Preparation method of hydrogenation catalyst and catalyst

Abstract

The invention discloses a preparation method of a hydrogenation catalyst and the catalyst. The method comprises the following steps: adding a copper oxide precursor, a metal oxide auxiliary agent precursor and a carrier precursor into a solvent, and mixing to obtain a mixed solution; dropwise adding an alkaline solution into the mixed solution to neutralize and precipitate; aging, filtering and washing after the precipitation is completed to obtain a precipitation mixture; drying the precipitate mixture; placing the dried precipitate mixture in an oxidizing atmosphere environment, and roasting at 300-450 DEG C to obtain a roasted product; and mixing the roasted product with graphite, tabletting and forming to obtain a matrix catalyst, and crushing and screening the matrix catalyst to obtain the catalyst. The catalyst prepared by the method has the advantages of high conversion rate, good selectivity, high conversion rate and selectivity after long-time use, and good catalytic stability.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a preparation method of a hydrogenation catalyst and a catalyst. Background Art

[0002] Ethanol is an important chemical raw material and clean energy, widely used in solvents, disinfectants, food, fuel and other industries, and can also be used to make beverages, dyes, flavors and ethanol gasoline. Due to its non-polluting fuel characteristics, ethanol can be added to gasoline in a certain proportion to increase the octane number of gasoline, make ethanol gasoline burn more fully, reduce the emission of polluting gases such as CO and hydrocarbons, reduce air pollution, and reduce the use of gasoline, reducing the degree of dependence on petroleum resources, which is in line with my country's national conditions of more coal, less oil and poor gas. Therefore, my country's demand for ethanol has also increased.

[0003] The main methods for producing ethanol in industry include biological fermentation, ethylene hydration, synthesis gas method, etc. Biological fermentation is the most commonly used method for preparing ethanol at present. This method mainly uses corn, sugarcane and other food crops as raw materials to obtain ethanol through fermentation, but the price of food is high, and there may be a situation of competing with people for food, which is not conducive to the global food supply. In addition to the fermentation method, the preparation of ethanol by ethylene hydration requires a large amount of petroleum resources, and the price of petroleum is expensive, and the cost of producing ethanol is high, and the economic efficiency is not optimistic. In addition, this method has high requirements for equipment materials and high investment costs due to the strong corrosiveness of the concentrated sulfuric acid used, and there is no obvious competitiveness in my country's economic environment. Synthesis gas directly synthesizes ethanol. Although this method requires fewer process steps, the conversion rate of synthesis gas and the selectivity of ethanol are low. Therefore, this method needs to explore better catalysts to achieve large-scale production for preparing ethanol. For example, in the reaction of preparing ethanol by hydrogenation of dimethyl oxalate, the role of the catalyst is crucial. The catalyst prepared in the prior art is used in the process of preparing ethanol by hydrogenation of dimethyl oxalate, and there are problems such as low raw material conversion rate and ethanol selectivity, which leads to the method of preparing ethanol by hydrogenation of dimethyl oxalate being restricted. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a method for preparing a hydrogenation catalyst and a catalyst, so as to solve the problem of low raw material conversion rate and selectivity in the process of preparing ethanol by hydrogenation of dimethyl oxalate.

[0005] In a first aspect, an embodiment of the present invention provides a method for preparing a dimethyl oxalate hydrogenation catalyst, comprising:

[0006] Adding a copper oxide precursor, a metal oxide auxiliary agent precursor, and a carrier precursor into a solvent and mixing them to obtain a mixed solution;

[0007] Adding alkaline solution dropwise to the mixed solution to neutralize the precipitate;

[0008] After precipitation is completed, aging, filtering and washing are performed to obtain a precipitation mixture;

[0009] drying the precipitated mixture;

[0010] The dried precipitated mixture is placed in an oxidizing atmosphere and calcined at 300-450° C. to obtain a calcined product;

[0011] The calcined product is mixed with graphite and then pressed into tablets to obtain a matrix catalyst;

[0012] The base catalyst is crushed and sieved to obtain the catalyst.

[0013] Optionally, the step of adding an alkaline solution dropwise to the mixed solution to neutralize the precipitation comprises:

[0014] Add alkaline solution dropwise to the mixed solution at 60-85°C to neutralize the precipitate.

[0015] Optionally, the mass ratio of the calcined product to the graphite is 100:(0.5-3); and / or

[0016] The metal ion concentration in the mixed solution is 0.7-2 mol / l.

