Copper-based catalyst, preparation method and application thereof, and methanol synthesis method

Abstract

The invention relates to the field of catalysts, in particular to a copper-based catalyst, a preparation method and application thereof and a methanol synthesis method. The preparation method comprises the following steps: step a, preparing a catalyst precursor containing a copper element, a zinc element and an aluminum element by a coprecipitation method; and b, carrying out in-situ treatment on the catalyst precursor prepared in the step a in a CO2 / CH4 atmosphere. The catalyst prepared by the method disclosed by the invention is good in stability, and when the catalyst disclosed by the invention is used for synthesizing methanol, the generation of higher alkanes causing wax precipitation can be effectively inhibited from the source under the condition of high Fe content or sudden temperature change, so that the stable operation of the catalyst is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of catalysts, and in particular to a copper-based catalyst and a preparation method and application thereof, and a methanol synthesis method. Background Art

[0002] Methanol is an important carbon-based chemical product and deep-processing raw material. It can be used to manufacture a variety of organic products such as methyl chloride, methylamine and dimethyl sulfate. It is also a raw material for pesticides (insecticides, acaricides) and medicines.

[0003] The industrial production of methanol mainly adopts the catalytic conversion route of synthesis gas, and copper catalysts are generally used as catalysts. However, due to the occurrence of side reactions in the methanol synthesis process, the device generates a mixture of higher alkanes, namely paraffin, to varying degrees during the production process. It is generally believed that the formation of paraffin is related to the Fe content in the catalyst and the reaction temperature. The higher the Fe content and the sudden change in reaction temperature will lead to severe waxing. The formation of paraffin causes waxing in the methanol synthesis cooling system, which not only increases the system resistance, but also affects the heat exchange effect of the methanol synthesis cooler, resulting in a decrease in the efficiency of the crude methanol separator, exceeding the methanol content in the circulating gas, and more serious side reactions, which may even cause liquid hammering of the compressor.

[0004] Most of the prior art adopts an online dewaxing method to passively reduce the impact of wax deposition on methanol production. CN209721996U discloses a methanol synthesis system that can remove paraffin produced during the synthesis process. The cold side outlet of the tower preheater is connected to the inlet of the dewaxing device. The dewaxing device includes a tower body, and a separation internal is arranged inside the tower body. The inlet of the dewaxing device is arranged at the middle and lower part of the tower body side wall near the separation internal. The top of the tower body is provided with a methanol gas outlet, and the methanol gas outlet is connected to the air inlet of the methanol water cooler. The top of the tower body is also provided with a steam inlet. The bottom of the tower body is provided with a methanol discharge port and a paraffin discharge port. The methanol discharge port is connected to the hot side inlet of the plate heat exchanger. Liquid methanol enters the methanol expansion tank after cooling through the plate heat exchanger. The cooled methanol gas enters the methanol high-pressure separator. The liquid separated from the methanol high-pressure separator enters the methanol expansion tank. The gas from the top of the methanol high-pressure separator enters the circulating compressor for compression. It can effectively solve the problem of wax hanging on the inner wall of the water cooler and the high-pressure separator, and ensure long-term stable operation of production. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the catalyst in the prior art may cause the generation of higher alkanes due to high Fe content or sudden temperature change, thereby affecting the stability of the catalyst, and to provide a copper-based catalyst and its preparation method and application and a methanol synthesis method, wherein the catalyst has the characteristics of good stability.

[0006] In order to achieve the above object, the first aspect of the present invention provides a method for preparing a copper-based catalyst, the preparation method comprising:

[0007] Step a, preparing a catalyst precursor containing copper, zinc and aluminum elements by coprecipitation method;

[0008] Step b: treating the catalyst precursor prepared in step a in situ under a CO2 / CH4 atmosphere.

[0009] The second aspect of the present invention provides a copper-based catalyst prepared by the preparation method described in the first aspect.

[0010] The third aspect of the present invention provides an application of the catalyst described in the second aspect in methanol synthesis.

