CN115364859B

CN115364859B - Catalyst for synthesizing glyoxylate, preparation method and application thereof

Info

Publication number: CN115364859B
Application number: CN202110541716.2A
Authority: CN
Inventors: 龚海燕; 刘俊涛; 孙凤侠
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2024-05-28
Anticipated expiration: 2041-05-18
Also published as: CN115364859A

Abstract

The invention discloses a catalyst for synthesizing glyoxylate and a preparation method and application thereof. The catalyst comprises the following components in parts by weight: a) 0.5-15 parts of active component copper calculated by copper element; b) 0.1-10 parts of auxiliary agent 1 in terms of elements; c) 75 to 99.5 portions of carrier. The catalyst has only one hydrogen reduction peak which characterizes the active component Cu through an H ₂ -TPR test. The catalyst with uniformly distributed active components is prepared by pretreating the carrier under a certain atmosphere to adjust the binding force between the carrier and the active components and simultaneously adjusting the electronic effect of the catalyst by using polyvalent auxiliaries such as molybdenum, iron, vanadium, cobalt, manganese and the like.

Description

Catalyst for synthesizing glyoxylate, preparation method and application thereof

Technical Field

The invention relates to a catalyst for synthesizing glyoxylate from glycolate, a preparation method and application thereof.

Background

Glyoxylate is a substance with two functional groups of aldehyde and ester, can be subjected to various reactions, can be used for synthesizing medicines and natural compounds, and can be hydrolyzed to obtain glyoxylate which is an important raw material in the aspects of synthetic perfume, medical intermediates, foods, varnish raw materials, dyes, plastic additives and the like.

The production of glyoxalic acid mainly comprises oxalic acid electrolytic reduction method and glyoxal nitric acid oxidation method, and the two methods can realize the production of industrial glyoxalic acid, but have high production cost and large pollution, and the high impurity content of the product can not be used in high-end fields such as medical intermediates.

In recent years, the development of C1 chemical technology in China is rapid, the annual production of ethylene glycol from 2021-year synthesis gas can reach 1000 ten thousand tons, and a large amount of byproduct glycolate is brought to the market, so that a route for producing glyoxylate by taking glycolate as a raw material is beginning to be paid attention to. Although the route is superior to the existing industrialized technology in economical and environmental protection, the byproducts such as oxalic acid monoester and the like are also generated due to poor catalyst performance or improper control of process conditions. According to the standard requirement of glyoxylate, the oxalic acid content of the first-grade product is less than 1%, the oxalic acid content of the first-grade product is less than 0.5%, and the oxalic acid content of the synthesis of certain medicines and high-end materials is higher, so that the problem that the technology must be solved in the industrial process is how to simultaneously improve the conversion rate of glycolate and inhibit the generation of oxalate.

Although many studies have been made on this reaction in various countries at present, the patent and literature techniques disclosed and reported in the art cannot achieve both complete conversion of glycolate and suppression of oxalate formation in the product. For example, patent US4340748 discloses a method for preparing glyoxylate by gas-phase catalytic oxidation of glycolate using V, mo, ag, cu as component a and Sn, sb, bi as component B supported on a carrier at 100-600 ℃, preferably 200-400 ℃ with an oxygen-containing gas, but the glycolate is not completely converted, the maximum glycolate conversion is about 99.2%, the selectivity is 89%, and the rest 11% of byproduct components are not disclosed. A series of Fe ₁₂Co₈ catalysts are prepared in the reaction of preparing glyoxylate from methyl glycolate by using Liu Fangfang's paper of Shanghai application technology university, but the conversion rate of methyl glycolate is only 76%, and the selectivity of glyoxylate is only 70%. Although the above-mentioned techniques clearly disclose the composition of the reaction product, it is known from the conversion and selectivity that the above-mentioned techniques contain glycolic acid ester which is highly reactive, and even very high content of impurities such as oxalic acid monoester, and thus, it is impossible to obtain high quality glyoxylate product when used in industrial production.

