CN110818566A - A kind of method for preparing cyclopentanol from cyclopentene - Google Patents

Abstract

The application discloses a method for preparing cyclopentanol and co-producing ethanol from cyclopentene and acetic acid. Firstly, cyclopentene and acetic acid are subjected to addition reaction under the action of an acid catalyst, and the obtained product is rectified and purified to obtain cyclopentyl acetate; the reaction process provided by the invention has the advantages of high conversion per pass, good reaction stability, no use of any solvent, high efficiency, environmental protection, no pollution and good industrial production prospect.

Description

A kind of method for preparing cyclopentanol from cyclopentene

technical field

The present application relates to a method for preparing cyclopentanol from cyclopentene, and belongs to the field of catalytic synthesis.

Background technique

Cyclopentanol is an important fine chemical raw material, which is widely used in the synthesis of pharmaceutical intermediates and the production of flavors and fragrances. The traditional production method of cyclopentanol takes adipic acid as raw material, firstly obtains cyclopentanone through decarboxylation, and then adds hydrogenation to obtain cyclopentanol. Since the reaction process produces a large amount of pollutants and the source of the raw material adipic acid is restricted, this production method is gradually eliminated.

Cyclopentene is one of the by-products of naphtha cracking to ethylene, and cyclopentanol can be synthesized by direct or indirect hydration. For example, Japanese Patent JP2003212803 reports the method for preparing cyclopentanol by direct hydration of cyclopentene catalyzed by acidic cation exchange resin. The feed is fed according to the molar ratio of cyclopentene to water of 1.2 to 3.0, and the single-pass conversion rate of cyclopentene is only 3.5%. Although adding a solvent such as phenol can improve the conversion rate, the phenolic hydroxyl group easily induces side reactions, which reduces the selectivity and also brings great difficulties to the subsequent separation. Chinese patent CN102399133A proposes a method for the indirect hydration of cyclopentene to prepare cyclopentanol. Specifically, cyclopentene is first reacted with acetic acid to generate cyclopentyl acetate. After the product is separated by rectification, transesterification occurs with methanol in the presence of a CaO catalyst. Generate cyclopentanol and methyl acetate. Although the conversion rate and selectivity are obviously improved compared with the direct hydration method, the process is complicated and the energy consumption is high. Patent CN108069819A adopts catalytic rectification device to replace traditional device to carry out the hydrolysis reaction of cyclopentyl acetate, which simplifies the overall process, but the cost of the device is relatively high, and the space-time yield of the catalytic rectification device is low. Patent CN108003018A improves the indirect hydration method, chooses to carry out addition reaction and transesterification reaction under supercritical conditions, the conversion rate of cyclopentene reaches 92%, and the selectivity of cyclopentanol is higher than 95%, but the supercritical high temperature and high pressure conditions Too harsh, not conducive to industrial applications.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the application proposes a new method for preparing cyclopentanol from cyclopentene, which is characterized in that comprising the following steps:

(a) cyclopentene and acetic acid carry out addition reaction under the action of acid catalyst to obtain cyclopentyl acetate;

(b) Hydrogenation of cyclopentyl acetate under the action of a metal catalyst produces cyclopentanol and co-produces ethanol.

Optionally, step (a) is an addition reaction of cyclopentene and acetic acid under the action of an acid catalyst, and the reaction product is purified by rectification to obtain cyclopentyl acetate.

Optionally, step (a) is an addition reaction of cyclopentene and acetic acid under the action of an acid catalyst, and the reaction product is purified by rectification to obtain cyclopentyl acetate with a purity greater than 95%.

Optionally, the conversion rate of cyclopentene in step (a) is above 39.2%, and the selectivity of cyclopentyl acetate is above 90%.

Optionally, the conversion rate of cyclopentene in step (a) is above 80%, and the selectivity of cyclopentyl acetate is above 90%.

Optionally, in step (b), the conversion rate of cyclopentyl acetate is over 95%, the selectivity of cyclopentanol is over 50%, and the selectivity of ethanol is between 30% and 35%.

Optionally, the acid catalyst described in step (a) is selected from at least one of supported inorganic acids, cation exchange resins, and molecular sieves.

Optionally, the inorganic acid in the supported inorganic acid is selected from at least one of sodium hydrogen sulfate, sodium hydrogen phosphate, AlCl ₃ , and heteropolyacids, and the carrier in the supported inorganic acid is selected from silica , at least one of diatomaceous earth and kaolin.

Optionally, the heteropolyacid is selected from at least one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, and silico-molybdic acid.

Optionally, the supported inorganic acid catalyst is a phosphotungstic acid supported silica catalyst. In the present application, the phosphotungstic acid supported silica catalyst is prepared by the prior art, such as impregnation method.

