阅读说明：本技术 一种低羰基化合物含量甲醇合成催化剂及其制备方法和应用 (Methanol synthesis catalyst with low content of carbonyl compounds, and preparation method and application thereof ) 是由 陈群 何明阳 钱俊峰 孙中华 周维友 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种低羰基化合物含量甲醇合成催化剂及其制备方法和应用,为了解决传统催化反应合成得到的甲醇中羰基化合物的含量难以控制、含量较高的问题,采用的催化剂中Cu/Zn/Al/卤素的质量比为24～56∶16～40∶4.3～10.8∶0.5～3,并提出了该催化剂制备方法,能够使卤素与活性组分之间形成较强的相互作用,形成氧化物和卤化物的共生或杂生,从结构上确保了在高活性和高稳定性的基础上,催化使用后能够显著降低甲醇产品中的羰基化化合物含量,粗甲醇中杂质羰基化合物的含量低于30ppm,明显低于MTO级甲醇原料对该杂质的限制要求。(The invention discloses a low-carbonyl-compound-content methanol synthesis catalyst and a preparation method and application thereof, aiming at solving the problems that the content of a carbonyl compound in methanol synthesized by the traditional catalytic reaction is difficult to control and the content is high, the mass ratio of Cu/Zn/Al/halogen in the adopted catalyst is 24-56: 16-40: 4.3-10.8: 0.5-3, and the preparation method of the catalyst is provided, so that the halogen and an active component can form stronger interaction to form oxide and halide symbiosis or impurity generation, the content of the carbonylation compound in a methanol product can be obviously reduced after the catalyst is used on the basis of ensuring high activity and high stability, and the content of the carbonyl compound in crude methanol is lower than 30ppm and is obviously lower than the limit requirement of an MTO-grade methanol raw material on the impurity.)

1. A methanol synthesis catalyst with low content of carbonyl compounds is characterized by comprising the following components: comprises Cu/Zn/Al/halogen in a mass ratio of 24-57: 16-40: 4.3-10.8: 0.5-3.

2. The catalyst for methanol synthesis with low content of carbonyl compounds as claimed in claim 1, wherein, the halogen is one of Cl and F.

3. The method for preparing the catalyst for synthesizing methanol with low content of carbonyl compounds according to claim 1 or 2, characterized in that a mixed solution of soluble salts of copper, zinc and aluminum and a precipitant solution are added into a neutralization barrel for precipitation reaction and are continuously stirred; after the precipitation is finished, aging, washing and filtering to obtain a ternary filter cake; and soaking the ternary filter cake in a halide solution, stirring and pulping, then evaporating the pulped halide solution to dryness, putting the obtained powder in a muffle furnace for primary roasting, then washing, drying, then carrying out secondary roasting, and finally carrying out tabletting molding to obtain the catalyst.

4. The method for preparing the catalyst for synthesizing methanol with low content of carbonyl compounds according to claim 3, wherein the soluble salts of copper, zinc and aluminum are nitrates, and the total salt concentration is 0.5-2 mol/L.

5. The method for preparing the catalyst for synthesizing methanol with low content of carbonyl compounds according to claim 3, wherein the precipitant solution is one of aqueous solutions of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and ammonium carbonate, and the concentration is 0.5-2 mol/L.

6. The method for preparing the catalyst for synthesizing methanol with low content of carbonyl compounds according to claim 3, wherein the precipitation reaction temperature is 50-70 ℃, and the pH value of the solution in the neutralization tank is 7.0-8.0; the aging temperature is 60-75 ℃, and the aging time is 30-60 min.

7. The method for preparing the catalyst for synthesizing methanol with low content of carbonyl compounds according to claim 3, characterized in that deionized water is used for washing after precipitation and roasting, the water temperature is 25-75 ℃, and the washing is carried out until the content of Na or K in a filter cake is lower than 500 ppm.

