CN105435799A - Catalyst for ethanol preparation by ethyl acetate hydrogenation and preparation method for catalyst - Google Patents

Abstract

The catalyst for producing ethanol by hydrogenation of ethyl acetate according to the present invention has the sum of the mass percentages of its components being 100%, wherein: copper oxide is 40wt% to 70wt%; auxiliary agent is 10wt% to 50wt%; the balance is oxidation aluminum. The preparation method of the catalyst comprises the following preparation steps: (1) configuring a metal salt solution; (2) configuring a precipitating agent solution; (3) mixing the metal salt solution and the precipitating agent solution, and obtaining a slurry through water bath, precipitation, ultrasonic treatment, and static aging; (4) The dry material is obtained by filtering, washing and drying; (5) the catalyst is obtained by roasting, tableting, pulverizing and sieving to 40-60 mesh. The catalyst of the present invention has the effect of promoting the dispersion of active components, reducing the particle size of the active components, and improving the performance of the catalytic reaction. Compared with the existing catalyst, it has higher raw material conversion rate and better ethanol selectivity, which is beneficial to The technology of esterification and hydrogenation to produce ethanol is more perfect and improves the efficiency.

Description

Catalyst for producing ethanol by hydrogenation of ethyl acetate and preparation method thereof

technical field

The invention relates to the technical field of catalyst preparation, and relates to a catalyst for preparing ethanol, in particular to a catalyst for preparing ethanol by hydrogenating ethyl acetate, a preparation method and application thereof.

Background technique

Ethanol, commonly known as alcohol, is an important chemical raw material widely used in the production and manufacture of paints, coatings, inks, pharmaceuticals and food. In addition, ethanol is a kind of oil additive and fuel with great application potential. Its latent heat of vaporization in oxygen content is better than anti-violence performance. The pollutants in it are significantly reduced, and it has been recognized and promoted worldwide.

The traditional synthesis methods of ethanol mainly include ethylene hydration and fermentation. At present, the application of ethylene hydration is limited to some extent due to the large consumption of ethylene, an important chemical raw material. The fermentation method refers to a method of converting disaccharides and polysaccharides into ethanol by using various sugar-containing agricultural products and by-products of agriculture and forestry as raw materials through hydrolysis and fermentation.

At present, there are four main industrial processes for producing ethanol from coal: (1) chemical catalysis of syngas; (2) anaerobic fermentation of syngas; (3) hydrogenation of syngas by acetic acid; (4) hydrogenation of syngas by acetic esterification. The first two process routes belong to the direct method, and the latter two process routes belong to the indirect method. From the perspective of the reaction principle, the direct method has the shortest reaction path, but due to its low conversion rate of carbon monoxide, the selectivity of ethanol is low, and the utilization rate of raw materials is low. Although the indirect method has a long reaction path, the conversion rate of its raw materials and the selectivity of ethanol can reach a higher level, and the requirements for the reaction device and process conditions are relatively low, and the cost is relatively low. There are more methods to use and continue to study, and the research and development of catalysts is a major content. The copper-based catalysts currently used in the production of ethanol are prone to sintering and aggregation under high temperature conditions, resulting in instability or deactivation of the catalyst. Therefore, the development of catalysts with high temperature sintering resistance and high activity has important practical significance for the technology of hydrogenation of acetate to produce ethanol.

Contents of the invention

The purpose of the present invention is to solve the above problems and provide a catalyst for producing ethanol by hydrogenation of ethyl acetate, which uses copper oxide (CuO) as the active component, zinc oxide (ZnO), cobalt oxide (CoO), Nickel oxide (NiO) and/or manganese oxide (MnO ₂ ) are used as additives, and alumina (Al ₂ O ₃ ) is used as a carrier; it can promote the dispersion of active components, reduce the particle size of active components and improve catalytic performance. Effect. The second object of the present invention is to provide the preparation method of the catalyst, which helps to improve the dispersion of the active component copper, reduce the particle size of copper, and improve the stability of the catalyst by controlling the formation of the specific precursor structure of the catalyst sex and activity. The catalyst prepared by the invention is beneficial to the perfection of the technology of producing ethanol by the hydrogenation of acetate and the improvement of benefit.

