阅读说明：本技术 基于钯系负载型催化剂的环戊醇的制备方法 (Preparation method of cyclopentanol based on palladium supported catalyst ) 是由 常慧 黄勇 叶军明 陆鑫 孙骏 瞿卫国 于 2019-10-16 设计创作，主要内容包括：本发明属于有机化工技术领域,公开了一种基于钯系负载型催化剂的环戊醇的制备方法。该方法具体步骤如下：(1)氧化反应：以环戊烯为原料,采用双氧水为氧化剂,加入催化剂、助剂和溶剂,进行氧化反应,生成1,2-环氧环戊烷；(2)加氢反应：以1,2-环氧环戊烷为原料,加入氢气和钯系负载型催化剂,在釜式或固定床反应器中进行加氢反应,得到环戊醇；本发明提供的环戊醇制备方法对环境友好,操作条件温和,可有效提高环戊醇的收率,并减少强酸制备工艺对设备和环境造成的污染。(The invention belongs to the technical field of organic chemical industry, and discloses a preparation method of cyclopentanol based on a palladium-based supported catalyst. The method comprises the following specific steps: (1) and (3) oxidation reaction: cyclopentene is used as a raw material, hydrogen peroxide is used as an oxidant, and a catalyst, an auxiliary agent and a solvent are added for oxidation reaction to generate 1, 2-epoxycyclopentane; (2) hydrogenation reaction: taking 1, 2-epoxy cyclopentane as a raw material, adding hydrogen and a palladium supported catalyst, and carrying out hydrogenation reaction in a kettle type or fixed bed reactor to obtain cyclopentanol; the preparation method of cyclopentanol provided by the invention is environment-friendly, has mild operation conditions, can effectively improve the yield of cyclopentanol, and reduces the pollution of a strong acid preparation process to equipment and environment.)

1. A preparation method of cyclopentanol based on a palladium supported catalyst is characterized by comprising the following steps:

(1) and (3) oxidation reaction: cyclopentene is taken as a raw material, hydrogen peroxide is taken as an oxidant, and a catalyst, a solvent and an auxiliary agent are added for oxidation reaction to obtain 1, 2-epoxycyclopentane;

(2) hydrogenation reaction: 1, 2-epoxy cyclopentane is used as a raw material, hydrogen is introduced under the action of a palladium supported catalyst, and hydrogenation reaction is carried out in a fixed bed or a kettle type reactor to obtain cyclopentanol.

2. The process according to claim 1, wherein in the step (1), the catalyst is tungstic acid catalyst or molecular sieve catalyst, the solvent is acetone, and the auxiliary agent is NaHCO₃The hydrogen peroxide is 50 wt% of hydrogen peroxide.

3. The method according to claim 2, wherein in the step (1), the catalyst is a TS-1 molecular sieve catalyst.

4. The method according to claim 1, wherein the temperature of the oxidation reaction in the step (1) is 20 to 50 ℃.

5. The method according to claim 4, wherein the temperature of the oxidation reaction in the step (1) is 30 to 40 ℃.

6. The production method according to claim 1, wherein in the step (2), the conditions of the hydrogenation reaction are as follows: the temperature is 80-150 ℃, the pressure is 3-10 MPa, and the liquid hourly space velocity is 0.1-0.8 h^-1。

7. The production method according to claim 6, wherein in the step (2), the conditions of the hydrogenation reaction are as follows: the temperature is 90-120 ℃, the pressure is 4-8 MPa, and the liquid hourly space velocity is 0.2-0.6 h^-1。

8. The production method according to claim 1, wherein in the step (2), the palladium-based supported catalyst is a modified palladium-based supported catalyst obtained by impregnating a palladium-based supported catalyst with a small amount of lead and bismuth.