8. The method for preparing the catalyst for synthesizing methanol with low content of carbonyl compounds according to claim 3, wherein the temperature of the halide solution is 30-60 ℃; stirring and pulping, pouring the mixture into a rotary evaporator for evaporation, and controlling the evaporation temperature to be 60-75 ℃.

9. The preparation method of the methanol synthesis catalyst with the low carbonyl compound content according to claim 3, wherein the primary roasting temperature of a muffle furnace is 200-300 ℃, and the roasting time is 3-6 h; the secondary roasting muffle furnace is used for roasting in one of nitrogen and argon, the roasting temperature is 350-500 ℃, and the roasting time is 2-6 hours.

10. Use of a catalyst prepared according to any one of claims 3 to 9, wherein the catalyst is used in a methanol synthesis reaction.

Technical Field

The invention belongs to the technical field of catalytic material preparation, and particularly relates to a catalyst for preparing MTO-grade methanol and a preparation method thereof.

Background

Methanol is an important carbon chemical industry basic product, and with the rapid development of the modern coal chemical industry and the urgent need of clean energy in the world, the new methanol market is developed, the scale of a methanol device is continuously enlarged, the quality of a methanol product is continuously improved, and the vigorous development of a large methanol technology is promoted. The performance of the methanol synthesis catalyst is a mark of the overall technical level of methanol and is the key point of upgrading the methanol technology. The catalyst for synthesizing methanol used in industry at present is copper-zinc-aluminum catalyst, and the structure and the performance of the catalyst are determined by the composition and the preparation method of the catalyst. The development of the big methanol technology further promotes the research and development of the high-performance methanol synthesis catalyst, and Chinese patent CN103480377B discloses a method for preparing the methanol synthesis catalyst by a seed induction method, wherein [ Cu ] is introduced in the copper-zinc binary precipitation process₂CO₃(OH)₂]The content of the active intermediate phase is improved, and the activity and the stability of the catalyst are further improved. Chinese patent CN103480378B discloses a catalyst suitable for a methanol synthesis plant at low temperature and low pressure, which is obtained by preparing a high activity matrix with low impurity content by using an alkaline solution containing potassium as an impurity replacement auxiliary. Most of the patents on methanol synthesis catalysts, including the above two patents, are aimed at improving the activity and stability of the catalyst. However, the selectivity of methanol synthesis catalysts, especially the level of the limitation of the main impurities, is different due to the different downstream demand of methanol, and thus the selectivity of methanol catalysts is also an important performance indicator. Chinese patent CN104353464B discloses a method for preparing a methanol synthesis catalyst using silicon dioxide as a carrier, which adopts a coprecipitation method to prepare an active matrix, and the active matrix is pulped with silica sol to form a precipitate mixture, and the catalyst obtained by post-treatment has lower selectivity of dimethyl ether and ethanol.

At present, methanol produced by large-scale methanol devices at home and abroad is mainly used as a raw material for preparing olefin (MTO) from methanol, and the content of carbonyl compounds in the methanol is an important quality control index and generally required not to exceed 50 ppm. The existing methanol synthesis catalyst technology has the specific research and preparation technology in this aspect.

Disclosure of Invention

The invention aims to provide a catalyst for synthesizing methanol with low content of carbonyl compounds and a preparation method thereof aiming at the synthesis of MOT-grade methanol.

The invention is mainly characterized in that a copper-zinc-aluminum catalyst containing halogen is prepared by adopting a precipitation-soaking-heat treatment method, and the catalyst contains copper halide.

The technical scheme is as follows: the purpose of the invention is realized by the following technical scheme:

a methanol synthesis catalyst with low carbonyl compound content has a mass ratio of Cu/Zn/Al/halogen of 24-57: 16-40: 4.3-10.8: 0.5-3, wherein the halogen is one of Cl and F. (elemental content was determined by inductively coupled plasma emission spectrometer measurement)

The preparation method of the catalyst comprises the steps of adding a mixed solution of soluble salts of copper, zinc and aluminum and a precipitant solution into a neutralization barrel in a concurrent flow manner for precipitation reaction, and continuously stirring; after the precipitation is finished, aging, washing and filtering to obtain a ternary filter cake; and soaking the ternary filter cake in a halide solution, stirring and pulping, then evaporating the halide solution to dryness, putting the obtained powder in a muffle furnace for primary roasting, then washing, drying, then carrying out secondary roasting, and finally carrying out tabletting molding to obtain the catalyst.

