Sulfur-tolerant oxalate hydrogenation catalyst and preparation method and application thereof

Abstract

The invention provides a sulfur-resistant oxalate hydrogenation catalyst as well as a preparation method and application thereof. The method comprises the following steps: 1) reacting a zinc-aluminum mixed metal solution with an alkaline precipitator, and calcining to obtain a zinc-aluminum mixed carrier; 2) loading molybdenum oxide on a zinc-aluminum mixed carrier to obtain a catalyst M; 3) preparing a copper salt solution, and adding an organic silicon source to obtain a Cu / SiO2 catalyst, namely a catalyst N; 4) sequentially filling a catalyst M and a catalyst N from top to bottom during use; in production practice, under the reaction conditions that the sulfur content is smaller than 20 mg / Nm < 3 >, the reaction temperature is 190 DEG C, the reaction pressure is 2.5 MPa, the mass space velocity of dimethyl oxalate is 0.5 g / h and the hydrogen-ester ratio is 80, the conversion rate of dimethyl oxalate is 100%, the selectivity of ethylene glycol is larger than 97%, and the catalyst can stably operate for 1000 h, does not attenuate performance and shows good sulfur resistance and coking resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogenation catalysts, and in particular to a thioxalate-resistant hydrogenation catalyst and a preparation method and application thereof, which are applied in the production process of preparing ethylene glycol thioxalate-resistant hydrogenation catalyst by hydrogenating coke oven gas. Background Art

[0002] Coke oven gas (COG) is produced during the coking process and contains a significant amount of recyclable gases, including methane, hydrogen, carbon monoxide, and carbon dioxide (Table 1). After purification, COG can be used as fuel gas or as synthesis gas for the production of chemical feedstocks such as hydrogen, urea, methanol, and dimethyl ether. Therefore, COG recovery plays a crucial role in the clean utilization of my country's coal resources. However, due to its high impurity content (Table 2), COG generally requires purification before reuse. Sulfides, in particular, can poison catalysts in subsequent processes, permanently deactivating them. In existing COG desulfurization processes, the majority of H2S is removed during wet desulfurization. However, organic sulfur species, such as carbonyl sulfide, mercaptans, and thiophenes, require hydroconversion. This involves converting the organic sulfur species into hydrogen sulfide over a hydrodesulfurization catalyst, which is then absorbed by a desulfurizer.

[0003]

[0004] Ethylene glycol (EG) is an important organic chemical raw material, primarily used in the polyester industry. It is also a crucial raw material for the production of resins, lubricants, plasticizers, paints, adhesives, surfactants, and many other products. The primary production process for EG is the ethylene oxide hydration method, which involves oxidizing ethylene to ethylene oxide, which is then hydrated to form EG. This method is highly dependent on petroleum resources. However, in my country, due to the relatively abundant sources of synthesis gas, the production of EG from synthesis gas has gradually developed in recent years and has attracted increasing attention from scientific researchers.

[0005] Currently, there are few reports on catalysts for synthesizing ethylene glycol using coke oven gas hydrogenation. CN112408322A proposes a system and method for producing ethanol and ethylene glycol synthesis gas by carbonization of coke oven gas. After removing tar, naphthalene, and sulfur from the coke oven gas, the gas undergoes oxidation and conversion reactions to generate a conversion gas containing H₂, CO, and CO₂. After heat recovery, cooling, water separation, and decarbonization, CO and H₂ are recovered using pressure swing adsorption. CN113387772A discloses a method for synthesizing ethylene glycol from coke oven gas. The gas undergoes tar and dust removal, compression, crude desulfurization, adsorption and regeneration in a TSA adsorption tower, further compression, fine desulfurization, cooling, and cryogenic separation before being used in ethylene glycol synthesis. The recycling and reuse of the coke oven gas involves complex purification and separation steps. CN109053370A proposes a process for producing ethylene glycol from coke oven gas and calcium carbide tail gas. The coke oven tail gas undergoes compression, conversion, purification, fine desulfurization, and separation before being used in ethylene glycol synthesis. The recycling of coke oven gas in CN110002955A, CN108046987A, CN106566574A and CN102115684A generally requires compression, deoiling, desulfurization and separation before use. However, in actual applications, unstable operating conditions often lead to excessive sulfur content. Sulfides in the raw gas poison the catalyst, reducing reaction activity and thus shortening the catalyst's service life. Summary of the Invention