Disclosure of Invention

The invention aims to solve the technical problem that the prior art has the problem of high content of glycolate and oxalate in a reaction product of preparing glyoxylate by oxidizing glycolate, and provides a novel catalyst for synthesizing glyoxylate, a preparation method and application. The catalyst is used in the reaction of preparing glyoxylate by oxidizing glycollic acid, and has the characteristic of low content of glycollate and oxalate in reaction products.

Specifically, the first aspect of the invention provides a catalyst for synthesizing glyoxylate, which comprises the following components in parts by weight:

a) 0.5-15 parts of active component copper calculated by copper element;

b) 0.1-10 parts of auxiliary agent 1 in terms of elements;

c) 75-99.5 parts of carrier;

The catalyst has only one hydrogen reduction peak which characterizes the active component Cu through an H ₂ -TPR test.

Further, the catalyst is characterized in that the temperature difference between the maximum peak position of the reduction peak and the peak position of the reduction start of the active component Cu is less than 30 ℃ and/or the temperature difference between the peak position of the reduction end and the maximum peak position of the reduction peak is less than 30 ℃ through the H ₂ -TPR test. Preferably, the difference between the temperature of the peak position of the Cu reduction peak and the temperature of the peak position of the reduction start is <20 ℃, and/or the difference between the temperature of the peak position of the reduction end and the temperature of the peak position of the reduction peak is <20 ℃.

Further, the catalyst H ₂ -TPR characterization data: the Cu reduction peak temperature is 200 ℃ + -10 ℃, preferably 200 ℃ + -7 ℃.

Further, the catalyst preferably contains 1 to 10 parts of active component copper;

further, the auxiliary agent 1 is at least one selected from molybdenum, iron, vanadium, cobalt and manganese.

Further, the carrier is at least one selected from titanium oxide, silicon oxide, magnesium oxide, zirconium oxide and cerium oxide.

Further, the catalyst, preferably the molar ratio of promoter 1 to active component copper is from 0.3 to 5, more preferably from 0.7 to 3.

The second aspect of the present invention is to provide a preparation method of a catalyst for synthesizing glyoxylate, the method comprising the steps of:

a) Preparing an organic amine solution, and regulating the pH value to 9-12 to obtain a solution a;

b) Adding carrier powder into the solution a, stirring for 2-24 hours at 120-180 ℃, filtering, washing until the electric conductivity of the washing liquid is less than 100 mu s/cm, preferably less than 50 mu s/cm, and drying the filtered material to obtain carrier powder b;

c) Preparing soluble salt water solution of copper and an auxiliary agent 1, and regulating the pH value to 2-5 to obtain a solution c;

d) Adding the powder b into water and/or alcohol to prepare slurry d;

e) Adding the solution c into the slurry d under stirring to obtain slurry e;

f) And e) refluxing and heating the slurry e obtained in the step e) to obtain slurry f, and drying and roasting the slurry f to obtain the synthetic glyoxylate catalyst.

Further, the organic amine in step a) includes, but is not limited to, one or more of a fatty amine, an amide and an alcohol amine, preferably one or more of a fatty amine and an amide. The mass concentration of the organic amine solution is 0.1% -1.3%. The pH value is preferably adjusted by sodium hydroxide and/or nitric acid.

Further, in step c) the pH of the solution is adjusted using an acid and/or ammonia. The mass concentration of the soluble brine solution of copper and auxiliary 1 in step c) is: 0.25 to 20 percent. Wherein the molar ratio of the auxiliary agent 1 to copper is 0.2-5, more preferably 0.3-4.

Further, the amount of water and/or alcohol used in step d) is 2 to 5 times the mass of the carrier.

Further, in the step e), the feeding time is controlled to be 30-180 min. The mass ratio of the added amount of the solution c to the slurry d in the step e) is 0.5-5:1.

Further, the heating reflux in the step f) is reflux heating at 95-105 ℃ for 2-20 hours. The drying can adopt any conventional drying method to evaporate the excessive moisture in the slurry after the backflow; the roasting is preferably carried out for 3-8 hours at 400-580 ℃ to obtain the synthetic glyoxylate catalyst.

In a third aspect, the present invention provides the use of the catalyst described above for the synthesis of glyoxylate.