In order to achieve the above object, the present invention adopts the following technical solutions.

A catalyst for producing ethanol by hydrogenation of ethyl acetate, characterized in that the sum of the mass percentages of its components is 100%, wherein:

Copper oxide (CuO) 40wt% ~ 70wt%;

Auxiliary 10wt% ~ 50wt%;

The balance is alumina (Al ₂ O ₃ ).

Optionally, the additive is one or more of zinc oxide (ZnO), cobalt oxide (CoO), nickel oxide (NiO) and/or manganese oxide (MnO ₂ ).

In order to achieve the above-mentioned second purpose, the present invention adopts the following technical solutions.

The preparation method of the catalyst for preparing ethanol by hydrogenation of ethyl acetate is characterized in that it comprises the following preparation steps:

(1) Weigh a certain amount of metal salt and dissolve it in deionized water, heat and stir to obtain solution A;

(2) Weigh a certain amount of precipitant and dissolve it in deionized water, heat and stir to obtain solution B;

(3) Place solution A of step (1) and solution B of step (2) in two pear-shaped separating funnels, first add solution A to the three-necked flask, and then add the solution to the three-necked flask B; or add solution B to the three-necked flask first, and then add solution A to the three-necked flask; or add solution A and solution B to the three-necked flask at the same time, and carry out a water bath at a temperature of 40 to 80°C. The solution flow rate keeps the pH value of the solution at 6-10, stirring and mixing for 1 hour; precipitation; then ultrasonic treatment for 0.5-2 hours, and finally standing and aging for 8-16 hours to obtain a slurry;

(4) Filter the slurry obtained in step (3), and then rinse it with deionized water until the filtrate does not contain Na ⁺ ions; collect the filter cake and put it in an oven, and dry it overnight at 110°C to obtain a dry material;

(5) Put the dry material obtained in step (4) in a muffle furnace, roast it at 200-600°C for 2-8 hours, press it and pulverize it, and then sieve it to 40-60 mesh to obtain the target product—— Catalyst for hydrogenation of ethyl acetate to ethanol.

Optionally, the metal salt in step (1) is a nitrate, and the nitrate is Cu(NO ₃ ) ₂ ·3H _-2 O; Zn(NO ₃ ) ₂ ·6H ₂ O; Al(NO ₃ ) One or more of ₃ ·9H ₂ O; Mg(NO ₃ ) ₂ ·6H2O; Ni(NO ₃ ) ₂ ·6H2O; Co(NO ₃ ) ₂ ·6H2O.

Further, in the step (1), the nitrate is weighed according to the molar ratio of copper oxide to the sum of all auxiliary agents being 0.5-2:5.

Optionally, the precipitating agent described in step (2) is one or a mixture of sodium carbonate (Na ₂ CO ₃ ), sodium hydroxide (NaOH), ammonia water (NH ₃ ·H ₂ O).

Further, in the step (2), according to the mole of sodium carbonate (Na ₂ CO ₃ ), or sodium hydroxide (NaOH), or ammonia water (NH ₃ ·H ₂ O), or their mixture in solution B The concentration is 1mol/L for preparation.

Further, the filtration described in step (4) adopts suction filtration.

The application of the catalyst in the hydrogenation of ethyl acetate to produce ethanol is characterized in that the catalyst is subjected to reduction treatment before use, the reduction temperature is 200-400° C., the pressure is 0.1-2 MPa, and the reduction time is 1-6 hours.

The application of the catalyst in the hydrogenation of ethyl acetate to produce ethanol is characterized in that a tubular fixed-bed reactor is used for the reaction, the reaction temperature is 200-300°C, the reaction pressure is 0.1-4MPa, and the ethyl acetate liquid is empty The rate is 0.5~2h ^-1 , H ₂ /ethyl acetate=2~50mol.

The positive effect of the present invention is:

(1) The catalyst of the present invention uses copper oxide as the active component and ZnO, CoO, NiO and/or _MnO as additives, which can promote the dispersion of the active component, reduce the particle size of the active component, and improve the catalytic performance Effect.

(2) The preparation method of the present invention adopts the co-precipitation method and uses additives for modification. By controlling the formation of the specific precursor structure of the catalyst, it helps to improve the dispersion of the active component copper oxide and reduce the particle size of copper. Improve catalyst stability and activity.