The invention is firstly roasted in the air and then in the argon, the roasting in the air is carried out at a lower temperature to obtain the copper-zinc-aluminum oxide, the roasting in the inert atmosphere is carried out at a higher temperature to obtain part of the halides of the copper and the zinc, and therefore, the oxide and the halide of the copper and the zinc exist in the final catalyst at the same time.

Further, the soluble salts of copper, zinc and aluminum are nitrates, and the total salt concentration is 0.5-2 mol/L.

The precipitant solution is one of water solutions of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and ammonium carbonate, and the concentration of the precipitant solution is 0.5-2 mol/L.

The precipitation reaction temperature is 50-70 ℃, and the pH value of the solution in the neutralization barrel is 7.0-8.0.

The precipitation aging temperature is 60-75 ℃, and the aging time is 30-60 min.

And deionized water is used for washing the precipitate, the water temperature is 25-75 ℃, and the precipitate is washed until the Na or K content in the filter cake is lower than 500 ppm.

The temperature of the halide solution is 30-60 ℃.

Wherein, after stirring and pulping, pouring the mixture into a rotary evaporator for evaporation, and controlling the evaporation temperature to be 60-75 ℃.

The primary roasting temperature of the muffle furnace is 200-300 ℃, and the roasting time is 3-6 h.

And washing after roasting by using deionized water at the water temperature of 25-75 ℃ until the Na or K content in the filter cake is lower than 500 ppm.

The secondary roasting muffle furnace is used for roasting in one of nitrogen and argon, the roasting temperature is 350-500 ℃, and the roasting time is 2-6 hours.

The catalyst is used for methanol synthesis reaction, firstly, the catalyst is crushed to 0.425-1.180 mm, the reaction is carried out on a stainless steel fixed bed reactor, the catalyst is arranged in a constant temperature section, and quartz sand is filled in the upper section and the lower section of a catalyst bed layer; the catalyst is activated before use, the activating atmosphere is hydrogen-containing hydrogen-nitrogen mixed gas, and the space velocity is 2000h^-1The temperature programming is that the temperature rises to 230 ℃ from the room temperature at the speed of 5 ℃/min and is kept for 2 h; then switching to reaction gas with the volume composition of 13-14% of CO and 3-5% of CO₂55% -65% of H₂The balance being N₂(ii) a The reaction temperature is 230 ℃ and the pressure is 5 MPa. After the reaction is stable, the content of carbonyl compounds in the obtained crude methanol is lower than 30ppm and lower than the limit requirement of MTO-grade methanol raw material on the impurities.

Has the advantages that:

the preparation method of the catalyst provided by the invention can form stronger interaction between halogen and active components, structurally ensures that the catalyst has high selectivity, is used for methanol synthesis reaction, and can obviously reduce the content of carbonylation compounds in methanol products on the basis of high activity and high stability.

Detailed Description

The following examples are intended only to further illustrate the present invention and are not intended to limit the present invention.

Example 1

Weighing 52.5g of copper nitrate, 104.4g of zinc nitrate and 33.9g of aluminum nitrate, dissolving in deionized water to prepare a 0.5mol/L mixed nitrate solution, and preheating to 50 ℃; adding the mixed nitrate solution and 0.5mol/L sodium carbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, controlling the temperature in the neutralization barrel to be constant at 50 ℃, and controlling the pH to be 7.0; aging after precipitation, controlling the aging temperature at 60 ℃ and the aging time at 30 min; then, carrying out suction filtration and washing by using deionized water at 25 ℃ until the Na content in a filter cake is lower than 500 ppm; dissolving 0.8g of sodium chloride in deionized water at 30 ℃, soaking a filter cake in the sodium chloride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 60 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment at 200 ℃ for 6h in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 25 ℃ until the content of Na in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 350 ℃ for 6h in a nitrogen atmosphere, cooling the obtained powder to room temperature, and tabletting and molding to obtain the catalyst Cat 1.

