Process for the preparation of ipa by hydrogenation of acetone

Abstract

The present application relates to chemical raw material preparation technical field, disclose a kind of method for preparing IPA by acetone hydrogenation, the method comprises: S1: acetone raw material is mixed with oxidizing agent and is contacted to obtain mixture material, then the mixture material is refined to obtain purified acetone;S2: in hydrogen atmosphere, purified acetone carries out hydrogenation reaction to obtain IPA product;Wherein, the water content in purified acetone is not higher than 1500ppm.The IPA product of the present application only needs simple dehydration, distillation, and the IPA product obtained can meet the requirements of high-end wafer manufacturing (line width ≤90nm) in terms of cation, water content, etc.

Description

Technical Field

[0001] This invention relates to the field of chemical raw material preparation technology, specifically to a method for preparing IPA by hydrogenation of acetone. Background Technology

[0002] Ultra-clean high-purity isopropanol (IPA) is mainly used for chip cleaning and is a key basic functional chemical in the IC manufacturing process, playing a crucial role in chip etching, cleanliness, yield, and reliability. With the further development of integrated circuits, especially the widespread application of very large-scale integrated circuits, the quality requirements for isopropanol are becoming increasingly stringent, with strict requirements placed on organic impurities, metal content, particulate matter, and moisture content. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems of low IPA selectivity and high organic impurity content in the existing process of acetone hydrogenation to isopropanol (IPA). This invention provides a method for preparing IPA by acetone hydrogenation. This method facilitates efficient and stable operation of the acetone hydrogenation process, improves acetone conversion and IPA selectivity, and reduces the content of organic impurities in the IPA product.

[0004] In the process of acetone hydrogenation to IPA, there are problems such as low acetone conversion rate, low IPA selectivity, and high organic impurity content in the IPA product. The inventors found that excessive water content in acetone causes the above problems. The water in acetone mainly comes from water contained in the acetone raw material, water generated during acetone refining, and water absorbed from the environment. Through research, the inventors found that water molecules compete with substrate molecules for adsorption at the active sites of the catalyst, reducing the activity of the acetone hydrogenation catalyst, thus leading to problems such as high organic impurity content in the IPA product and unstable catalyst operation.

[0005] Based on the above findings, the first aspect of the present invention provides a method for preparing IPA by hydrogenation of acetone, the method comprising: S1: Acetone raw material is mixed and contacted with an oxidizing agent to obtain a mixture, which is then purified to obtain purified acetone. S2: In a hydrogen atmosphere, purified acetone is subjected to a hydrogenation reaction to obtain IPA product; The water content in the purified acetone is no higher than 1500 ppm.

[0006] Preferably, the water content in the purified acetone is not higher than 1000 ppm.

[0007] Preferably, the water content in the purified acetone is not higher than 500 ppm.

[0008] Preferably, the purification method in step S1 includes: sequentially dehydrating and distilling the mixture to obtain the purified acetone.

[0009] Preferably, the dehydration method includes one or more of the following: adsorption with adsorbent materials or similar substances, chemical reaction drying, and membrane separation. The adsorption with adsorbent materials or similar substances is preferred. The method for dehydrating the mixture using adsorption with adsorbent materials or similar substances includes: passing the mixture through one or at least two adsorption columns packed with dehydrating agents connected in series for dehydration.

[0010] Preferably, the dehydrating agent includes one or more of activated carbon, molecular sieve, diatomaceous earth, silica gel, resin, and salts that can form crystalline hydrates.

[0011] Preferably, during the distillation process, the fraction collected at 54-58°C is the purified acetone.

[0012] Preferably, the distillation is atmospheric distillation; and / or during the distillation process, the temperature of the distillation vessel is 60-100℃, preferably 70-80℃.

[0013] Preferably, the mixing contact conditions in step S1 include: room temperature and pressure; and a contact time of 0.5-10 hours, preferably 3-8 hours.

[0014] Preferably, the amount of the oxidizing agent is 0.01-0.1% of the mass of the acetone raw material, and more preferably 0.02-0.08%.

[0015] Preferably, the oxidizing agent comprises a bidentate ligand metal complex after oxidation.

[0016] Preferably, the acetone raw material includes one or more of industrial-grade acetone, analytical-grade acetone, and electronic-grade acetone.

