阅读说明：本技术 一种己二酸直接加氢制1，6-己二醇催化剂的制备方法及应用 (Preparation method and application of catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid ) 是由 梁长海 李晓越 罗靖洁 于 2019-10-21 设计创作，主要内容包括：本发明属于多相催化技术领域,提供了一种己二酸直接加氢制1,6-己二醇催化剂的制备方法及应用。具体的采用包括铱、钯、铂、铼中的一种或两种的组合作为活性组分,负载于包括纳米碳管、活性炭及石墨等一种或一种以上载体的组合,在不采用或加入HCl、HF、Na<Sub>2</Sub>CO<Sub>3</Sub>、NaHCO<Sub>3</Sub>或NaOH中一种或一种以上混合的辅助分散剂的条件下,研制金属总含量为0.3-5.0wt％的负载型催化剂。采用连续搅拌釜式反应器,在2-10MPa压力,80-220℃温度范围内,催化加氢己二酸2-10h。本发明针对1,6-己二醇制备工艺苛刻、产能较低、工艺条件复杂等问题,开发新型高效负载型贵金属催化剂,具有较高的实用性。(The invention belongs to the technical field of heterogeneous catalysis, and provides a preparation method and application of a catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid. Specifically, one or two of iridium, palladium, platinum and rhenium are used as active components, and are loaded on one or more carriers of carbon nanotubes, activated carbon, graphite and the like, and HCl, HF and Na are not used or added 2 CO 3 、NaHCO 3 Or one or more mixed auxiliary dispersing agents in NaOH, and the total metal content is 0.3-5.0wt percent. Catalytic hydrogenation is carried out in a continuous stirred tank reactor under the pressure of 2-10MPa and at the temperature of 80-220 DEG CAdipic acid for 2-10 h. Aiming at the problems of harsh preparation process, low productivity, complex process conditions and the like of the 1, 6-hexanediol, the invention develops a novel high-efficiency supported noble metal catalyst and has high practicability.)

1. A preparation method of a catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid is characterized by comprising the following steps:

using carbon material as carrierTaking a metal salt precursor solution of one or two of iridium, palladium, platinum and rhenium metal salts, and controlling the total metal loading amount to be 0.3-5 wt%; aging at room temperature for 12H without adding or adding auxiliary dispersion solution to adjust pH value of the solution, vacuum filtering, washing, transferring to a forced air drying oven, and drying overnight to obtain sample powder, and calcining at 200-600 deg.C for 2-8H in a tubular furnace mixed atmosphere of hydrogen and argon, wherein H₂The volume fraction is not less than 10 percent, and the obtained adipic acid is directly hydrogenated to prepare the 1, 6-hexanediol catalyst.

2. The method of claim 1, wherein the auxiliary dispersing solution comprises HCl, HF, Na₂CO₃、NaHCO₃And one or a mixture of two or more of NaOH.

3. The method according to claim 1 or 2, wherein the carbon material comprises one or a mixture of two or more of carbon nanotubes, activated carbon, and graphite.

4. The method according to claim 1 or 2, wherein the metal salt precursor comprises one or a mixture of two or more of acetylacetone salt, chloride, nitrate, and ammonium salt.

5. The method according to claim 3, wherein the metal salt precursor comprises one or more of acetylacetone salt, chloride, nitrate, and ammonium salt.

6. The application of the catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid is characterized by comprising the following steps of:

adding adipic acid, a solvent and a reduced catalyst into a high-pressure reaction kettle, sealing the reaction kettle, filling hydrogen, replacing air in the kettle for 3 times, filling 2-10MPa pressure, and reacting at 80-220 ℃ for 2-10 h; and after the reaction is finished, cooling to room temperature, discharging gas to normal pressure, detecting reaction products by gas chromatography and liquid chromatography respectively after centrifugal separation, and separating to obtain the 1, 6-hexanediol product.

7. The use of claim 6, wherein the mass concentration of the adipic acid in the solvent is 1-5%, the mass ratio of the catalyst to the adipic acid is 10-40%, and the solvent is one or a mixture of more than two of ethanol, water and diethyl ether.

Technical Field

The invention belongs to the technical field of heterogeneous catalysis, and particularly relates to a preparation method and application of a catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid. The high-efficiency supported noble metal catalyst is designed, and has high practicability aiming at solving the problems of harsh preparation process, low productivity, complex process conditions and the like of the 1, 6-hexanediol.

Background

1, 6-hexanediol is an important fine chemical raw material and is mainly used for producing high-quality chemical products such as polyurethane elastomer resin, polyester plasticizers, food additives and the like. In the production process of the dye and the polyester, the hexanediol can effectively improve the buffer performance, the color and the adsorption capacity of the product and has excellent light stability. In the production of polyurethane, the hexanediol can effectively improve the hydrolysis resistance and mechanical strength of products, and the performance of the polyurethane produced by using the hexanediol as a raw material is far higher than that of other types of polyurethane. Therefore, hexanediol is known as a new base stone for organic synthesis, and the development and optimization of the production process of hexanediol have important industrial application prospects.

At present, adipic acid is generally adopted as a raw material at home and abroad to produce 1, 6-hexanediol, and dimethyl adipate is firstly generated through an esterification reaction with methanol under the action of a catalyst, or the dimethyl adipate is directly adopted as the raw material to produce the 1, 6-hexanediol through catalytic hydrogenation. The intermittent esterification hydrogenation alcohol preparation process is generally carried out in a high-pressure reaction kettle, and the reaction pressure is too high and even exceeds 30 MPa. The harsh production conditions cause the danger coefficient of the production process to be extremely high, the stability to be poor and the industrialization process to be not facilitated; the continuous hydrogenation alcohol preparation process is adopted, although the esterification hydrogenation process can be carried out under the condition that the pressure is lower than 10MPa, the liquid space velocity is low, the hydrogen-ester molar ratio is as high as 300, and the energy utilization rate is extremely low.