[0017] Optionally, the copper oxide precursor includes at least one of copper chloride, copper sulfate and copper nitrate; and / or

[0018] The metal oxide auxiliary agent precursor includes at least one of an aluminum oxide precursor, an iron oxide precursor, a zinc oxide precursor, and a nickel oxide precursor, and the metal oxide auxiliary agent precursor includes at least one of an aluminum oxide precursor and an iron oxide precursor; and / or

[0019] The aluminum oxide precursor includes at least one of aluminum chloride, aluminum sulfate, and aluminum nitrate; and / or

[0020] The iron oxide precursor includes at least one of ferric chloride, ferric sulfate and ferric nitrate; and / or

[0021] The zinc oxide precursor includes at least one of zinc chloride, zinc sulfate and zinc nitrate; and / or

[0022] The nickel oxide precursor includes at least one of nickel chloride, nickel sulfate and nickel nitrate; and / or

[0023] The carrier precursor includes at least one of zirconium chloride, zirconium sulfate and zirconium nitrate; and / or

[0024] The alkaline solution is selected from at least one of an alkali metal carbonate solution, an alkali metal bicarbonate solution and an alkali metal hydroxide solution.

[0025] Optionally, the step of mixing the calcined product with graphite and then pressing the mixture into tablets comprises:

[0026] The calcined product is ground and mixed with graphite and a support material, and then pressed into tablets to obtain a matrix catalyst; the mass of the graphite is 1.2-3.5% of the mass of the calcined product, and the mass ratio of the support material to the calcined product is (0.4-0.8):1;

[0027] The preparation method of the loading material comprises:

[0028] Grind and mix aluminum oxide, titanium dioxide, carbon powder, boron, copper nitrate, and zinc nitrate to obtain a mixture;

[0029] The mixture was calcined at 420-560°C in vacuum for 1-2.5h;

[0030] The mixture is then placed in the first atmosphere and calcined at 680-850° C. for 0.5-1 h;

[0031] The mixture is then placed in a second atmosphere and calcined at 880-1020° C. for 0.5-1 h;

[0032] The mixture is then placed in a third atmosphere and calcined at 620-700° C. for 0.2-0.6 h;

[0033] grinding the calcined mixture to obtain a supported matrix;

[0034] placing the loaded substrate in an impregnation solution for impregnation;

[0035] The impregnated support substrate is placed in a vacuum and calcined at 400-550°C for 1-3h;

[0036] Then, the mixture is placed in an oxidizing atmosphere and calcined at 550-650°C for 2-4 hours to obtain a supported material;

[0037] The mass ratio of aluminum oxide to titanium dioxide is (2-4): 1, the mass of carbon powder is 0.8-2.5% of the mass of aluminum oxide, the mass of boron is 0.5-1.2% of the mass of aluminum oxide, the mass of copper nitrate is 1.8-4% of the mass of aluminum oxide, and the mass of zinc nitrate is 1.2-3% of the mass of aluminum oxide;

[0038] The first atmosphere includes nitrogen and methane, the second atmosphere includes nitrogen and silane; the third atmosphere includes nitrogen and oxygen; the volume content of methane in the first atmosphere is 6-15%, the volume content of silane in the second atmosphere is 4-10%; the volume content of oxygen in the third atmosphere is 5-12%;

[0039] The impregnation solution comprises an aqueous solution of copper nitrate, iron nitrate, barium nitrate and zirconium nitrate. The concentration of copper nitrate in the impregnation solution is 0.3-2 mol / l, the concentration of iron nitrate is 0.5-2 mol / l, the concentration of barium nitrate is 0.2-0.6 mol / l and the concentration of zirconium nitrate is 0.5-2 mol / l.

[0040] In a second aspect, an embodiment of the present invention provides a dimethyl oxalate hydrogenation catalyst, comprising:

[0041] A carrier, wherein an active component is loaded on the carrier, the carrier includes at least one of aluminum oxide, silicon dioxide and zirconium oxide, the active component includes a main active component and a metal oxide additive, the main active component includes copper oxide, and the metal oxide additive includes at least one of zinc oxide, aluminum oxide, iron oxide and nickel oxide.

[0042] Optionally, the main active component accounts for 30-60% by mass of the catalyst, and the metal oxide additive accounts for 20-40% by mass of the catalyst.

[0043] Optionally, the main active component is copper oxide, the metal oxide additives include zinc oxide, aluminum oxide and iron oxide, and the carrier is zirconium oxide.

[0044] Optionally, the zinc oxide and aluminum oxide account for 20-30% by mass of the catalyst, the iron oxide accounts for 20-40% by mass of the catalyst, and the zirconium oxide accounts for 20-40% by mass of the catalyst.

[0045] In a third aspect, an embodiment of the present invention provides a method for preparing ethanol by hydrogenating dimethyl oxalate, comprising:

[0046] Placing a catalyst in a reactor; the catalyst is a catalyst prepared by the method described in the above embodiment or a catalyst described in the above embodiment;

[0047] Reduction with hydrogen at 260-290°C for 1-2.5h;

[0048] Add dimethyl oxalate and hydrogen into the reactor for reaction at a temperature of 200-280°C and a liquid hourly space velocity of 0.2-0.7h -1 , hydrogen ester molar ratio is 100-200.