Further, the application is that glycollate and oxygen-containing gas are contacted with a catalyst to perform oxidation reaction to generate glyoxylate.

Further, the application includes:

a) The glycolate and the oxygen-containing gas are contacted with a catalyst to carry out oxidation reaction, so that reaction products of glyoxylate, oxalate, unreacted glycolate, water, unreacted oxygen-containing gas and carbon dioxide are obtained;

b) And c), separating gas from liquid of the reaction product of the step a), wherein the liquid phase is a material flow rich in glyoxylate, glycolate, oxalate and water, and the gas phase is a tail gas material flow containing unreacted oxygen-containing gas and carbon dioxide gas.

The oxygen-containing gas is a mixed gas of nitrogen and oxygen or air.

A flow controller is arranged on the oxygen or air pipeline; and a detection device is arranged on the tail gas flow pipeline for continuously detecting the oxygen concentration in the gas phase.

Further, the molar concentration of oxygen in the tail gas is controlled to be 0.1% -1% by adjusting the oxygen or air flow, and preferably the molar concentration of oxygen in the tail gas is controlled to be 0.2% -0.7%.

Further, the reaction temperature for synthesizing the glyoxylate is 170-230 ℃, preferably 180-220 ℃; the pressure is-0.5-1.5 MPa, the weight hourly space velocity of the glycolate liquid is 0.1-1.5 hours ^-1, and the volume airspeed of the nitrogen in the oxygen-containing gas is 500-3000 hours ^-1.

Because the reaction of preparing glyoxylate by oxidizing glycolate is a series reaction, the preparation of glyoxylate by oxidizing hydroxyl groups in glycolate into carbonyl groups is an intermediate step of the reaction, and if the activity distribution of the catalyst is uneven, incomplete conversion of raw materials and excessive oxidation of part of carbonyl groups in glyoxylate into carboxyl groups are easy to occur. According to research, in the oxidation process of glycolate, the energy barrier of the reaction of hydroxyl oxidation to carbonyl is lower, and the energy barrier of the reaction of carbonyl oxidation to carboxyl is higher, and if the distribution of active sites of the catalyst and acting force between reactants can be accurately controlled, the excessive oxidation of carbonyl can be inhibited, and the generation of oxalate in the reaction can be reduced.

On one hand, the catalyst with uniformly distributed active components is prepared by pretreating the carrier under a certain atmosphere to adjust the binding force between the carrier and the active components and simultaneously using multi-valence auxiliaries such as molybdenum, iron, vanadium, cobalt, manganese and the like to adjust the electronic effect of the catalyst. On the other hand, the catalyst for preparing the glyoxylate by oxidizing the glycolate, which is characterized by amorphous and single-layer dispersion structure and narrow distribution of H ₂ -TPR reduction peaks on a carrier, is prepared by controlling the preparation conditions of the catalyst, and has the characteristics of uniform activity and low oxidation-reduction starting points.

In a further aspect, the invention controls the oxygen concentration in the reactor through tail gas detection, improves the conversion rate of glycollate and reduces the generation of oxalate.

By adopting the method, the content of the glycolate of the liquid-phase product can be as low as 0.12 percent, and the content of the oxalate can be as low as 0.11 percent, so that a better technical effect is obtained.

Drawings

FIG. 1 shows the TPR reduction spectrum of the catalyst prepared in example 1 of the present invention.

FIG. 2 shows the TPR reduction spectrum of the catalyst prepared in comparative example 1 of the present invention.

Detailed Description

The invention is further illustrated below in connection with specific embodiments, but it should be understood that the specific embodiments do not limit the scope of protection.

In the invention, a Rigaku ZSX 100e type XRF instrument is adopted as a catalyst component, and the test conditions are as follows: the rhodium target is an excitation source, the maximum power is 3600W, the tube voltage is 60KV, and the tube current is 120mA.