[0006] The purpose of the present invention is to provide a sulfur oxalate resistant hydrogenation catalyst and its preparation method and application, which can 3 The thioxalate-resistant hydrogenation catalyst showed excellent sulfur resistance and anti-coking ability, thereby streamlining the tedious fine desulfurization, deoiling and separation processes in the production of ethylene glycol from coke oven gas, and has certain guiding significance for the synthesis of high-value-added product ethylene glycol by hydrogenation of coke oven gas.

[0007] To achieve the above object, the present invention provides the following technical solutions: A method for preparing a thiooxalate-resistant hydrogenation catalyst comprises the following steps: S1. A zinc-aluminum mixed metal solution is prepared by mixing an aluminum salt and a zinc salt in a molar ratio of 1:0.2-0.6. The prepared zinc-aluminum mixed metal solution and an alkaline precipitant are added to a reactor in parallel, the pH value is controlled to be 7-8, and the reaction is carried out at a temperature of 50-90° C. After the reaction is completed, the mixture is calcined at 400-600° C. for 4-10 hours to obtain a zinc-aluminum mixed carrier. S2. Add the prepared zinc-aluminum support to a molybdenum salt aqueous solution, immerse at 40-70° C. for 3-8 h, dry at 120° C., and calcine at 350-650° C. for 4-8 h. The catalyst is recorded as catalyst M; the molybdenum loading is 8-20 wt % of the total mass of catalyst M. S3, prepare a copper salt solution, add ammonia water to synthesize a copper ammonia solution, then add an organosilicon source, stir and mix well, transfer to a hydrothermal reactor, react at 180-250° C. for 16 hours, take out, filter, wash, dry, and calcine at 350° C. for 3 hours to obtain a silicon-modified Cu / SiO2 catalyst, recorded as catalyst N, with a copper loading mass to silicon loading mass ratio of 10-40:60-90; S4. When used in the synthesis of ethylene glycol by hydrogenation of coke oven gas, catalyst M and catalyst N are loaded in order from top to bottom, so that the coke oven gas and hydrogen first pass through catalyst N and then through catalyst M.

[0008] As an improvement to the above technical solution, in step S2, the molybdenum salt aqueous solution is further added with an additive A, wherein the additive A is at least one of the nitrates and chlorides of Fe, Ni, and Co, and the loading amount of the additive A is 2 to 10 wt% of the total mass of the catalyst M; in step S3, an additive B is added simultaneously with the addition of the organosilicon, wherein the additive B is at least one of the nitrates and chlorides of Zn and Al, and the loading amount of the additive B is 1 to 8 wt% of the total mass of the catalyst N.

[0009] As an improvement to the above technical solution, the aluminum salt is any one of nitrate, chloride, and acetate, or a combination of two thereof; and the zinc salt is one of zinc nitrate, chloride, and acetate, or a combination of two thereof.

[0010] As an improvement to the above technical solution, the alkaline precipitant is at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, ammonium carbonate, sodium hydroxide, and potassium hydroxide.

[0011] As an improvement to the above technical solution, in step S2, the molybdenum salt is at least one of sodium molybdate and ammonium molybdate.

[0012] As an improvement to the above technical solution, in step S3, the copper salt is any one of copper nitrate, chloride, acetate, or a combination of two thereof; and the molar amount of the ammonia water is 4 to 5 times the molar amount of copper.