[0049] The catalyst prepared by the method of the present invention has high conversion rate and good selectivity, and still has high conversion rate and selectivity after long-term use, which shows that the catalyst has good catalytic stability and can be used efficiently for a long time in the production process. DETAILED DESCRIPTION

[0050] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present invention can be implemented in an order other than those described herein. In addition, the term "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0052] The preparation method of the dimethyl oxalate hydrogenation catalyst according to the embodiment of the present invention comprises:

[0053] Adding a copper oxide precursor, a metal oxide auxiliary agent precursor, and a carrier precursor into a solvent and mixing them to obtain a mixed solution;

[0054] Adding alkaline solution dropwise to the mixed solution to neutralize the precipitate;

[0055] After precipitation is completed, aging, filtering and washing are performed to obtain a precipitation mixture;

[0056] drying the precipitated mixture;

[0057] The dried precipitate mixture is placed in an oxidizing atmosphere and calcined at 300-450° C. to obtain a calcined product; the oxidizing atmosphere may be a mixture of oxygen and nitrogen, wherein the volume of oxygen in the mixture is 5-25%;

[0058] The calcined product is mixed with graphite and then pressed into tablets to obtain a matrix catalyst;

[0059] The base catalyst is crushed and sieved to obtain the catalyst. The catalyst can be crushed and sieved into particles of 20-40 mesh as the catalyst;

[0060] During the preparation process, an alkaline solution is added dropwise to the mixed solution to neutralize the precipitate. The temperature of the precipitation process can be 65°C, the stirring speed can be 120r / min, the precipitant dropping speed can be 5ml / min, and the mixture is stirred for 5min after the addition is completed. Then, the stirring is turned off and the mixture is aged at a constant temperature for 4h. After the aging is completed, the supernatant is poured out and the precipitate is washed 3-5 times, then filtered and washed to obtain a precipitate mixture. The precipitate mixture can be placed in a vacuum environment and dried at 65°C for 3h.

[0061] In some embodiments, the step of adding an alkaline solution to the mixed solution to neutralize the precipitate may include:

[0062] Add alkaline solution dropwise to the mixed solution at 60-85°C to neutralize the precipitate.

[0063] Optionally, the mass ratio of the calcined product to the graphite may be 100:(0.5-3).

[0064] Optionally, the metal ion concentration in the mixed solution is 0.7-2 mol / l

[0065] In some embodiments, the copper oxide precursor includes at least one of copper chloride, copper sulfate, and copper nitrate. For example, the copper oxide precursor may be copper chloride, copper sulfate, or copper nitrate.

[0066] Optionally, the metal oxide auxiliary agent precursor includes at least one of an aluminum oxide precursor, an iron oxide precursor, a zinc oxide precursor, and a nickel oxide precursor, and the metal oxide auxiliary agent precursor includes at least one of an aluminum oxide precursor and an iron oxide precursor.

[0067] Optionally, the aluminum oxide precursor includes at least one of aluminum chloride, aluminum sulfate, and aluminum nitrate. For example, the aluminum oxide precursor may be aluminum chloride, aluminum sulfate, or aluminum nitrate.

[0068] Optionally, the iron oxide precursor includes at least one of iron chloride, iron sulfate, and iron nitrate. For example, the iron oxide precursor may be iron chloride, iron sulfate, or iron nitrate.

[0069] Optionally, the zinc oxide precursor includes at least one of zinc chloride, zinc sulfate, and zinc nitrate. For example, the zinc oxide precursor includes zinc chloride, zinc sulfate, or zinc nitrate.

[0070] Optionally, the nickel oxide precursor includes at least one of nickel chloride, nickel sulfate, and nickel nitrate. For example, the nickel oxide precursor may be nickel chloride, nickel sulfate, or nickel nitrate.

[0071] Optionally, the carrier precursor includes at least one of zirconium chloride, zirconium sulfate, and zirconium nitrate. For example, the carrier precursor may be zirconium chloride, zirconium sulfate, or zirconium nitrate.

[0072] In an embodiment of the present invention, the alkaline solution is selected from at least one of an alkali metal carbonate solution, an alkali metal bicarbonate solution and an alkali metal hydroxide solution. For example, the alkaline solution is selected from an alkali metal carbonate solution, an alkali metal bicarbonate solution or an alkali metal hydroxide solution.

