Preparation method of ketone alcohol compound

Abstract

The invention provides a method for preparing a ketone alcohol compound. The method comprises the following steps: carrying out dehydrogenation reaction on a diol compound as shown in a formula 1 in the presence of a catalyst to generate a ketone alcohol compound as shown in a formula 2; wherein the catalyst comprises a first active component, and the first active component comprises Cu and Ru. The method disclosed by the invention is simple in process, high in product selectivity, high in purity and simple in post-treatment.

Description

Technical Field

[0001] This invention relates to the field of chemical technology, and specifically to a method for preparing ketol compounds. Background Technology

[0002] α-Hydroxyacetone, also known as acetone alcohol, has the molecular formula C3H6O2. It possesses a hydroxyl group and an active unsaturated carbonyl group, and is a high-value organic synthetic intermediate widely used in pharmaceutical synthesis, textile manufacturing, cosmetics, and food industries. It is primarily used to synthesize 4-methylimidazole, acetone aldehyde, pyruvic acid, and lactic acid. The main synthetic routes for α-hydroxyacetone include the oxidation of 1,2-propanediol, esterification and hydrolysis of haloacetone, condensation of acetaldehyde and formaldehyde, and dehydration of glycerol.

[0003] Currently, there are few methods for directly preparing α-hydroxyacetone from 1,2-propanediol. For example, the selective catalytic oxidation of 1,2-propanediol using an electrolytic silver catalyst to co-produce α-hydroxyacetone and acetone aldehyde involves a reaction temperature of 300-500℃, posing certain safety risks under oxidant conditions. Furthermore, the selectivity for α-hydroxyacetone is only 36-39%, and the subsequent product separation process is quite complex. CN110813364A uses a bimetallic nanocatalyst to catalytically oxidize 1,2-propanediol to prepare pyruvic acid and hydroxyacetone. However, the catalyst cost is high, the selectivity for hydroxyacetone is less than 70%, and the subsequent separation process also presents problems. All the above methods involve the co-production of α-hydroxyacetone from 1,2-propanediol. On the one hand, α-hydroxyacetone is not the primary target product, resulting in low selectivity; on the other hand, the product composition is complex, making subsequent separation processes complex and difficult, and it is difficult to obtain a high-purity α-hydroxyacetone product.

[0004] CN109896941A uses a vanadium-containing catalyst to catalytically hydrogenate carbohydrates to produce hydroxyacetone. This method has low raw material costs, but the yield of hydroxyacetone is only 4-35%, which is low, and byproducts such as methyl lactate and sorbitol are also generated. CN114315550A proposes a one-pot synthesis method for hydroxyacetone, using acetone, alkali metal bromide, inorganic acid binder, phase transfer catalyst, and hydrogen peroxide as raw materials. After the reaction, high-purity hydroxyacetone is obtained by extraction. However, this method consumes a large amount of solvent and the extraction step is relatively complex, making it unsuitable for the continuous production of α-hydroxyacetone.

[0005] Therefore, it is necessary to improve the production process of α-hydroxyacetone to increase the yield of hydroxyacetone, reduce production costs, avoid complex post-processing operations, and simplify the process flow. Summary of the Invention

[0006] In order to solve one of the above-mentioned technical problems in the prior art, the present invention provides a method for preparing ketol compounds.

[0007] The technical solution of the present invention is as follows:

[0008] This invention provides a method for preparing ketol compounds, comprising subjecting a diol compound of Formula 1 to a dehydrogenation reaction in the presence of a catalyst to generate a ketol compound of Formula 2;

[0009]

[0010] The catalyst includes a first active component, which includes Cu and Ru.

[0011] In Formulas 1 and 2, R1 is selected from C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl or a combination thereof; R2 is selected from hydrogen, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl or a combination thereof.

[0012] According to some embodiments of the present invention, in Formulas 1 and 2, R1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, C6-C10 aryl, C3-C10 heteroaryl, or combinations thereof. In some embodiments, R1 is selected from C1-C6 alkyl, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, or hexyl. In some embodiments, R1 is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or tert-butyl. In some embodiments, R1 is selected from methyl or ethyl. In some embodiments, R1 is methyl.