[0017] Preferably, in step S2, the hydrogenation catalyst used in the hydrogenation reaction includes one or more of copper-based catalysts, nickel-based catalysts, and ruthenium-based catalysts, with copper-based catalysts being the most preferred.

[0018] Preferably, in step S2, the conditions for the hydrogenation reaction include: Inlet temperature 70-140℃, reaction pressure 2-8MPa; and / or The molar ratio of hydrogen to acetone is (1-30):1; the acetone space velocity is 0.1-3h. -1 .

[0019] Through the above technical solution, acetone raw material and oxidizing agent are mixed and contacted to obtain a mixture. The mixture is then purified to obtain purified acetone. At the same time, the water content in the purified acetone is controlled at 1500ppm or below, which is beneficial to the efficient and stable operation of the acetone hydrogenation reaction. The inventors found through experiments that if the water content exceeds this range, water molecules will compete with substrate molecules for adsorption at the active sites of the catalyst, reducing the activity of the acetone hydrogenation catalyst. This leads to problems such as high organic impurity content in the IPA product and unstable catalyst operation. Furthermore, the IPA product of this invention only requires simple dehydration and distillation to obtain an IPA product with cation and water content that meet the requirements of high-end wafer manufacturing (linewidth ≤90nm). Detailed Implementation

[0020] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] In this invention, unless otherwise specified, "room temperature" refers to 20-30℃; "purity" refers to mass content.

[0022] This invention provides a method for preparing IPA by hydrogenation of acetone, the method comprising: S1: Acetone raw material is mixed and contacted with an oxidizing agent to obtain a mixture, which is then purified to obtain purified acetone. S2: In a hydrogen atmosphere, purified acetone is subjected to a hydrogenation reaction to obtain IPA product; The water content in the purified acetone is no higher than 1500 ppm.

[0023] In this invention, the water content is measured by the Karl Fischer method.

[0024] In this invention, acetone raw material is mixed and contacted with an oxidizing agent to obtain a mixture, which is then purified to obtain purified acetone. At the same time, the water content in the purified acetone is controlled to be 1500 ppm or below, which is beneficial to the efficient and stable operation of the acetone hydrogenation reaction, increases the conversion rate of acetone and the selectivity of IPA, and can better reduce the content of organic impurities in the IPA product.

[0025] According to a preferred embodiment of the present invention, the water content in the purified acetone is no higher than 1000 ppm. Using the aforementioned method, the conversion rate and yield of acetone can be better increased.

[0026] According to a preferred embodiment of the present invention, the water content in the purified acetone is no higher than 500 ppm. Using the aforementioned method, the conversion rate and yield of acetone can be better increased.

[0027] According to a particularly preferred embodiment of the present invention, the purification method in step S1 includes: sequentially dehydrating and distilling the mixture to obtain the purified acetone. Using the aforementioned method, the conversion rate of acetone and the selectivity of IPA can be further increased, and the content of organic impurities in the IPA can be reduced.

[0028] In this invention, the dehydration method is not particularly limited as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, the dehydration method includes one or more of the following: adsorption by adsorbent material or similar substances, chemical reaction drying, and membrane separation.

[0029] According to a particularly preferred embodiment of the present invention, the dehydration method is an adsorption method using an adsorbent or similar material. The method for dehydrating the mixture using an adsorbent or similar material includes: passing the mixture through one or at least two adsorption columns packed with a dehydrating agent in series for dehydration.

[0030] In this invention, there is no particular limitation on the number of adsorption columns in the adsorption column filled with dehydrating agent through which the mixture flows, as long as the water content in the acetone can be reduced to the required water content.

[0031] In this invention, the dehydrating agent is an adsorbent or similar material. As long as the purpose of this invention can be achieved, there are no special restrictions on the specific selection of the dehydrating agent. According to a preferred embodiment of this invention, the dehydrating agent includes one or more of activated carbon, molecular sieves (e.g., 4A molecular sieve, 3A molecular sieve), diatomaceous earth, silica gel, resin (e.g., polyacrylic acid superabsorbent resin), and salts that can form crystalline hydrates (e.g., copper sulfate, calcium sulfate, sodium sulfate).

[0032] According to a preferred embodiment of the present invention, during the distillation process, the fraction collected at 54-58°C is the purified acetone. Using the aforementioned method, the conversion rate of acetone and the yield of IPA can be better improved, and the content of organic impurities in the IPA product can be reduced.