[0073] The steps of mixing the calcined product with graphite and then pressing the tablets into shape include:

[0074] The calcined product is ground and mixed with graphite and a support material, and then pressed into tablets to obtain a matrix catalyst; the mass of the graphite is 1.2-3.5% of the mass of the calcined product, and the mass ratio of the support material to the calcined product is (0.4-0.8):1;

[0075] The preparation method of the loading material comprises:

[0076] Grind and mix aluminum oxide, titanium dioxide, carbon powder, boron, copper nitrate, and zinc nitrate to obtain a mixture;

[0077] The mixture was calcined at 420-560°C in vacuum for 1-2.5h;

[0078] The mixture is then placed in the first atmosphere and calcined at 680-850° C. for 0.5-1 h;

[0079] The mixture is then placed in a second atmosphere and calcined at 880-1020° C. for 0.5-1 h;

[0080] The mixture is then placed in a third atmosphere and calcined at 620-700° C. for 0.2-0.6 h;

[0081] grinding the calcined mixture to obtain a supported matrix;

[0082] placing the loaded substrate in an impregnation solution for impregnation;

[0083] The impregnated support substrate is placed in a vacuum and calcined at 400-550°C for 1-3h;

[0084] Then, the mixture is placed in an oxidizing atmosphere and calcined at 550-650°C for 2-4 hours to obtain a supported material;

[0085] The mass ratio of aluminum oxide to titanium dioxide is (2-4): 1, the mass of carbon powder is 0.8-2.5% of the mass of aluminum oxide, the mass of boron is 0.5-1.2% of the mass of aluminum oxide, the mass of copper nitrate is 1.8-4% of the mass of aluminum oxide, and the mass of zinc nitrate is 1.2-3% of the mass of aluminum oxide;

[0086] The first atmosphere includes nitrogen and methane, the second atmosphere includes nitrogen and silane; the third atmosphere includes nitrogen and oxygen; the volume content of methane in the first atmosphere is 6-15%, the volume content of silane in the second atmosphere is 4-10%; the volume content of oxygen in the third atmosphere is 5-12%;

[0087] The impregnation solution comprises an aqueous solution of copper nitrate, iron nitrate, barium nitrate and zirconium nitrate. The concentration of copper nitrate in the impregnation solution is 0.3-2 mol / l, the concentration of iron nitrate is 0.5-2 mol / l, the concentration of barium nitrate is 0.2-0.6 mol / l and the concentration of zirconium nitrate is 0.5-2 mol / l.

[0088] The dimethyl oxalate hydrogenation catalyst of the embodiment of the present invention comprises:

[0089] A carrier, wherein an active component is loaded on the carrier, the carrier includes at least one of aluminum oxide, silicon dioxide and zirconium oxide, the active component includes a main active component and a metal oxide additive, the main active component includes copper oxide, and the metal oxide additive includes at least one of zinc oxide, aluminum oxide, iron oxide and nickel oxide.

[0090] In some embodiments, the main active component accounts for 30-60% by mass of the catalyst, and the metal oxide additive accounts for 20-40% by mass of the catalyst.

[0091] In other embodiments, the main active component is copper oxide, the metal oxide additives include zinc oxide, aluminum oxide and iron oxide, and the carrier is zirconium oxide.

[0092] In an embodiment of the present invention, the mass percentage of the zinc oxide and the aluminum oxide in the catalyst is 20-30%, the mass percentage of the iron oxide in the catalyst is 20-40%, and the mass percentage of the zirconium oxide in the catalyst is 20-40%.

[0093] The method for preparing ethanol by hydrogenating dimethyl oxalate according to the embodiment of the present invention comprises:

[0094] Placing a catalyst in a reactor; the catalyst is a catalyst prepared by the method described in the above embodiment or a catalyst described in the above embodiment;

[0095] Reduction with hydrogen at 260-290°C for 1-2.5h;

[0096] Add dimethyl oxalate and hydrogen into the reactor for reaction at a temperature of 200-280°C and a liquid hourly space velocity of 0.2-0.7h -1 , hydrogen ester molar ratio is 100-200.

[0097] The present invention will be further described below through some specific embodiments.

[0098] Example 1

[0099] Preparation method of dimethyl oxalate hydrogenation catalyst:

[0100] Adding copper oxide precursor copper nitrate, metal oxide auxiliary agent precursor, and carrier precursor into deionized water to obtain a mixed solution;

[0101] Add sodium hydroxide solution dropwise to the mixed solution at 60°C to neutralize the precipitate;

[0102] After precipitation is completed, aging, filtering and washing are performed to obtain a precipitation mixture;

[0103] The precipitated mixture was dried at 65 °C in vacuum;

[0104] The dried precipitate mixture is placed in an oxidizing atmosphere and calcined at 300° C. to obtain a calcined product; the oxidizing atmosphere is a mixture of oxygen and nitrogen, wherein the volume of oxygen in the mixture is 5%;

[0105] The calcined product is mixed with graphite and then pressed into tablets to obtain a matrix catalyst;

[0106] The base catalyst is crushed and screened to obtain a catalyst; the crushed and screened particles with a size of 20-40 mesh are used as a catalyst;

[0107] The mass ratio of the calcined product to graphite is 100:0.5;

[0108] The metal oxide additive precursor includes aluminum nitrate, an aluminum oxide precursor, iron nitrate, an iron oxide precursor, zinc nitrate, a zinc oxide precursor, nickel sulfate, and the carrier precursor is zirconium nitrate.

