m and the radius of 0.12 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying methylal and propionic acid, and reacting the gasified methylal and propionic acid with inert atmosphere N₂Mixing, wherein the molar ratio of the methylal to the propionic acid is 1/5, the volume of the methylal and the propionic acid after gasification accounts for 10 percent of the total gas volume, and the mass space velocity of the formaldehyde and the propionic acid on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and 1atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 500h of reaction are shown in Table 1.

Example 46

Adding vanadium pentoxide and phosphorus pentoxide into a mixed solution of sorbitol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 deg.C for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.6 mu m and the radius of 0.11 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 10/1, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 47

Adding vanadium pentoxide and phosphorus pentoxide into a mixed solution of sorbitol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 deg.C for 24 h. The resulting mixtureFiltered, washed and dried to obtain a mixture containing 1.5 vol% of butane and 18.5 vol% of O₂N of (A)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.6 mu m and the radius of 0.11 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 1/10, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6h of reaction are shown in Table 1.

Example 48

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 5/1, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 49

Adding vanadium pentoxide and phosphorus pentoxide into a mixed solution of sorbitol and water (wherein the mass of the water accounts for 50%) according to a P/V molar ratio of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 ℃ for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane、18.5vol％O₂N of (A)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.6 mu m and the radius of 0.11 mu m).

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 1/5, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 50

Adding vanadium pentoxide and phosphorus pentoxide into a mixed solution of sorbitol and water (wherein the mass of the water accounts for 50%) according to a P/V molar ratio of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 ℃ for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (2)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the rod-shaped VPO catalyst (with the length of 1.6 mu m and the radius of 0.11 mu m).

Tabletting and molding the obtained sample to 20-60 meshes, adding the sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 3/1, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 51

Adding vanadium pentoxide and phosphorus pentoxide into a mixed solution of sorbitol and water (wherein the mass of the water accounts for 50%) according to the molar ratio of P/V of 1.2, stirring at room temperature for 30min, and crystallizing in an oven at 170 deg.C for 24 h. The resulting mixture was filtered, washed and dried to 1.5 vol% butane, 18.5 vol% O₂N of (A)₂In the atmosphere 6Roasting at 50 deg.c for 15 hr to obtain rod-shaped VPO catalyst with length of 1.6 micron and radius of 0.11 micron.

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 1/3, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Example 52

Tabletting the obtained sample to 20-60 meshes, adding the obtained sample into a fixed bed reactor, gasifying trioxymethylene and methyl propionate, and reacting the gasified sample with inert atmosphere N₂Mixing, wherein the molar ratio of the formaldehyde to the methyl propionate is 1/1, the gasified volume of the formaldehyde and the methyl propionate accounts for 25 percent of the total gas volume, and the mass space velocity of the formaldehyde and the methyl propionate on the catalyst is 1h^-1The reaction is carried out at 390 ℃ and under the condition of 10atm, the gas chromatography is used for on-line monitoring, and the yield and the selectivity of the product after 6 hours of reaction are shown in Table 1.

Comparative example 1

Putting vanadium pentoxide into mixed alcohol solution of benzyl alcohol and isobutanol (5g V)₂O₅And 100mL of alcoholic solution), the volume ratio of the benzyl alcohol to the isobutanol is 3:1, the heating reflux is carried out for 3h at the temperature of 120 ℃, then phosphoric acid with the mass fraction of 85% is added, the reflux is continued for 12h, and the adding amount of the phosphoric acid is 1.2 according to the molar ratio of P/V in the phosphoric acid and the vanadium pentoxide. At the same time, the surfactant PVP-K30 (10 mg/mL) was added. Filtering the obtained solid, and air drying at 100 deg.CDrying for 6h in the presence of 1.5 vol% butane, 18.5 vol% O₂N of (A)₂Roasting for 15h at 650 ℃ in the atmosphere to obtain the amorphous VPO catalyst.