[0013] As an improvement to the above technical solution, the organic silicon source is at least one of methyl orthosilicate and ethyl orthosilicate.

[0014] As an improvement to the above technical solution, in step S2, the loading volume ratio of catalyst M to catalyst N is 2-4:6-8. As an improvement to the above technical solution, the conditions for the catalytic hydrogenation include: reaction temperature of 190-240°C, reaction pressure of 2.0-3.0 MPa, mass space velocity of dimethyl oxalate of 0.5-1 g / h, and hydrogen-ester ratio of 40-80.

[0015] The present invention also provides a thioxalate-resistant hydrogenation catalyst, comprising a catalyst M and a catalyst N sequentially loaded from top to bottom; the catalyst M is a zinc-aluminum mixed carrier of zinc-modified γ-Al2O3 impregnated and solidified with molybdenum oxide, and the catalyst N is a Cu / SiO2 catalyst.

[0016] The reaction mechanism of the present invention is as follows: ① sulfur-containing compounds are adsorbed on the desulfurization active metal Mo; ② C-S bonds of the sulfur-containing compounds adsorbed on the metal surface are broken; ③ the desulfurized compounds then leave the metal center and sulfur is deposited on the metal surface; ④ the sulfur deposited on the metal migrates to the surface of the sulfur storage component ZnO through a sulfur transfer reaction, and the metal component regains activity. Therefore, when faced with coke oven gas with excessive sulfur content due to unstable operating conditions, the catalyst exhibits excellent sulfur resistance.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention uses zinc-modified macroporous γ-Al2O3 as a carrier. The large pore size increases the diffusion rate of the feed gas. The zinc modification of the carrier also enhances the catalyst's sulfur tolerance. The addition of Fe, Ni, and Co additives promotes the conversion of organic sulfur to inorganic sulfur, which is ultimately absorbed by zinc and molybdenum oxides, preventing it from affecting hydrogenation active sites. The increased number of acidic sites facilitates the decomposition of organic macromolecules, reducing its impact on subsequent hydrogenation catalysts and further enhancing the catalyst's anti-coking ability. Furthermore, by employing a synthesis method involving an organosilicon source and copper-ammonia double hydrolysis, the strong metal-support interaction (SMSI) between the active component copper and silica is enhanced, weakening the Ostwald ripening of copper atoms. The addition of zinc and aluminum additives also exhibits a certain degree of sulfur tolerance.

[0018] In the process of synthesizing ethylene glycol from dimethyl oxalate by hydrogenation of coke oven gas, coke oven gas is used as the hydrogenation raw material, thereby improving the utilization efficiency of industrial tail gas. In the reaction process, the catalyst synthesized and layered by the above method has a dimethyl oxalate conversion rate of 100% and an ethylene glycol selectivity of >97% under the reaction conditions of sulfur content <20 mg / Nm3, reaction temperature of 190°C, reaction pressure of 2.5 MPa, dimethyl oxalate mass space velocity of 0.5 g / h, and hydrogen-ester ratio of 80. The catalyst can operate stably for 1000 hours without performance degradation, showing good sulfur resistance and anti-coking ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a stability test diagram of the catalyst of the present invention; Figure 2 This is the stability test diagram of single catalyst N. DETAILED DESCRIPTION

[0020] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below in conjunction with specific embodiments. Obviously, the embodiments described are only a part of embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0021] In the present invention, the dimethyl oxalate hydrogenation and thioxalate-resistant hydrogenation catalyst is preferably subjected to a reduction treatment before use to reduce the CuO in the dimethyl oxalate hydrogenation and thioxalate-resistant hydrogenation catalyst to Cu, thereby having better activity. The obtained activated catalyst is then used to catalyze the hydrogenation of dimethyl oxalate to produce ethylene glycol.

[0022] In the present invention, the reduction treatment is preferably carried out in a hydrogen atmosphere, the temperature of the reduction treatment is preferably 150-320° C., more preferably 250° C., and the time is preferably 8-12 h, preferably 10 h.