[0033] According to a particularly preferred embodiment of the present invention, the distillation is atmospheric distillation, and during the distillation process, the temperature of the reboiler is 60-100°C, preferably 70-80°C. By employing the aforementioned method, the water content in purified acetone can be further reduced, thereby increasing the conversion rate of acetone and the selectivity of IPA, and reducing the content of organic impurities in the IPA product.

[0034] In this invention, the mixing and contact conditions in step S1 are not particularly limited as long as the objective of the invention can be achieved. According to a preferred embodiment of the invention, the mixing and contact conditions in step S1 include: room temperature and pressure; and a contact time of 0.5-10 hours, preferably 3-8 hours. Using the aforementioned method, the content of organic impurities in IPA products can be better reduced.

[0035] In this invention, the amount of oxidizing agent used is not particularly limited as long as the purpose of this invention can be achieved. According to a preferred embodiment of this invention, the amount of oxidizing agent used is 0.01-0.1% of the mass of acetone raw material, preferably 0.02-0.08%. By adopting the aforementioned scheme, the content of organic impurities in IPA products can be better reduced, the yield of purified acetone can be increased, and the selectivity of IPA can be increased at the same time.

[0036] According to the present invention, the type of oxidizing agent is not particularly limited as long as the objective of the present invention can be achieved. According to a preferred embodiment of the present invention, the oxidizing agent comprises a bidentate ligand metal complex after oxidation. Using the aforementioned scheme, the conversion rate of acetone and the selectivity of IPA can be better increased, while the content of organic impurities in the IPA product can be reduced.

[0037] According to a particularly preferred embodiment of the present invention, in the bidentate ligand metal complex, the compound providing the ligand is as shown in formula (1), and the compound providing the coordinating atom is a metal salt; Equation (1), In equation (1), X is -C(R3)-, R 11 R 12 R 21 R 22 R3 is independently selected from H, C1-C5 alkyl, benzyl, naphthyl, and C1-C3 alkyl-substituted phenyl; n is an integer from 0 to 6.

[0038] In this invention, it is understood that -C(R3)- represents the number of carbon atoms participating in the formation of the ring in formula (1), and R3 represents the substituent attached to the carbon atom. When n is 0, the compound in formula (1) has a five-membered ring structure, and when n is 1, the compound in formula (1) has a six-membered ring structure. According to a particularly preferred embodiment of this invention, in formula (1), n ​​is an integer from 0 to 3. By adopting the aforementioned scheme, the conversion rate of acetone and the yield of IPA can be better increased, while the content of organic impurities in the IPA product can be reduced.

[0039] In this invention, the term "C1-C5 alkyl" can refer to either branched alkyl or straight-chain alkyl. Examples of C1-C5 alkyl groups include methyl, ethyl, isopropyl, n-propyl, butyl, pentyl, etc. According to a particularly preferred embodiment of the invention, R...11 R 12 R 21 R 22 The phenyl groups are independently selected from H, C1-C3 alkyl, benzyl, and methyl-substituted phenyl groups. Using the aforementioned scheme, the conversion rate of acetone and the selectivity of IPA can be further increased.

[0040] According to a particularly preferred embodiment of the present invention, R3 is H or a C1-C3 alkyl group. Using the aforementioned scheme, the conversion rate of acetone and the selectivity of IPA can be further increased.

[0041] In this invention, the term "metal salt" refers to a salt whose cation is a metal cation, such as nitrates and chlorides. The metal element in the metal salt is not particularly limited as long as it achieves the objectives of this invention. According to a preferred embodiment of this invention, the metal element in the metal salt is selected from one or more transition metals from the fourth and fifth periods, preferably one or more of Mn, Co, and Mo. Using the aforementioned approach, the content of organic impurities in IPA can be better reduced.

[0042] In this invention, it is understood that the bidentate ligand metal complex is obtained by a coordination reaction between a compound (ligand) of formula (1) providing the ligand and a metal salt providing the coordinating atom. The bidentate ligand metal complex after oxidation refers to the one obtained after oxidation of the bidentate ligand metal complex. Those skilled in the art can select the conditions of the coordination reaction and the conditions of the oxidation reaction, as well as the amounts of ligand, metal salt, and oxidant as needed. For example, the molar ratio of ligand to metal salt is (1-1.5):1, and the molar ratio of oxidant to metal salt is (1-1.5):1.