(3) Compared with the existing catalysts, the catalyst prepared by the present invention has a higher conversion rate of raw materials and better ethanol selectivity, which is beneficial to the perfection of the technology of producing ethanol by esterification and hydrogenation of acetate and the improvement of efficiency.

detailed description

The specific implementation manner of the present invention is introduced below, and 4 examples and 4 application examples are provided. However, it should be noted that implementation of the present invention is not limited to the following embodiments.

Example 1

A kind of preparation method of the catalyst that is used for ethyl acetate hydrogenation to produce ethanol, comprises following preparation steps:

(1) Weigh 24.15g Cu(NO ₃ ) ₂ 3H _-2 O, 6.525g Zn(NO ₃ ) ₂ 6H ₂ O and 18.75g Al(NO ₃ ) ₃ 9H ₂ O in deionized water, heat and stir , to prepare a mixed salt solution with a concentration of 1mol/L (solution A).

(2) Weigh and dissolve Na ₂ CO ₃ in deionized water, heat and stir, and prepare solution B with a concentration of 1mol/L.

(3) Put the solution A of step (1) and the solution B of step (2) in two pear-shaped separating funnels respectively, and then mix them: first add solution A to a three-necked flask, and then add Add solution B to the three-necked flask; or add solution B to the three-necked flask first, and then add solution A to the three-necked flask; or add solution A and solution B to the three-necked flask at the same time.

A water bath was carried out at a temperature of 60°C; the pH of the solution was maintained at 10 by adjusting the flow rate of the solution, and stirred and mixed for 1 hour; precipitation; then ultrasonic treatment for 0.5 hours, and finally standing and aging for 12 hours to obtain a slurry.

(4) Filter the slurry obtained in step (3), and then rinse it with deionized water until the filtrate does not contain Na ⁺ ions; collect the filter cake and put it in an oven, and dry it overnight at 110°C to obtain a dry material.

(5) Put the dry material obtained in step (4) in a muffle furnace, roast it at 450°C for 4 hours, press it and pulverize it, and then sieve it to 40-60 mesh to obtain Catalyst A.

Application Example 1

Catalyst A prepared in Example 1 was used in the production process of ethyl acetate hydrogenation to produce ethanol.

Catalyst A was subjected to reduction treatment before use: reduction with pure _H2 at 350°C for 4 hours under normal pressure.

When in use, put catalyst A in a tubular fixed-bed reactor, lower the temperature of the tubular fixed-bed reactor to 260° C., and raise the pressure to 2.0 MPa.

Under the conditions of reaction temperature of 260°C, reaction pressure of 2.0MPa, ethyl acetate liquid phase space velocity of 2h ^-1 , and molar ratio of hydrogen to ethyl acetate = 5mol, the conversion rate of ethyl acetate was 99%, and the conversion rate of ethanol was The selectivity is 98.36%.

Example 2

A kind of preparation method of the catalyst that is used for ethyl acetate hydrogenation to produce ethanol, comprises following preparation steps:

(1) Weigh 24.15gCu(NO ₃ ) ₂ 3H- ₂ O, 2.5641gMg(NO ₃ ) ₂ 6H ₂ O and 18.75gAl(NO ₃ ) ₃ 9H ₂ O in deionized water and prepare the concentration 1mol/L mixed salt solution (solution A).

(2) Weigh NaOH and dissolve it in deionized water to prepare solution B with a concentration of 1mol/L.

(3) (basically the same as embodiment 1).

Precipitation was carried out at a temperature of 40° C., the pH value was controlled to 6, and the mixture was continuously stirred for 1 hour; after the precipitation was completed, the mixture was sonicated for 1 hour, and then stood and aged for 8 hours to obtain a slurry.

(4) (same as embodiment 1).

(5) Put the dried material obtained in step (4) into a muffle furnace and roast at 200°C for 6 hours, press and pulverize, and then sieve to 40-60 mesh to obtain catalyst B.

Application Example 2

Catalyst B prepared in Example 2 was used in the production process of ethyl acetate hydrogenation to produce ethanol.