[0011] A fourth aspect of the present invention provides a method for synthesizing methanol, the method comprising: reacting raw materials containing CO and H2 under the copper-based catalyst conditions described in the second aspect.

[0012] Through the above technical solution, the present invention has the following advantages:

[0013] The catalyst prepared by the method of the present invention has good stability. When the catalyst of the present invention is used for the synthesis of methanol, the generation of higher alkanes causing wax deposition can be effectively suppressed from the source under the conditions of high Fe content or sudden temperature change, thereby ensuring the stable operation of the catalyst. DETAILED DESCRIPTION

[0014] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0015] The present invention provides a method for preparing the catalyst, which comprises:

[0016] Step a, preparing a catalyst precursor containing copper, zinc and aluminum elements by coprecipitation method;

[0017] Step b: treating the catalyst precursor prepared in step a in situ under a CO2 / CH4 atmosphere.

[0018] The catalyst prepared by the method of the present invention has good stability. When the catalyst of the present invention is used for the synthesis of methanol, the generation of higher alkanes causing wax deposition can be effectively suppressed from the source under the conditions of high Fe content or sudden temperature change, thereby ensuring the stable operation of the catalyst.

[0019] According to a preferred embodiment of the present invention, the volume concentration of carbon dioxide in the CO2 / CH4 atmosphere is 10-50%, and the volume concentration of methane is 50-90%.

[0020] According to a preferred embodiment of the present invention, the in-situ treatment conditions include: a volume space velocity of 1000-2000h -1 , temperature is 300-500℃, pressure is 0.1-5MPa.

[0021] According to a preferred embodiment of the present invention, the in-situ treatment is carried out by performing at least one alternating CO2 / CH4 purge in opposite directions.

[0022] According to a preferred embodiment of the present invention, step a comprises: adding alkaline substances to a mixed solution containing a copper source, a zinc source and an aluminum source for co-precipitation to obtain a precipitate, and the precipitate is washed, dried, roasted and formed.

[0023] According to a preferred embodiment of the present invention, the alkaline substance includes at least one of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide and potassium hydroxide; and / or

[0024] According to a preferred embodiment of the present invention, the co-precipitation conditions include: a temperature of 50-70° C. and a system pH of 7-8.

[0025] In the present invention, the copper source, zinc source and aluminum source can be conventionally selected in the art, corresponding to soluble compounds of each element.

[0026] In the present invention, the alkaline substance is first prepared into a solution with a concentration of 0.5-2 mol / L and then added into the mixed solution.

[0027] In the present invention, the conditions for washing, drying, calcining and molding can be selected according to conventional techniques in the art. For example, the washing adopts centrifugal washing with deionized water at room temperature, the amount of water used each time is 3-5 times the volume of the precipitate, and a total of 5-10 washing times; the drying temperature is 100-120°C, and the drying time is 2-5h; the calcination is performed in an air atmosphere at a temperature of 300-500°C and a calcination time of 1-2h.

[0028] According to a preferred embodiment of the present invention, in the mixed solution, the molar ratio of the copper source, the zinc source and the aluminum source is 2-8:2-5:1-3 based on the elements.

[0029] The present invention provides a copper-based catalyst prepared by the preparation method of the present invention.

[0030] The present invention provides an application of the catalyst of the present invention in methanol synthesis.

[0031] The catalyst of the present invention is used for the synthesis of methanol, and can effectively suppress the generation of higher alkanes causing wax deposition from the source under the conditions of high Fe content or sudden temperature change, thereby ensuring the stable operation of the catalyst.

[0032] The present invention provides a method for synthesizing methanol, which comprises: reacting raw materials containing CO and H2 under the conditions of the copper-based catalyst described in the present invention.

[0033] According to a preferred embodiment of the present invention, the reaction conditions include: the raw material volume percentage is 13-15% CO, 3-5% CO2, 65-70% H2; the balance is N2; and / or the raw gas volume space velocity is 10000-100000h -1 ; and / or temperature 220-280°C; and / or pressure 3-8MPa. The reaction time depends on the specific working conditions.