[0043] According to a preferred embodiment of the present invention, the preparation method of the oxidizing agent includes: in the presence of a solvent, the compound represented by formula (1) undergoes a coordination reaction with a metal salt, followed by the addition of an oxidizing agent to carry out an oxidation reaction, and finally the solvent is removed and optionally the oxidizing agent is separated. After the oxidation reaction, a purification step can be selected as needed, for example, using conventional methods in the art such as extraction or drying.

[0044] In this invention, the type of solvent can be selected as needed. In the specific reaction process, a solvent can be used to coordinate the compound shown in formula (1) into a solution containing the compound shown in formula (1), and a solvent can be used to prepare a solution containing the metal salt. Then, the solution containing the compound shown in formula (1) and the solution containing the metal salt are subjected to a coordination reaction. Those skilled in the art can select the type and amount of solvent as needed to ensure the smooth progress of the coordination reaction. The specific type and amount of solvent have no effect on achieving the purpose of this invention, and will not be elaborated on in this invention.

[0045] In this invention, in order to ensure the stable progress of the coordination reaction, those skilled in the art can select the conditions of the coordination reaction as needed, for example, stirring the reaction at room temperature for 1-10 hours in an inert atmosphere; in order to ensure the smooth progress of the oxidation reaction, those skilled in the art can select the conditions of the oxidation reaction as needed, for example, reacting at room temperature for 1-5 hours.

[0046] In this invention, in order to ensure the smooth progress of the oxidation reaction, those skilled in the art can select the type of oxidant as needed. According to one embodiment of this invention, the oxidant includes one or more of oxygen, hydrogen peroxide, cumene peroxide, peracetic acid, tert-butyl hydrogen peroxide, peroxypropionic acid, perchlorate, permanganate, and dichromate.

[0047] In this invention, as long as the purpose of this invention can be achieved, the source of the acetone raw material is not particularly limited. Based on the acetone raw materials available on the market, the acetone raw material includes one or more of the following: industrial grade acetone (purity of 99-99.5%), analytical grade acetone (purity of 99.5-99.9%), and electronic grade acetone (purity of 99.9-99.97%).

[0048] In this invention, unless otherwise specified, purity refers to mass content.

[0049] According to a preferred embodiment of the present invention, in step S2, the hydrogenation catalyst used in the hydrogenation reaction includes one or more of copper-based catalysts, nickel-based catalysts, and ruthenium-based catalysts, preferably copper-based catalysts. Copper-based catalysts are very sensitive to impurities such as water, and industrial-grade acetone is commonly used in the prior art for the preparation of IPA. However, the method of hydrogenation for the preparation of IPA using the method of the present invention can better increase the conversion rate of purified acetone and the selectivity of IPA.

[0050] In this invention, "copper-based catalyst" refers to a catalyst with copper as the active component. It can be a supported catalyst (the support can be alumina, silicon dioxide, etc.) or a composite catalyst containing copper. Nickel-based catalysts and ruthenium-based catalysts are similar to copper-based catalysts and can be supported or composite. There are no restrictions on the specific types of hydrogenation catalysts in this invention, and they will not be elaborated here.

[0051] According to a preferred embodiment of the present invention, in step S2, the conditions for the hydrogenation reaction include: an inlet temperature of 70-140°C and a reaction pressure of 2-8 MPa.

[0052] According to a preferred embodiment of the present invention, in step S2, the conditions for the hydrogenation reaction include: a molar ratio of hydrogen to acetone of (1-30):1; and an acetone space velocity of 0.1-3 h⁻¹. -1 .

[0053] The present invention will be described in detail below through embodiments. In the following embodiments and comparative examples: Purified acetone conversion rate = (1 - acetone content in the GC chromatogram of the IPA product after reaction / acetone content in the chromatogram of purified acetone from the raw material) 100%; IPA selectivity = the percentage of peak area of ​​IPA in non-acetone substances in the GC chromatography of the IPA product after reaction; The purity of purified acetone is equal to the percentage of acetone peak area in the purified acetone as determined by the gas chromatography area normalization method.