[0109] The metal ion concentration in the mixed solution is 0.7 mol / l, the copper ion concentration in the mixed solution is 0.1 mol / l, the aluminum ion concentration in the mixed solution is 0.2 mol / l, the iron ion concentration in the mixed solution is 0.1 mol / l, the zinc ion concentration in the mixed solution is 0.1 mol / l, the nickel ion concentration in the mixed solution is 0.1 mol / l, and the zirconium ion concentration in the mixed solution is 0.1 mol / l.

[0110] Example 2

[0111] Preparation method of dimethyl oxalate hydrogenation catalyst:

[0112] Adding copper oxide precursor copper nitrate, metal oxide auxiliary agent precursor, and carrier precursor into deionized water to obtain a mixed solution;

[0113] Add sodium hydroxide solution dropwise to the mixed solution at 85°C to neutralize the precipitate;

[0114] After precipitation is completed, aging, filtering and washing are performed to obtain a precipitation mixture;

[0115] The precipitation mixture was dried at 75 °C in vacuum;

[0116] The dried precipitate mixture is placed in an oxidizing atmosphere and calcined at 450° C. to obtain a calcined product; the oxidizing atmosphere is a mixture of oxygen and nitrogen, wherein the volume of oxygen in the mixture is 18%;

[0117] The calcined product is mixed with graphite and then pressed into tablets to obtain a matrix catalyst;

[0118] The base catalyst is crushed and screened to obtain a catalyst; the crushed and screened particles with a size of 20-40 mesh are used as a catalyst;

[0119] The mass ratio of the calcined product to graphite is 100:3;

[0120] The metal oxide additive precursor includes aluminum nitrate, an aluminum oxide precursor, iron nitrate, an iron oxide precursor, zinc nitrate, a zinc oxide precursor, nickel sulfate, and the carrier precursor is zirconium nitrate.

[0121] The metal ion concentration in the mixed solution is 2 mol / l, the copper ion concentration in the mixed solution is 0.5 mol / l, the aluminum ion concentration in the mixed solution is 0.6 mol / l, the iron ion concentration in the mixed solution is 0.3 mol / l, the zinc ion concentration in the mixed solution is 0.3 mol / l, the nickel ion concentration in the mixed solution is 0.2 mol / l, and the zirconium ion concentration in the mixed solution is 0.1 mol / l.

[0122] Example 3

[0123] Preparation method of dimethyl oxalate hydrogenation catalyst:

[0124] Adding copper oxide precursor copper nitrate, metal oxide auxiliary agent precursor, and carrier precursor into deionized water to obtain a mixed solution;

[0125] Add sodium hydroxide solution dropwise to the mixed solution at 75°C to neutralize the precipitate;

[0126] After precipitation is completed, aging, filtering and washing are performed to obtain a precipitation mixture;

[0127] The precipitation mixture was dried at 80 °C in vacuum;

[0128] The dried precipitate mixture is placed in an oxidizing atmosphere and calcined at 380° C. to obtain a calcined product; the oxidizing atmosphere is a mixture of oxygen and nitrogen, wherein the volume of oxygen in the mixture is 12%;

[0129] The calcined product is mixed with graphite and then pressed into tablets to obtain a matrix catalyst;

[0130] The base catalyst is crushed and screened to obtain a catalyst; the crushed and screened particles with a size of 20-40 mesh are used as a catalyst;

[0131] The mass ratio of the calcined product to graphite is 100:1.5;

[0132] The metal oxide additive precursor includes aluminum nitrate, an aluminum oxide precursor, iron nitrate, an iron oxide precursor, zinc nitrate, a zinc oxide precursor, nickel sulfate, and the carrier precursor is zirconium nitrate.

[0133] The metal ion concentration in the mixed solution is 1.6 mol / l, the copper ion concentration in the mixed solution is 0.4 mol / l, the aluminum ion concentration in the mixed solution is 0.5 mol / l, the iron ion concentration in the mixed solution is 0.2 mol / l, the zinc ion concentration in the mixed solution is 0.2 mol / l, the nickel ion concentration in the mixed solution is 0.2 mol / l, and the zirconium ion concentration in the mixed solution is 0.1 mol / l.

