Catalyst for preparing propyl alcohol through propionaldehyde hydrogenation as well as preparation method and application of catalyst

Abstract

The invention relates to a catalyst for preparing propyl alcohol through propionaldehyde hydrogenation and a preparation method and application of the catalyst, and relates to the technical field of catalysts, and the catalyst for preparing propyl alcohol through propionaldehyde hydrogenation mainly comprises copper oxide, zinc oxide, aluminum oxide and a performance additive, the performance additive is one or a mixture of two of oxides of metal elements in the IA family, the IIA family and the IV family in the periodic table of elements. Compared with the prior art, the preparation process of the catalyst is simple, the prepared catalyst is used for propionaldehyde hydrogenation reaction, the yield of propionaldehyde reaches 99.6% or above, meanwhile, the content of impurities such as 2-methyl-3-pentanone in the obtained product is reduced, and remarkable economic benefits and social benefits can be generated.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a catalyst for producing propanol by hydrogenating propionaldehyde, and a preparation method and application thereof. Background Art

[0002] N-propyl alcohol is widely used as a low-molecular-weight fatty alcohol. Currently, propanal is primarily produced globally using the ethylene hydroformylation process, followed by catalytic hydrogenation to produce propanol. Because this production method is similar to that of butanol, the catalyst used for the catalytic hydrogenation of propanal is often replaced by a butanol hydrogenation catalyst, resulting in relatively low selectivity for the hydrogenated product. Aldehyde hydrogenation catalysts have been reported in numerous documents and patents, and aldehyde vapor phase hydrogenation primarily utilizes copper oxide-zinc oxide-aluminum oxide catalysts. For example, CN100590108C describes propionaldehyde hydrogenation as a vapor-phase hydrogenation over a copper-zinc catalyst, the primary weight components of which are 29.4% to 50% copper oxide and 49.4% to 70% zinc oxide. However, CN100564338 indicates that the crude product of hydrogenation using this catalyst contains 0.3% to 4% propyl propionate as a byproduct. CN1045548C provides a nickel-containing catalyst for hydrogenating propionaldehyde to propanol, the hydrogenated product of which contains 0.7% unconverted aldehyde and a small amount of byproducts. CN1011232B and CN1021636C disclose aldehyde hydrogenation catalysts, the product of which contains 0.3% propyl propionate. These catalysts are based on a copper oxide-zinc oxide catalyst with the addition of a selectivity improver, comprising one or a combination of alkali metals, nickel, and cobalt. CN1251796C provides a catalyst for hydrogenating butyraldehyde to butanol, which can also be used to hydrogenate related aldehydes to produce corresponding aldehydes. CN103506125A discloses a propionaldehyde hydrogenation catalyst, including a catalyst and a method for preparing the catalyst. The propionaldehyde hydrogenation product contains 0.5% to 3.1% propyl propionate. The catalyst provided in the aforementioned patent can be used to hydrogenate C1-C8 aldehydes to produce the corresponding alcohols. However, the catalyst's disadvantage is that when used to hydrogenate propionaldehyde to produce propanol, it produces a certain amount of propyl propionate and 2-methyl-3-pentanone as byproducts. Summary of the Invention

[0003] To solve the above problems, the present invention provides a catalyst for hydrogenating propionaldehyde to propanol, and a preparation method and application thereof.

[0004] In a first aspect, the present invention provides a catalyst for hydrogenating propionaldehyde to propanol, wherein the main components of the catalyst include copper oxide, zinc oxide, aluminum oxide and a modification aid, and the modification aid is a mixture of one or two oxides of metal elements in Group IA, Group IIA and Group IV A of the periodic table.

[0005] Furthermore, in terms of weight percentage, the content of the copper oxide is 20% to 40%.

[0006] Furthermore, in terms of weight percentage, the content of zinc oxide is 45% to 70%.

[0007] Furthermore, in terms of weight percentage, the content of aluminum oxide is 0.1% to 6%.

[0008] Furthermore, the modification aid includes magnesium oxide and silicon oxide.

[0009] Furthermore, the content of the magnesium oxide is 0.1% to 5% by weight; and the content of the silicon oxide is 0.1% to 10% by weight.