[0034] The present invention will be described in detail below through examples. In the following examples, the product quantitative analysis adopts Agilent 8890 gas chromatograph, three valves and five columns, equipped with an FID detector and a TCD detector. Among them, He is used as the carrier gas to analyze the hydrogen composition, hydrogen is used as the carrier gas to analyze CO\CO2\N2\CH4, and FID analyzes hydrocarbons. Among them, CO\CO2\N2\CH4\O2\N2\C2H6\C2H4 are all corrected by standard gas for the corresponding relationship between content and peak area. Except for H2>0.99, the curve fitting factor of other gases is all>0.999. The Fe content of the catalyst is determined by inductively coupled atomic emission spectrometer (ICP-AES) method. Unless otherwise specified, the raw materials are all commercially available.

[0035] Example 1

[0036] The catalyst copper / zinc / aluminum molar ratio is 2:2:3, and the alkali solution is a 0.5 mol / L sodium carbonate aqueous solution; a nitrate mixed solution of 2 mol / L copper, 2 mol / L zinc and 3 mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500 mL of deionized water, and the neutralization temperature is controlled to be 50°C and the pH value is 7 to obtain a precipitate; the precipitate is centrifugally washed, and water is used each time for 3 times the volume of the precipitate, and a total of 5 times, and the washed precipitate is placed in a 100°C drying oven for drying for 5 hours, and then transferred to a muffle furnace for roasting, air atmosphere, 300°C for treatment for 2 hours; the roasted precipitate is sheeted into a φ5×5mm cylindrical shape; and then treated in situ in a CO2 / CH4 atmosphere in a methanol synthesis reactor, and the treatment conditions are: CO2 volume content is 10% (the balance is methane, the same below), and the gas (volume, the same below) space velocity is 1000h -1The treatment temperature and pressure were 500°C and 5MPa respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 2h. Then it was adjusted to mixed gas entered from bottom to top and exited for 0.5h to obtain catalyst GX1.

[0037] Example 2

[0038] The catalyst copper / zinc / aluminum molar ratio is 2:4:3, and the alkali solution is a 0.8 mol / L sodium bicarbonate aqueous solution; a nitrate mixed solution of 2 mol / L copper, 4 mol / L zinc and 3 mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500 mL of deionized water, and the neutralization temperature is controlled to be 55°C and the pH value is 7 to obtain a precipitate; the precipitate is centrifugally washed, and water is used three times the volume of the precipitate each time, and a total of 4 washings are performed, and the washed precipitate is placed in a 100°C drying oven for 5 hours, and then transferred to a muffle furnace for roasting, air atmosphere, 350°C for 2 hours; the roasted precipitate is sheeted into a φ5×3 mm cylindrical shape; and then treated in situ in a CO2 / CH4 atmosphere in a methanol synthesis reactor, and the treatment conditions are: CO2 volume content is 15%, gas space velocity is 1000h -1 The treatment temperature and pressure were 500°C and 5MPa respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 1 hour. Then it was adjusted to mixed gas entering from bottom to top and exiting for 1 hour to obtain catalyst GX2.

[0039] Example 3

[0040] The catalyst copper / zinc / aluminum molar ratio is 2:5:1, and the alkali solution is a 1 mol / L potassium carbonate aqueous solution; a nitrate mixed solution of 2 mol / L copper, 5 mol / L zinc and 1 mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500 mL of deionized water, and the neutralization temperature is controlled to be 60°C and the pH value is 7 to obtain a precipitate; the precipitate is centrifugally washed, and water is used each time for 4 times the volume of the precipitate, and a total of 4 washings are performed, and the washed precipitate is placed in a 100°C drying oven for 5 hours, and then transferred to a muffle furnace for roasting, in an air atmosphere, and treated at 400°C for 2 hours; the roasted precipitate is sheeted into a φ3×3mm cylindrical shape; and then treated in situ in a CO2 / CH4 atmosphere in a methanol synthesis reactor, and the treatment conditions are: CO2 volume content is 20%, and the gas space velocity is 1000h -1 The treatment temperature and pressure were 500°C and 4MPa respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 1.5h. Then it was adjusted to mixed gas entered from bottom to top and exited for 1h to obtain catalyst GX3.