Reduction treatment of catalyst B before use: reduction with pure H ₂ at 0.1 MPa, 400°C for 1 h.

When in use, 1g of catalyst A is placed in a tubular fixed-bed reactor, hydrogen and ethyl acetate enter the reactor after being preheated and mixed, the temperature of the tubular fixed-bed reactor is lowered to 260°C, and the pressure is increased to 2.0MPa. Under the conditions of reaction temperature of 260°C, reaction pressure of 2.0MPa, ethyl acetate liquid phase space velocity of 0.5h ^-1 , and molar ratio of hydrogen to ethyl acetate = 2mol, the conversion rate of ethyl acetate was 99%, and the conversion rate of ethanol was The selectivity is 98.7%.

Example 3

A kind of preparation method of the catalyst that is used for ethyl acetate hydrogenation to produce ethanol, comprises following preparation steps:

(1) Weigh 24.15gCu(NO ₃ ) ₂ 3H- ₂ O, 2.9081gNi(NO ₃ ) ₂ 6H ₂ O and 18.75gAl(NO ₃ ) ₃ 9H ₂ O in deionized water and prepare the concentration 1mol/L mixed salt solution (solution A).

(2) Weigh NH ₃ ·H ₂ O and dissolve it in deionized water to prepare solution B with a concentration of 1mol/L.

(3) (basically the same as embodiment 1).

Precipitation was carried out at a temperature of 80°C, the pH value was controlled to 9, and the mixture was continuously stirred for 1 hour; after the precipitation was completed, it was ultrasonicated for 2 hours, and then left to age for 16 hours to obtain a slurry.

(4) (same as embodiment 1).

(5) Put the dry material obtained in step (4) into a muffle furnace and roast at 600°C for 2 hours, press and pulverize, and then sieve to 40-60 mesh to obtain catalyst C.

Application Example 3

Catalyst C prepared in Example 3 was used in the production process of ethyl acetate hydrogenation to produce ethanol.

Reduction treatment of catalyst C before use: reduction with pure H ₂ at 200°C for 6 hours at 2 MPa.

Under the condition that the reaction temperature is 240°C, the reaction pressure is 2.0 MPa, the ethyl acetate liquid phase space velocity is 2 h ^-1 , and the molar ratio of hydrogen to ethyl acetate = 50 mol, the conversion rate of ethyl acetate is 99%, and the conversion rate of ethanol is The selectivity is 95.61%.

Example 4

A kind of preparation method of the catalyst that is used for ethyl acetate hydrogenation to produce ethanol, comprises following preparation steps:

(1) Weigh 24.15gCu(NO ₃ ) ₂ 3H- ₂ O, 2.9105gCo(NO ₃ ) ₂ 6H ₂ O and 18.75gAl(NO ₃ ) ₃ 9H ₂ O in deionized water and prepare the concentration 1mol/L mixed salt solution (solution A).

(2) Weigh Na ₂ CO ₃ , NaOH, NH ₃ ·H ₂ O and dissolve them in deionized water to prepare solution B with a concentration of 1mol/L.

(3) (basically the same as embodiment 1).

Precipitation was carried out at a temperature of 60°C, the pH value was controlled to be 7, and the mixture was stirred continuously for 1 hour; after the precipitation was completed, it was ultrasonicated for 0.5 hours, and then left to age for 12 hours to obtain a slurry.

(4) (same as embodiment 1).

(5) Put the dried material obtained in step (4) into a muffle furnace and roast at 450°C for 5 hours, press and pulverize, and then sieve to 40-60 mesh to obtain catalyst D.

Application Example 4

The catalyst D prepared in Example 4 was used in the production process of ethyl acetate hydrogenation to produce ethanol.

Catalyst D was subjected to reduction treatment before use: reduction with pure H ₂ at 300°C for 4 h under normal pressure.

When in use, put 1 g of catalyst D in a tubular fixed-bed reactor, lower the temperature of the tubular fixed-bed reactor to 260° C., and raise the pressure to 2.0 MPa.

Under the condition that the reaction temperature is 260°C, the reaction pressure is 2.0MPa, the ethyl acetate liquid phase space velocity is 2h ^-1 , and the molar ratio of hydrogen to ethyl acetate = 10mol, the conversion rate of ethyl acetate is 99%, and the conversion rate of ethanol is The selectivity is 96.58%.