[0010] Furthermore, the catalyst for producing propanol by hydrogenating propionaldehyde further comprises graphite; the content of the graphite is 1% to 3% by weight.

[0011] In a second aspect, the present invention provides a method for preparing the catalyst for hydrogenating propionaldehyde to propanol according to any one of the first aspects, such as Figure 1 As shown, the preparation method comprises the following steps:

[0012] The salts of the metal components are prepared into a solution in proportion, and then precipitated with a precipitant and then aged to obtain a mixed solution;

[0013] The mixed solution is filtered, and the obtained precipitate is washed and dried to obtain a first solid;

[0014] crushing and calcining the first solid to obtain a second solid;

[0015] The second solid material, water and graphite are mixed and then pressed into shape to obtain the catalyst for hydrogenating propanal to propanol.

[0016] Furthermore, the working condition parameters of the coprecipitation reaction include: a temperature of 60 to 70°C, and an endpoint pH value of the coprecipitation reaction of 7.5; the working condition parameters of the calcination include: calcination at 300 to 350°C for 3 to 5 hours; and the working condition parameters of the aging treatment include: a temperature of 70 to 75°C and a time of 20 to 60 minutes.

[0017] In a third aspect, a catalyst for hydrogenating propanol to produce propanol as described in any one of the first aspects or a catalyst for hydrogenating propanol to produce propanol obtained by the preparation method as described in any one of the second aspects is used in hydrogenating propanal to produce propanol, wherein the weight content of 2-methyl-3-pentanone in the obtained product is ≤0.02wt%.

[0018] The above technical solution provided by the embodiment of the present invention has at least the following advantages compared with the prior art:

[0019] The present invention provides a catalyst for hydrogenating propanal to propanol, a preparation method, and applications thereof. Compared with the prior art, the catalyst preparation process of the present invention is simple. The catalyst prepared is used in the propanal hydrogenation reaction, achieving a propanal yield of over 99.6%. The catalyst also reduces the content of impurities such as 2-methyl-3-pentanone in the resulting product, thereby generating significant economic and social benefits. Specifically:

[0020] The present invention provides a catalyst, a preparation method and an application thereof, which are mainly used for hydrogenating propionaldehyde to produce propanol. The catalyst has high selectivity for propanol and effectively reduces propyl propionate and 2-methyl-3-pentanone in the hydrogenation product.

[0021] (1) The active ingredients are more evenly dispersed;

[0022] (2) The carrier has better thermal conductivity, which allows for timely heat removal and better selectivity;

[0023] (3) Adding metal additives can effectively promote the synergistic effect of metal carriers, inhibit their sintering and agglomeration during the reaction, reduce the loss of metals during the reaction, and enhance the stability of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0026] Figure 1 The present invention provides a process flow diagram of a method for preparing a catalyst for hydrogenating propionaldehyde to propanol. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings 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 making creative efforts shall fall within the scope of protection of the present invention.

[0028] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0029] The catalyst of the present invention primarily comprises copper oxide, zinc oxide, and aluminum oxide, and also contains a modifying agent, which is a compound of one or a mixture of two of metal elements from Groups IA, IIA, and IV A of the periodic table, such as potassium, sodium, magnesium, calcium, strontium, barium, and silicon. The catalyst comprises the following steps: preparing a solution of salts of the metal components in appropriate proportions, then precipitating the solution with a precipitant, aging the solution, washing the solution, drying the solution, grinding the solution, granulating the solution, calcining the solution, and pressing the solution into tablets.

[0030] The precipitation method of the present invention is a reverse addition co-precipitation method. A precipitant solution is added to a precipitation tank, stirred evenly and heated, and then a preheated copper-zinc mixture is added for neutralization and precipitation. The precipitant is one of sodium carbonate, sodium bicarbonate, ammonium bicarbonate, ammonium carbonate, or ammonia water. The precipitation temperature is 30°C to 80°C, and the precipitation endpoint pH is 6.5 to 8.0. The modifying agent is added by beating or dry mixing; the insoluble modifying agent is added during the beating process; and the soluble agent is added during the granulation process. The calcination temperature during the preparation process is 300°C to 450°C. The obtained catalyst is a cylindrical tablet with a diameter of 5mm to 7mm and a height of 5mm to 7mm, and a specific surface area of 30m2 / g to 80m2 / g.