[0041] Example 4

[0042] The catalyst copper / zinc / aluminum molar ratio is 4:2:1, and the alkali solution is a 1.5 mol / L potassium bicarbonate aqueous solution; a nitrate mixed solution of 4 mol / L copper, 2 mol / L zinc and 1 mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500 mL of deionized water, and the neutralization temperature is controlled to be 65°C and the pH value is 7.5 to obtain a precipitate; the precipitate is centrifugally washed, and water is used each time for 4 times the volume of the precipitate, and a total of 5 washings are performed, and the washed precipitate is placed in a 120°C drying oven for 3 hours, and then transferred to a muffle furnace for roasting, in an air atmosphere, and treated at 450°C for 2 hours; the roasted precipitate is sheeted into a φ5×5mm cylindrical shape; and then treated in situ in a methanol synthesis reactor under a CO2 / CH4 atmosphere, and the treatment conditions are: CO2 volume content is 25%, and the gas space velocity is 1000h -1 The treatment temperature and pressure were 500°C and 4MPa respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 2h. Then it was adjusted to mixed gas entered from bottom to top and exited for 1h to obtain catalyst GX4.

[0043] Example 5

[0044] The catalyst copper / zinc / aluminum molar ratio is 6:3:1, and the alkali solution is a 1.7 mol / L sodium hydroxide aqueous solution; a nitrate mixed solution of 6 mol / L copper, 3 mol / L zinc and 1 mol / L aluminum is added to a 5L neutralization barrel containing 500 mL of deionized water in parallel with an alkaline solution, and the neutralization temperature is controlled to be 70°C and the pH value is 7.5 to obtain a precipitate; the precipitate is centrifugally washed, and water is used each time for 4 times the volume of the precipitate, and a total of 4 washings are performed, and the washed precipitate is placed in a 120°C drying oven for drying for 3 hours, and then transferred to a muffle furnace for roasting, in an air atmosphere, and treated at 500°C for 1 hour; the roasted precipitate is sheeted into a φ5×5mm cylindrical shape; and then treated in situ in a methanol synthesis reactor under a CO2 / CH4 atmosphere, and the treatment conditions are: CO2 volume content is 30%, and the gas space velocity is 1500h -1 The treatment temperature and pressure were 400°C and 3MPa respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 2h. Then it was adjusted to mixed gas entered from bottom to top and exited for 1h to obtain catalyst GX5.

[0045] Example 6

[0046] The catalyst copper / zinc / aluminum molar ratio is 8:2:2, and the alkali solution is a 1.8 mol / L potassium hydroxide aqueous solution; a nitrate mixed solution of 8 mol / L copper, 2 mol / L zinc and 2 mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500 mL of deionized water, and the neutralization temperature is controlled to be 70°C and the pH value is 8 to obtain a precipitate; the precipitate is centrifugally washed, and water is used each time for 5 times the volume of the precipitate, and a total of 5 washings are performed, and the washed precipitate is placed in a 120°C drying oven for drying for 3 hours, and then transferred to a muffle furnace for roasting, in an air atmosphere, and treated at 500°C for 1 hour; the roasted precipitate is sheeted into a φ5×5mm cylindrical shape; and then treated in situ in a methanol synthesis reactor under a CO2 / CH4 atmosphere, and the treatment conditions are: CO2 volume content is 40%, gas space velocity is 1500h -1 The treatment temperature and pressure were 400°C and 3MPa respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 2h. Then it was adjusted to mixed gas entering from bottom to top and exiting for 1h to obtain catalyst GX6.