9. The method according to claim 8, wherein the preparation of the modified palladium-based supported catalyst in the step (2) comprises the steps of:

(a) loading a modified component and a coagent:

preparing a precursor of a modified component lead and a precursor of an active additive bismuth into a solution, and soaking the palladium supported catalyst in the solution for 2-6 hours at the temperature of 60-80 ℃ by adopting an isometric soaking method to obtain a palladium supported catalyst precursor; drying the precursor at the temperature of 90-110 ℃ for 2-4 h; roasting the precursor by stages, wherein the temperature of the first stage is 225 ℃, the time is 1.5-2.5 h, the temperature of the second stage is 280-310 ℃, and the time is 3-6 h, so as to obtain the palladium supported catalyst loaded with the modified component and the active additive;

(b) and (3) catalyst reduction:

adding a certain amount of 20 wt% hydrazine hydrate solution into the catalyst obtained in the step (a), reducing for 1-4 h at 60-80 ℃, washing the reduced material with deionized water until the pH value of a washing solution is close to neutral, and drying to obtain the modified palladium supported catalyst.

10. The preparation method according to claim 9, wherein in the step (a), the precursor of the modified component lead is one or more of lead sulfate, lead nitrate or lead acetate; the precursor of the active auxiliary agent bismuth is one or more of bismuth nitrate, bismuth acetate or bismuth sulfate.

11. The method according to claim 9, wherein in the step (a), the dipping time is preferably 3 to 5 hours, the drying temperature is 100 to 105 ℃, the staged firing second stage temperature is 290 to 300 ℃, and the staged firing second stage time is 4 to 5 hours.

12. The preparation method of the lead-free composite material of the invention is characterized in that, in the step (a), the concentration of the solution prepared by the precursor of the lead as the active component and the precursor of the bismuth as the active additive is 0.4-1.0 mol/L, so that the molar ratio of the lead to the palladium is 0.1: 1-0.4: 1, and the molar ratio of the lead to the bismuth is kept at 1: 1.

Technical Field

The invention belongs to the technical field of organic chemical industry, and particularly relates to a preparation method of cyclopentanol based on a palladium supported catalyst, in particular to a method for oxidizing cyclopentene to generate 1, 2-epoxycyclopentane and then generating the cyclopentanol by further hydrogenating the 1, 2-epoxycyclopentane under the action of the palladium supported catalyst.

Background

Cyclopentanol is colorless viscous liquid, has aromatic smell, is an important intermediate of fine chemical products of medicines and pesticides, and is mainly used for preparing bromocyclopentane, chlorocyclopentane, antibacterial drugs, antiallergic drugs and the like. At present, cyclopentanol is only produced abroad by Indian alkali metal company and Japanese Zeon company, and domestic reports are only smooth Tianzhu chemical manufacturing company, the capacity is 1000 tons/year, and the device is in a production stop state at present, mainly because the product cost of the reduction process adopting cyclopentanone as the raw material is high. At present, the global yield of cyclopentanol is about ten thousand tons, the market vacancy is large, and China needs to import about 3000 tons every year.

In the traditional cyclopentanol production, adipic acid is mainly used as a raw material, cyclopentanone is prepared through high-temperature decarboxylation and then is obtained through hydrogenation, but the generation of a large amount of pollutants and the limited raw material source limit the further development of the process. In recent years, due to the wide source and low price of the C5 olefin fraction, the research on the production of cyclopentanol by using the C5 fraction as a raw material has attracted great interest. The C5 fraction is a byproduct of ethylene production by naphtha steam cracking, has rich resources and low cost, and can obtain cyclopentene from dicyclopentadiene fraction through depolymerization and selective hydrogenation. Cyclopentene can be either indirectly hydrated or directly hydrated to produce cyclopentanol, and can also be directly oxidized to produce cyclopentanol and cyclopentanone. Wherein, cyclopentene is directly oxidized into homogeneous reaction, the conversion rate is low, and the selectivity is poor; although the indirect hydration method has the advantages of high conversion rate and good selectivity, the sulfuric acid has serious corrosion to equipment, the energy consumption of the concentration process is large when the sulfuric acid is recovered and reused, and the environmental pollution is serious; the direct hydration method solves the problems of equipment corrosion and large energy consumption, and a plurality of documents report the technology for preparing organic alcohol by directly hydrating olefin, wherein a catalyst is acidic substances such as strong-acid cation exchange resin, solid acid, zeolite and the like, so that the olefin and the water directly react to generate the alcohol.