Patent CN103124713 describes a process for preparing 1, 6-hexanediol by hydrogenation of caprolactone and/or its oligomer or polymer, the catalyst uses copper as main active center, Mn, Ba and other elements as auxiliary agent, and Cr₂O₃As a carrier, the conversion rate of raw materials reaches 99.7 percent, 1The selectivity of 6-hexanediol can reach 96.7%. However, the pressure required by the hydrogenation reaction is as high as 10-35 MPa, and great potential safety hazards exist.

Patent CN101679157A reports a process for the preparation of 1, 5-pentanediol and/or 1, 6-hexanediol by esterification of monocarboxylic and dicarboxylic acids and hydrogenation in the presence of a copper-containing catalyst. However, the operating pressure of the method is up to 25MPa, the reaction temperature reaches 275 ℃, and the copper-based catalyst is easy to sinter and deactivate.

Patent CN104549254A reports a metal-supported catalyst for preparing 1, 6-hexanediol by directly reducing adipic acid, and Ru-based trimetal and/or tetrametallic catalysts are supported by taking activated carbon as a carrier, so that higher yield of hexanediol is obtained under the conditions of 5MPa and 180 ℃. However, the catalyst adopts 3-4 noble metal components, and the components and the preparation process are complicated and the cost is high.

In conclusion, the catalyst for preparing the 1, 6-hexanediol by directly hydrogenating the adipic acid, which is simple and efficient in preparation process, is developed, the preparation of the 1, 6-hexanediol with high yield is realized at lower reaction temperature and reaction pressure, the production process is simplified, the production cost is saved, the energy utilization rate is improved, and the catalyst has great strategic significance on the structure adjustment and transformation upgrading of petrochemical products.

Disclosure of Invention

The invention provides a catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid. Aiming at improving the energy utilization rate and solving the problems of harsh preparation process, low productivity, complex process conditions and the like of the 1, 6-hexanediol, a novel high-efficiency supported noble metal catalyst is developed, and the 1, 6-hexanediol is generated by directly hydrogenating adipic acid by adopting a continuous stirred tank reactor. The production process has low energy consumption and high energy utilization rate, and can effectively catalyze and convert the 1, 6-hexanediol as the target product.

The technical scheme of the invention is as follows:

a preparation method of a catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid comprises the following steps:

taking a carbon material as a carrier, taking a metal salt precursor solution of one or two of iridium, palladium, platinum and rhenium metal salts, and controlling the total metal loading amount to be 0.3-5 wt%; aging at room temperature for 12H without adding or adding auxiliary dispersion solution to adjust pH value of the solution, vacuum filtering, washing, transferring to a forced air drying oven, and drying overnight to obtain sample powder, and calcining at 200-600 deg.C for 2-8H in a tubular furnace mixed atmosphere of hydrogen and argon, wherein H₂The volume fraction is not less than 10 percent, and the obtained adipic acid is directly hydrogenated to prepare the 1, 6-hexanediol catalyst.

The carbon material comprises one or more of carbon nano tube, activated carbon and graphite.

The auxiliary dispersion solution comprises HCl, HF and Na₂CO₃、NaHCO₃And one or a mixture of two or more of NaOH.

The metal salt precursor comprises one or a mixture of more than two of acetylacetone salt, chloride, nitrate and ammonium salt.

The application of a catalyst for preparing 1, 6-hexanediol by directly hydrogenating adipic acid comprises the following steps:

adding adipic acid, a solvent and a reduced catalyst into a high-pressure reaction kettle, sealing the reaction kettle, filling hydrogen, replacing air in the kettle for 3 times, filling 2-10MPa pressure, and reacting at 80-220 ℃ for 2-10 h; and after the reaction is finished, cooling to room temperature, discharging gas to normal pressure, detecting reaction products by gas chromatography and liquid chromatography respectively after centrifugal separation, and separating to obtain the 1, 6-hexanediol product.

The mass concentration of the adipic acid in the solvent is 1-5%, the mass ratio of the catalyst to the adipic acid is 10-40%, and the solvent is one or a mixture of more than two of ethanol, water and ether.

The invention has the beneficial effects that: 1, 6-hexanediol is prepared by directly hydrogenating adipic acid at relatively low temperature and pressure by adopting a low-content supported noble metal-based catalyst. According to the method of the present invention, in some examples, the conversion of adipic acid was 87.98% and the selectivity of 1, 6-hexanediol was 40.88%, depending on the set reaction parameters.

Drawings

FIG. 1 is an X-ray diffraction (XRD) pattern of a 3 wt% Ir/C catalyst.

FIG. 2 is 3 wt% Ir₁Re₁X-ray diffraction (XRD) pattern of the/C catalyst.

FIG. 3 is 3 wt% Ir₁Re₁Transmission electron microscopy images of/C catalysts.

FIG. 4 is 3 wt% Ir₁Re₂Catalyst in H₂And (5) characterization results of temperature programmed desorption under the atmosphere.

Detailed Description

The present invention is further illustrated by the following examples, which are intended to be purely exemplary of the invention and are not to be construed as limiting the scope of the invention.