[0031] The propionaldehyde hydrogenation catalyst provided by the present invention is prepared by adopting the above-mentioned catalyst preparation method.

[0032] Generally speaking, all the raw materials added during the preparation process can be converted into the components of the catalyst.

[0033] In some embodiments, the mass composition of the catalyst includes: copper oxide is 20% to 40%, for example, 20%, 25%, 30%, 35%, 40% or a range consisting of any two thereof; zinc oxide is 45% to 70%, for example, 45%, 50%, 55%, 60%, 70% or a range consisting of any two thereof; aluminum oxide is 0.1% to 6%, for example, 0.1%, 1%, 2%, 4%, 6% or a range consisting of any two thereof; magnesium oxide is 0.1% to 6%. 5%, for example, 0.1%, 1%, 2%, 3%, 5% or a range consisting of any two thereof; calcium oxide is 0.1% to 4%, for example, 0.1%, 1%, 2%, 3%, 4% or a range consisting of any two thereof; graphite is 1% to 3%, for example, 1%, 1.5%, 2%, 2.5%, 3% or a range consisting of any two thereof; silicon oxide is 0.1% to 10%, for example, 0.1%, 1%, 3%, 6%, 10% or a range consisting of any two thereof.

[0034] The catalyst of the present invention is primarily used for hydrogenating propionaldehyde to propanol and exhibits high low-temperature activity, high propanol selectivity, and catalytic stability. The catalyst of the present invention is evaluated in a tubular reactor and requires reduction activation before use. The reduction process utilizes a low-concentration hydrogen atmosphere, using nitrogen as a carrier gas, with a controlled hydrogen content of 1% to 10%. The reduction temperature is controlled between 160°C and 220°C, with a maximum temperature not exceeding 230°C. After the reduction is complete, the reactor temperature is lowered to the desired reaction temperature for activity evaluation.

[0035] It should be noted that the components and raw materials involved in the propionaldehyde hydrogenation to propanol catalyst and its preparation method and application provided in the embodiment of the present invention, unless otherwise specified or specified, can be directly commercially available products or homemade using existing public preparation methods; at the same time, the steps and parameters involved, unless otherwise specified or specified, can be carried out according to the processing technology of the prior art or directly using existing equipment, and the present invention document will not repeat them one by one.

[0036] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are intended to illustrate the present invention only and are not intended to limit the scope of the invention. The experimental methods in the following examples where specific conditions are not specified are generally measured in accordance with national standards. If there are no corresponding national standards, then the methods are carried out in accordance with general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0037] Example 1

[0038] A mixed solution was prepared by taking 500 ml of 1.0 M copper nitrate solution, 1710 ml of 1.0 M zinc nitrate solution, and 2 ml of 1.0 M aluminum nitrate solution. The mixed solution was co-precipitated with a sodium carbonate solution in a precipitation tank with stirring. The precipitation temperature was controlled at 65°C, and the pH value at the precipitation end point was 7.5. The mixture was then aged at 72°C for 30 min, washed, dried, crushed, and calcined at 350°C. An appropriate amount of water and graphite were added, and the mixture was finally pressed into Φ6.5×6 cylindrical tablets to obtain a usable catalyst RH1.

[0039] Example 2

[0040] 500 ml of 1.0 M copper nitrate solution, 1173 ml of 1.0 M zinc nitrate solution, 16 ml of 1.0 M aluminum nitrate solution, and 40 ml of 1.0 M calcium nitrate solution were prepared into a mixed solution, which was co-precipitated with a sodium carbonate solution in a stirred precipitation tank. The precipitation temperature was controlled at 65° C., and the pH value at the precipitation endpoint was 7.5. The mixture was then aged at 72° C. for 30 min, washed, dried, crushed, and calcined at 350° C. 1 g of potassium carbonate was prepared into 100 ml of an aqueous solution, which was evenly mixed into the above-mentioned base material. The mixture was then dried, calcined at 380° C., an appropriate amount of water and graphite were added, and the mixture was finally pressed into Φ6.5×6 cylindrical tablets to obtain a usable catalyst RH2.