[0047] Example 7

[0048] The catalyst copper / zinc / aluminum molar ratio is 8:5:3, and the alkali solution is a 2mol / L sodium hydroxide aqueous solution; a nitrate mixed solution of 8mol / L copper, 5mol / L zinc and 3mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500mL of deionized water, and the neutralization temperature is controlled to be 70°C and the pH value is 8 to obtain a precipitate; the precipitate is centrifugally washed, and water is used each time for 5 times the volume of the precipitate, and a total of 5 washings are performed, and the washed precipitate is placed in a 120°C drying oven for 2h, and then transferred to a muffle furnace for roasting, in an air atmosphere, and treated at 500°C for 1h; the roasted precipitate is sheeted into a φ5×5mm cylindrical shape; and then treated in situ in a CO2 / CH4 atmosphere in a methanol synthesis reactor, and the treatment conditions are: CO2 volume content is 50%, and the gas space velocity is 2000h -1 The treatment temperature and pressure were 300°C and normal pressure respectively. The treatment sequence was: CO2 / CH4 mixed gas first entered from top to bottom and exited for 2 hours. Then it was adjusted to mixed gas entered from bottom to top and exited for 1 hour to obtain catalyst GX7.

[0049] Comparative Example 1

[0050] The catalyst copper / zinc / aluminum molar ratio is 8:5:3, and the alkali solution is a 2 mol / L sodium hydroxide aqueous solution; a nitrate mixed solution of 8 mol / L copper, 5 mol / L zinc and 3 mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500 mL of deionized water, and the neutralization temperature is controlled to be 70°C and the pH value is 8 to obtain a precipitate; the precipitate is centrifugally washed, and water is used 5 times the volume of the precipitate each time, and washed 5 times in total, and the washed precipitate is placed in a 120°C drying oven to dry for 2 hours, and then transferred to a muffle furnace for roasting, in an air atmosphere, and treated at 500°C for 1 hour; the roasted precipitate is sheeted into a φ5×5mm cylinder to obtain a catalyst T1.

[0051] Comparative Example 2

[0052] The catalyst copper / zinc / aluminum molar ratio is 8:5:3, and the alkali solution is a 2mol / L sodium hydroxide aqueous solution; a nitrate mixed solution of 8mol / L copper, 5mol / L zinc and 3mol / L aluminum is added to a 5L neutralization barrel containing 500mL deionized water in parallel with an alkaline solution, and the neutralization temperature is controlled to be 70°C and the pH value is 8 to obtain a precipitate; the precipitate is centrifugally washed, and water is used 5 times the volume of the precipitate each time, and a total of 5 washings are performed, and the washed precipitate is placed in a 120°C drying oven for 2h, and then transferred to a muffle furnace for roasting, in an air atmosphere, 500°C for 1h; the roasted precipitate is formed into a φ5×5mm cylindrical piece; and then treated in situ in a CO2 atmosphere in a methanol synthesis reactor, and the treatment conditions are: in a CO2 atmosphere, the gas space velocity is 2000h -1 The treatment temperature and pressure were 300°C and normal pressure respectively. The treatment sequence was: first, top-in and bottom-out, with a treatment time of 2 h. Then, the mixed gas was adjusted to bottom-in and top-out, with a treatment time of 1 h to obtain catalyst T2.

[0053] Comparative Example 3

[0054] The catalyst copper / zinc / aluminum molar ratio is 8:5:3, and the alkali solution is a 2mol / L sodium hydroxide aqueous solution; a nitrate mixed solution of 8mol / L copper, 5mol / L zinc and 3mol / L aluminum and an alkaline solution are added in parallel to a 5L neutralization barrel containing 500mL of deionized water, and the neutralization temperature is controlled to be 70°C and the pH value is 8 to obtain a precipitate; the precipitate is centrifugally washed, and the water used each time is 5 times the volume of the precipitate, and a total of 5 times is washed, and the washed precipitate is placed in a 120°C drying oven for 2h, and then transferred to a muffle furnace for roasting, in an air atmosphere, 500°C for 1h; the roasted precipitate is sheeted into a φ5×5mm cylindrical shape; and then treated in situ in a methanol synthesis reactor under a CH4 atmosphere, and the treatment conditions are: under a CH4 atmosphere, the gas space velocity is 2000h -1The treatment temperature and pressure were 300°C and normal pressure respectively. The treatment sequence was: first, top-in and bottom-out, with a treatment time of 2 h. Then, the mixed gas was adjusted to bottom-in and top-out, with a treatment time of 1 h to obtain catalyst T3.