[0013] According to some embodiments of the present invention, in Formulas 1 and 2, R2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C10 aryl, C3-C10 heteroaryl, or combinations thereof. In some embodiments, R2 is selected from hydrogen or C1-C6 alkyl, such as hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, or hexyl. In some embodiments, R2 is selected from hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or tert-butyl. In some embodiments, R2 is selected from hydrogen, methyl, or ethyl. In some embodiments, R2 is hydrogen.

[0014] According to some embodiments of the present invention, the diol compound represented by Formula 1 includes 1,2-propanediol, and the ketol compound represented by Formula 2 includes α-hydroxyacetone.

[0015] According to some embodiments of the present invention, the method includes subjecting 1,2-propanediol to a dehydrogenation reaction in the presence of the catalyst to produce α-hydroxyacetone.

[0016] According to some embodiments of the present invention, in the first active component of the catalyst, the mass of Cu accounts for 0.1% to 99.9% of the total mass of Cu and Ru, for example, 0.1%, 0.5%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 90%, 95%, 99%, 99.9%, or any value between therewith. In some embodiments, in the first active component of the catalyst, the mass of Cu accounts for 75% to 99% of the total mass of Cu and Ru. In some embodiments, in the first active component of the catalyst, the mass of Cu accounts for 90% to 99% of the total mass of Cu and Ru. In some embodiments, in the first active component of the catalyst, the mass of Cu accounts for 95% to 99% of the total mass of Cu and Ru.

[0017] According to some embodiments of the present invention, the mass ratio of Cu to Ru in the first active component is (4-100):1, for example, 4:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 100:1, or any value between them. In some embodiments, the mass ratio of Cu to Ru in the first active component is (4-50):1. In some embodiments, the mass ratio of Cu to Ru in the first active component is (15-30):1. In some embodiments, the mass ratio of Cu to Ru in the first active component is (20-30):1.

[0018] According to some embodiments of the present invention, the catalyst further includes a second active component, which includes one or more of Cr, Fe, Ni, Zn, Al, Mo, Ce, and Ag. In some embodiments, the mass ratio of the first active component to the second active component is (0.1–40):(0–30). In some embodiments, the mass ratio of the first active component to the second active component is (10–40):(0.1–30).

[0019] According to some embodiments of the present invention, the catalyst further includes a support for loading the active component. In some embodiments, the support includes one or more of alumina, silica, zirconium dioxide, molecular sieve, and activated carbon. In some embodiments, the support is silica. In some embodiments, the average particle size of the support is 1-3 mm.

[0020] In some embodiments, the loading of the first active component in the catalyst is 0.1 wt% to 40 wt%, for example, 0.1 wt%, 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or any value between therewith. In some embodiments, the loading of the first active component in the catalyst is 10 wt% to 40 wt%. In some embodiments, the loading of the first active component in the catalyst is 20 wt% to 40 wt%.

[0021] In some embodiments, the catalyst has a Cu loading of 10 wt% to 30 wt%, for example, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, 30 wt%, or any value between therewith. In some embodiments, the catalyst has a Cu loading of 15 wt% to 30 wt%. In some embodiments, the catalyst has a Cu loading of 15 wt% to 25 wt%.

[0022] In some embodiments, the Ru loading in the catalyst is 0.1 wt% to 5 wt%, for example, 0.1 wt%, 0.2 wt%, 0.5%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 4 wt%, 5 wt%, or any value between therewith. In some embodiments, the Ru loading in the catalyst is 0.5 wt% to 3 wt%. In some embodiments, the Ru loading in the catalyst is 1.5 wt% to 2.5 wt%.

[0023] In some embodiments, the loading of the second active component is 0–30 wt%. In some embodiments, the loading of the second active component is 0%. In some embodiments, the loading of the second active component is 0.1 wt%–30 wt%.

[0024] According to some embodiments of the present invention, the catalyst is prepared by a method comprising the following steps:

[0025] The support was added to a solution containing copper and ruthenium ions to obtain a support loaded with copper and ruthenium.

[0026] The catalyst is obtained by drying and calcining the support loaded with copper and ruthenium.

[0027] In some embodiments, the mass ratio of copper ions to the support in the solution containing copper and ruthenium ions is (0.1–0.3):1, preferably (0.15–0.3):1. In some embodiments, the mass ratio of copper ions to the support in the solution containing copper and ruthenium ions is (0.001–0.05):1, preferably (0.005–0.03):1.

