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Cyclopentanol from cyclopentene

Chemical formula      C5H10O Molar mass              86.1323 g/mol Appearance            Colorless liquid Density                    0.949 g/mL Melting point           −19 °C (−2 °F; 254 K) Boiling point              139 to 140 °C / 760 Torr

CN-112661602-B    Preparation method of cyclopentanol based on copper catalyst    
中 国石油化工股份有限公司, 中国石化上海石油化工股份有限公司    2019-10-16                                                                                                                                                  2019-10-16    Application filed by China Petroleum and Chemical Corp, Sinopec Shanghai Petrochemical Co Ltd   

Abstract
The invention belongs to the technical field of organic chemical industry, and discloses a preparation method of cyclopentanol based on a copper catalyst. The method comprises the following specific steps: (1) oxidation reaction: taking cyclopentene as a raw material, adopting hydrogen peroxide as an oxidant, adding a catalyst, an auxiliary agent and a solvent, and performing an oxidation reaction to generate 1, 2-cyclopentane epoxide; (2) hydrogenation reaction: taking 1, 2-epoxy cyclopentane as raw material, adding hydrogen and copper catalyst, and carrying out hydrogenation reaction in a reactor to obtain cyclopentanol. The cyclopentanol preparation method provided by the invention is environment-friendly, has mild operation conditions, can effectively improve the yield of cyclopentanol, and reduces the pollution of the strong acid preparation process to equipment and environment.


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 products such as bromocyclopentane, chlorocyclopentane, antibacterial agents, antiallergic agents and the like.

At present, the production of cyclopentanol is only indian Alkali metal limited company and Japanese Zeon corporation, the domestic report is only Fushun chemical manufacturing limited company, the productivity is 1000 tons/year, and the device is in a production stopping state at present, and the main reason is that the product cost of the reduction process adopting cyclopentanone as a raw material is high. At present, the global yield of cyclopentanol is about ten thousand tons, the market vacancy is larger, and about 3000 tons are required to be imported every year in China.

The traditional cyclopentanol production mainly uses adipic acid as a raw material, and cyclopentanone is prepared by high-temperature decarboxylation and then hydrogenation, but the generation of a large amount of pollutants and limited raw material sources limit the further development of the process.

In recent years, due to wide sources and low price of C5 olefin fractions, 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 price, and can obtain cyclopentene from dicyclopentadiene fraction by depolymerization and selective hydrogenation.

Cyclopentene can be used for preparing cyclopentanol through indirect hydration or direct hydration, and cyclopentanol and cyclopentanone can be produced through direct oxidation. The cyclopentene is directly oxidized into a homogeneous reaction, so that 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, sulfuric acid has serious corrosion to equipment, the concentration process has high energy consumption 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 high energy consumption, and a plurality of documents report the technology for preparing the organic alcohol by directly hydrating the olefin, wherein the 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 discloses a method for preparing cyclopentanol by hydration of cyclopentene by using strong acid cation exchange resin, wherein the single pass conversion rate of cyclopentene is about 3.5% and the selectivity is about 98% under the condition that the feeding mole ratio of cyclopentene to water is 1.2-3.0.

The patent CN1676506A proposes a method for preparing cyclopentanol by hydration of cyclopentene, which takes cyclopentene and water as raw materials, and prepares cyclopentanol by hydration reaction of a fixed bed under the combined catalysis of a main catalyst and a cocatalyst, wherein the feeding mole ratio of the cyclopentene and the water is 0.8-5.0, the volume airspeed is 1-10 hr -1, the 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 trialkyl hexylamine, the single pass conversion rate of the 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 cyclopentene acetate, wherein the modified sulfonic cation exchange resin is prepared by sequentially soaking conventional sulfonic cation exchange resin in toluene and methyl isobutyl ketone; (2) The material obtained in the step (1) enters a rectifying tower, an azeotrope is formed between the lower part of the rectifying tower and water, hydrolysis reaction is carried out between the material and water under the action of a sulfonic cation exchange resin catalyst filled in the upper part of the rectifying tower, cyclopentanol is produced at the top of the rectifying tower, and acetic acid is produced at the bottom of the rectifying tower.

From the prior art, CN1676506A and CN106674003A can prepare cyclopentanol, but the single pass conversion rate of cyclopentene is low, so that the single pass yield of cyclopentanol is low, or the reaction system uses strong acid to severely corrode equipment, pollute the environment, have higher equipment requirements and high operation difficulty, and correspondingly increase the operation cost and energy consumption, thereby being unfavorable 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 copper-based catalyst. The method takes cyclopentene as a raw material, and firstly adopts an oxidation process to prepare cyclopentane epoxide; then taking the cyclopentane epoxide as a raw material and adopting a hydrogenation process to prepare the cyclopentanol. The method can effectively solve the defects of low yield, serious equipment corrosion and environmental pollution caused by the use of sulfuric acid and the like in the existing cyclopentanol preparation process, and has the advantages of low raw material cost, high oxidation process yield, simple operation, environment-friendliness, mild hydrogenation process condition, easy operation, high cyclopentanol yield and good selectivity.