Comparative example 1

Weighing 52.5g of copper nitrate, 104.4g of zinc nitrate and 33.9g of aluminum nitrate, dissolving in deionized water to prepare a 0.5mol/L mixed nitrate solution, and preheating to 50 ℃; adding the mixed nitrate solution and 0.5mol/L sodium carbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, controlling the temperature in the neutralization barrel to be constant at 50 ℃, and controlling the pH to be 7.0; aging after precipitation, controlling the aging temperature at 60 ℃ and the aging time at 30 min; then, carrying out suction filtration and washing by using deionized water at 25 ℃ until the Na content in a filter cake is lower than 500 ppm; and then drying in a drying oven at 100 ℃, finally placing in a muffle furnace, roasting at 350 ℃ for 6h in a nitrogen atmosphere, cooling the obtained powder to room temperature, tabletting and molding to obtain the catalyst Cat 1'.

Example 2

Weighing 78.8g of copper nitrate, 60.9g of zinc nitrate and 37.6g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 1mol/L, and preheating to 55 ℃; adding the mixed nitrate solution and 1mol/L sodium bicarbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, stirring vigorously, controlling the temperature in the neutralization barrel to be constant at 55 ℃, and controlling the pH to be 7.2; aging after precipitation, controlling the aging temperature to be 65 ℃ and the aging time to be 40 min; then, centrifugally washing the filter cake by using deionized water at 40 ℃ until the Na content in the filter cake is lower than 500 ppm; dissolving 4.2g of potassium chloride in deionized water at 40 ℃, soaking a filter cake in a potassium chloride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 65 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment for 5 hours at 250 ℃ in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 40 ℃ until the content of K in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 400 ℃ for 5 hours in a nitrogen atmosphere, cooling the obtained powder to room temperature, and tabletting and molding to obtain the catalyst Cat 2.

Comparative example 2

Weighing 78.8g of copper nitrate, 60.9g of zinc nitrate and 37.6g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 1mol/L, and preheating to 55 ℃; adding the mixed nitrate solution and 1mol/L sodium bicarbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, stirring vigorously, controlling the temperature in the neutralization barrel to be constant at 55 ℃, and controlling the pH to be 7.2; aging after precipitation, controlling the aging temperature to be 65 ℃ and the aging time to be 40 min; then, centrifugally washing the filter cake by using deionized water at 40 ℃ until the Na content in the filter cake is lower than 500 ppm; then drying in a drying oven at 100 ℃, finally putting into a muffle furnace, and roasting for 5 hours at 400 ℃ in a nitrogen atmosphere to obtain powder.

Dissolving 4.2g of potassium chloride in deionized water at 40 ℃, soaking the obtained powder in a potassium chloride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 65 ℃, transferring the powder into a muffle furnace after evaporation, carrying out heat treatment for 5h at 250 ℃ in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 40 ℃ until the content of K in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 350 ℃ in a nitrogen atmosphere for 3h, cooling to room temperature, and tabletting for forming to obtain the catalyst Cat 2'.

The main difference between example 2 and comparative example 2 is that the halogen is introduced by soaking in the stage of precipitate before roasting, the precipitate is in the form of hydrate, the introduced halogen ions are easy to access copper and zinc ions, and the symbiosis or impurity of oxide and halide is more easily formed in the subsequent roasting. In contrast to the comparative example 2, halogen is introduced by soaking after copper, zinc and aluminum are roasted, oxides of copper and zinc after roasting are partially crystallized, the structure is relatively complete, halogen ions are not easy to approach copper and zinc ions, particularly, internal copper and zinc are not easy to approach, the symbiosis or the mixed generation of oxides and halides is difficult to form in subsequent roasting, and the effect of the catalyst is mainly realized by the symbiosis or the mixed generation of the oxides of copper and zinc and the halides. Therefore, example 2 is superior in catalytic effect to comparative example 2.