In the invention, the catalyst H ₂ -TPR is characterized by adopting a Micromeritics AutoChem II 2920 type chemical adsorption instrument, taking 50mg of sample, purging Ar at normal temperature before testing, and then performing programmed heating reduction from room temperature to 300 ℃ by using 10% (v/v) H ₂/Ar mixed gas with a heating program of 10 ℃/min. The starting temperature of the reduction peak is the temperature at which a tangent line at the inflection point at the front side of the copper reduction peak in the TPR spectrogram intersects with the bottom of the peak, and the ending temperature of the reduction peak is the temperature at which a tangent line at the inflection point at the rear side of the copper reduction peak in the TPR spectrogram intersects with the bottom of the peak.

In the invention, the liquid phase product composition adopts Shimadzu LC-20A liquid chromatography. Analysis conditions: agilent C18 column; the temperature of the column box is 35 ℃, the detection wavelength is 212nm, and the sample injection amount is 2 mu L.

The invention is further illustrated by the following examples.

[ Example 1]

A) 0.5g of ethylenediamine is dissolved in 100ml of water and the pH is adjusted to 10 with sodium hydroxide and/or nitric acid to give solution a.

B) 20g of silicon oxide powder was added to the solution a, placed in an autoclave at a constant temperature of 130℃and stirred for 5 hours. And after the washing is finished, filtering the carrier, washing the carrier with deionized water for a plurality of times, detecting the conductivity of the washing liquid, and when the conductivity of the washing liquid is less than 50 mu s/cm, finishing the washing, filtering out powder, and drying at 120 ℃ to obtain the powder b.

C) 5.2g of copper nitrate and 8.3g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

E) Adding the solution c into the slurry d under stirring, and controlling the feeding time to be 120min to obtain slurry e.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

G) And (5) evaporating excessive water in the slurry f to dryness to obtain powder g.

H) Roasting the powder g at 450 ℃ to obtain a catalyst A1 for preparing glyoxylate by oxidizing glycolate, wherein the H ₂ -TPR reduction spectrum of the catalyst A1 is shown in figure 1, the hydrogen reduction peaks of Cu are only 1, and the analysis and test results are shown in table 1.

[ Example 2]

A) 0.7g of trimethylamine is dissolved in 100ml of water and the pH is adjusted to 10 with sodium hydroxide and/or nitric acid to obtain solution a.

B) 20g of silicon oxide powder was added to the solution a, placed in an autoclave at a constant temperature of 140℃and stirred for 5 hours. And after the washing is finished, filtering the carrier, washing the carrier with deionized water for a plurality of times, detecting the conductivity of the washing liquid, and when the conductivity of the washing liquid is less than 50 mu s/cm, finishing the washing, filtering out powder, and drying at 120 ℃ to obtain the powder b.

D) Powder b was added to 100ml of water to give slurry d.

F) Slurry e was heated at 100deg.C under reflux for 8 hours to give slurry f.

H) The powder g was calcined at 400℃to obtain a catalyst A2 for preparing glyoxylate by oxidation of glycolate, and the analytical test results are shown in Table 1.

[ Example 3]

A) 0.2g of isobutyramide was dissolved in 100ml of water and the pH was adjusted to 10 with sodium hydroxide and/or nitric acid to give solution a.

D) Powder b was added to 40ml of water to give slurry d.

F) Slurry e was heated at 95℃under reflux for 8 hours to give slurry f.

H) The powder g was calcined at 550℃to obtain a catalyst A3 for preparing glyoxylate by oxidation of glycolate, and the analytical test results are shown in Table 1.

[ Example 4]

A) 1.2g of isopropanolamine is dissolved in 100ml of water and the pH is adjusted to 10 with sodium hydroxide and/or nitric acid to give solution a.

C) 5.2g of copper nitrate and 5.8g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 5 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

E) And adding the solution c into the slurry d under stirring, and controlling the feeding time to be 170min to obtain slurry e.

F) Slurry e was heated at 100deg.C under reflux for 8 hours to give slurry f.

H) The powder g was calcined at 500℃to obtain a catalyst A4 for preparing glyoxylate by oxidation of glycolate, and the analytical test results are shown in Table 1.

[ Example 5]

A) 0.1g of diethanolamine is dissolved in 100ml of water and the pH is adjusted to 12 with sodium hydroxide and/or nitric acid to obtain solution a.

C) 5.2g of copper nitrate and 10.5g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 2 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

E) Adding the solution c into the slurry d under stirring, and controlling the feeding time to be 35min to obtain slurry e.