Comparative example 2

Vanadium pentoxide was put into a mixed alcohol solution of benzyl alcohol and isobutanol (5g V)₂O₅And 100mL of alcoholic solution), the volume ratio of the benzyl alcohol to the isobutanol is 1:1, the heating reflux is carried out for 3h at the temperature of 140 ℃, then phosphoric acid with the mass fraction of 85 percent is added, the reflux is continued for 12h, and the adding amount of the phosphoric acid is 1.6 according to the molar ratio of the P/V in the phosphoric acid and the vanadium pentoxide. At the same time, the surfactant PVP-K90 (10 mg/mL) was added. And carrying out suction filtration on the obtained solid, carrying out forced air drying at 140 ℃ for 9h, carrying out air roasting at 800 ℃ for 4h, and activating in 3.0 volume percent butane air mixed gas for 24h to obtain the granular VPO catalyst.

Comparative example 3

Putting vanadium pentoxide into mixed alcohol solution of benzyl alcohol and isobutanol (5g V)₂O₅And 100mL of alcoholic solution), the volume ratio of the benzyl alcohol to the isobutanol is 1:1, the mixture is heated and refluxed for 6h at 140 ℃, then phosphoric acid with the mass fraction of 85 percent is added, the reflux is continued for 12h, and the adding amount of the phosphoric acid is calculated according to the phosphoric acid and the pentoxideThe P/V molar ratio in the vanadium was 1.6. At the same time, PEG2000 (40 mg/mL) as a surfactant was added. The obtained solid is filtered, dried by blowing at 140 ℃ for 6h, roasted at 800 ℃ for 4h, and activated in 3.0 volume percent butane air mixed gas for 12h for use.

Comparative example 4

Mixing vanadium pentoxide and phosphorus pentoxide mechanically according to P/V of 1.2, mechanically grinding uniformly, and placing the mixture in a container containing 1.5 vol% of butane and 18.5 vol% of O₂N of (A)₂Roasting at 650 ℃ in the atmosphere for 15h, and then using.

TABLE 1 reaction evaluation results

As can be seen from examples 1-6, the optimum preferred range of P/V is 1.0-1.6; as can be seen from examples 7 to 20, the polyol solvent or the mixed solution of the polyol and water has a better catalytic activity; from examples 21-25, it can be seen that moderate crystallization temperatures (170-; from examples 34 to 36, it can be seen that the long-term crystallization (24h) is more advantageous for the catalytic activity; as can be seen from examples 26-30, the most preferred calcination atmosphere is an oxidizing atmosphere containing butane; from examples 30-33, it can be seen that moderate temperatures and moderate calcination times (550 ℃ C., 650 ℃ C., 15-24 hours) are more favorable for the catalytic reaction; from examples 37 to 40, it can be seen that the optimum catalyst mass space velocity is from 0.5 to 1h^-1(ii) a As can be seen from examples 41-44, the optimum reaction temperature is 340-390 ℃; as can be seen from examples 46-52, the optimum molar ratio of formaldehyde to methyl propionate is from 10/1 to 5/1 or from 1/5 to 1/10. From the comparative examples it can be seen that amorphous or particulate VPO catalysts prepared by the conventional process are less active.

Claims

1. A method of synthesizing methacrylic acid or methyl methacrylate, characterized by:

on a fixed bed reactor, after one or more than two of propionic acid, propionic anhydride or methyl propionate and formaldehyde are gasified and diluted by inert carrier gas, methacrylic acid and/or methyl methacrylate are generated by reaction on a rod-shaped VPO catalyst;

the preparation process of the rod-shaped VPO catalyst comprises the following steps:

crystallizing the precursor salt of vanadium and the precursor salt of P in a solvent, filtering, washing, drying and roasting the obtained solid to obtain the rod-shaped VPO catalyst.

2. The method of claim 1, wherein:

the molar ratio of one or more than two of propionic acid, propionic anhydride or methyl propionate to formaldehyde is as follows: 10/1-1/10;

the inert atmosphere comprises: n is a radical of₂One or more of Ar and He;

the total volume of one or more than two of formaldehyde and propionic acid or propionic anhydride or methyl propionate in the gas phase accounts for 5-25% of the total gas volume;

the total mass space velocity of one or more than two of formaldehyde and propionic acid or propionic anhydride or methyl propionate on the catalyst is as follows: 0.5-5h^-1；

The reaction temperature is as follows: 280 ℃ and 480 ℃;

the reaction pressure is as follows: 0.5-30 atm.