Optionally, the weight percentage of the inorganic acid in the supported inorganic acid is 5-25%.

Optionally, the cation exchange resin catalyst is a sulfonic acid type strongly acidic macroporous ion exchange resin.

Optionally, the Hammett index H ₀ <-10 of the acid strength of the cation exchange resin catalyst, and the H ⁺ exchange capacity of the ion exchange resin is above 1.0 mmol/L.

Optionally, the molecular sieve is selected from the topology structure of at least one of FAU type molecular sieve, BEA type molecular sieve, and MFI type molecular sieve.

Optionally, the molecular sieve is selected from at least one of HY, Hβ, and HZSM-5 molecular sieves.

Optionally, measured by NH ₃ chemisorption measurement, the molecular sieve has a weak acid center density of 0.005-0.35 mmol/g, a medium-strength acid center density of 0.01-0.5 mmol/g, and a strong acid center density of 0.003-0.15 mmol/g .

Optionally, the acid catalyst described in step (a) is selected from at least one of supported inorganic acids, cation exchange resins and molecular sieves.

Optionally, the inorganic acid in the supported inorganic acid is selected from at least one of sodium hydrogen sulfate, sodium hydrogen phosphate, AlCl and heteropolyacids, and the carrier in the supported inorganic _acid is selected from silica , at least one of diatomite and kaolin, and the weight percentage of the inorganic acid in the above-mentioned supported inorganic acid is 5 to 25%;

The cation exchange resin is a sulfonic acid type strongly acidic macroporous ion exchange resin, the Hammett index H ₀ <-10 of its acid strength, and the H ⁺ exchange capacity of the ion exchange resin is above 1.0 mmol/L;

The molecular sieve is selected from at least one of HY, Hβ and HZSM-5 molecular sieves whose topological structures are FAU, BEA, MFI, and measured by NH chemisorption measurement, the weak _acid center density of the molecular sieve is 0.005-0.35mmol/g, The density of medium-strength acid centers is 0.01-0.5 mmol/g, and the density of strong acid centers is 0.003-0.15 mmol/g.

Optionally, the addition reaction conditions described in step (a) are:

The reaction temperature is 50～180 ℃;

The reaction pressure is 0.1～2.0Mpa;

The molar ratio of cyclopentene and acetic acid is 0.1 to 5.0;

The feed space velocity of cyclopentene is 0.6-3.0 g/g/h.

Optionally, the addition reaction conditions described in step (a) are:

The reaction temperature is 70～120 ℃;

The reaction pressure is 0.1～1.0Mpa;

The molar ratio of cyclopentene and acetic acid is 0.2 to 1.0;

The feed space velocity of cyclopentene is 0.8-2.0 g/g/h.

Optionally, the addition reaction conditions described in step (a) are as follows:

The reaction temperature is 50-180°C, preferably 70-120°C;

The reaction pressure is 0.1～2.0Mpa, preferably 0.1～1.0Mpa

The molar ratio of cyclopentene and acetic acid is 0.1-5.0, preferably 0.2-1.0;

The feed space velocity of cyclopentene is 0.6-3.0 g/g/h, preferably 0.8-2.0 g/g/h.

Optionally, the upper limit of the reaction temperature is selected from 180°C, 170°C, 160°C, 150°C, 140°C, 130°C, 120°C, 110°C, 100°C or 90°C; the lower limit is selected from 90°C, 80°C , 70°C, 60°C or 50°C.

Optionally, the upper limit of the reaction pressure is selected from 2.0Mpa, 1.8Mpa, 1.5Mpa, 1.2Mpa or 1.0Mpa; the lower limit is selected from 1.0Mpa, 0.8Mpa, 0.5Mpa, 0.2Mpa or 0.1Mpa.

Optionally, the upper limit of the molar ratio of cyclopentene and acetic acid is selected from 5.0:1, 4.0:1, 3.0:1, 2.0:1 or 1.0:1; the lower limit is selected from 1.0:1, 1:2, 1:3 , 1:4, 1:5, 1:6 or 1:10.

Optionally, the upper limit of the feed space velocity of cyclopentene is selected from 3.0g/g/h, 2.5g/g/h, 2.0g/g/h or 1.5g/g/h; the lower limit is selected from 1.5g/g/h g/h, 1.0 g/g/h or 0.6 g/g/h.

Optionally, the metal catalyst described in step (b) includes metal oxides; the metal oxides are selected from copper oxide, zinc oxide, aluminum oxide, manganese oxide, nickel oxide, chromium oxide, gallium oxide, zirconium oxide, At least one of molybdenum oxide.