[0023] The sulfur-resistant oxalate hydrogenation catalyst for dimethyl oxalate hydrogenation of the present invention is preferably used to produce ethylene glycol by hydrogenation of coke oven gas. When the catalyst is used in the reaction of producing ethylene glycol by hydrogenation of coke oven gas, under the reaction conditions of a reaction temperature of 190°C, a reaction pressure of 2.5 MPa, a dimethyl oxalate mass space velocity of 0.5 g / h, and a hydrogen-to-ester ratio of 80, the dimethyl oxalate conversion rate is 100% and the ethylene glycol selectivity is greater than 97%. In particular, the catalyst can operate stably for 1000 hours without performance degradation under the condition that coke oven gas is used as the hydrogen source. Therefore, the catalyst of the present invention exhibits good stability when used to produce ethylene glycol by hydrogenation of dimethyl oxalate using coke oven gas. Specific examples thereof are as follows. Example

[0024] (1) Dissolve 5 g of zinc nitrate and 10 g of aluminum nitrate in water to prepare 500 mL of a zinc-aluminum mixed metal solution, which is then added to a reactor in parallel with a 1 mol / L sodium carbonate solution. The pH value of the system is controlled to be 7, and the reaction is carried out at a temperature of 60°C. After the reaction is completed, the solution is calcined at 500°C for 5 h to obtain a zinc-aluminum mixed carrier.

[0025] (2) 5 g of zinc-aluminum mixed carrier was added to an aqueous solution containing 1.2 g of ammonium molybdate and 1 g of ferric nitrate. After immersion at 40 °C for 3 h, it was dried at 120 °C and calcined at 350 °C for 5 h. The catalyst was recorded as catalyst M. (3) Take 100 mL of 0.8 mol / L copper nitrate solution, add 21 mL of 25% ammonia water to prepare a copper ammonia solution, add 45 mL of ethyl orthosilicate and 2 g of zinc nitrate, stir and dissolve, transfer to a hydrothermal reactor, react at 180 ° C for 16 h, take out, filter, wash, dry, and calcine at 350 ° C for 3 h to obtain a Cu / SiO2 catalyst modified with an additive, which is recorded as catalyst N.

[0026] (4) Take 2.1 mL of catalyst M and 4.9 mL of catalyst N and load the reaction tube with the measured catalyst M and catalyst N in order from top to bottom. Perform catalyst evaluation tests according to the reaction conditions. This is referred to as Example 1.

[0027] Example 1-1 The synthesis method of Example 1-1 is consistent with that of Example 1, wherein zinc nitrate (auxiliary agent B) is not added in step (3), and the catalyst evaluation test is carried out according to the reaction conditions.

[0028] Example 1-2 The synthesis method of Example 1-2 is consistent with that of Example 1, wherein only 7 ml of catalyst M is loaded in step (4), and the catalyst evaluation test is performed according to the reaction conditions.

[0029] Examples 1-3 The synthesis method of Examples 1-3 is consistent with that of Example 1, wherein only 7 ml of catalyst N is loaded in step (4), and the catalyst evaluation test is performed according to the reaction conditions. Example

[0030] 16 g of aluminum chloride and 10 g of zinc chloride were dissolved in water to prepare 800 mL of a zinc-aluminum mixed metal solution, which was then added to a reactor in parallel with a 1 mol / L ammonium bicarbonate solution. The pH value of the system was controlled to be 7, and the reaction was carried out at a temperature of 70°C. After the reaction was completed, the solution was calcined at 550°C for 4 hours to obtain a zinc-aluminum mixed carrier.

[0031] 10 g of the zinc-aluminum mixed carrier was added to an aqueous solution containing 2 g of ammonium molybdate, 1.2 g of ferric nitrate and 0.5 g of nickel nitrate. The mixture was immersed at 50°C for 4 h, dried at 120°C and calcined at 350°C for 5 h. The catalyst was recorded as catalyst M.