[0054] Example 1 Preparation of oxidizing reagents: In an inert atmosphere, a ligand solution containing the ligand shown in formula (1-1) and a molar ratio of molybdenum chloride to ligand providing Mo atoms are mixed at a molar ratio of 1:1.1. After a coordination reaction is carried out at room temperature with magnetic stirring for 5 hours, an oxidant (potassium permanganate, with a molar ratio of 1.25:1 to the metal salt) is added for an oxidation reaction for 2 hours. After desolvation, extraction, and drying, the product is obtained. Equation (1-1); Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with an oxidizing agent (0.03 wt% of the industrial-grade acetone) at room temperature and pressure for 5 hours to obtain a mixture. The mixture was then passed through an adsorption column packed with 3A molecular sieves for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 74°C, and the fraction collected at 54-58°C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.0 h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0055] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0056] Example 2 Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with an oxidizing agent (same as in Example 1, but at 0.03 wt% of the industrial-grade acetone) for 5 hours at room temperature and pressure to obtain a mixture. The mixture was then passed through two adsorption columns packed with 3A molecular sieves in series for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 74°C, and the fraction collected at 54-58°C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.0 h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0057] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0058] Example 3 Preparation of oxidizing reagents: In an inert atmosphere, a ligand solution containing the ligands shown in formula (1-3) and a molybdenum chloride solution providing Mo atoms are mixed at a molar ratio of molybdenum chloride to ligand of 1:1.1. After a coordination reaction with magnetic stirring at room temperature for 5 hours, an oxidant (cumene peroxide, with a molar ratio of 1.25:1 to the metal salt) is added to carry out an oxidation reaction for 2 hours. After desolvation, extraction, and drying, the product is obtained. Equation (1-3); Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with an oxidizing agent (0.03 wt% of the industrial-grade acetone) at room temperature and pressure for 5 h to obtain a mixture. The mixture was then passed through an adsorption column packed with 3A molecular sieve for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 80 °C, and the fraction collected at 54-58 °C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.5h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0059] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0060] Example 4 Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with an oxidizing agent (same as in Example 1, but at 0.03 wt% of the industrial-grade acetone) for 5 hours at room temperature and pressure to obtain a mixture. The mixture was then passed through an adsorption column packed with polyacrylic acid superabsorbent resin for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 74°C, and the fraction collected at 54-58°C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.0 h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0061] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0062] Example 5 Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with chromium trioxide (0.03 wt% of industrial-grade acetone) at room temperature and pressure for 5 hours to obtain a mixture. The mixture was then passed through an adsorption column packed with 3A molecular sieve for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 74°C, and the fraction collected at 54-58°C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.0 h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0063] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0064] Example 6 Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with an oxidizing agent (same as in Example 1, but at 0.03 wt% of the industrial-grade acetone) at room temperature and pressure for 15 h to obtain a mixture. The mixture was then passed through an adsorption column packed with 3A molecular sieves for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 74 °C, and the fraction collected at 54-58 °C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.0 h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0065] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0066] Example 7 Preparation of IPA products: Industrial-grade acetone with a purity of 98% was mixed with an oxidizing agent (same as in Example 1, but at 0.1 wt% of the industrial-grade acetone) for 5 hours at room temperature and pressure to obtain a mixture. The mixture was then passed through an adsorption column packed with 3A molecular sieves for dehydration to obtain dehydrated acetone. The dehydrated acetone was then distilled at atmospheric pressure at a bottom temperature of 74°C, and the fraction collected at 54-58°C was used to purify the acetone. Purified acetone was fed into an acetone hydrogenation reactor packed with 5% by weight Cu / SiO2 catalyst for hydrogenation reaction (reaction inlet temperature 100℃, reaction pressure 4MPa, hydrogen to acetone molar ratio 8:1, acetone space velocity 1.0 h⁻¹). -1 (This leads to the acquisition of IPA products.)

[0067] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0068] Comparative Example 1 The method of Example 2 is different in that: no dehydration treatment is performed, that is, industrial grade acetone with a purity of 98% is mixed with an oxidizing agent (0.03 wt% of industrial grade acetone) at room temperature and pressure for 5 hours to obtain a mixture. Then, the mixture is distilled at atmospheric pressure at a distillation column temperature of 74°C, and the fraction collected at 54-58°C is used to purify acetone. The rest is the same as in Example 2.

