A catalyst for preparing methanol from waste liquid of ethylene glycol production by using synthesis gas, a preparation method and application thereof

Abstract

This invention provides a catalyst for preparing methanol from waste liquid generated during ethylene glycol production from syngas, along with its preparation method and application, belonging to the field of resource comprehensive utilization technology. This invention uses silica as a support to improve the dispersibility of the copper-based catalyst and auxiliary metals in the catalyst, thereby enhancing the catalytic effect. This invention uses a copper-based catalyst, CuZr₂O₃. x Using one or more of Fe, Ce, and K as the main catalyst, the interaction between the auxiliary metal and the copper-based catalyst can be utilized to improve the catalytic effect, thereby enabling methyl formate, methyl acetal, and dimethyl carbonate in the waste liquid from syngas-to-ethylene glycol production to participate in the reaction and form methanol. The results of the examples show that after treating the waste liquid from syngas-to-ethylene glycol production using the catalyst provided by this invention, the methanol content in the liquid product is higher than 92%, achieving resource utilization of the waste liquid from syngas-to-ethylene glycol production.

Description

Technical Field

[0001] This invention relates to the field of comprehensive resource utilization technology, and in particular to a catalyst for preparing methanol from waste liquid produced from ethylene glycol using syngas, its preparation method, and its application. Background Technology

[0002] The principle of ethylene glycol production from syngas is as follows: Under the action of catalysts such as palladium (Pd), carbon monoxide in the syngas undergoes gas-phase oxidative coupling with methyl nitrite to generate dimethyl oxalate and nitric oxide (NO). The generated NO reacts with methanol and oxygen recycled from subsequent processes to regenerate methyl nitrite, completing the cycle. Using H2 from the syngas, the dimethyl oxalate generated in the previous step is hydrogenated and reduced to produce the target product, ethylene glycol. However, in the syngas-to-ethylene glycol process, poor catalyst selectivity and other issues lead to the generation of mixed waste liquids containing methyl formate, methyl acetal, methanol, and dimethyl carbonate. These waste liquids form azeotropes with methanol, making efficient separation and utilization difficult.

[0003] To address the issue of waste liquids such as methyl formate, the commonly used process involves separating methyl formate from the syngas-to-ethylene glycol system through recycling and refining. However, methyl formate is a byproduct of syngas-to-ethylene glycol production, and its production volume is relatively small, accounting for less than 2%. Using this method to recover low-concentration methyl formate from complex waste liquids involves large equipment investments, complex processes, and high costs, and it currently has no industrial applications. Another existing technology uses distillation to concentrate the methyl formate before hydrogenation to convert it into methanol. The hydrogenated liquid product is then returned to the esterification section of the coal-to-ethylene glycol synthesis system for recycling. This process is lengthy, and the product still contains small amounts of unconverted methyl formate and other untreated byproducts such as methylal, which continue to accumulate in the system, requiring periodic discharge and generating waste liquid. Furthermore, this technology does not address the treatment of methylal in the waste liquid.

[0004] Therefore, how to achieve comprehensive utilization of waste liquid resources from syngas to ethylene glycol production under simple process conditions is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a catalyst for preparing methanol from waste liquid generated from ethylene glycol production using syngas, its preparation method, and its application. The catalyst provided by this invention can synthesize methanol from waste liquid generated from ethylene glycol production using syngas, thereby realizing the resource utilization of waste liquid.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a catalyst for preparing methanol from waste liquid generated during ethylene glycol production from syngas, the catalyst comprising a support and a copper-based catalyst and an auxiliary metal supported on the support;

[0008] The carrier is silicon dioxide;

[0009] The copper-based catalyst is CuZr2O x 3.5≤x≤4;

[0010] The additive metal includes one or more of Fe, Ce and K; the molar ratio of copper to additive metal in the copper-based catalyst is 1:(0.1~1).

[0011] Preferably, the total mass percentage of the copper-based catalyst and the auxiliary metal is 10-20% of the mass percentage of the catalyst.