Embodiments 1 to 4 of the present invention and application examples 1 to 4 prove that the catalyst prepared by the present invention for the hydrogenation of ethyl acetate to produce ethanol has higher raw material conversion and better ethanol selectivity.

Claims (10)

1. for the catalyst of ethyl acetate hydrogenation ethanol production, it is characterized in that, the mass percent sum of its each constituent is 100%, wherein:

Cupric oxide 40wt% ~ 70wt%;

Auxiliary agent 10wt% ~ 50wt%;

Surplus is aluminium oxide.

2. as claimed in claim 1 for a catalyst for ethyl acetate hydrogenation ethanol production, it is characterized in that, described auxiliary agent is one or more of zinc oxide, cobalt oxide, nickel oxide and/or manganese oxide.

3., as claimed in claim 1 for a preparation method for the catalyst of ethyl acetate hydrogenation ethanol production, it is characterized in that, comprise following preparation process:

(1) take a certain amount of slaine and be dissolved in deionized water, after adding thermal agitation, obtain solution A;

(2) take a certain amount of precipitating reagent and be dissolved in deionized water, after adding thermal agitation, obtain solution B;

(3) solution B of the solution A of step (1) and step (2) is placed in two pear shape separatory funnels respectively, first solution A is added in there-necked flask, and then add solution B in described there-necked flask; Or first solution B is added in there-necked flask, and then add solution A in described there-necked flask; Or solution A and solution B being added in there-necked flask simultaneously, at the temperature of 40 ~ 80 DEG C, carries out water-bath, by regulating solution flow rate to keep the pH value of solution to be 6 ~ 10, being uniformly mixed 1 hour; Precipitation; Then ultrasonic process 0.5 ~ 2 hour, finally leaves standstill aging 8 ~ 16 hours, obtains slurry;

(4) slurry that step (3) obtains is filtered, then use deionized water rinsing, until not containing Na in filtrate ⁺ion; Put into baking oven after being collected by filter cake, 110 DEG C of dried overnight, obtain dried material;

(5) dried material that step (4) obtains is placed in Muffle furnace, roasting 2 ~ 8 hours in 200 ~ 600 DEG C of temperature, after compressing tablet is pulverized, is sized to 40 ~ 60 orders, obtains target product---for the catalyst of ethyl acetate hydrogenation ethanol production.

4. a preparation method as claimed in claim 3, is characterized in that, the slaine described in step (1) is nitrate, and described nitrate is Cu (NO ₃) ₂3H _-2o; Zn (NO ₃) ₂6H ₂o; Al (NO ₃) ₃9H ₂o; Mg (NO3) 26H2O; Ni (NO3) 26H2O; One or more in Co (NO3) 26H2O.

5. a preparation method as claimed in claim 4, is characterized in that, in described step (1), is that 0.5 ~ 2:5 takes nitrate by the mol ratio of cupric oxide and all auxiliary agent sums.

6. a preparation method as claimed in claim 3, is characterized in that, the precipitating reagent described in step (2) is the mixture of one or more of sodium carbonate, NaOH, ammoniacal liquor.

7. a preparation method as claimed in claim 6, is characterized in that, in described step (2), is that 1mol/L prepares by sodium carbonate or NaOH or ammoniacal liquor or the molar concentration of their mixture in solution B.

8. a preparation method as claimed in claim 3, is characterized in that, the filtration described in step (4) adopts suction filtration mode.

9. the application of catalyst described in ethyl acetate hydrogenation ethanol production, is characterized in that, before using, catalyst is carried out reduction treatment, reduction temperature is 200 ~ 400 DEG C, and pressure is 0.1 ~ 2MPa, and the recovery time is 1 ~ 6h.

10. the application of catalyst described in ethyl acetate hydrogenation ethanol production, is characterized in that, adopt tubular fixed-bed reactor to react, reaction temperature is 200 ~ 300 DEG C, and reaction pressure is 0.1 ~ 4MPa, and ethyl acetate liquid air speed is 0.5 ~ 2h ^-1, H ₂/ ethyl acetate=2 ~ 50mol.