Example 3

Weighing 70g of copper nitrate, 87g of zinc nitrate and 35.5g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 1.5mol/L, and preheating to 60 ℃; adding the mixed nitrate solution and 1.5mol/L potassium bicarbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, and controlling the temperature in the neutralization barrel to be constant at 60 ℃ and the pH to be 7.5; aging after precipitation, controlling the aging temperature at 70 ℃ and the aging time at 50 min; then, centrifugal washing is carried out by deionized water at 50 ℃ until the content of K in a filter cake is lower than 500 ppm; dissolving 6.6g of sodium fluoride in deionized water at 50 ℃, soaking a filter cake in a sodium fluoride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 70 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment at 300 ℃ for 3h in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 50 ℃ until the content of Na in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 450 ℃ for 3h in an argon atmosphere, cooling the obtained powder to room temperature, and tabletting and molding to obtain the catalyst Cat 3.

Comparative example 3

Weighing 70g of copper nitrate, 87g of zinc nitrate and 35.5g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 1.5mol/L, and preheating to 60 ℃; adding the mixed nitrate solution and 1.5mol/L potassium bicarbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, and controlling the temperature in the neutralization barrel to be constant at 60 ℃ and the pH to be 7.5; aging after precipitation, controlling the aging temperature at 70 ℃ and the aging time at 50 min; then, centrifugal washing is carried out by deionized water at 50 ℃ until the content of K in a filter cake is lower than 500 ppm; 6.6g of sodium fluoride is dissolved in deionized water at 50 ℃, a filter cake is soaked in the sodium fluoride solution for pulping, slurry is poured into a rotary evaporator for evaporation at 70 ℃, the powder is moved into a muffle furnace after being evaporated to dryness, the powder is roasted for 3 hours at 450 ℃ in an argon atmosphere, the obtained powder is cooled to room temperature and then is tableted and molded to obtain the catalyst Cat 3'.

If calcination is carried out only in air and not subsequently in argon, a stable halide cannot be formed and the effect of reducing the carbonyl compound content in methanol is considerably poor, as compared with example 3.

Example 4

Weighing 87.5g of copper nitrate, 69.6g of zinc nitrate and 18.8g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 2mol/L, and preheating to 65 ℃; adding the mixed nitrate solution and 2mol/L ammonium bicarbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a concurrent flow manner, violently stirring, controlling the temperature in the neutralization barrel to be constant at 65 ℃ and controlling the pH to be 7.8; aging after precipitation, controlling the aging temperature to be 75 ℃ and the aging time to be 60 min; dissolving 3.1g of potassium fluoride in deionized water at 55 ℃, soaking a filter cake in a potassium fluoride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 75 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment at 300 ℃ for 3h in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 60 ℃ until the content of K in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 500 ℃ for 2h in an argon atmosphere, cooling the obtained powder to room temperature, and tabletting to obtain the catalyst Cat 4.

Example 5

105g of copper nitrate, 34.8g of zinc nitrate and 39.7g of aluminum nitrate are weighed and dissolved in deionized water to prepare a mixed nitrate solution with the concentration of 1mol/L, and the mixed nitrate solution is preheated to 70 ℃; adding the mixed nitrate solution and 1.5mol/L sodium carbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, and controlling the temperature in the neutralization barrel to be constant at 70 ℃ and the pH to be 8; aging after precipitation, controlling the aging temperature to be 75 ℃ and the aging time to be 30 min; then, carrying out centrifugal washing by using deionized water at 65 ℃ until the Na content in a filter cake is lower than 500 ppm; dissolving 3.1g of potassium fluoride in deionized water at 60 ℃, soaking a filter cake in a potassium fluoride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 75 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment at 300 ℃ for 3h in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 65 ℃ until the content of K in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 400 ℃ for 4h in a nitrogen atmosphere, cooling the obtained powder to room temperature, and tabletting to obtain the catalyst Cat 5.