Japanese patent JP2003212803 uses strong acid cation exchange resin to hydrate cyclopentene to prepare cyclopentanol, under the condition that the charging molar ratio of cyclopentene and water is 1.2-3.0, the conversion per pass of cyclopentene is about 3.5%, and the selectivity is about 98%.

In China petrochemical patent CN1676506A, cyclopentene and water are used as raw materials, and the cyclopentene and water are subjected to hydration reaction in a fixed bed under the combined catalysis of a main catalyst and a cocatalyst to prepare the cyclopentanol, wherein the feeding molar ratio of the cyclopentene to the water is 0.8-5.0, and the volume space velocity is 1-10 hr^-1The reaction temperature is 130-180 ℃, the reaction pressure is 1.0-3.0 MPa, the main catalyst is strong acid cation resin, the cocatalyst is trialkylamine, the conversion per pass of cyclopentene is 2.3-8.9%, and the selectivity is 98%.

Patent CN106674003A discloses a method for preparing cyclopentanol by hydration of cyclopentene, which comprises the following steps: (1) cyclopentene and acetic acid are subjected to addition reaction under the action of modified sulfonic cation exchange resin to generate cyclopentyl acetate, and the modified sulfonic cation exchange resin is prepared by sequentially soaking conventional sulfonic cation exchange resin in toluene and methyl isobutyl ketone; (2) and (2) feeding the material obtained in the step (1) into a rectifying tower, forming an azeotrope with water at the lower part of the rectifying tower, carrying out hydrolysis reaction with water under the action of a sulfonic cation exchange resin catalyst filled at the upper part of the rectifying tower, extracting a product cyclopentanol at the tower top, and extracting acetic acid at the tower bottom.

In the prior art, both CN1676506A and CN106674003A can be used for preparing cyclopentanol, but the conversion per pass of cyclopentene is not high, so that the yield per pass of cyclopentanol is low, or the reaction system uses strong acid to corrode equipment seriously, which causes environmental pollution, high requirement on equipment, high operation difficulty, and increased operation cost and energy consumption, which is not suitable for industrial production.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention aims to provide a preparation method of cyclopentanol based on a palladium-based supported catalyst. The invention takes cyclopentene as raw material, firstly adopts oxidation process to prepare 1, 2-epoxy cyclopentane; then using 1, 2-epoxy cyclopentane as raw material and adopting hydrogenation process to prepare cyclopentanol. The method can effectively solve the defects of low yield, equipment corrosion caused by using sulfuric acid, serious environmental pollution and the like in the existing cyclopentanol preparation process.

The following is a specific technical scheme of the invention:

a preparation method of cyclopentanol based on a palladium-based supported catalyst comprises the following steps:

(1) and (3) oxidation reaction: cyclopentene is taken as a raw material, hydrogen peroxide is taken as an oxidant, and a catalyst, a solvent and an auxiliary agent are added for oxidation reaction to obtain 1, 2-epoxycyclopentane;

(2) hydrogenation reaction: 1, 2-epoxy cyclopentane is used as a raw material, hydrogen is introduced under the action of a palladium supported catalyst, and hydrogenation reaction is carried out in a kettle type or fixed bed reactor to obtain cyclopentanol.

Further, in the step (1), the catalyst is a tungstic acid catalyst or a molecular sieve catalyst, preferably a TS-1 molecular sieve catalyst, the solvent is acetone, and the auxiliary agent is NaHCO₃The hydrogen peroxide is preferably 50 wt% hydrogen peroxide.

Further, in the step (1), the temperature of the oxidation reaction is 20 to 50 ℃, preferably 30 to 40 ℃.

Further, in the step (2), the hydrogenation reaction conditions are as follows: the temperature is 80-150 ℃, the pressure is 3-10 MPa, and the liquid hourly space velocity is 0.1-0.8 h^-1. Preferably, the conditions of the hydrogenation reaction are as follows: the temperature is 90-120 ℃, the pressure is 4-8 MPa, and the liquid hourly space velocity is 0.2-0.6 h^-1。

Further, in the step (2), the palladium-based supported catalyst is a modified palladium-based supported catalyst, and is obtained by impregnating a palladium-based supported catalyst with a small amount of lead and bismuth.