[0134] Example 4

[0135] The difference between Example 4 and Example 3 is:

[0136] The steps of mixing the calcined product with graphite and then pressing the tablets into shape include:

[0137] The calcined product, graphite and a supporting material are ground and mixed, and then pressed into tablets to obtain a matrix catalyst; the mass of the graphite is 1.2% of the mass of the calcined product, and the mass ratio of the supporting material to the calcined product is 0.4:1;

[0138] The preparation method of the loading material comprises:

[0139] Grind and mix aluminum oxide, titanium dioxide, carbon powder, boron, copper nitrate, and zinc nitrate to obtain a mixture;

[0140] The mixture was calcined at 420 °C for 2.5 h in vacuum;

[0141] The mixture was then placed in the first atmosphere and calcined at 850° C. for 0.5 h;

[0142] The mixture was then placed in a second atmosphere and calcined at 1020°C for 0.5 h;

[0143] The mixture was then placed in a third atmosphere and calcined at 620°C for 0.6h;

[0144] grinding the calcined mixture to obtain a supported matrix;

[0145] placing the loaded substrate in an impregnation solution for impregnation;

[0146] The impregnated support substrate was calcined at 400 °C for 3 h in vacuum;

[0147] Then, the mixture was placed in an oxidizing atmosphere and calcined at 650°C for 2 h to obtain a supported material;

[0148] The mass ratio of aluminum oxide to titanium dioxide is 2:1, the mass of carbon powder is 0.8% of the mass of aluminum oxide, the mass of boron is 0.5% of the mass of aluminum oxide, the mass of copper nitrate is 4% of the mass of aluminum oxide, and the mass of zinc nitrate is 1.2% of the mass of aluminum oxide;

[0149] The first atmosphere includes nitrogen and methane, the second atmosphere includes nitrogen and silane; the third atmosphere includes nitrogen and oxygen; the volume content of methane in the first atmosphere is 6%, the volume content of silane in the second atmosphere is 4%; the volume content of oxygen in the third atmosphere is 5%;

[0150] The impregnation solution includes an aqueous solution of copper nitrate, iron nitrate, barium nitrate and zirconium nitrate. The concentration of copper nitrate in the impregnation solution is 0.3 mol / l, the concentration of iron nitrate is 0.5 mol / l, the concentration of barium nitrate is 0.6 mol / l, and the concentration of zirconium nitrate is 2 mol / l.

[0151] Example 5

[0152] The difference between Example 5 and Example 3 is:

[0153] The steps of mixing the calcined product with graphite and then pressing the tablets into shape include:

[0154] The calcined product, graphite and a supporting material are ground and mixed, and then pressed into tablets to obtain a matrix catalyst; the mass of the graphite is 3.5% of the mass of the calcined product, and the mass ratio of the supporting material to the calcined product is 0.8:1;

[0155] The preparation method of the loading material comprises:

[0156] Grind and mix aluminum oxide, titanium dioxide, carbon powder, boron, copper nitrate, and zinc nitrate to obtain a mixture;

[0157] The mixture was calcined at 560 °C for 1 h in vacuum;

[0158] The mixture was then placed in the first atmosphere and calcined at 680°C for 1 h;

[0159] The mixture was then calcined at 880°C for 1 h in a second atmosphere;

[0160] The mixture was then placed in a third atmosphere and calcined at 700°C for 0.2h;

[0161] grinding the calcined mixture to obtain a supported matrix;

[0162] placing the loaded substrate in an impregnation solution for impregnation;

[0163] The impregnated support substrate was calcined at 550 °C for 1 h in vacuum;

[0164] Then, the mixture was placed in an oxidizing atmosphere and calcined at 550°C for 4 hours to obtain a supported material;

[0165] The mass ratio of aluminum oxide to titanium dioxide is 4:1, the mass of carbon powder is 2.5% of the mass of aluminum oxide, the mass of boron is 1.2% of the mass of aluminum oxide, the mass of copper nitrate is 1.8% of the mass of aluminum oxide, and the mass of zinc nitrate is 3% of the mass of aluminum oxide;

[0166] The first atmosphere includes nitrogen and methane, the second atmosphere includes nitrogen and silane; the third atmosphere includes nitrogen and oxygen; the volume content of methane in the first atmosphere is 15%, the volume content of silane in the second atmosphere is 10%; the volume content of oxygen in the third atmosphere is 12%;

[0167] The impregnation solution includes an aqueous solution of copper nitrate, iron nitrate, barium nitrate and zirconium nitrate. The concentration of copper nitrate in the impregnation solution is 2 mol / l, the concentration of iron nitrate is 2 mol / l, the concentration of barium nitrate is 0.2 mol / l, and the concentration of zirconium nitrate is 0.5 mol / l.