[0032] (3) Take 100 mL of 1 mol / L copper nitrate solution, add 27 mL of 25% ammonia water to prepare a copper ammonia solution, add 50 mL of ethyl orthosilicate and 4 g of zinc nitrate, stir and dissolve, transfer to a hydrothermal reactor, react at 200 ° C for 16 h, take out, filter, wash, dry, and calcine at 350 ° C for 3 h to obtain a Cu / SiO2 catalyst modified with an additive, which is recorded as catalyst N.

[0033] (4) Take 1.2 mL of catalyst M and 2.8 mL of catalyst N and load the reaction tube with the measured catalyst M and catalyst N in order from top to bottom. Perform catalyst evaluation tests according to the reaction conditions. This is referred to as Example 2. Example

[0034] 20g of aluminum nitrate and 10g of zinc acetate were dissolved in water to prepare 800mL of zinc-aluminum mixed metal solution, which was added into the reactor in parallel with 0.5mol / L sodium hydroxide solution. The pH value of the system was controlled to 8, and the reaction was carried out at a temperature of 80°C. After the reaction was completed, it was calcined at 600°C for 4h to obtain a zinc-aluminum mixed carrier.

[0035] 15 g of the zinc-aluminum mixed carrier was added to an aqueous solution containing 1.5 g of sodium molybdate, 1 g of ferric chloride and 0.2 g of cobalt nitrate. The mixture was immersed at 60°C for 5 h, dried at 120°C and calcined at 500°C for 6 h. The catalyst was recorded as catalyst M.

[0036] (3) Take 100 mL of 0.5 mol / L copper nitrate solution, add 14 mL of 25% ammonia water to prepare a copper ammonia solution, add 20 mL of ethyl orthosilicate and 1.2 g of aluminum nitrate, stir and dissolve, transfer to a hydrothermal reactor, react at 200 ° C for 16 h, take out, filter, wash, dry, and calcine at 350 ° C for 3 h to obtain a Cu / SiO2 catalyst modified with an additive, which is recorded as catalyst N.

[0037] (4) Take 1.5 mL of catalyst M and 3.5 mL of catalyst N and load the reaction tube with the measured catalyst M and catalyst N in order from top to bottom. Perform catalyst evaluation tests according to the reaction conditions. This is recorded as Example 3. Example

[0038] 16 g of aluminum nitrate and 8 g of zinc nitrate were dissolved in water to prepare 800 mL of a zinc-aluminum mixed metal solution, which was then added to a reactor in parallel with a 1.5 mol / L ammonium carbonate solution. The pH value of the system was controlled to be 8, and the reaction was carried out at a temperature of 60°C. After the reaction was completed, the solution was calcined at 550°C for 8 hours to obtain a zinc-aluminum mixed carrier.

[0039] 10 g of the zinc-aluminum mixed carrier was added to an aqueous solution containing 2.5 g of ammonium molybdate, 1.5 g of nickel nitrate and 0.5 g of cobalt nitrate. The mixture was immersed at 60°C for 6 h, dried at 120°C and calcined at 600°C for 8 h. The catalyst was recorded as catalyst M.

[0040] (3) Take 100 mL of 0.6 mol / L copper nitrate solution, add 17 mL of 25% concentrated ammonia water to prepare a copper ammonia solution, then add 25 mL of methyl orthosilicate, 2 g of zinc nitrate and 1 g of aluminum nitrate. After stirring and dissolving, transfer to a hydrothermal reactor and react at 250 °C for 16 h. After filtering, washing and drying, calcinate at 350 °C for 3 h to obtain a Cu / SiO2 catalyst modified with an additive, which is recorded as catalyst N.