[0028] In some embodiments, the drying temperature is 60°C to 150°C. In some embodiments, the calcination temperature is 300°C to 600°C.

[0029] According to some embodiments of the present invention, the temperature of the dehydrogenation reaction is 200°C to 350°C, for example, 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 340°C, 350°C, or any value between them. In some embodiments, the temperature of the dehydrogenation reaction is 260°C to 350°C. In some embodiments, the temperature of the dehydrogenation reaction is 260°C to 300°C.

[0030] According to some embodiments of the present invention, the pressure of the dehydrogenation reaction is 0.95 atm to 1.05 atm.

[0031] According to some embodiments of the present invention, the catalyst is first reduced and activated in a hydrogen atmosphere before the dehydrogenation reaction. In some embodiments, the reduction and activation temperature is 200°C to 400°C, for example, 200°C, 220°C, 250°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C, or any value between them. In some embodiments, the reduction and activation time is 1 h to 6 h. In some embodiments, the hydrogen flow rate during the reduction and activation is 1 L / min to 5 L / min.

[0032] According to some embodiments of the present invention, the dehydrogenation reaction is carried out in a reactor. The reactors described in this invention include, but are not limited to, fixed-bed reactors, fluidized-bed reactors, or batch reactors.

[0033] According to some embodiments of the present invention, the volume hourly space velocity (VHSV) of the diol compound represented by Formula 1 is 0.5 h⁻¹. -1 ~15h -1 For example, 0.5h -1 1h -1 2h -1 3h -1 4h -1 5h -1 6h -1 8h -1 10h -1 12h-1 15h -1 Or any value in between. According to some embodiments of the present invention, the volume hourly space velocity of the diol compound represented by Formula 1 is 1 h⁻¹. -1 ~6h -1 According to some embodiments of the present invention, the volume hourly space velocity (VHSV) of the diol compound represented by Formula 1 is 1 h⁻¹. -1 ~3h -1 .

[0034] According to some embodiments of the present invention, the diol compound is preheated before being introduced into the reactor.

[0035] According to some embodiments of the present invention, the method further includes a step of separating and purifying the products after the dehydrogenation reaction.

[0036] In some embodiments, the separation and purification includes distillation purification.

[0037] In some embodiments, the distillation purification is carried out under atmospheric pressure (e.g., 0.95 atm to 1.05 atm) or negative pressure conditions (e.g., 1 kPa to 10 kPa).

[0038] According to some embodiments of the present invention, the distillation purification is carried out in a distillation column. The distillation column of the present invention includes, but is not limited to, packed columns, plate columns, etc.

[0039] In some embodiments, the distillation purification is carried out under conditions of 0.95 atm to 1.05 atm, the reboiler temperature of the distillation column is 140°C to 180°C, the top temperature of the column is 80°C to 120°C, and the reflux ratio is 1 to 10, preferably 2 to 6.

[0040] In some embodiments, the distillation purification is carried out under conditions of 1 kPa-10 kPa, preferably 2 kPa-6 kPa, the reboiler temperature of the distillation column is 90°C-160°C, the top temperature of the column is 40°C-100°C, and the reflux ratio is 1-10, preferably 2-6.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The method of the present invention uses diol compounds as raw materials. By selecting a supported copper-ruthenium catalyst, secondary hydroxyl groups can be converted into corresponding ketones, thus synthesizing ketol compounds in one step. The process is simple, with both high raw material conversion rate and product selectivity, and the raw material cost is low, and the subsequent separation process is simple.

[0043] 2. The method of the present invention, combined with the corresponding purification process, yields a product with high purity, which is convenient for continuous production and suitable for industrial application. Attached Figure Description

[0044] Figure 1 This is a process flow diagram of a specific embodiment of the method for preparing α-hydroxyacetone according to this application. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way.

[0046] Unless otherwise specified, all reagents used in the following experiments of this invention are commercially available products or reagents prepared according to conventional methods. Unless otherwise specified, all methods used in the experiments are conventional experimental methods. Unless otherwise specified, all instruments used in the experiments are commercially available.