[0041] Example 3

[0042] A mixed solution was prepared by taking 500 ml of 1.0 M copper nitrate solution, 896 ml of 1.0 M zinc nitrate solution, 26 ml of 1.0 M aluminum nitrate solution, and 40 g of JN-25 silica sol. The mixed solution was co-precipitated with a sodium carbonate solution in a precipitation tank with stirring. The precipitation temperature was controlled at 65°C, and the pH value at the precipitation end point was 7.5. The mixture was then aged at 72°C for 30 min, washed, dried, crushed, and calcined at 350°C. An appropriate amount of water and graphite were added, and the mixture was finally pressed into Φ6.5×6 cylindrical tablets to obtain a usable catalyst RH3.

[0043] Example 4

[0044] A mixed solution was prepared by taking 500 ml of 1.0 M copper nitrate solution, 698 ml of 1.0 M zinc nitrate solution, 45 ml of 1.0 M aluminum nitrate solution, and 50 ml of 1.0 M magnesium nitrate solution. The mixed solution was co-precipitated with a sodium carbonate solution in a stirred precipitation tank. The precipitation temperature was controlled at 65°C, and the pH value of the precipitation end point was 7.5. The mixture was then aged at 72°C for 30 minutes, washed, dried, crushed, and calcined at 350°C. 1 g of potassium carbonate was prepared into 100 ml of an aqueous solution, which was evenly mixed with the above-mentioned base material. The mixture was then dried, calcined at 380°C, and an appropriate amount of water and graphite were added. Finally, the mixture was pressed into Φ6.5×6 cylindrical tablets to obtain a usable catalyst RH4.

[0045] Example 5

[0046] Take 500 ml of 1.0 M copper nitrate solution, 550 ml of 1.0 M zinc nitrate solution, and 58 ml of 1.0 M aluminum nitrate solution to prepare a mixed solution, and co-precipitate the mixed solution with sodium carbonate solution in a precipitation tank with stirring. The precipitation temperature is controlled at 65°C, and the pH value of the precipitation end point is 7.5. Then, it is aged at 72°C for 30 minutes, and then washed, dried, crushed, and calcined at 350°C. An appropriate amount of water and graphite are added, and finally, it is pressed into Φ6.5×6 cylindrical tablets to obtain a usable catalyst RH5.

[0047] Comparative Example 1

[0048] Similar to Example 3, except that sodium bicarbonate was used as the precipitant, the precipitation temperature was controlled at 30°C to 40°C, the pH value at the precipitation endpoint was 6.5, the calcination temperature was 300°C, and the tablets were pressed into Φ5×5 cylindrical tablets to finally obtain catalyst DRH1.

[0049] Comparative Example 2

[0050] Similar to Example 3, except that ammonium bicarbonate was used as the precipitant, the precipitation temperature was controlled at 40°C to 50°C, the pH value at the precipitation endpoint was 7.0, the calcination temperature was 350°C, and the tablets were pressed into Φ6×5.5 cylindrical tablets to finally obtain catalyst DRH2.

[0051] Comparative Example 3

[0052] Similar to Example 3, except that ammonium carbonate was used as the precipitant, the precipitation temperature was controlled at 50°C to 60°C, the pH value at the precipitation endpoint was 7.5, the calcination temperature was 400°C, and the tablets were pressed into Φ6×6.5 cylindrical tablets to finally obtain catalyst DRH3.

[0053] Comparative Example 4

[0054] Similar to Example 3, except that: ammonia water was used as the precipitant, the precipitation temperature was controlled at 70°C to 80°C, the pH value at the precipitation endpoint was 8.0, the roasting temperature was 450°C, and the tablets were pressed into Φ5.5×6.5 cylindrical tablets to finally obtain catalyst DRH4.

[0055] Comparative Example 5

[0056] Similar to Example 3, the only difference is that sodium bicarbonate is used as the precipitant, and the catalyst DRH5 is finally obtained.

[0057] Test Case

[0058] In this example, the catalysts RH1, RH2, RH3, RH4, and RH5 prepared in Example 1, Example 2, Example 3, Example 4, and Example 5 and Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5 were subjected to physical and chemical characterization, and tested on a single-tube fixed-bed reactor detection device. The test conditions were: pressure 0.4 MPa to 0.6 MPa, reaction starting temperature 125°C ± 2°C, propionaldehyde liquid space velocity 0.36 h -1 , the molar ratio of hydrogen to aldehyde is 10-30, the reaction product is analyzed, and the measurement results are shown in Table 1 below.

