阅读说明：本技术 一种1,6-己二酸制备1,6-己二醇反应工艺 (Reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid ) 是由 黄冬 袁俊秀 曾志强 于 2018-09-06 设计创作，主要内容包括：一种1,6-己二酸制备1,6-己二醇反应工艺。包括如下步骤：(1)、将原料1,6-己二酸与甲醇分别加入配料罐,配料罐中加入固体酸催化剂进行预酯化；(2)、将步骤(1)配置的原料液利用泵按一定空速送入装有固体酸催化剂的预热器中,预热器中装有固体酸催化剂进行酯化反应；(3)、预热好的原料液与氢气混合均匀进入装有Cu/ZnO/Al<Sub>2</Sub>O<Sub>3</Sub>-SiO<Sub>2</Sub>催化剂的固定床反应器进行加氢反应；(4)、步骤(3)所得反应物经冷凝器、气液分离得1,6-己二醇产品。本发明创新性的将配料罐与预热器进行组合,利用其进行酯化反应,缩短了1,6-己二醇反应工艺,降低生产成本。(A reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid. The method comprises the following steps: (1) respectively adding the raw materials 1, 6-adipic acid and methanol into a proportioning tank, and adding a solid acid catalyst into the proportioning tank for pre-esterification; (2) feeding the raw material liquid prepared in the step (1) into a preheater filled with a solid acid catalyst by using a pump at a certain airspeed, wherein the preheater is filled with the solid acid catalyst for esterification reaction; (3) the preheated raw material liquid and hydrogen are uniformly mixed and enter the reactor filled with Cu/ZnO/Al 2 O 3 ‑SiO 2 The fixed bed reactor of the catalyst carries out hydrogenation reaction; (4) the reaction obtained in the step (3)The product is separated by a condenser and gas-liquid to obtain the 1, 6-hexanediol product. The invention innovatively combines the batching tank and the preheater, and utilizes the batching tank and the preheater to carry out esterification reaction, thereby shortening the reaction process of 1, 6-hexanediol and reducing the production cost.)

1. A reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid is characterized in that: the reaction process comprises the following steps: (1) respectively adding 1, 6-adipic acid and methanol serving as raw materials into a mixing tank, and adding 5-10 wt% of a solid acid catalyst into the mixing tank to perform pre-esterification reaction; (2) pumping the raw material liquid prepared in the step (1) for 0.5-1 h^-1Sending the mixture into a preheater filled with a solid acid catalyst, wherein the temperature of the preheater is 100-150 ℃, and the filling amount of the solid acid catalyst is 50-100 mL; (3) uniformly mixing the preheated raw material liquid and hydrogen, and feeding the mixture into a fixed bed reactor filled with a hydrogenation catalyst to carry out hydrogenation reaction; (4) and (4) carrying out gas-liquid separation on the reactant obtained in the step (3) by a condenser to obtain a 1, 6-hexanediol product.

2. The reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid according to claim 1, wherein the molar ratio of 1, 6-adipic acid to methanol in the pre-esterification reaction is 1:4 to 1:10, the temperature of the mixing tank is 60 to 90 ℃, and the stirring is carried out for 20 to 60 min.

3. The process of claim 1, 6-hexanediol from 1, 6-adipic acid, wherein the solid acid catalyst is a heteropolyacid.

4. The reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid according to claim 1, wherein the hydrogenation reaction temperature is 150-215 ℃, the molar ratio of hydrogen to ester is 30: 1-130: 1, the reaction pressure is 2-8 MPa, and the volume space velocity is 0.5-1.5 h^-1。

5. The process of claim 1, 6-hexanediol from 1, 6-adipic acid, wherein the hydrogenation catalyst is Cu/ZnO/Al₂O₃-SiO₂A catalyst.

6. The process for preparing 1, 6-hexanediol from 1, 6-adipic acid according to claim 5, wherein the hydrogenation catalyst is Cu/ZnO/Al₂O₃-SiO₂The components of (A): cu content of 30-50%, ZnO content of 10-25%, and carrier Al₂O₃-SiO₂The content is 50-70%.