[0041] (4) Take 1.8 mL of catalyst M and 4.2 mL of catalyst N and load the reaction tube with the measured catalyst M and catalyst N in order from top to bottom. Perform catalyst evaluation tests according to the reaction conditions. This is recorded as Example 4. Example

[0042] 24 g of aluminum nitrate and 16 g of zinc nitrate were dissolved in water to prepare 1000 mL of zinc-aluminum mixed metal solution, which was added into the reactor in parallel with 1.5 mol / L ammonium carbonate solution. The pH value of the system was controlled to 8, and the reaction was carried out at a temperature of 60°C. After the reaction was completed, the solution was calcined at 500°C for 5 hours to obtain a zinc-aluminum mixed carrier.

[0043] 15 g of the zinc-aluminum mixed carrier was added to an aqueous solution containing 3 g of ammonium molybdate, 1.5 g of ferric nitrate and 0.5 g of cobalt nitrate. The mixture was immersed at 60°C for 6 h, dried at 120°C and calcined at 600°C for 5 h. The catalyst was recorded as catalyst M.

[0044] (3) Take 100 mL of 0.8 mol / L copper nitrate solution, add 24 mL of 25% concentrated ammonia water to prepare a copper ammonia solution, then add 30 mL of methyl orthosilicate, 2 g of zinc nitrate and 2 g of aluminum nitrate. After stirring and dissolving, transfer to a hydrothermal reactor and react at 250 °C for 16 h. After filtering, washing and drying, calcinate at 350 °C for 3 h to obtain a Cu / SiO2 catalyst modified with an additive, which is recorded as catalyst N.

[0045] (4) Take 1.2 mL of catalyst M and 2.8 mL of catalyst N and load the reaction tube with the measured catalyst M and catalyst N in order from top to bottom. Perform catalyst evaluation tests according to the reaction conditions. This is recorded as Example 5. Example

[0046] 18 g of aluminum nitrate and 9 g of zinc acetate were dissolved in water to prepare 700 mL of a zinc-aluminum mixed metal solution, which was then added to a reactor in parallel with a 0.6 mol / L sodium hydroxide solution. The pH value of the system was controlled to be 8, and the reaction was carried out at a temperature of 70°C. After the reaction was completed, the solution was calcined at 600°C for 4 hours to obtain a zinc-aluminum mixed carrier.

[0047] 12 g of the zinc-aluminum mixed carrier was added to an aqueous solution containing 1.2 g of sodium molybdate, 0.9 g of ferric chloride and 0.2 g of cobalt nitrate, and immersed at 60°C for 5 h. The mixture was then dried at 120°C and calcined at 500°C for 6 h. The catalyst was recorded as catalyst M.

[0048] (3) Take 100 mL of 0.6 mol / L copper nitrate solution, add 17 mL of 25% ammonia water to prepare a copper ammonia solution, add 24 mL of ethyl orthosilicate and 1.5 g of zinc nitrate, stir and dissolve, transfer to a hydrothermal reactor, react at 200 ° C for 16 h, take out, filter, wash, dry, and calcine at 350 ° C for 3 h to obtain a Cu / SiO2 catalyst modified with an additive, which is recorded as catalyst N.

[0049] (4) Take 1.2 mL of catalyst M and 2.8 mL of catalyst N and load the reaction tube with the measured catalyst M and catalyst N in order from top to bottom. Perform catalyst evaluation tests according to the reaction conditions. This is recorded as Example 6.

[0050]

[0051] It can be seen from Table 3 that the doping of ZnO into the carrier γ-Al2O3 in catalyst M, on the one hand, increases its own specific surface area, improves the dispersion of active components and the diffusion of macromolecular compounds in the pores, and thus improves the catalyst's sulfur treatment activity. On the other hand, the addition of ZnO increases the sulfur-fixing effect of the catalyst itself. Sulfur is absorbed by the catalyst carrier in the form of ZnS, reducing the poisoning of the active component Mo, thereby increasing the sulfur resistance and service life of the catalyst.