[0059] Table 1 Comparison of catalyst performance between examples and comparative examples

[0060]

[0061] The data in Table 1 show that the catalysts prepared by this method exhibit good propionaldehyde conversion and propanol selectivity, especially the catalytic performance of Example 3, with a conversion rate and selectivity exceeding 99.7%, and the by-products propyl propionate and 2-methyl-3-pentanone significantly lower than the existing industry level. After the catalysts were used for 300 hours, ICP analysis of the metal element content showed that the metal element content of each catalyst in the examples did not change significantly, indicating that the addition of the additive improved the stability of the catalyst structure.

[0062] Various embodiments of the present invention may be presented in the form of a range; it should be understood that the description in a range format is only for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention; therefore, the range description should be considered to have specifically disclosed all possible subranges and single numerical values within the range. For example, the description of a range from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated herein, it is intended to include any cited numeral (fractional or integer) within the indicated range.

[0063] The foregoing description is intended only to provide specific embodiments of the present invention, which will enable those skilled in the art to understand and implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments shown herein, but is intended to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A catalyst for preparing propanol by hydrogenation of propionaldehyde, characterized in that The catalyst for hydrogenating propanol to propanol mainly comprises copper oxide, zinc oxide, aluminum oxide and a modification aid, wherein the modification aid is a mixture of one or two oxides of metal elements in Group IA, Group IA and Group IV A of the periodic table.

2. The catalyst for preparing propanol by hydrogenation of propionaldehyde according to claim 1, wherein Calculated in weight percentage, the content of the copper oxide is 20% to 40%.

3. The catalyst for preparing propanol by hydrogenation of propionaldehyde according to claim 1, wherein Calculated in weight percentage, the content of zinc oxide is 45% to 70%.

4. The catalyst for preparing propanol by hydrogenation of propionaldehyde according to claim 1, wherein Calculated in weight percentage, the content of the aluminum oxide is 0.1% to 6%.

5. The catalyst for preparing propanol by hydrogenation of propionaldehyde according to claim 1, wherein The modification aids include magnesium oxide and silicon oxide.

6. The catalyst for producing propanol by hydrogenation of propionaldehyde according to claim 5, wherein Calculated by weight percentage, the content of magnesium oxide is 0.1% to 5%; calculated by weight percentage, the content of silicon oxide is 0.1% to 10%.

7. The catalyst for hydrogenating propionaldehyde to propanol according to any one of claims 1 to 6, characterized in that The catalyst for preparing propanol by hydrogenating propionaldehyde further comprises graphite; the content of the graphite is 1% to 3% by weight.

8. A method for preparing the catalyst for hydrogenating propionaldehyde to propanol according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The salts of the metal components are prepared into a solution in proportion, and then precipitated with a precipitant and then aged to obtain a mixed solution; The mixed solution is filtered, and the obtained precipitate is washed and dried to obtain a first solid; crushing and calcining the first solid to obtain a second solid; The second solid material, water and graphite are mixed and then pressed into shape to obtain the catalyst for hydrogenating propanal to propanol.

9. The method for preparing a catalyst for hydrogenating propionaldehyde to propanol according to any one of claims 1 to 6, wherein: The working condition parameters of the coprecipitation reaction include: a temperature of 60-70°C, and an endpoint pH value of the coprecipitation reaction of 7.5; the working condition parameters of the roasting include: roasting at 300-350°C for 3-5 hours; the working condition parameters of the aging treatment include: a temperature of 70-75°C and a time of 20-60 minutes.

10. Use of the catalyst for preparing propanol by hydrogenation of propionaldehyde according to any one of claims 1 to 7 or the catalyst for preparing propanol by hydrogenation of propionaldehyde obtained by the preparation method according to any one of claims 8 to 9 in preparing propanol by hydrogenation of propionaldehyde, characterized in that: The weight content of 2-methyl-3-pentanone in the obtained product is less than or equal to 0.02 wt%.

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