Further, in the step (2), the preparation of the modified palladium-based supported catalyst comprises the steps of:

(a) loading a modified component and a coagent:

preparing a precursor of a modified component lead and a precursor of an active additive bismuth into a solution, and soaking the palladium supported catalyst in the solution for 2-6 hours at the temperature of 60-80 ℃ by adopting an isometric soaking method to obtain a palladium supported catalyst precursor; drying the precursor at the temperature of 90-110 ℃ for 2-4 h; roasting the precursor by stages, wherein the temperature of the first stage is 225 ℃, the time is 1.5-2.5 h, the temperature of the second stage is 280-310 ℃, and the time is 3-6 h, so as to obtain the palladium supported catalyst loaded with the modified component and the active additive;

(b) and (3) catalyst reduction:

adding a certain amount of 20 wt% hydrazine hydrate solution into the catalyst obtained in the step (a), reducing for 1-4 h at 60-80 ℃, washing the reduced material with deionized water until the pH value of a washing solution is close to neutral, and drying to obtain the modified palladium supported catalyst.

Further, in the step (a), the precursor of the modified component lead is one or more of lead sulfate, lead nitrate or lead acetate; the precursor of the active auxiliary agent bismuth is one or more of bismuth nitrate, bismuth acetate or bismuth sulfate.

In the step (a), the soaking time is preferably 3-5 h, the drying temperature is preferably 100-105 ℃, the temperature of the staged roasting second stage is preferably 290-300 ℃, and the time of the staged roasting second stage is preferably 4-5 h.

Further, in the step (a), the concentrations of the solutions prepared from the precursor of the lead as the active component and the precursor of the bismuth as the active additive are both 0.4-1.0 mol/L, so that the molar ratio of the lead to the palladium is 0.1: 1-0.4: 1, and the molar ratio of the lead to the bismuth is kept at 1: 1.

Further, in the step (2), the reactor is a fixed bed reactor.

In the technical scheme provided by the invention, in the oxidation reaction stage, a TS-1 molecular sieve is used asCatalyst, cyclopentene as raw material, hydrogen peroxide as oxidant, NaHCO₃As an auxiliary agent, acetone is a solvent and can be oxidized to generate 1, 2-epoxycyclopentane, under a mild condition, the conversion rate of cyclopentene is 60-75%, and the selectivity is close to 100%. In the hydrogenation reaction stage, the 1, 2-epoxycyclopentane can be hydrogenated further to generate cyclopentanol and cyclopentane, which belongs to parallel competition reaction, the yield of the cyclopentanol depends on the activity and selectivity of the catalyst, the palladium supported catalyst is further modified, and the selectivity of the catalyst is further improved due to the synergistic effect of lead and the auxiliary agent bismuth, so that the yield of the cyclopentanol is improved. The technical scheme provided by the invention avoids the problems of high raw material cost, low conversion rate, poor selectivity, equipment corrosion and environmental pollution in the prior art.

Compared with the prior art, the invention has the beneficial effects that:

after the oxidation reaction and the hydrogenation reaction are carried out, the method can effectively solve the defects existing in the prior art: the yield of cyclopentanol is low, and the equipment corrosion and environmental pollution are serious by using sulfuric acid. In the method provided by the invention, the yield of the oxidation reaction stage is high, the operation is simple, and the method is safe and friendly to the environment; the hydrogenation reaction stage has mild conditions, easy operation, high yield of cyclopentanol and good selectivity.

Detailed description of the preferred embodiments

The details of the present invention are further described below by way of examples. Cyclopentanol was prepared in examples 1 to 10 by the following procedure:

(1) and (3) oxidation reaction: cyclopentene is used as a raw material, hydrogen peroxide is used as an oxidant, a catalyst is a TS-1 molecular sieve catalyst, acetone is used as a solvent, and NaHCO is used as an auxiliary agent₃And carrying out oxidation reaction to prepare the 1, 2-epoxy cyclopentane.

(2) Hydrogenation reaction: 1, 2-epoxy cyclopentane is used as a raw material, hydrogen is introduced under the action of a palladium supported catalyst, and hydrogenation reaction is carried out in a kettle type or fixed bed reactor to obtain cyclopentanol.