F) Slurry e was heated at 95℃under reflux for 8 hours to give slurry f.

H) The powder g was calcined at 500℃to obtain a catalyst A5 for preparing glyoxylate by oxidation of glycolate, and the analytical test results are shown in Table 1.

[ Example 6]

C) 0.3g of copper nitrate and 0.1g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to obtain solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A6 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 7]

C) 11.5g of copper nitrate and 11g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A7 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 8]

C) 0.8g of copper acetate and 4g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A8 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 9]

C) 6.5g of copper nitrate and 10.3g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A9 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 10 ]

C) 5g of copper nitrate and 5.5g of ammonium heptamolybdate were dissolved in 120ml of deionized water and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A10 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 11 ]

A) 0.5g of ethylenediamine is dissolved in 100ml of water and the pH is adjusted to 9 with sodium hydroxide and/or nitric acid to give solution a.

C) 5g of copper nitrate and 1g of ammonium metavanadate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A11 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 12 ]

C) 5g of copper nitrate and 4.5g of cobalt acetate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A12 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 13 ]

C) 5g of copper nitrate, 1.8g of cobalt acetate and 2.5g of manganese acetate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to obtain solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A13 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 14 ]

B) 20g of magnesium oxide powder was added to the solution a, placed in an autoclave at a constant temperature of 140℃and stirred for 5 hours. And after the washing is finished, filtering the carrier, washing the carrier with deionized water for a plurality of times, detecting the conductivity of the washing liquid, and when the conductivity of the washing liquid is less than 50 mu s/cm, finishing the washing, filtering out powder, and drying at 120 ℃ to obtain the powder b.

C) 5g of copper nitrate and 8.3g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 3 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A14 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 15 ]

B) 10g of titanium oxide powder and 10g of zirconium oxide powder having a particle size of 30 to 60nm and 87% of the total number of crystal grains were added to the solution a, placed in an autoclave at a constant temperature of 140℃and stirred for 5 hours. And after the washing is finished, filtering the carrier, washing the carrier with deionized water for a plurality of times, detecting the conductivity of the washing liquid, and when the conductivity of the washing liquid is less than 50 mu s/cm, finishing the washing, filtering out powder, and drying at 120 ℃ to obtain the powder b.

C) 5g of copper nitrate and 8.5g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 4 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A15 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 16 ]

B) 20g of cerium oxide powder was added to the solution a, placed in an autoclave at a constant temperature of 140℃and stirred for 5 hours. And after the washing is finished, filtering the carrier, washing the carrier with deionized water for a plurality of times, detecting the conductivity of the washing liquid, and when the conductivity of the washing liquid is less than 50 mu s/cm, finishing the washing, filtering out powder, and drying at 120 ℃ to obtain the powder b.

C) 5g of copper nitrate and 8.5g of ferric nitrate were dissolved in 120ml of deionized water, and the pH was adjusted to 5 with nitric acid and/or aqueous ammonia to give solution c.

D) Powder b was added to 50ml of water to give slurry d.

F) Slurry e was heated at 105℃under reflux for 8 hours to give slurry f.

H) The powder g is roasted at 450 ℃ to obtain a catalyst A16 for preparing glyoxylate by oxidizing glycolate, and the analysis and test results are shown in Table 1.

[ Example 17 ]

A) The preparation method was changed as follows according to the formulation of example 2: 0.7g of trimethylamine is dissolved in 100ml of water and the pH is adjusted to 13 with sodium hydroxide and/or nitric acid to give solution a.

B) 20g of silicon oxide powder was added to the solution a, placed in an autoclave at a constant temperature of 140℃and stirred for 5 hours. And after the washing is finished, filtering the carrier, washing the carrier with deionized water for a plurality of times, detecting the conductivity of the washing liquid, and when the conductivity of the washing liquid reaches 150 mu s/cm, finishing the washing, filtering out powder, and drying at 120 ℃ to obtain the powder b.

D) Powder b was added to 100ml of water to give slurry d.