Optionally, the metal catalyst in step (b) includes copper oxide, and the mass content of the copper oxide is 5-60%;

The metal catalyst also includes at least one of zinc oxide, aluminum oxide, manganese oxide, nickel oxide, chromium oxide, gallium oxide, zirconium oxide, and molybdenum oxide; wherein, the mass content of copper oxide is 5-60%.

Optionally, the metal catalyst described in step (b) includes copper oxide and one or more of zinc, aluminum, manganese, nickel, chromium, gallium, zirconium, and molybdenum oxides, wherein the mass content of copper oxide is 5 ~60%.

Optionally, the hydrogenation reaction conditions described in step (b) are:

The reaction temperature is 150～300 ℃;

The reaction pressure is 2～6Mpa;

The molar ratio of hydrogen and cyclopentyl acetate is 5 to 80;

The mass space velocity of cyclopentyl acetate is 0.3 to 2.0 g/g/h.

Optionally, the hydrogenation reaction conditions described in step (b) are:

The reaction temperature is 200～250 ℃;

The reaction pressure is 3～5Mpa;

The molar ratio of hydrogen and cyclopentyl acetate is 10-50;

The mass space velocity of cyclopentyl acetate is 0.8 to 1.2 g/g/h.

Optionally, the hydrogenation reaction conditions described in step (b) are as follows:

The reaction temperature is 150-300°C, preferably 200-250°C;

The reaction pressure is 2～6Mpa, preferably 3～5Mpa;

The molar ratio of hydrogen and cyclopentyl acetate is 5-80, preferably 10-50;

The mass space velocity of cyclopentyl acetate is 0.3-2.0 g/g/h, preferably 0.8-1.2 g/g/h.

Optionally, the upper limit of the reaction temperature is selected from 300°C, 280°C, 250°C or 200°C; the lower limit is selected from 200°C, 180°C or 150°C.

Optionally, the upper limit of the reaction pressure is selected from 6.0Mpa, 5Mpa or 4Mpa; the lower limit is selected from 4Mpa, 3Mpa or 2Mpa.

Optionally, the upper limit of the molar ratio of hydrogen and cyclopentyl acetate is selected from 80:1, 60:1, 70:1, 50:1 or 40:1; the lower limit is selected from 40:1, 30:1, 20:1 , 10:1 or 5:1.

Optionally, the upper limit of the feed space velocity of cyclopentyl acetate is selected from 2.0g/g/h, 1.8g/g/h, 1.5g/g/h or 1.2g/g/h; the lower limit is selected from 1.2g /g/h, 1.0g/g/h or 0.8g/g/h.

Optionally, the addition reaction described in step (a) and the hydrogenation reaction described in step (b) are independently performed in one or more reactors; preferably, the reactors are selected from fixed bed At least one of a reactor and a tank reactor.

Optionally, the addition and hydrogenation reactions are carried out in one or more reactors, and the reactors are selected from at least one of a fixed bed reactor and a tank reactor.

The beneficial effects of this application include but are not limited to:

(1) The present application provides a method for preparing cyclopentanol from cyclopentene and co-producing ethanol. The method has high efficiency, good reaction stability, simple preparation of the used catalyst and low cost.

(2) The above method provided by the present application does not use organic solvents, is environmentally friendly, and can be used in large-scale industrial applications.

Detailed ways

The present application will be described in detail below with reference to the examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials used in this application were purchased commercially and used directly without special treatment.

Product analysis was carried out on Agilent 7890B gas chromatography, FID detector, the addition reaction product was analyzed by FFAP chromatographic column, and the hydrogenation reaction product was analyzed by HP-5 chromatographic column.

Macroporous strong acid ion exchange resin and phosphotungstic acid were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

The supported phosphotungstic acid catalyst HPW/SiO ₂ is prepared by the impregnation method according to the records in the literature "Molecular Catalysis", 2011, 25(6), 503-507, wherein the weight content of phosphotungstic acid is 20%.

The HY molecular sieve catalyst was purchased from Nankai Catalyst Factory. The molecular sieve had a weak acid center density of 0.35 mmol/g and a strong acid center density of 0.11 mmol/g as measured by NH ₃ chemisorption assay.

Example 1

60 ml of macroporous strong acid ion exchange resin Amberlyst 15 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 90°C, and the reaction pressure was 0.1 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 4:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 85%, and the selectivity to cyclopentyl acetate was 98%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/zinc oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, and then The temperature was lowered to 200°C, the reaction pressure was adjusted to 3Mpa, the hydrogen flow rate was 40ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 0.78g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 96.7%, the selectivity of cyclopentanol was 60%, and the selectivity of ethanol was 30%.