[0012] This invention also provides a method for preparing a catalyst for producing methanol from waste liquid of ethylene glycol production using syngas, as described in the above technical solution, comprising the following steps:

[0013] (1) Mix a soluble copper source, a soluble zirconium source and water to obtain a metal ion solution;

[0014] (2) The metal ion solution and the ethanol solution of tetraethyl orthosilicate obtained in step (1) are added dropwise to the sodium bicarbonate solution to carry out a precipitation reaction. Then the solid obtained from the precipitation reaction is dried first to obtain the catalyst precursor.

[0015] (3) The catalyst precursor obtained in step (2) is subjected to a first calcination to obtain a support for the copper-based catalyst;

[0016] (4) The support for the copper-based catalyst obtained in step (3) is mixed with the auxiliary metal solution and impregnated. Then, the catalyst is subjected to a second drying and a second calcination in sequence.

[0017] Preferably, in step (1), the concentration of copper ions in the metal ion solution is 0.1–2.0 mol / L; and the concentration of zirconium ions in the metal ion solution is 0.2–4.0 mol / L.

[0018] Preferably, the concentration of sodium bicarbonate solution in step (2) is 0.1 to 2.0 mol / L.

[0019] Preferably, the temperatures of the first drying in step (2) and the second drying in step (4) are independently 100-120°C; and the times of the first drying and the second drying are independently 10-20 hours.

[0020] Preferably, the concentration of the ethanol solution of tetraethyl orthosilicate in step (2) is 10-20 wt%.

[0021] Preferably, the temperature of the precipitation reaction in step (2) is 50-90°C; and the pH value of the precipitation reaction is 7.0-8.0.

[0022] Preferably, the temperatures of the first calcination in step (3) and the second calcination in step (4) are independently 450–600°C; and the times of the first and second calcinations are independently 6–12 h.

[0023] The present invention also provides the application of the catalyst for preparing methanol from the waste liquid of ethylene glycol production from syngas as described in the above technical solution, or the catalyst for preparing methanol from the waste liquid of ethylene glycol production from syngas prepared by the preparation method described in the above technical solution.

[0024] This invention provides a catalyst for preparing methanol from waste liquid generated during ethylene glycol production from syngas. The catalyst comprises a support and a copper-based catalyst and an auxiliary metal supported on the support; the support is silica; and the copper-based catalyst is CuZr₂O. x The additive metal comprises one or more of Fe, Ce, and K; the molar ratio of copper to additive metal in the copper-based catalyst is 1:(0.1~1). This invention uses silica as a support to improve the dispersibility of the copper-based catalyst and additive metal in the catalyst, thereby improving the catalytic effect. This invention uses the copper-based catalyst CuZr2O... x Using one or more of Fe, Ce, and K as the main catalyst, the interaction between the auxiliary metal and the copper-based catalyst can enhance the catalytic effect, thereby enabling methyl formate, methyl acetal, and dimethyl carbonate in the waste liquid from ethylene glycol production from syngas to participate in the reaction and form methanol. The results of the examples show that after treating the waste liquid from ethylene glycol production from syngas using the catalyst provided by this invention, the methanol content in the liquid product is higher than 92%. This allows for the resource utilization of the waste liquid from ethylene glycol production from syngas as a raw material, yielding a product with a high methanol concentration. Detailed Implementation

[0025] This invention provides a catalyst for preparing methanol from waste liquid generated during ethylene glycol production from syngas, the catalyst comprising a support and a copper-based catalyst and an auxiliary metal supported on the support;

[0026] The carrier is silicon dioxide;

[0027] The copper-based catalyst is CuZr2O x 3.5≤x≤4;

[0028] The additive metal includes one or more of Fe, Ce and K; the molar ratio of copper to additive metal in the copper-based catalyst is 1:(0.1~1).

[0029] The catalyst provided by this invention includes a support. In this invention, the support is silica. By using silica as a support, this invention can provide abundant attachment sites for copper-based catalysts and auxiliary metals, thereby improving the dispersibility of copper-based catalysts and auxiliary metals.