[0047] As used herein, the term "alkyl" includes straight-chain alkyl groups having 1 to 10 carbon atoms and branched alkyl groups having 3 to 10 carbon atoms. The number of carbon atoms in an alkyl group can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. Specific examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, etc.

[0048] As used herein, the term "cycloalkyl" includes both monocycloalkyl and polycycloalkyl groups, and the number of carbon atoms in a cycloalkyl group can be, for example, 3, 4, 5, 6, 7, 8, 9, or 10. Specific examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, etc.

[0049] As used herein, the term "aryl" refers to a group derived from an aromatic carbon ring. An aryl group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl; in other words, an aryl group can be a monocyclic aryl, a fused-ring aryl, two or more monocyclic aryl groups conjugated by carbon-carbon bonds, a monocyclic aryl and a fused-ring aryl group conjugated by carbon-carbon bonds, or two or more fused-ring aryl groups conjugated by carbon-carbon bonds. That is, unless otherwise stated, two or more aromatic groups conjugated by carbon-carbon bonds can also be considered as aryl groups in this application. Fused-ring aryl groups may include, for example, bicyclic fused aryl (e.g., naphthyl), tricyclic fused aryl (e.g., phenanthrene, fluorene, anthracene), etc. The aryl group does not contain heteroatoms such as B, N, O, S, P, Se, and Si. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, fluorenyl, spirodifluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, triphenylene, perylene, benzo[9,10]phenanthryl, pyrene, benzofluoranthryl, etc. Base, etc.

[0050] As used herein, the term "heteroaryl" refers to a monovalent aromatic ring or its derivative containing 1, 2, 3, 4, 5, or 6 heteroatoms, which can be one or more of B, O, N, P, Si, Se, and S. Heteroaryl groups can be monocyclic or polycyclic; in other words, a heteroaryl group can be a single aromatic ring system or a system of multiple aromatic rings conjugated by carbon-carbon bonds, and any aromatic ring system can be a single aromatic monocyclic ring or a fused aromatic ring. For example, heteroaryl groups may include, but are not limited to, thiopheneyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, isoquinolinyl, indolyl, carbazoleyl, benzoxazolyl, benzoimidazolyl, benzothiazolyl, benzocarbazoleyl, benzothiaphenyl, dibenzothiaphenyl, thiaphenothiaphenyl, benzofuranyl, phenanthrololinyl, isoxazolyl, thiadiazolyl, phenthiaazinyl, silfluorenyl, dibenzofuranyl, and N-phenylcarbazoleyl, N-pyridylcarbazoleyl, N-methylcarbazoleyl, etc.

[0051] According to a specific embodiment of the present invention, a method for preparing α-hydroxyacetone is provided, the process flow diagram of which is shown below. Figure 1 As shown, the feedstock 1,2-propanediol is first preheated in a preheater, then introduced into the reactor, where a catalytic dehydrogenation reaction occurs on a catalyst bed supported on copper and ruthenium to produce α-hydroxyacetone. The product after the reaction is separated and purified by a distillation unit to obtain high-purity α-hydroxyacetone. The reactor can be a fixed-bed reactor, a fluidized-bed reactor, or a batch reactor. Before the feedstock 1,2-propanediol is introduced into the reactor, the catalyst packed in the fixed bed is first reduced and activated with hydrogen.

[0052] The loading of Cu and Ru in the catalysts in the following examples was tested by XRF.

[0053] In the following examples, the 1,2-propanediol conversion rate (%) was calculated using the following formula:

[0054] 1,2-Propanediol conversion Where, n 进料 Indicates the feed molar amount of 1,2-propanediol; n 剩余 This indicates the molar amount of 1,2-propanediol remaining after the reaction that did not participate in the reaction.

[0055] In the following examples, the selectivity / % of α-hydroxyacetone was calculated using the following formula:

[0056] α-Hydroxyacetone selectivity Where, n α-羟基丙酮Indicates the molar amount of α-hydroxyacetone obtained after the reaction; n 进料 Indicates the feed molar amount of 1,2-propanediol; n 剩余 This indicates the molar amount of 1,2-propanediol remaining after the reaction that did not participate in the reaction.

[0057] Example 1 Catalyst Preparation

[0058] 1.1 Take 50g of SiO2 spheres with an average particle size of 1-3mm, remove surface impurity ions by acid washing and water washing, and dry at 120℃ to serve as catalyst support.