[0168] Example 6

[0169] The difference between Example 6 and Example 3 is:

[0170] The steps of mixing the calcined product with graphite and then pressing the tablets into shape include:

[0171] The calcined product, graphite and a support material are ground and mixed, and then pressed into tablets to obtain a matrix catalyst; the mass of the graphite is 2% of the mass of the calcined product, and the mass ratio of the support material to the calcined product is 0.6:1;

[0172] The preparation method of the loading material comprises:

[0173] Grind and mix aluminum oxide, titanium dioxide, carbon powder, boron, copper nitrate, and zinc nitrate to obtain a mixture;

[0174] The mixture was calcined at 480 °C for 1.5 h in vacuum;

[0175] The mixture was then placed in the first atmosphere and calcined at 750°C for 0.5h;

[0176] The mixture was then calcined at 930°C for 1 h in a second atmosphere;

[0177] The mixture was then placed in a third atmosphere and calcined at 660°C for 0.4h;

[0178] grinding the calcined mixture to obtain a supported matrix;

[0179] placing the loaded substrate in an impregnation solution for impregnation;

[0180] The impregnated support substrate was calcined at 460 °C for 2 h in vacuum;

[0181] Then, the mixture was placed in an oxidizing atmosphere and calcined at 600°C for 3 h to obtain a supported material;

[0182] The mass ratio of aluminum oxide to titanium dioxide is 3:1, the mass of carbon powder is 1.5% of the mass of aluminum oxide, the mass of boron is 0.8% of the mass of aluminum oxide, the mass of copper nitrate is 3% of the mass of aluminum oxide, and the mass of zinc nitrate is 2.2% of the mass of aluminum oxide;

[0183] The first atmosphere includes nitrogen and methane, the second atmosphere includes nitrogen and silane; the third atmosphere includes nitrogen and oxygen; the volume content of methane in the first atmosphere is 10%, the volume content of silane in the second atmosphere is 8%; the volume content of oxygen in the third atmosphere is 7%;

[0184] The impregnation solution includes an aqueous solution of copper nitrate, iron nitrate, barium nitrate and zirconium nitrate. The concentration of copper nitrate in the impregnation solution is 1.5 mol / l, the concentration of iron nitrate is 1.5 mol / l, the concentration of barium nitrate is 0.4 mol / l, and the concentration of zirconium nitrate is 1.4 mol / l.

[0185] The performance of the catalyst prepared in the above examples was tested.

[0186] The method for preparing ethanol by hydrogenating dimethyl oxalate comprises:

[0187] Placing a catalyst in a reactor; the catalyst is the catalyst prepared in the example;

[0188] Reduction with hydrogen at 270°C for 2.5h;

[0189] Dimethyl oxalate and hydrogen were added to the reactor for reaction at a temperature of 260°C and a liquid hourly space velocity of 0.7 h -1 , hydrogen ester molar ratio is 160.

[0190] The properties of the catalysts in the above examples are shown in Table 1.

[0191] Table 1 Performance of the catalyst in the above examples

[0192]

[0193] As can be seen from Table 1, the conversion rate of dimethyl oxalate can reach more than 99%, and the selectivity of ethanol can reach more than 97%. The catalyst prepared in the above embodiment has a high conversion rate and good selectivity, and still has a high conversion rate and selectivity after long-term use, indicating that the catalyst has good catalytic stability and can be used efficiently for a long time in the production process.

[0194] The above is described in conjunction with the embodiments of the present invention, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for preparing a dimethyl oxalate hydrogenation catalyst, characterized in that: include: Adding a copper oxide precursor, a metal oxide auxiliary agent precursor, and a carrier precursor into a solvent and mixing them to obtain a mixed solution; Adding alkaline solution dropwise to the mixed solution to neutralize the precipitate; After precipitation is completed, aging, filtering and washing are performed to obtain a precipitation mixture; drying the precipitated mixture; The dried precipitated mixture is placed in an oxidizing atmosphere and calcined at 300-450° C. to obtain a calcined product; The calcined product is mixed with graphite and then pressed into tablets to obtain a matrix catalyst; The base catalyst is crushed and sieved to obtain the catalyst.

2. The preparation method according to claim 1, characterized in that: The step of adding an alkaline solution dropwise to the mixed solution to neutralize the precipitation comprises: Add alkaline solution dropwise to the mixed solution at 60-85°C to neutralize the precipitate.

3. The preparation method according to claim 1, characterized in that: The mass ratio of the calcined product to the graphite is 100:(0.5-3); and / or The metal ion concentration in the mixed solution is 0.7-2 mol / l.