[0030] In this invention, the particle size of the silicon dioxide is preferably 10–50 nm, more preferably 20–30 nm. By controlling the particle size of the silicon dioxide within the above range, this invention achieves a larger specific surface area.

[0031] The catalyst provided by this invention comprises a copper-based catalyst and a promoter metal supported on the support. In this invention, the copper-based catalyst is CuZr₂O. x 3.5≤x≤4. This invention utilizes the aforementioned copper-based catalyst, where the interaction between Cu and Zr enhances the catalytic effect of the catalytic reaction.

[0032] In this invention, the auxiliary metal includes one or more of Fe, Ce, and K. By adding the auxiliary metal, this invention can improve the catalytic effect by utilizing the interaction between the copper-based catalyst and the auxiliary metal, thereby enabling the selective conversion of various components in the waste liquid from syngas to ethylene glycol into methanol.

[0033] In this invention, the molar ratio of copper to the auxiliary metal in the copper-based catalyst is 1:(0.1-1). As one embodiment of this invention, the molar ratio of copper to the auxiliary metal in the copper-based catalyst can be 1:0.1, 1:0.2, 1:0.5, 1:0.6, 1:0.8, or 1:1. By controlling the molar ratio of copper to the auxiliary metal in the copper-based catalyst within the above range, this invention can improve the catalyst effect and promote the selective conversion of components in the waste liquid into methanol.

[0034] In this invention, the total mass percentage of the copper-based catalyst and the auxiliary metal is preferably 10-20% of the catalyst. As one embodiment of this invention, the total mass percentage of the copper-based catalyst and the auxiliary metal can be 10%, 12%, 15%, 16%, 18%, or 20% of the catalyst.

[0035] This invention also provides a method for preparing a catalyst for producing methanol from waste liquid of ethylene glycol production using syngas, as described in the above technical solution, comprising the following steps:

[0036] (1) Mix a soluble copper source, a soluble zirconium source and water to obtain a metal ion solution;

[0037] (2) The metal ion solution and the ethanol solution of tetraethyl orthosilicate obtained in step (1) are added dropwise to the sodium bicarbonate solution to carry out a precipitation reaction. Then the solid obtained from the precipitation reaction is dried first to obtain the catalyst precursor.

[0038] (3) The catalyst precursor obtained in step (2) is subjected to a first calcination to obtain a support for the copper-based catalyst;

[0039] (4) The support for the copper-based catalyst obtained in step (3) is mixed with the auxiliary metal solution and impregnated. Then, the catalyst is subjected to a second drying and a second calcination in sequence.

[0040] This invention mixes a soluble copper source, a soluble zirconium source, and water to obtain a metal ion solution.

[0041] In this invention, the soluble copper source is preferably one or more of copper nitrate, copper sulfate, and copper acetylacetonate.

[0042] In this invention, the soluble zirconium source is preferably zirconium oxynitrate.

[0043] The present invention does not have any particular limitation on the method of mixing the soluble copper source, the soluble zirconium source and water, as long as the soluble copper source and the soluble zirconium source can be dissolved in water.

[0044] In this invention, the concentration of copper ions in the metal ion solution is preferably 0.1–2.0 mol / L, more preferably 0.5–1.0 mol / L; the concentration of zirconium ions in the metal ion solution is preferably 0.2–4.0 mol / L, more preferably 0.5–2.0 mol / L. This invention controls the concentrations of copper and zirconium ions in the metal ion solution within the above ranges, achieving suitable reaction concentrations.

[0045] After obtaining the metal ion solution, the present invention adds the metal ion solution and the ethanol solution of tetraethyl orthosilicate dropwise into the sodium bicarbonate solution to carry out a precipitation reaction. Then, the solid obtained from the precipitation reaction is subjected to a first drying to obtain the catalyst precursor.

[0046] In this invention, the concentration of the sodium bicarbonate solution is preferably 0.1–2.0 mol / L, more preferably 0.15–2.0 mol / L. This invention uses sodium bicarbonate solution as a precipitant to cause copper and zirconium sources in the metal ion solution to precipitate.