[0059] 23.10 g Cu(NO3)2·6H2O and 1.03 g RuCl3 were dissolved in 20 mL of deionized water, and the above catalyst support was added. After mixing evenly, the mixture was dried at 100 °C for 12 h and calcined at 550 °C for 4 h to obtain a (10 wt% Cu-1 wt% Ru) / SiO2 catalyst with a copper loading of 10 wt% and a ruthenium loading of 1 wt%.

[0060] 1.2 Using the same steps as those used to prepare the (10wt% Cu-1wt% Ru) / SiO2 catalyst, the amounts of Cu(NO3)2·6H2O and RuCl3 were adjusted to prepare catalysts with the following compositions: (15wt% Cu-1wt% Ru) / SiO2, (20wt% Cu-1wt% Ru) / SiO2, (20wt% Cu-0.2wt% Ru) / SiO2, (20wt% Cu-5wt% Ru) / SiO2, (30wt% Cu-1wt% Ru) / SiO2, (10wt% Cu) / SiO2, 15% Cu / SiO2, 20% Cu / SiO2, and 21% Cu / SiO2.

[0061] 1.3 Using the same steps as the preparation of the above (10wt% Cu-1wt% Ru) / SiO2 catalyst, RuCl3 was replaced with Cr(NO3)3·9H2O, and the amounts of Cu(NO3)2·6H2O and Cr(NO3)3·9H2O were adjusted to prepare a catalyst with a composition of (20wt% Cu-1wt% Cr) / SiO2.

[0062] Example 2: Catalytic Dehydrogenation Experiment of 1,2-Propanediol

[0063] 50 mL of 10 wt% Cu / SiO2 catalyst was packed into a fixed bed. After N2 was introduced for replacement, H2 was introduced at a flow rate of 2 L / min, and the temperature was initially raised to 350 °C. The reduction time was 4 h. After the catalyst reduction was completed, the temperature of the fixed bed reactor was adjusted to the reaction temperature of 260 °C, and 1,2-propanediol was introduced at a volume hourly space velocity (VHSV) of 3.0 h⁻¹. -1 The product from the fixed bed outlet was analyzed by gas chromatography.

[0064] Following the same procedure, the 10wt% Cu / SiO2 catalyst was replaced with the catalysts shown in Table 1 below for evaluation. The conversion of 1,2-propanediol and the selectivity of α-hydroxyacetone are shown in Table 1.

[0065] Table 1

[0066]

[0067]

[0068] As shown in Table 1 above, the addition of ruthenium to the supported copper catalyst helps to improve the selectivity of α-hydroxyacetone. For example, with the same total metal loading, the selectivity of α-hydroxyacetone can be increased from 89.61% to 95.14% using a (20wt% Cu-1wt% Ru) / SiO2 catalyst compared to a 21wt% Cu / SiO2 catalyst. Furthermore, this application found that, with the same total metal loading, catalysts simultaneously loaded with copper and ruthenium exhibit higher 1,2-propanediol conversion and α-hydroxyacetone selectivity compared to catalysts simultaneously loaded with copper and chromium.

[0069] Example 3 Catalytic Dehydrogenation Experiment of 1,2-Propanediol

[0070] A fixed-bed reactor was packed with 50 mL of (20 wt% Cu - 1 wt% Ru) / SiO2 catalyst. After N2 replacement, H2 was introduced at a flow rate of 2 L / min, and the temperature was initially raised to 350 °C. The reduction time was 4 h. After the catalyst reduction was completed, the temperature of the fixed-bed reactor was adjusted to the reaction temperature of 220 °C, and 1,2-propanediol was introduced at a volume hourly space velocity (VHSV) of 3.0 h⁻¹. -1 The product from the fixed bed outlet was analyzed by gas chromatography.

[0071] Following the same procedure, the reaction temperature was adjusted to 240℃, 260℃, 280℃, 300℃, 320℃, and 350℃ for evaluation. The conversion rate of 1,2-propanediol and the selectivity of α-hydroxyacetone are shown in Table 2.