[0052] The catalysts obtained in Examples 1-6 above were used in the reaction of preparing ethylene glycol from dimethyl oxalate by hydrogenation of coke oven gas, and the catalytic performance of the catalysts was investigated.

[0053] The reduction and evaluation process of the above-mentioned catalyst was carried out in a laboratory-scale fixed-bed reactor. The catalyst was fixed in the constant temperature section of the reactor with quartz sand. The reduction temperature was 250°C, the flow rate of reducing gas H2 was 100 mL / min, and the reduction time was 10 hours. After the reduction was completed, the temperature was lowered to 190°C and the reactor pressure was increased to 2.5 MPa.

[0054] Dimethyl oxalate was transported by a liquid feed pump, vaporized, and then mixed with coke oven gas before entering the reactor. The mass space velocity of dimethyl oxalate was 0.5 g / h, and the hydrogen-to-ester ratio (molar ratio) was 80. The condensed liquid product was taken out at regular intervals, and the composition of the liquid product was analyzed by gas chromatograph, and the dimethyl oxalate conversion rate and ethylene glycol selectivity were calculated.

[0055] The conversion rate of dimethyl oxalate and the selectivity of ethylene glycol are calculated according to the following formula: Conversion rate of dimethyl oxalate = (mass of dimethyl oxalate feed - mass of dimethyl oxalate in liquid product) / mass of dimethyl oxalate feed; Ethylene glycol selectivity = mass of dimethyl oxalate consumed to produce ethylene glycol / mass of all converted dimethyl oxalate.

[0056] The test was carried out under the following reaction conditions: reaction temperature: 190°C; reaction pressure: 2.5 MPa; dimethyl oxalate mass space velocity of 0.5 g / hour, hydrogen-ester ratio of 80, and the experimental results are shown in Table 4 below.

[0057]

[0058] From the results in Table 4, it can be seen that the catalyst for preparing ethylene glycol by hydrogenation of dimethyl oxalate via coke oven gas has achieved unexpected technical results, which indicates that compared with the existing dimethyl oxalate hydrogenation catalyst, the hydrogenation catalyst of the present invention has excellent sulfur resistance and anti-coking capabilities.

[0059] By the attached Figure 1 、 2 The stability test curve also shows that: the catalyst N alone causes the sulfur content in the coke oven gas to exceed the standard due to unstable operating conditions, which seriously poisons the catalyst and has poor stability performance. However, when the catalysts M and N of the present invention are loaded in layers, the catalyst can operate stably for 1000 hours without performance degradation, showing good sulfur resistance and anti-coking ability, and has good prospects for industrial application.

[0060] The terms and expressions used in this specification are used as terms and expressions of description only, and not of limitation, and there is no intention in the use of these terms and expressions to exclude any equivalents of the features shown and described or their components.

[0061] Although several embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. On the contrary, it should be appreciated by those skilled in the art that any variations and improvements may be made to these embodiments without departing from the principles of the present invention. The scope of protection of the present invention is determined by the appended claims and their equivalents.

Claims

1. A method for preparing a thiooxalate-resistant hydrogenation catalyst, characterized in that: The following steps are involved: S1. A zinc-aluminum mixed metal solution is prepared by mixing an aluminum salt and a zinc salt in a molar ratio of 1:0.2-0.

6. The prepared zinc-aluminum mixed metal solution and an alkaline precipitant are added to a reactor in parallel, the pH value is controlled to be 7-8, and the reaction is carried out at a temperature of 50-90° C. After the reaction is completed, the mixture is calcined at 400-600° C. for 4-10 hours to obtain a zinc-aluminum mixed carrier. S2. Add the prepared zinc-aluminum support to a molybdenum salt aqueous solution, immerse at 40-70° C. for 3-8 h, dry at 120° C., and calcine at 350-650° C. for 4-8 h. The catalyst is recorded as catalyst M; the molybdenum loading is 8-20 wt % of the total mass of catalyst M. S3, prepare a copper salt solution, add ammonia water to synthesize a copper ammonia solution, then add an organosilicon source, stir and mix well, transfer to a hydrothermal reactor, react at 180-250° C. for 16 hours, take out, filter, wash, dry, and calcine at 350° C. for 3 hours to obtain a Cu / SiO2 catalyst, recorded as catalyst N, with a ratio of copper loading mass to silicon loading mass of 10-40:60-90; S4. When used in the synthesis of ethylene glycol by hydrogenation of coke oven gas, catalyst M and catalyst N are loaded in order from top to bottom, so that the coke oven gas and hydrogen first pass through catalyst N and then through catalyst M.