4. The preparation method according to claim 1, characterized in that: The copper oxide precursor includes at least one of copper chloride, copper sulfate and copper nitrate; and / or The metal oxide auxiliary agent precursor includes at least one of an aluminum oxide precursor, an iron oxide precursor, a zinc oxide precursor, and a nickel oxide precursor, and the metal oxide auxiliary agent precursor includes at least one of an aluminum oxide precursor and an iron oxide precursor; and / or The aluminum oxide precursor includes at least one of aluminum chloride, aluminum sulfate, and aluminum nitrate; and / or The iron oxide precursor includes at least one of ferric chloride, ferric sulfate and ferric nitrate; and / or The zinc oxide precursor includes at least one of zinc chloride, zinc sulfate and zinc nitrate; and / or The nickel oxide precursor includes at least one of nickel chloride, nickel sulfate and nickel nitrate; and / or The carrier precursor includes at least one of zirconium chloride, zirconium sulfate and zirconium nitrate; and / or The alkaline solution is selected from at least one of an alkali metal carbonate solution, an alkali metal bicarbonate solution and an alkali metal hydroxide solution.

5. The preparation method according to claim 1, characterized in that: The steps of mixing the calcined product with graphite and then pressing the tablets into shape include: The calcined product is ground and mixed with graphite and a support material, and then pressed into tablets to obtain a matrix catalyst; the mass of the graphite is 1.2-3.5% of the mass of the calcined product, and the mass ratio of the support material to the calcined product is (0.4-0.8):1; The preparation method of the loading material comprises: Grind and mix aluminum oxide, titanium dioxide, carbon powder, boron, copper nitrate, and zinc nitrate to obtain a mixture; The mixture was calcined at 420-560°C in vacuum for 1-2.5h; The mixture is then placed in the first atmosphere and calcined at 680-850° C. for 0.5-1 h; The mixture is then placed in a second atmosphere and calcined at 880-1020° C. for 0.5-1 h; The mixture is then placed in a third atmosphere and calcined at 620-700° C. for 0.2-0.6 h; grinding the calcined mixture to obtain a supported matrix; placing the loaded substrate in an impregnation solution for impregnation; The impregnated support substrate is placed in a vacuum and calcined at 400-550°C for 1-3h; Then, the mixture is placed in an oxidizing atmosphere and calcined at 550-650°C for 2-4 hours to obtain a supported material; The mass ratio of aluminum oxide to titanium dioxide is (2-4): 1, the mass of carbon powder is 0.8-2.5% of the mass of aluminum oxide, the mass of boron is 0.5-1.2% of the mass of aluminum oxide, the mass of copper nitrate is 1.8-4% of the mass of aluminum oxide, and the mass of zinc nitrate is 1.2-3% of the mass of aluminum oxide; The first atmosphere includes nitrogen and methane, the second atmosphere includes nitrogen and silane; the third atmosphere includes nitrogen and oxygen; the volume content of methane in the first atmosphere is 6-15%, the volume content of silane in the second atmosphere is 4-10%; the volume content of oxygen in the third atmosphere is 5-12%; The impregnation solution comprises an aqueous solution of copper nitrate, iron nitrate, barium nitrate and zirconium nitrate. The concentration of copper nitrate in the impregnation solution is 0.3-2 mol / l, the concentration of iron nitrate is 0.5-2 mol / l, the concentration of barium nitrate is 0.2-0.6 mol / l and the concentration of zirconium nitrate is 0.5-2 mol / l.

6. A dimethyl oxalate hydrogenation catalyst, characterized in that: include: A carrier, wherein an active component is loaded on the carrier, the carrier includes at least one of aluminum oxide, silicon dioxide and zirconium oxide, the active component includes a main active component and a metal oxide additive, the main active component includes copper oxide, and the metal oxide additive includes at least one of zinc oxide, aluminum oxide, iron oxide and nickel oxide.

7. The dimethyl oxalate hydrogenation catalyst according to claim 6, characterized in that The mass percentage of the main active component in the catalyst is 30-60%, and the mass percentage of the metal oxide additive in the catalyst is 20-40%.

8. The dimethyl oxalate hydrogenation catalyst according to claim 6, characterized in that The main active component is copper oxide, the metal oxide additives include zinc oxide, aluminum oxide and iron oxide, and the carrier is zirconium oxide.

9. The dimethyl oxalate hydrogenation catalyst according to claim 8, characterized in that The mass percentage of the zinc oxide and the aluminum oxide in the catalyst is 20-30%, the mass percentage of the iron oxide in the catalyst is 20-40%, and the mass percentage of the zirconium oxide in the catalyst is 20-40%.

10. A method for preparing ethanol by hydrogenating dimethyl oxalate, characterized in that: include: Placing a catalyst in a reactor; the catalyst is a catalyst prepared by the method according to any one of claims 1 to 5 or a catalyst according to any one of claims 6 to 9; Reduction with hydrogen at 260-290°C for 1-2.5h; Add dimethyl oxalate and hydrogen into the reactor for reaction at a temperature of 200-280°C and a liquid hourly space velocity of 0.2-0.7h -1 , hydrogen ester molar ratio is 100-200.

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