[0047] In this invention, the concentration of the ethanol solution of tetraethyl orthosilicate is preferably 10-20 wt%, more preferably 15-18 wt%.

[0048] In this invention, the volume ratio of the metal ion solution, the ethanol solution of tetraethyl orthosilicate, and the sodium bicarbonate solution is preferably 1:(1-2):1, more preferably 1:2:1.

[0049] The present invention does not have a particular limitation on the dropping rate, which can be adjusted as needed to ensure that the metal ion solution, the ethanol solution of tetraethyl orthosilicate and the sodium bicarbonate solution are mixed evenly.

[0050] In this invention, the temperature of the precipitation reaction is preferably 50–90°C, more preferably 60–80°C. This invention does not specifically limit the time of the precipitation reaction; it is sufficient to react until no more precipitate is formed. In this invention, the pH value of the precipitation reaction is preferably 7.0–8.0. Controlling the pH value of the precipitation reaction within the above range in this invention is more conducive to promoting the complete precipitation of the auxiliary metal ions.

[0051] In this invention, the precipitation reaction is preferably carried out under stirring. This invention does not have a particular limitation on the stirring speed; it can be adjusted to ensure uniform mixing of the components.

[0052] The present invention preferably involves solid-liquid separation of the product obtained from the precipitation reaction to obtain a solid. The present invention does not specify a particular method for solid-liquid separation; any conventional solid-liquid separation method may be used.

[0053] In this invention, the temperature of the first drying step is preferably 100–120°C, more preferably 110–115°C; the drying time is preferably 10–20 h, more preferably 12–15 h. This invention removes liquid from a solid by drying.

[0054] After obtaining the catalyst precursor, the present invention performs a first calcination on the catalyst precursor to obtain a support for the copper-based catalyst.

[0055] In this invention, the preferred temperature for the first calcination is 450–600°C; the preferred calcination time is 6–12 hours. As one embodiment of this invention, the temperature for the first calcination can be 450°C, 500°C, 550°C, or 600°C; the calcination time can be 6 hours, 8 hours, 10 hours, or 12 hours. This invention, through calcination, decomposes the solid obtained from the precipitation reaction into metal oxides and forms oxygen vacancies.

[0056] After obtaining the support for the copper-based catalyst, the present invention mixes the support for the copper-based catalyst with an auxiliary metal solution, performs an impregnation treatment, and then performs a second drying and a second calcination in sequence to obtain the catalyst.

[0057] In this invention, the auxiliary metal in the auxiliary metal solution is preferably one or more of ferric nitrate, cerium nitrate, and potassium nitrate.

[0058] In this invention, the concentration of the auxiliary metal solution is preferably 0.01–1.0 mol / L. As one embodiment of this invention, the concentration of the auxiliary metal solution can be 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.5 mol / L, 1.0 mol / L, 1.5 mol / L, or 2.0 mol / L. By controlling the concentration of the auxiliary metal solution within the above range, this invention facilitates the thorough impregnation of the auxiliary metal solution into the support of the copper-based catalyst.

[0059] In this invention, the volume ratio of the support for the copper-based catalyst to the auxiliary metal solution is preferably 1:(1 to 1.5), more preferably 1:(1 to 1.2). By controlling the volume ratio of the support for the copper-based catalyst to the auxiliary metal solution within the above range, this invention can control the molar ratio of copper to auxiliary metal in the copper-based catalyst to be 1:(0.1 to 1).

[0060] In this invention, the impregnation treatment is preferably an equal-volume impregnation.

[0061] In this invention, the temperature of the second drying is preferably 100–120°C, more preferably 110–115°C; the drying time is preferably 10–20 h, more preferably 12–15 h. This invention removes liquid from a solid by drying.

[0062] In this invention, the preferred temperature for the second calcination is 450–600°C; the preferred calcination time is 6–12 hours. As one embodiment of this invention, the temperature for the second calcination can be 450°C, 500°C, 550°C, or 600°C; the calcination time can be 6 hours, 8 hours, 10 hours, or 12 hours. This invention, through calcination, decomposes the auxiliary metal solution to form metal oxides and creates oxygen vacancies.