3. The method of claim 2, wherein:

the molar ratio of one or more than two of propionic acid, propionic anhydride or methyl propionate to formaldehyde is as follows: 10/1-3/1 or 1/3-1/10;

the total mass space velocity of one or more than two of formaldehyde and propionic acid or propionic anhydride or methyl propionate on the catalyst is as follows: 0.5-3h^-1；

The reaction temperature is as follows: 310 ℃ and 430 ℃.

4. A method according to claim 3, characterized by:

the molar ratio of one or more than two of propionic acid, propionic anhydride or methyl propionate to formaldehyde is as follows: 10/1-5/1 or 1/5-1/10;

the total mass space velocity of one or more than two of formaldehyde and propionic acid or propionic anhydride or methyl propionate on the catalyst is as follows: 0.5-1h^-1；

The reaction temperature is as follows: 340 ℃ and 390 ℃.

5. The method of claim 1, wherein:

dissolving a precursor salt of vanadium and a precursor salt of P in a solvent according to a certain P/V molar ratio, then carrying out crystallization treatment for a period of time at a certain temperature, filtering, washing and drying the obtained solid, and roasting the solid for a period of time at a certain atmosphere and temperature to obtain a rod-shaped VPO catalyst;

the precursor salts of P are: NH (NH)₄H₂PO₄Ammonium metaphosphate, sodium pyrophosphate, sodium phosphate, POCl₃85% phosphoric acid, P₂O₅One or more than two of the above;

the molar ratio of P/V is 0.5-2.5;

the solvent is as follows: one or more of water, C1-C6 monohydric alcohol or C2-C6 dihydric alcohol or C3-C5 polyalcohol which is liquid at room temperature, aqueous solution of C6-C16 polyalcohol which is solid at room temperature, lactic acid or aqueous solution thereof (wherein the mass fraction of acid in the aqueous solution is 5-50%), and citric acid aqueous solution (wherein the mass fraction of acid in the aqueous solution is 5-50%); the mass of the solvent accounts for 50-95% of the total mass of the materials;

the roasting atmosphere is as follows: inert atmosphere (including N)₂One or more than two of Ar and He), oxygen-containing atmosphere (wherein the volume fraction of oxygen is 5-99%), butane-containing oxygen-containing atmosphere (wherein the volume fraction of butane is 1-5%, and the integral number of oxygen is 15-19%);

roasting temperature: 350-850 ℃; roasting time: 6-72 h.

6. The method of claim 1 or 5, wherein:

the molar ratio of P/V is 0.8-2.0;

the solvent is as follows: one or more of water, monohydric alcohol of C1-C6, dihydric alcohol of C2-C6, polyhydric alcohol of C3-C6 and mixed solvent of alcohol and water (wherein the mass fraction of the water is 5-95%);

the roasting atmosphere is as follows: one or more of oxygen-containing atmosphere (wherein the volume fraction of oxygen is 5-99%), butane-containing oxygen-containing atmosphere (wherein the volume fraction of butane is 1-5%, and the integral number of oxygen is 15-19%);

roasting temperature: 450 ℃ and 750 ℃; roasting time: 12-36 h.

7. The method of claim 1 or 5, wherein:

the molar ratio of P/V is 1.0-1.6;

the solvent is as follows: one or more than two of ethanol, ethylene glycol, propylene glycol, butanediol, glycerol or water solution thereof, mixed solvent of alcohol and water (wherein the mass fraction of the water is 5-95%), aqueous solution of erythritol, pentaerythritol, xylitol, glucose and sorbitol (wherein the mass fraction of the alcohol is 5-50%);

the roasting atmosphere is as follows: one or more than two of butane-containing oxygen-containing atmospheres (wherein the volume fraction of butane is 1-5%, and the oxygen integration number is 15-19%);

roasting temperature: 550-650 ℃; roasting time: 15-24 h.