The TS-1 molecular sieve catalysts in the embodiments 1-10 are provided by China Shanghai petrochemical institute, and specific experimental parameters and result representations of the oxidation reaction and the hydrogenation reaction and analytical methods, test standards, characterization results and modification experimental parameters of the palladium supported catalyst are respectively shown in tables 2-5.

[ examples 1 to 10 ]

First, oxidation reaction

The cyclopentene conversion and 1, 2-epoxycyclopentane selectivity were calculated as follows:

wherein (cyclopentene content)_inRepresents the inlet mole content of cyclopentene; (cyclopentene content)_outRepresents the cyclopentene outlet molar content; (1, 2-Cyclopentalene oxide molar content)_outRepresents the molar content of 1, 2-epoxycyclopentane in the reaction solution after the oxidation reaction; (cyclopentene molar content) in represents the cyclopentene inlet molar content; (cyclopentene molar content) out represents the cyclopentene outlet molar content.

The oxidation reactor is a kettle type reactor, cyclopentene and acetone are added into the reaction kettle in proportion, and then TS-1 molecular sieve catalyst and auxiliary agent NaHCO are added in proportion₃And hydrogen peroxide for oxidation reaction. The oxidation products were analyzed by gas chromatography. The reaction temperature, the reactant ratio, and the reaction results are shown in Table 1.

TABLE 1

Hydrogenation reaction

The conversion of 1, 2-epoxycyclopentane and the cyclopentanol selectivity were calculated as follows:

is selected to have a size ofThe stainless steel tubular fixed bed reactor is used as a reactor for hydrogenation reaction. 100ml of a hydrogenation catalyst was charged in the reactor, wherein the palladium supported catalyst was used in example 1 and purchased from the institute of force and chemical engineering, homogeneous science, Shandong, the physical property indexes, analytical methods, and test standards thereof are shown in tables 2 and 3, respectively, and the modified palladium supported catalyst was used in examples 2 to 10 and obtained by impregnating the palladium supported catalyst with a small amount of lead and bismuth, and specifically included the following steps: (a) loading a modified component and a coagent: preparing a solution with the concentration of 0.4-1.0 mol/L from lead sulfate and bismuth nitrate to ensure that the molar ratio of lead to palladium is 0.1: 1-0.4: 1 and the molar ratio of lead to bismuth is kept at 1:1, and soaking a palladium supported catalyst in the solution at the temperature of 60-80 ℃ for 2-6 hours by adopting an isometric impregnation method to obtain a palladium supported catalyst precursor; drying the precursor at the temperature of 90-110 ℃ for 2-4 h; roasting the precursor by stages, wherein the temperature of the first stage is 225 ℃, the time is 1.5-2.5 h, the temperature of the second stage is 280-310 ℃, and the time is 3-6 h, so as to obtain the palladium supported catalyst loaded with the modified component and the active additive; (b) and (3) catalyst reduction: adding a certain amount of 20 wt% hydrazine hydrate solution into the catalyst obtained in the step (a), reducing for 1-4 h at 60-80 ℃, washing the reduced material with deionized water until the pH value of a washing solution is close to neutral, and drying to obtain the modified palladium supported catalyst. The experimental parameters of the preparation process are shown in Table 4.

Before feeding, nitrogen is used for replacing, oxygen in the reactor is driven out, the temperature of the system is raised to a required temperature, the reaction feeding amount is controlled by a feeding pump, and the pressure of the system is regulated by a back pressure valve arranged in a high molecular tank. Preheating 1, 2-cyclopentane epoxide, pumping into a reactor from the top at a set speed, introducing hydrogen into the reactor through a gas distributor, and mixing the 1, 2-cyclopentane epoxide with the hydrogen, and introducing the mixture into a catalyst bed layer for hydrogenation reaction. The hydrogenated product enters a gas-liquid separator from the bottom of the reactor, and the liquid-phase product enters a product storage tank. The unreacted hydrogen separated by the gas-liquid separator is decompressed by an adjusting valve, enters a wet gas meter for metering, is emptied, or is returned to the reaction system after being compressed. The hydrogenation product was analyzed by gas chromatography. The reaction experiment condition parameters, reactant ratios and reaction results are shown in Table 5.

TABLE 2

TABLE 3

TABLE 4

TABLE 5