E) Adding the solution c into the slurry d under stirring, and controlling the feeding time to be 120min. Obtaining slurry e;

f) Reflux-heating the slurry e at 100 ℃ for 8 hours to obtain slurry f;

g) Evaporating excessive water in the slurry f to dryness to obtain powder g;

h) Roasting the powder g at 400 ℃ to obtain a catalyst A17 for preparing glyoxylate by oxidizing glycolate, wherein the hydrogen reduction peaks of Cu are only 1, and the analysis and test results are shown in Table 1.

Example 18

The same procedure as in example 2 was repeated except that the corresponding trimethylamine, copper nitrate and ferric nitrate were dissolved in deionized water to prepare trimethylamine and active metal and auxiliary agent solutions, and the carrier not treated with amine was impregnated with the solutions to prepare a glyoxylate catalyst B3 by oxidation of glycolate, the catalyst B3 had 1 hydrogen reduction peak of Cu, and the results of the catalyst analysis and test are shown in Table 1.

[ Comparative example 1]

According to the formula of example 1, 5.2g of copper nitrate and 8.3g of ferric nitrate are dissolved in deionized water and then used for impregnating 20g of silicon oxide powder carrier, and the catalyst B1 is prepared by baking at 110 ℃ and roasting at 450 ℃ to obtain the glycolate catalyst. The H ₂ -TPR reduction spectrum of the catalyst is shown in figure 2, and has 2 hydrogen reduction peaks of Cu, and the analysis and test results are shown in table 1.

TABLE 1

[ Example 19 ]

The catalysts obtained in examples 1 to 18 were evaluated separately. Methyl glycolate is taken as a raw material and mixed with oxygen and nitrogen. The catalyst was evaluated at 190℃under a pressure of 0.15MPa, methyl glycolate weight space velocity of 0.4 hours ^-1, nitrogen volume space velocity of 2000 hours ^-1 and an oxygen content of 0.5% in the tail gas, and the reaction results are shown in Table 2.

[ Comparative example 2]

The catalysts obtained in [ comparative example 1 ] were evaluated separately. Methyl glycolate is taken as a raw material and mixed with oxygen and nitrogen. The catalyst was evaluated at 190℃and 0.15MPa, 0.4 hr ^-1, 2000 hr ^-1, and 0.5% oxygen content in the tail gas, and the reaction results are shown in Table 2.

TABLE 2

Catalyst numbering	Methyl glycolate/%	Monomethyl oxalate/%
			A1	0.12	0.11
A2	0.20	0.09
			A3	0.14	0.11
A4	0.42	0.21
			A5	0.27	0.23
A6	0.31	0.15
			A7	0.37	0.31
A8	0.24	0.14
			A9	0.22	0.14
A10	0.15	0.11
			A11	0.18	0.12
A12	0.20	0.12
			A13	0.14	0.11
A14	0.16	0.13
			A15	0.19	0.18
A16	0.21	0.13
			A17	0.42	0.38
A18	0.37	0.48
			B1	0.93	0.56

As can be seen, with the catalyst of the present invention, the glycolate and oxalate impurities in the product were significantly lower than in the comparative examples.

[ Example 20 ]

The catalyst obtained in [ example 2 ] was subjected to reaction evaluation, and the process conditions were changed to conduct the test, and the reaction conditions and the results are shown in Table 3.

TABLE 3 Table 3

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[ Example 21 ]

The catalyst obtained in [ example 2 ] was evaluated. Ethyl glycolate is taken as a raw material to be mixed with oxygen and nitrogen. The catalyst was evaluated at 190℃and 0.15MPa, 0.4 hr ^-1 in methyl glycolate weight space velocity, 2000 hr ^-1 in nitrogen volume space velocity, and 0.5% in tail gas oxygen mole content, and the reaction results are shown in Table 4.

TABLE 4 Table 4

The above describes in detail the specific embodiments of the present invention, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.