[0063] The method provided by this invention is simple to operate and can produce catalysts with high catalytic activity.

[0064] The present invention also provides the application of the catalyst for preparing methanol from the waste liquid of ethylene glycol production from syngas as described in the above technical solution, or the catalyst for preparing methanol from the waste liquid of ethylene glycol production from syngas prepared by the preparation method described in the above technical solution.

[0065] This invention does not specifically limit the method of using the catalyst in the preparation of methanol from ethylene glycol production wastewater from syngas; conventional catalyst application methods can be used. In this invention, the preferred method includes: mixing the ethylene glycol production wastewater from syngas, hydrogen, and the catalyst to carry out a catalytic reaction to obtain the product.

[0066] In this invention, the composition of the waste liquid from the synthesis gas to ethylene glycol production preferably includes 5% to 85% methyl formate, 10% to 60% methanol, 1% to 30% methyl acetal, and 0.5% to 10% dimethyl carbonate; more preferably, it includes 10% to 90% methyl formate, 15% to 40% methanol, 5% to 20% methyl acetal, and 1% to 5% dimethyl carbonate.

[0067] In this invention, the conditions for the catalytic reaction preferably include: a liquid hourly space velocity (LHSV) of 0.01–2 h⁻¹. -1 More preferably 0.5 to 1 hour -1 The preferred hydrogen-liquid molar ratio is 10–80, more preferably 20–60; the preferred reaction pressure is 1.0–6.0 MPa, more preferably 2.0–5.0 MPa; and the preferred reaction temperature is 120–350 °C, more preferably 150–300 °C. By controlling the catalytic conditions within the above ranges, the present invention can improve the catalytic effect.

[0068] This invention uses a copper-based catalyst CuZr2O x Using one or more of Fe, Ce, and K as the main catalyst, the interaction between the auxiliary metal and the copper-based catalyst can be utilized to improve the catalytic effect of the catalyst. This allows methyl formate, methyl acetal, and dimethyl carbonate in the waste liquid from the production of ethylene glycol from syngas to participate in the reaction and form methanol.

[0069] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0070] Example 1

[0071] A catalyst for preparing methanol from waste liquid produced from ethylene glycol using syngas, the catalyst comprising a support and a copper-based catalyst and an auxiliary metal supported on the support;

[0072] The carrier is silicon dioxide with a particle size of 20–30 nm;

[0073] The copper-based catalyst is CuZr2O x 3.5≤x≤4;

[0074] The auxiliary metal is Fe; the molar ratio of copper to auxiliary metal in the copper-based catalyst is 1:0.6;

[0075] The method for preparing the catalyst for producing methanol from the waste liquid of ethylene glycol production from syngas is as follows:

[0076] (1) Copper nitrate, zirconium oxynitrate and water are mixed to obtain a metal ion solution; the concentration of copper ions in the metal ion solution is 1.0 mol / L; the concentration of zirconium ions in the metal ion solution is 2.0 mol / L;

[0077] (2) Add 10 mL of the metal ion solution and 15 mL of ethanol solution of tetraethyl orthosilicate with a concentration of 15 wt% dropwise to 10 mL of sodium bicarbonate solution with a concentration of 2.0 mol / L, and carry out a precipitation reaction at a pH of 7.0-8.0 and 60 °C. Then filter the precipitation reaction to obtain a solid, and dry the obtained solid at 110 °C for 10 h to obtain a catalyst precursor.

[0078] (3) The catalyst precursor obtained in step (2) is calcined at 550°C for 10 hours to obtain a support for the copper-based catalyst.

[0079] (4) The support for the copper-based catalyst obtained in step (3) is mixed with a 1.0 mol / L ferric nitrate solution and subjected to an equal-volume impregnation treatment. Then, it is dried for 10 h at 110 °C and calcined for 6 h at 500 °C to obtain the catalyst (abbreviated as Fe). 0.6 CuZr2O x ).