[0055] Example 8

[0056] Methanol synthesis catalytic performance test: carried out in a fixed bed tubular reactor (id = 30mm), the catalyst loading amount is 50mL, the raw gas volume composition is CO / CO2 / H2 / N2=15%:3%:70%:12%; the raw gas space velocity is 10000h -1 The reaction temperature was 230°C, the pressure was 5MPa, and sampling and analysis were performed after 2 hours of reaction.

[0057] Temperature sudden change test: After the performance test, maintain the reaction pressure, drop the temperature to 200℃, then quickly raise it to 280℃, stabilize it for 2h, and then take samples for analysis. This is the result after the temperature sudden change.

[0058] The quantitative analysis of the product was performed using an Agilent 8890 gas chromatograph with three valves and five columns, equipped with an FID detector and a TCD detector. He was used as the carrier gas to analyze the hydrogen composition, hydrogen was used as the carrier gas to analyze CO\CO2\N2\CH4, and FID was used to analyze hydrocarbons. CO\CO2\N2\CH4\O2\N2\C2H6\C2H4 were all corrected for the corresponding relationship between content and peak area using standard gas. The curve fitting factor was greater than 0.999 for H2, and the fitting factors for other gases were greater than 0.999. The Fe content of the catalyst was determined by inductively coupled atomic emission spectrometer (ICP-AES). The test results are shown in Table 1.

[0059] Table 1

[0060]

[0061] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a copper-based catalyst, characterized in that: The preparation method comprises: Step a, preparing a catalyst precursor containing copper, zinc and aluminum elements by coprecipitation method; Step b: treating the catalyst precursor prepared in step a in situ under a CO2 / CH4 atmosphere.

2. The preparation method according to claim 1, wherein The volume concentration of carbon dioxide in the CO2 / CH4 atmosphere is 10-50%, and the volume concentration of methane is 50-90%.

3. The preparation method according to claim 1 or 2, wherein The conditions of the in-situ treatment include: a volume space velocity of 1000-2000h -1 , temperature is 300-500℃, pressure is 0.1-5MPa.

4. The preparation method according to any one of claims 1 to 3, wherein The in-situ treatment is carried out by performing at least one alternating CO2 / CH4 purge in opposite directions.

5. The preparation method according to any one of claims 1 to 4, wherein: The step a comprises: adding alkaline substances to a mixed solution containing a copper source, a zinc source and an aluminum source for co-precipitation to obtain a precipitate, and the precipitate is washed, dried, roasted and formed.

6. The preparation method according to any one of claims 1 to 5, wherein: The alkaline substance includes at least one of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium hydroxide and potassium hydroxide; and / or The co-precipitation conditions include: a temperature of 50-70° C. and a system pH of 7-8.

7. The preparation method according to any one of claims 1 to 6, wherein: In the mixed solution, the molar ratio of the copper source, the zinc source and the aluminum source is 2-8:2-5:1-3 based on the elements.

8. A copper-based catalyst prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the copper-based catalyst according to claim 8 in methanol synthesis.

10. A method for synthesizing methanol, characterized in that: The method comprises: reacting a raw material containing CO and H2 under the copper-based catalyst conditions as claimed in claim 8; preferably, The reaction conditions include: The volume percentage of the raw material input is 13-15% CO, 3-5% CO2, 65-70% H2; the balance is N2; and / or Raw gas volume space velocity 10000-100000h -1 ; and / or Temperature 220-280°C; and / or Pressure 3-8MPa.

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