Claims

1. The catalyst for synthesizing the glyoxylate is characterized by comprising the following components in parts by weight:

a) 0.5-15 parts of active component copper, calculated by copper element;

b) 0.1-10 parts of an auxiliary agent 1 in terms of elements;

c) 75-99.5 parts of carrier;

The catalyst is characterized in that only one hydrogen reduction peak of the active component Cu is detected by an H ₂ -TPR test;

The catalyst is characterized in that the temperature difference between the highest peak position of the reduction peak and the position of the reduction starting peak of the active component Cu is less than 30 ℃ and the temperature difference between the position of the reduction ending peak and the highest peak position of the reduction peak is less than 30 ℃ through an H ₂ -TPR test;

the auxiliary agent 1 is at least one selected from molybdenum, iron, vanadium, cobalt and manganese.

2. The catalyst according to claim 1, characterized in that the temperature difference between the peak position of the Cu reduction peak and the peak position of the start of reduction is <20 ℃, and/or the temperature difference between the peak position of the end of reduction and the peak position of the reduction peak is <20 ℃.

3. The catalyst of claim 1 or 2, wherein the catalyst H ₂ -TPR characterization data: the Cu reduction peak temperature was 200 ℃ + -10 ℃.

4. The catalyst of claim 1 or 2, wherein the catalyst H ₂ -TPR characterization data: the Cu reduction peak temperature was 200 ℃ + -7 ℃.

5. The catalyst according to claim 1, wherein the molar ratio of the auxiliary agent 1 to the active component copper is 0.3-5.

6. The catalyst according to claim 1, wherein the molar ratio of the auxiliary agent 1 to the active component copper is 0.7-3.

7. A process for preparing a catalyst for the synthesis of glyoxylate according to any one of claims 1 to 6, comprising the steps of:

a) Preparing an organic amine solution, and adjusting the pH value to 9-12 to obtain a solution a;

b) Adding carrier powder into the solution a, stirring for 2-24 hours at 120-180 ℃, filtering, washing until the electric conductivity of the washing liquid is less than 100 mu s/cm, and drying the filtered material to obtain carrier powder b;

c) Preparing a soluble salt water solution of copper and an auxiliary agent 1, and regulating the pH value to 2-5 to obtain a solution c;

d) Adding the powder b into water to prepare slurry d;

e) Adding the solution c into the slurry d under stirring to obtain slurry e;

f) And (3) refluxing and heating the slurry e to obtain slurry f, and drying and roasting the slurry f to obtain the synthetic glyoxylate catalyst.

8. The method according to claim 7, wherein the washing liquid is filtered and washed in the step b) until the electric conductivity is less than 50 μs/cm.

9. The method according to claim 7, wherein the soluble brine solution of copper and auxiliary 1 in step c) has a mass concentration of: 0.25% -20%.

10. The preparation method according to claim 7, wherein the molar ratio of the auxiliary agent 1 to copper is 0.2-5.

11. The preparation method according to claim 7, wherein the molar ratio of the auxiliary agent 1 to copper is 0.3-4.

12. The method according to claim 7, wherein the amount of water used in step d) is 2 to 5 times the mass of the carrier.

13. The method according to claim 7, wherein the calcination in step f) is performed at 400 to 580 ℃ for 3 to 8 hours to obtain the catalyst for synthesizing glyoxylate.

14. Use of a catalyst according to any one of claims 1 to 6 or a catalyst prepared by a method according to any one of claims 7 to 13 in the synthesis of glyoxylate.

15. The application according to claim 14, characterized in that it comprises:

16. The use according to claim 14 or 15, wherein the molar concentration of oxygen in the exhaust is controlled to be 0.1% -1% by adjusting the oxygen or air flow.

17. The use according to claim 14 or 15, wherein the molar concentration of oxygen in the exhaust is controlled to be 0.2% -0.7% by adjusting the oxygen or air flow.

18. Use according to claim 14 or 15, characterized in that the reaction conditions for the synthesis of glyoxylate are as follows: the reaction temperature is 170-230 ℃; the pressure is-0.5-1.5 MPa, the hourly weight space velocity of the glycolate liquid is 0.1-1.5 hours ^-1, and the volume space velocity of nitrogen in the oxygen-containing gas is 500-3000 hours ^-1.

19. Use according to claim 14 or 15, characterized in that the reaction conditions for the synthesis of glyoxylate are as follows: the reaction temperature is 180-220 ℃.