The following is a specific technical scheme of the invention:
the preparation method of cyclopentanol based on copper-based catalyst comprises the following steps:
(1) Oxidation reaction: taking cyclopentene as a raw material, taking hydrogen peroxide as an oxidant, adding a catalyst, a solvent and an auxiliary agent, and carrying out an oxidation reaction to obtain 1, 2-cyclopentane epoxide;
(2) Hydrogenation reaction: taking 1, 2-epoxy cyclopentane as raw material, adding hydrogen and copper catalyst, and carrying out hydrogenation reaction in a 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, the auxiliary agent is NaHCO 3, and the hydrogen peroxide is preferably 50wt% 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 hydrogenation reaction conditions 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 copper-based catalyst is a modified copper-based catalyst, and is obtained by impregnating a small amount of lead and bismuth with the copper-based catalyst.
Further, in the step (2), the preparation of the modified copper-based catalyst includes the steps of:
(a) Modified component and active auxiliary agent load:
Preparing a precursor of modified component lead and a precursor of active auxiliary agent bismuth into a solution, and soaking a copper-based catalyst in the solution at 60-80 ℃ for 2-6 hours by adopting an equal volume soaking method to obtain a copper-based catalyst precursor; drying the precursor for 2-4 hours at the temperature of 90-110 ℃; roasting the precursor in stages, wherein the temperature of the first stage is 225 ℃ for 1.5-2.5 h, the temperature of the second stage is 280-310 ℃ for 3-6 h, and the copper catalyst loaded with the modified component and the active assistant is obtained;
(b) Catalyst activation:
And (c) activating the catalyst obtained in the step (a) at the temperature of 240 ℃ and under normal pressure, wherein the hydrogen flow rate is 150ml/min, and the activation time is 12h, so as to obtain the modified copper 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 bismuth is one or more of bismuth nitrate, bismuth acetate or bismuth sulfate.
Further, in the step (a), the impregnation time is preferably 3 to 5 hours, the drying temperature is preferably 100 to 105 ℃, and the stage-wise roasting second stage time is preferably 4 to 5 hours.
Further, in the step (a), the concentration of the precursor of the active component lead and the precursor of the active auxiliary agent bismuth are both between 0.4 and 1.0mol/L, so that the molar ratio of lead to palladium is between 0.1:1 and 0.4:1, and the molar ratio of lead to 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, TS-1 molecular sieve is used as a catalyst, cyclopentene is used as a raw material, hydrogen peroxide is used as an oxidant, naHCO 3 is used as an auxiliary agent, acetone is used as a solvent, 1, 2-cyclopentane epoxide can be generated by oxidation, and the cyclopentene conversion rate is 60-75% under a milder condition, and the selectivity is close to 100%. In the hydrogenation reaction stage, the 1, 2-epoxy cyclopentane can generate cyclopentanol and cyclopentane through one-step hydrogenation, the method belongs to parallel competition reaction, the yield of the cyclopentanol depends on the activity and selectivity of the catalyst, the selectivity of the active center of the copper catalyst is greatly improved through further modification treatment, the yield of the cyclopentanol is also improved, and the cyclopentene is used as a raw material, and through the combination of oxidation reaction and hydrogenation reaction, 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 oxidation reaction and hydrogenation reaction, the method can effectively solve the defects existing in the prior art: the cyclopentanol yield is low, and the sulfuric acid is used to severely corrode equipment and pollute the environment. In the method provided by the invention, the yield in 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 condition, easy operation, high cyclopentanol yield and good selectivity.


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JP-2001181222-A    Method for producing cyclopentanol     Nippon Zeon Co Ltd, 日本ゼオン株式会社    1999-12-27     


Abstract
PROBLEM TO BE SOLVED: To provide a method for producing cyclopentanol in high selectivity and high yield. SOLUTION: In producing cyclopentanol from cyclopentene by using a zeolite catalyst, a hydration reaction is carried out in a solvent selected from a group consisting of (1) cyclic alcohols, (2) glycol monoethers, (3) glycol monoesters, (4) 5-10C dialkyl ketones, (5) 5C or 7-10C cyclic ketones, (6) alkylaryl ketones and (7) mixture solvents of phenols with ethers.


 
    Example 1 An H-type crystalline aluminosilicate ZSM-5 (made by UOP, silica / alumina ratio =40)
After charging 5 g, water 10 g, cyclopentene 5 g, phenol 5 g, and n-butyl ether 3 g, 115
Reaction was carried out at 15 ° C. for 1.5 hours.
As a result, the conversion is 13.1% and the selectivity for cyclopentanol was 94.3%.       

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CN-103130630-B    Cyclopentanol  synthetic method     张若煜    2013-03-01   
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More examples here