2. The preparation method according to claim 1, characterized in that: In the step S2, the molybdenum salt aqueous solution is further added with an additive A, wherein the additive A is at least one of nitrates and chlorides of Fe, Ni, and Co, and the loading amount of the additive A is 2 to 10 wt% of the total mass of the catalyst M; in the step S3, an additive B is added simultaneously with the addition of the organosilicon, wherein the additive B is at least one of nitrates and chlorides of Zn and Al, and the loading amount of the additive B is 1 to 8 wt% of the total mass of the catalyst N.

3. The preparation method according to claim 1, wherein The aluminum salt is any one of nitrate, chloride, and acetate, or a combination of two thereof; the zinc salt is one of zinc nitrate, chloride, and acetate, or a combination of any two thereof; and the alkaline precipitant is at least one of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, ammonium carbonate, sodium hydroxide, and potassium hydroxide.

4. The preparation method according to claim 1, wherein The molybdenum salt is at least one of sodium molybdate and ammonium molybdate.

5. The preparation method according to claim 1, wherein In step S3, the copper salt is any one of copper nitrate, chloride, and acetate, or a combination of two thereof; the molar amount of the ammonia water is 4 to 5 times the molar amount of copper; and the organosilicon source is at least one of methyl orthosilicate and ethyl orthosilicate.

6. The preparation method according to claim 1, wherein The loading volume ratio of catalyst M to catalyst N is 2~4:6~8.

7. A thioxalate-resistant hydrogenation catalyst prepared by the preparation method according to any one of claims 1 to 6; the catalyst M and the catalyst N are sequentially loaded from top to bottom, so that the coke oven gas and hydrogen first pass through the catalyst N and then through the catalyst M; the catalyst M comprises a zinc-aluminum mixed carrier and molybdenum oxide supported on the zinc-aluminum mixed carrier; the catalyst N is a Cu / SiO2 catalyst.

8. The thiooxalate-resistant hydrogenation catalyst according to claim 1, wherein The zinc-aluminum mixed carrier is also loaded with oxides of Fe, Ni, and Co, and the oxides of Fe, Ni, and Co and molybdenum oxide are loaded on the zinc-aluminum mixed carrier in a mixed state; the Cu / SiO2 catalyst is also loaded with oxides of Zn and Al, and the oxides of Zn, Al and Cu / SiO2 are calcined in a mixed state.

9. A method for synthesizing ethylene glycol by hydrogenating coke oven gas, characterized in that: The method comprises the following steps: when synthesizing ethylene glycol by hydrogenating coke oven gas, catalytically reacting the coke oven gas with hydrogen in the presence of the thioxalate-resistant hydrogenation catalyst according to claim 8 or 9 to obtain ethylene glycol, wherein the thioxalate-resistant hydrogenation catalyst comprises a catalyst M and a catalyst N sequentially loaded from top to bottom, so that the coke oven gas and hydrogen first pass through the catalyst N and then pass through the catalyst M.

10. The method according to claim 9, wherein: The conditions for the catalytic hydrogenation include: a reaction temperature of 190-240° C., a reaction pressure of 2.0-3.0 MPa, a mass space velocity of dimethyl oxalate of 0.5-1 g / h, and a hydrogen-to-ester ratio of 40-80.

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