Example 6

Weighing 113.8g of copper nitrate, 40.9g of zinc nitrate and 20.9g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 1mol/L, and preheating to 70 ℃; adding the mixed nitrate solution and 1.5mol/L sodium carbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, and controlling the temperature in the neutralization barrel to be constant at 70 ℃ and the pH to be 8; aging after precipitation, controlling the aging temperature to be 75 ℃ and the aging time to be 30 min; then, carrying out centrifugal washing by using deionized water at 65 ℃ until the Na content in a filter cake is lower than 500 ppm; dissolving 2.5g of sodium chloride in deionized water at 60 ℃, soaking a filter cake in the sodium chloride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 75 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment at 300 ℃ for 3h in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 65 ℃ until the content of Na in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 400 ℃ for 4h in a nitrogen atmosphere, cooling the obtained powder to room temperature, and tabletting and molding to obtain the catalyst Cat 6.

Example 7

Weighing 122.5g of copper nitrate, 34.8g of zinc nitrate and 16.7g of aluminum nitrate, dissolving in deionized water to prepare a mixed nitrate solution of 1mol/L, and preheating to 70 ℃; adding the mixed nitrate solution and 1.5mol/L sodium carbonate solution into a neutralization barrel which is weighed with 100mL deionized water in a cocurrent manner, violently stirring, and controlling the temperature in the neutralization barrel to be constant at 70 ℃ and the pH to be 8; aging after precipitation, controlling the aging temperature to be 75 ℃ and the aging time to be 30 min; then, carrying out centrifugal washing by using deionized water at 65 ℃ until the Na content in a filter cake is lower than 500 ppm; dissolving 4.2g of potassium chloride in deionized water at 60 ℃, soaking a filter cake in a potassium chloride solution for pulping, pouring slurry into a rotary evaporator, evaporating at 75 ℃, transferring the powder into a muffle furnace after evaporation to dryness, carrying out heat treatment at 300 ℃ for 3h in the air, taking out the powder and cooling to room temperature, washing the powder with deionized water at 65 ℃ until the content of K in the powder is lower than 500ppm, drying in an oven at 100 ℃, finally placing the powder into the muffle furnace, roasting at 400 ℃ for 4h in a nitrogen atmosphere, cooling the obtained powder to room temperature, and tabletting to obtain the catalyst Cat 7.

The prepared catalyst is used for methanol synthesis reaction, firstly, the catalyst is crushed to 0.425-1.180 mm, and 2mL of catalyst is measured for standby; the reaction is carried out on a stainless steel fixed bed reactor, a catalyst is arranged in a constant temperature section, and quartz sand is filled in the upper section and the lower section of a catalyst bed layer; the catalyst is activated before use, the activating atmosphere is hydrogen-nitrogen mixed gas containing 5 vol.% of hydrogen, and the space velocity is 2000h^-1The temperature programming is that the temperature rises to 230 ℃ from the room temperature at the speed of 5 ℃/min and is kept for 2 h; then switching to reaction gas with the volume composition of 13-14% of CO and 3-5% of CO₂55% -65% of H₂The balance being N₂(ii) a The reaction temperature is 230 ℃ and the pressure is 5 MPa. Samples were taken 4h after the reaction was stable for quantitative chromatographic analysis and the results are shown in Table 1.

TABLE 1 catalytic performance of the catalyst in methanol synthesis reaction

And measuring the proportion of Cu, Zn, Al and halogen components in the catalyst by an ICP (inductively coupled plasma) method.

According to the analysis result of the catalyst performance test, the methanol synthesis catalyst prepared by the method has the advantages of high activity and high selectivity, and particularly, the content of the impurity carbonyl compound in the crude methanol is lower than 30ppm and lower than the limit requirement of MTO-grade methanol raw material on the impurity.