7. The process according to claim 5 or 6, wherein the catalyst support Al is₂O₃-SiO₂The preparation method comprises the following steps: (1) weighing Al₂O₃Powder and SiO₂Powder mixing, Al₂O₃90-95% of SiO by mass₂5-10% by mass, (2) adding about 1-5% of graphite into the powder for flaking.

Technical Field

The invention belongs to the field of fine chemical engineering, and relates to a reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid.

Background

1, 6-hexanediol is a solid at room temperature, melting point 42 ℃ and molecular weight 118.18. The 1, 6-hexanediol is mainly used for producing novel polyester, paint, adhesive, detergent, antifoaming agent, plasticizer and the like, is a newly-found important fine chemical raw material and is known as organic synthesized novel diamond. The polyester polyol prepared from 1, 6-hexanediol is used for modifying polyurethane elastomer, and the modified resin has excellent mechanical strength, heat resistance, water resistance and oxidation resistance. The 1, 6-hexanediol has a long carbon chain and relatively high flexibility, and can be used for preparing a novel polyester product with special performance; 1, 6-hexanediol is used for preparing a medical intermediate 1, 6-dibromohexane, so that indole hormone-inhibiting medicines with special curative effects on prostatitis can be synthesized; in addition, with the continuous improvement of living standard, the requirements of people on environment quality are higher and higher, and the demand of environment-friendly products is increased, so that the industry of the coating and the cross-linking agent develops towards the direction of environmental protection, no toxicity and no public hazard, and the 1, 6-hexanediol plays a greater role in preparing environment-friendly water-soluble resin coating, polyurethane cross-linking agent and the like.

At present, the industrial mature method for producing 1, 6-hexanediol mainly uses dimethyl adipate as a raw material to obtain a 1, 6-hexanediol product through hydrogenation reaction. Research institutions at home and abroad carry out a great deal of research on the preparation method of 1, 6-hexanediol, and there are two methods in general: one is to use dimethyl adipate to carry out hydrogenation reaction; another is direct reduction with adipic acid.

CN1011113128 discloses a method for preparing 1, 6-hexanediol by hydrogenation of 1, 6-dimethyl adipate, wherein the hydrogen-ester ratio is 50-150: 1, the load of a catalyst is 0.1-0.5 kg of ester/h, the catalyst is kg, the temperature is 150-300 ℃, the reaction pressure is 4-7 MPa, and Cu/ZnO/Al is adopted₂O₃The catalyst and the fixed bed reactor have the advantages that the conversion rate of 1, 6-dimethyl adipate is more than 99 percent, and the selectivity of 1, 6-hexanediol is more than 96 percent.

CN101138726 discloses a catalyst of 1, 6-hexanediol and a preparation method thereof, wherein the catalyst comprises 25-60% of CuO,25-60% of ZnO and Al₂O₃10-30%. The conversion rate of the 1, 6-adipic acid dimethyl ester is more than 99 percent, and the selectivity of the 1, 6-hexanediol is more than 96 percent.

CN101265158B discloses a method for preparing 1, 6-hexanediol, which comprises the steps of setting an esterification reaction tower to pre-esterify adipic acid and methanol by using a solid acid catalyst, rectifying the reactant, purifying and then carrying out hydrogenation reaction. The ratio of hydrogen to ester is 50-350: 1, the temperature is 150-250 ℃, the pressure is 2.5-10 MPa, the catalyst is 25-60% of CuO, 25-60% of ZnO and Al₂O₃10-30%. The reaction product is purified to obtain the 1, 6-hexanediol with the purity of more than 99 percent.