[0072] Table 2

[0073] Temperature / °C 1,2-Propanediol conversion rate / % α-Hydroxyacetone Selectivity / % 220 22.75 97.42 240 31.87 95.83 260 50.23 95.14 280 72.34 93.52 300 75.42 90.21 320 76.57 88.73 350 78.38 85.94

[0074] Example 4 Catalytic Dehydrogenation Experiment of 1,2-Propanediol

[0075] A fixed-bed reactor was packed with 50 mL of (20 wt% Cu - 1 wt% Ru) / SiO2 catalyst. After N2 was introduced for replacement, H2 was introduced at a flow rate of 2 L / min, and the temperature was initially raised to 350 °C. The reduction time was 4 h. After the catalyst reduction was completed, the temperature of the fixed-bed reactor was adjusted to the reaction temperature of 260 °C, and 1,2-propanediol was introduced at a volume hourly space velocity (VHSV) of 1.8 h⁻¹. -1 The product from the fixed bed outlet was analyzed by gas chromatography.

[0076] Following the same steps, adjust the raw material volume hourly space velocity to 3.0 h. -1 4.2h -1 6.0h -1 The conversion rates of 1,2-propanediol and the selectivity of α-hydroxyacetone were evaluated and are shown in Table 3.

[0077] Table 3

[0078] <![CDATA[Space velocity per hour -1 > 1,2-Propanediol conversion rate / % α-Hydroxyacetone Selectivity / % 1.8 58.36 97.58 3.0 50.23 95.14 4.2 45.76 94.63 6.0 40.23 94.37

[0079] Example 5: Purification Experiment of α-Hydroxyacetone

[0080] The product obtained in Example 4 at a reaction temperature of 260°C was fed into a distillation column. A packed column was selected, with a rectification section height of 80 cm and 3 mm θ rings as packing material. Under atmospheric pressure, the reboiler temperature was 160°C, the top temperature was 80°C, and the reflux ratio was 3. The top product was collected.

[0081] Following the same steps, the top temperature of the column was adjusted to 100℃ and 120℃. The purity of the outlet product was analyzed by gas chromatography. The purity of α-hydroxyacetone is shown in Table 4.

[0082] Table 4

[0083] Tower top temperature / ℃ α-Hydroxyacetone purity / % 80 93.46 100 94.12 120 92.54

[0084] Example 6: Purification Experiment of α-Hydroxyacetone

[0085] The product obtained in Example 4 at a reaction temperature of 260°C was fed into a distillation column. A packed column was selected, with a rectification section height of 80 cm and 3 mm θ rings as packing material. Under atmospheric pressure, the reboiler temperature was 160°C, the top temperature was 80°C, and the reflux ratio was 1. The top product was collected.

[0086] Following the same steps, the reflux ratio was adjusted to 3 and 5. The purity of the effluent was analyzed by gas chromatography. The purity of α-hydroxyacetone is shown in Table 5.

[0087] Table 5

[0088]

[0089]

[0090] Example 7: Purification Experiment of α-Hydroxyacetone

[0091] The product obtained in Example 4 at a reaction temperature of 260°C was fed into a distillation column. A packed column was selected, with a rectification section height of 80 cm and 3 mm θ rings as packing material. Under a negative pressure of 6 kPa, the reboiler temperature was 120°C, the top temperature was 65°C, and the reflux ratio was 3. The top product was collected.

[0092] Following the same steps, the system negative pressure was adjusted to 4 kPa and 2 kPa. The purity of the outlet product was analyzed by gas chromatography. The purity of α-hydroxyacetone is shown in Table 6.

[0093] Table 6

[0094] negative pressure / kPa α-Hydroxyacetone purity / % 6 89.35 4 91.34 2 94.91

[0095] As can be seen from the above embodiments, the method of the present invention uses diol compounds as raw materials and, by selecting a supported copper-ruthenium catalyst, can convert secondary hydroxyl groups into corresponding ketones, thus synthesizing ketol compounds in one step. The process is simple, possesses both high raw material conversion rate and product selectivity, and has low raw material cost, with a simple subsequent separation process. Furthermore, the method of the present invention, combined with appropriate purification processes, yields products with high purity, facilitating continuous production and making it suitable for industrial application.