[0080] Example 2

[0081] A catalyst for preparing methanol from waste liquid produced from ethylene glycol using syngas, the catalyst comprising a support and a copper-based catalyst and an auxiliary metal supported on the support;

[0082] The carrier is silicon dioxide with a particle size of 20–30 nm;

[0083] The copper-based catalyst is CuZr2O x 3.5≤x≤4;

[0084] The auxiliary metal is cerium; the molar ratio of copper to auxiliary metal in the copper-based catalyst is 1:0.15;

[0085] The preparation method of the catalyst for preparing methanol from ethylene glycol production wastewater using syngas differs from that in Example 1 in that the auxiliary metal solution is cerium nitrate; otherwise, it is the same as in Example 1. The resulting catalyst for preparing methanol from ethylene glycol production wastewater using syngas is abbreviated as Ce. 0.15 CuZr2O x .

[0086] Example 3

[0087] A catalyst for preparing methanol from waste liquid produced from ethylene glycol using syngas, the catalyst comprising a support and a copper-based catalyst and an auxiliary metal supported on the support;

[0088] The carrier is silicon dioxide with a particle size of 20–30 nm;

[0089] The copper-based catalyst is CuZr2O x 3.5≤x≤4;

[0090] The auxiliary metal is potassium; the molar ratio of copper to the auxiliary metal in the copper-based catalyst is 1:0.1;

[0091] The preparation method of the catalyst for preparing methanol from ethylene glycol production wastewater using syngas differs from that in Example 1 in that the auxiliary metal solution is potassium nitrate; otherwise, it is the same as in Example 1. The resulting catalyst for preparing methanol from ethylene glycol production wastewater using syngas is abbreviated as K. 0.1 CuZr2O x ;

[0092] The method for preparing the catalyst for producing methanol from the waste liquid of ethylene glycol production from syngas is as follows:

[0093] (1) Copper nitrate, zirconium oxynitrate and water are mixed to obtain a metal ion solution; the concentration of copper ions in the metal ion solution is 1.0 mol / L; the concentration of zirconium ions in the metal ion solution is 2.0 mol / L;

[0094] (2) Add 10 mL of the metal ion solution and 15 mL of ethanol solution of tetraethyl orthosilicate with a concentration of 15 wt% dropwise to 10 mL of sodium bicarbonate solution with a concentration of 2.0 mol / L, and carry out a precipitation reaction at a pH of 7.0-8.0 and 60 °C. Then filter the precipitation reaction to obtain a solid, and dry the obtained solid at 110 °C for 10 h to obtain a catalyst precursor.

[0095] (3) The catalyst precursor obtained in step (2) is calcined at 550°C for 10 hours to obtain a support for the copper-based catalyst.

[0096] (4) The support for the copper-based catalyst obtained in step (3) is mixed with a 1.0 mol / L potassium nitrate solution and subjected to an equal-volume impregnation treatment. Then, it is dried for 10 h at 110 °C and calcined for 6 h at 600 °C to obtain the catalyst (abbreviated as K). 0.1 CuZr2O x ).

[0097] Comparative Example 1

[0098] A method for preparing a catalyst for producing methanol from waste liquid generated from ethylene glycol production using syngas is as follows:

[0099] (1) Copper nitrate, zirconium oxynitrate and water are mixed to obtain a metal ion solution; the concentration of copper ions in the metal ion solution is 1.0 mol / L; the concentration of zirconium ions in the metal ion solution is 2.0 mol / L;

[0100] (2) Add 10 mL of the metal ion solution and 15 mL of ethanol solution of tetraethyl orthosilicate with a concentration of 15 wt% dropwise to 10 mL of sodium bicarbonate solution with a concentration of 2.0 mol / L, and carry out a precipitation reaction at a pH of 7.0-8.0 and 60 °C. Then filter the precipitation reaction to obtain a solid, and dry the obtained solid at 110 °C for 10 h to obtain a catalyst precursor.

[0101] (3) The catalyst precursor obtained in step (2) is calcined at 550°C for 10 h to obtain a support for the copper-based catalyst (referred to as CuZr2O). x ).