CN102372604A discloses a method for preparing 1, 6-hexanediol by hydrogenation of 1, 6-dimethyl adipate, wherein the reaction time is 5-12 h, the conversion rate of 1, 6-dimethyl adipate is 60-99.9% by adopting a noble metal catalyst and a batch reaction kettle, and the selectivity of 1, 6-hexanediol is more than 70% under the conditions that the hydrogen-ester ratio is 50-200: 1, the temperature is 150-220 ℃, the reaction pressure is 3-5 MPa, the stirring speed is 500-1000 rpm.

CN104549254 discloses a catalyst for preparing 1, 6-hexanediol by reduction between adipic acids, wherein the active component of the catalyst is one of Ru, Re, In and Ir, the catalyst adopts active carbon as a carrier, the reduction is carried out by using a reaction kettle, water is used as a solvent, the reaction temperature is 80-300 ℃, and the reaction pressure is 3-10 Mpa, so that the 1, 6-hexanediol is obtained.

In the above patent, 1, 6-hexanediol is prepared by hydrogenation reaction using dimethyl adipate, and the reaction process involves two steps: one step is adipate esterification reaction, and dimethyl adipate is obtained by purification; one step is the hydrogenation reaction of dimethyl adipate to obtain 1, 6-hexanediol. The operation flow is increased, the reaction time is prolonged, and the reaction cost is increased. The reaction process for preparing the hexanediol by directly reducing the adipic acid adopts a noble metal catalyst, and the reaction cost is high.

Disclosure of Invention

The invention aims to simplify the preparation process of 1, 6-hexanediol and reduce the reaction cost. The invention combines a proportioning tank and a preheater for esterification reaction, and the esterification product is directly subjected to ester hydrogenation reaction to obtain the 1, 6-hexanediol. Meanwhile, methanol generated by the reaction is recycled, and no waste liquid is generated in the whole reaction. The reaction time is reduced by 4-5 h compared with the step-by-step reaction time.

The reaction process for preparing 1, 6-hexanediol from 1, 6-adipic acid is characterized by comprising the following steps: the reaction process comprises the following steps: (1) respectively adding 1, 6-adipic acid and methanol serving as raw materials into a batching tank, and adding 5-10 wt% of a solid acid catalyst into the batching tank for pre-esterification; (2) pumping the raw material liquid prepared in the step (1) for 0.5-1 h^-1Feeding the air speed into a preheater filled with a solid acid catalyst, wherein the temperature of the preheater is 100-150 ℃, and the filling amount of the solid acid catalyst is 50-100 mL; (3) uniformly mixing the preheated raw material liquid and hydrogen, and feeding the mixture into a fixed bed reactor filled with a hydrogenation catalyst to carry out hydrogenation reaction; (4) and (4) carrying out gas-liquid separation on the reactant obtained in the step (3) by a condenser to obtain a 1, 6-hexanediol product.

The pre-esterification method is characterized in that the molar ratio of 1, 6-adipic acid to methanol is 1: 4-1: 10, the temperature of a batching tank is 60-90 ℃, and the pre-esterification is stirred for 20-60 min.

The solid acid catalyst is characterized in that the solid acid is a carbon-based heteropolyacid catalyst.

The hydrogenation reaction is characterized by having a reaction temperature of 150-215 ℃, a hydrogen-ester molar ratio of 30: 1-130: 1, a reaction pressure of 2-8 Mpa and a volume space velocity of 0.5-1.5 h^-1。

The hydrogenation catalyst in the invention is Cu/ZnO/Al₂O₃-SiO₂The catalyst is characterized by comprising 30-50% of Cu, 10-25% of ZnO and a carrier Al₂O₃-SiO₂The content is 50-70%.

Carrier Al in the invention₂O₃-SiO₂The preparation method of the carrier is characterized by comprising the following steps: (1) weighing a certain amount of Al₂O₃Powder and SiO₂Powder mixing, Al₂O₃90-95% of SiO by mass₂5-10% of mass content; (2) and adding about 1-5% of graphite into the powder for flaking.

The reaction process is characterized in that the conversion rate of 1, 6-adipic acid is 90-99%, and the selectivity of 1, 6-hexanediol is 90-96%.

Detailed Description