[0069] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0070] Comparative Example 2 The method of Example 2 differs in that: industrial-grade acetone does not come into contact with the oxidizing agent; that is, industrial-grade acetone with a purity of 98% flows with the oxidizing agent through two series-connected adsorption columns packed with 3A molecular sieves for dehydration to obtain dehydrated acetone; then the dehydrated acetone is distilled at atmospheric pressure at a bottom temperature of 74°C, and the fraction collected at 54-58°C is used to purify acetone.

[0071] The rest is the same as in Example 2.

[0072] The water content, acetone conversion rate, and IPA selectivity in purified acetone are shown in Table 1.

[0073] Table 1

[0074] As can be seen from the results in Table 1, the method of the present invention for preparing IPA in Examples 1-7 not only increases the yield of purified acetone and has good economic benefits, but also has a high conversion rate of purified acetone and a high yield of the final product IPA.

[0075] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing IPA by hydrogenation of acetone, characterized in that, The method includes: S1: Acetone raw material is mixed and contacted with an oxidizing agent to obtain a mixture, which is then purified to obtain purified acetone. S2: In a hydrogen atmosphere, purified acetone is subjected to a hydrogenation reaction to obtain IPA product; The water content in the purified acetone shall not exceed 1500 ppm; The amount of the oxidizing agent used is 0.01-0.1% of the mass of the acetone raw material; The oxidizing agent includes a bidentate ligand metal complex after oxidation reaction; In the bidentate ligand metal complex, the compound providing the ligand is shown in formula (1), and the compound providing the coordinating atom is a metal salt; Equation (1), In equation (1), X is -C(R3)-, R 11 R 12 R 21 R 22 R3 is independently selected from H, C1-C5 alkyl, benzyl, naphthyl, and C1-C3 alkyl-substituted phenyl; n is an integer from 0 to 6; The metal element in the metal salt is one or more of Mn, Co and Mo.

2. The method according to claim 1, wherein, The water content in purified acetone should not exceed 1000 ppm.

3. The method according to claim 1 or 2, wherein, The water content in purified acetone should not exceed 500 ppm.

4. The method according to claim 1 or 2, wherein, The purification method in step S1 includes: sequentially dehydrating and distilling the mixture to obtain the purified acetone.

5. The method according to claim 4, wherein, Dehydration methods include one or more of the following: adsorption with adsorbent materials or similar substances, chemical reaction drying, and membrane separation.

6. The method according to claim 5, wherein, Dehydration methods include adsorption using adsorbent materials or similar substances. Methods for dehydrating mixtures using adsorbent materials or similar substances include passing the mixture through one or at least two adsorption columns connected in series and packed with a dehydrating agent.

7. The method according to claim 6, wherein, The dehydrating agent includes one or more of activated carbon, molecular sieves, diatomaceous earth, silica gel, resin, and salts that can form crystalline hydrates.

8. The method according to claim 4, wherein, During the distillation process, the fraction collected at 54-58℃ is the purified acetone.

9. The method according to claim 8, wherein The distillation is atmospheric distillation; and / or During the distillation process, the temperature of the distillation vessel is 60-100℃.

10. The method according to claim 9, wherein, During the distillation process, the temperature of the distillation vessel is 70-80℃.

11. The method according to claim 1 or 2, wherein, The mixed contact conditions in step S1 include: ambient temperature and pressure; contact time of 0.5-10h.

12. The method according to claim 11, wherein, The mixed contact conditions in step S1 include a contact time of 3-8 hours.

13. The method according to claim 1 or 2, wherein, The amount of the oxidizing agent used is 0.02-0.08% of the mass of the acetone raw material.

14. The method according to claim 1 or 2, wherein, The acetone raw material includes one or more of industrial-grade acetone, analytical-grade acetone, and electronic-grade acetone.

15. The method according to claim 1 or 2, wherein, In step S2, the hydrogenation catalyst used in the hydrogenation reaction includes one or more of copper-based catalysts, nickel-based catalysts, and ruthenium-based catalysts.

16. The method according to claim 15, wherein, In step S2, the hydrogenation catalyst used in the hydrogenation reaction is a copper-based catalyst.

17. The method according to claim 1 or 2, wherein, In step S2, the conditions for the hydrogenation reaction include: Inlet temperature 70-140℃, reaction pressure 2-8MPa; and / or The molar ratio of hydrogen to acetone is (1-30):1; the acetone space velocity is 0.1-3h. -1 .

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