[0096] The technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made in accordance with the technical solutions of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing ketools, comprising subjecting a diol compound of Formula 1 to a dehydrogenation reaction in the presence of a catalyst to produce a ketool compound of Formula 2; in, The catalyst includes a first active component, which includes Cu and Ru; In Formulas 1 and 2, R1 is selected from C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl or a combination thereof; R2 is selected from hydrogen, C1-C10 alkyl, C3-C10 cycloalkyl, C6-C20 aryl, C3-C20 heteroaryl or a combination thereof.

2. The method according to claim 1, characterized in that, In the first active component, the mass of Cu accounts for 0.1% to 99.9% of the total mass of Cu and Ru, preferably 75% to 99%, more preferably 90% to 99%; Optionally, the catalyst further includes a second active component, which includes one or more of Cr, Fe, Ni, Zn, Al, Mo, Ce, and Ag. Preferably, the mass ratio of the first active component to the second active component is (0.1-40):(0-30), more preferably (10-40):(0.1-30).

3. The method according to claim 1 or 2, characterized in that, The catalyst further includes a support on which the active component is loaded; Preferably, the carrier comprises one or more of alumina, silicon dioxide, zirconium dioxide, molecular sieve, and activated carbon; Preferably, the loading of the first active component is 0.1 wt% to 40 wt%, more preferably 10 wt% to 40 wt%, and even more preferably 20 wt% to 40 wt%. Preferably, the loading of Cu in the catalyst is 10wt% to 30wt%, more preferably 15wt% to 30wt%; Preferably, the Ru loading in the catalyst is 0.1 wt% to 5 wt%, more preferably 0.5 wt% to 3 wt%. Preferably, the loading of the second active component is 0–30 wt%.

4. The method according to any one of claims 1 to 3, characterized in that, In Formulas 1 and 2, R1 is selected from C1-C6 alkyl, C3-C6 cycloalkyl, C6-C10 aryl, C3-C10 heteroaryl or a combination thereof; R2 is selected from hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C10 aryl, C3-C10 heteroaryl or a combination thereof; Preferably, R1 is selected from C1-C6 alkyl groups, more preferably methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl, and even more preferably methyl; Preferably, R2 is selected from hydrogen or C1-C6 alkyl, more preferably hydrogen, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl, and even more preferably hydrogen.

5. The method according to any one of claims 1 to 4, characterized in that, The diols represented by Formula 1 include 1,2-propanediol, and the ketols represented by Formula 2 include α-hydroxyacetone.

6. The method according to any one of claims 1 to 5, characterized in that, The temperature of the dehydrogenation reaction is 200℃~350℃, preferably 260℃~300℃; and / or, the pressure of the dehydrogenation reaction is 0.95atm~1.05atm.

7. The method according to any one of claims 1 to 6, characterized in that, Before the dehydrogenation reaction, the catalyst is first reduced and activated in a hydrogen atmosphere; Preferably, the reduction and activation temperature is 200℃~400℃, and the reduction and activation time is 1h~6h.

8. The method according to any one of claims 1 to 7, characterized in that, The dehydrogenation reaction is carried out in a reactor, which is a fixed-bed reactor, a fluidized-bed reactor, or a batch reactor. Preferably, the volume hourly space velocity (VHSV) of the diol compound represented by Formula 1 is 0.5 h⁻¹. -1 ~15h -1 Preferably 1 hour -1 ~6h -1 More preferably 1 hour -1 ~3h -1 .

9. The method according to any one of claims 1 to 8, characterized in that, It also includes the steps of separating and purifying the products after the dehydrogenation reaction; Preferably, the separation and purification includes distillation purification; Preferably, the distillation and purification are carried out under pressure conditions of 0.95 atm to 1.05 atm or 1 kPa to 10 kPa.

10. The method according to claim 9, characterized in that, The distillation and purification are carried out in a distillation column, which is either a packed column or a plate column. Preferably, the distillation and purification are carried out under a pressure of 0.95 atm to 1.05 atm, the reboiler temperature at the bottom of the distillation column is 140°C to 180°C, the top temperature is 80°C to 120°C, and the reflux ratio is 1 to 10, preferably 2 to 6; or, The distillation and purification are carried out under pressure conditions of 1 kPa-10 kPa, preferably 2 kPa-6 kPa. The temperature of the reboiler at the bottom of the distillation column is 90℃-160℃, the temperature at the top of the column is 40℃-100℃, and the reflux ratio is 1-10, preferably 2-6.

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