[0102] Application examples

[0103] The effects of the reaction conditions on the performance of the four catalysts prepared in Comparative Example 1 and Examples 1-3 were investigated using the same reaction conditions. The reaction temperature was 200°C, the reaction pressure was 3.0 MPa, the hydrogen-to-liquid ratio was 30, and the liquid hourly space velocity was 1.0 h⁻¹. -1 The liquid raw material composition was: methanol 26%, methyl formate 60%, methyl acetal 10%, and dimethyl carbonate 4%. The liquid products obtained from the four reactions were tested, and the results are shown in Table 1.

[0104] Table 1 shows the catalytic performance results of the catalysts prepared in Comparative Examples 1 and Examples 1-3.

[0105] catalyst Methanol content (wt%) in liquid phase product Comparative Example <![CDATA[CuZr2O x ]]> 65.6 Example 1 <![CDATA[Fe 0.6 CuZr2O x ]]> 92.2 Example 2 <![CDATA[Ce 0.15 CuZr2O x ]]> 93.0 Example 3 <![CDATA[K 0.1 CuZr2O x ]]> 95.1

[0106] As shown in Table 1, the catalyst prepared by the method provided in this invention can significantly increase the methanol content in the product when used to produce methanol from waste liquid generated from ethylene glycol production using syngas. Therefore, this invention addresses the current challenges in separating waste liquid containing methyl formate, methyl acetal, dimethyl carbonate, and methanol generated in the ethylene glycol production process, which are characterized by difficulties, high costs, and resource waste. The catalyst prepared in this invention can catalyze the conversion of methyl formate and methyl acetal in the waste liquid into methanol in a one-step process, with a simple process, low investment, and good economic and environmental benefits.

[0107] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a catalyst for producing methanol from waste liquid generated from ethylene glycol using syngas, comprising the following steps: (1) Mix a soluble copper source, a soluble zirconium source and water to obtain a metal ion solution; (2) The metal ion solution and the ethanol solution of tetraethyl orthosilicate obtained in step (1) are added dropwise to the sodium bicarbonate solution to carry out a precipitation reaction. Then the solid obtained from the precipitation reaction is dried first to obtain the catalyst precursor. (3) The catalyst precursor obtained in step (2) is subjected to a first calcination to obtain a support for the copper-based catalyst; (4) The support for the copper-based catalyst obtained in step (3) is mixed with the auxiliary metal solution and impregnated. Then, the catalyst is subjected to a second drying and a second calcination in sequence. The catalyst includes a support and a copper-based catalyst and an auxiliary metal supported on the support; The carrier is silicon dioxide; The copper-based catalyst is CuZr2O x 3.5≤x≤4; The auxiliary metal includes one or more of Fe, Ce and K; the molar ratio of copper to auxiliary metal in the copper-based catalyst is 1:(0.1~1); The total mass percentage of the copper-based catalyst and auxiliary metals is 10-20% of the catalyst mass.

2. The preparation method according to claim 1, characterized in that, In step (1), the concentration of copper ions in the metal ion solution is 0.1~2.0 mol / L; the concentration of zirconium ions in the metal ion solution is 0.2~4.0 mol / L.

3. The preparation method according to claim 1, characterized in that, The concentration of sodium bicarbonate solution in step (2) is 0.1~2.0 mol / L.

4. The preparation method according to claim 1, characterized in that, The temperatures for the first drying in step (2) and the second drying in step (4) are independently 100~120℃; the times for the first drying and the second drying are independently 10~20h.

5. The preparation method according to claim 1, characterized in that, In step (2), the concentration of the ethanol solution of tetraethyl orthosilicate is 10-20 wt%.

6. The preparation method according to claim 1, characterized in that, The precipitation reaction temperature in step (2) is 50~90℃; the pH value of the precipitation reaction is 7.0~8.

0.

7. The preparation method according to claim 1, characterized in that, The temperatures of the first calcination in step (3) and the second calcination in step (4) are independently 450~600℃; the times of the first calcination and the second calcination are independently 6~12h.

8. The application of the catalyst for preparing methanol from waste liquid of ethylene glycol production using syngas, prepared by the method according to any one of claims 1 to 7.