Example 2

60ml of macroporous strong acid ion exchange resin Amberlyst35 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 90°C, and the reaction pressure was 0.1 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 4:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 84.2%, and the selectivity of cyclopentyl acetate was 98.2%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/alumina (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, then The temperature was lowered to 200°C, the reaction pressure was adjusted to 3Mpa, the hydrogen flow rate was 40ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 0.78g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 96.5%, the selectivity of cyclopentanol was 59.7%, and the selectivity of ethanol was 30.5%.

Example 3

60ml of macroporous strong acid ion exchange resin Amberlyst36 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 90°C, and the reaction pressure was 0.1 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 4:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 81.4%, and the selectivity of cyclopentyl acetate was 98.1%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/zirconia (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, and then The temperature was lowered to 200°C, the reaction pressure was adjusted to 3Mpa, the hydrogen flow rate was 40ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 0.78g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 96.5%, the selectivity of cyclopentanol was 59.7%, and the selectivity of ethanol was 30.5%.

Example 4

60 ml of supported phosphotungstic acid catalyst HPW/ _SiO2 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 100°C, and the reaction pressure was 0.1 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 4:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 80.7%, and the selectivity of cyclopentyl acetate was 97.8%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/manganese oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, and then The temperature was lowered to 200°C, the reaction pressure was adjusted to 3Mpa, the hydrogen flow rate was 40ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 0.78g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 96.1%, the selectivity of cyclopentanol was 59.8%, and the selectivity of ethanol was 30.3%.

Example 5

60 ml of supported silicotungstic acid catalyst HSW/ _SiO2 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 120°C, and the reaction pressure was 0.1 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 4:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 84.9%, and the selectivity of cyclopentyl acetate was 97.1%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20～40 mesh copper oxide/nickel oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, then The temperature was lowered to 200°C, the reaction pressure was adjusted to 3Mpa, the hydrogen flow rate was 40ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 0.78g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 97.1%, the selectivity of cyclopentanol was 60.8%, and the selectivity of ethanol was 30.5%.

Example 6

60ml of HY molecular sieve catalyst was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 80°C, and the reaction pressure was 0.1 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 4:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 62.9%, and the selectivity of cyclopentyl acetate was 98.1%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/chromium oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, then The temperature was lowered to 200°C, the reaction pressure was adjusted to 3Mpa, the hydrogen flow rate was 40ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 0.78g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 95.1%, the selectivity of cyclopentanol was 60.9%, and the selectivity of ethanol was 30.8%.

Example 7

60 ml of macroporous strong acid ion exchange resin Amberlyst 15 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 90°C, and the reaction pressure was 0.1 MPa. The reactants, cyclopentene and acetic acid, were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 2:1. The feed space velocity of cyclopentene was 1.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 76.5%, and the selectivity of cyclopentyl acetate was 98.6%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/zinc oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, and then The temperature was lowered to 200°C, the reaction pressure was adjusted to 2Mpa, the hydrogen flow rate was 300ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 1.16g/g/h, and the reaction was carried out for 5h after sampling and analysis , the conversion rate of cyclopentyl acetate was 96.7%, the selectivity of cyclopentanol was 60%, and the selectivity of ethanol was 30%.

Example 8

60 ml of macroporous strong acid ion exchange resin Amberlyst 70 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 150°C, and the reaction pressure was 2.0 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 6:1. The feed space velocity of cyclopentene was 3.0 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 78.2%, and the selectivity of cyclopentyl acetate was 98.2%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/zinc oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, and then The temperature was lowered to 200°C, the reaction pressure was adjusted to 5Mpa, the hydrogen flow rate was 180ml/min, the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 1.19g/g/h, and the reaction was carried out for 5h and then sampled for analysis , the conversion rate of cyclopentyl acetate was 98.7%, the selectivity of cyclopentanol was 61.9%, and the selectivity of ethanol was 33.4%.

Example 9

60 ml of macroporous strong acid ion exchange resin Amberlyst 70 was charged into a stainless steel tubular fixed bed reactor. The reactor temperature was raised to 150°C, and the reaction pressure was 2.0 MPa. The reactants cyclopentene and acetic acid were respectively fed into the reactor, and the molar ratio of acetic acid to cyclopentene was 0.5:1. The feed space velocity of cyclopentene was 0.8 g/g/h. The reaction was run continuously for 250h. After the reaction product was collected, the product composition was analyzed by gas chromatography. The conversion of cyclopentene was 39.2%, and the selectivity of cyclopentyl acetate was 98.6%.

The addition reaction product is rectified to obtain cyclopentyl acetate with a purity greater than 95%. The specific steps of the hydrogenation reaction are as follows: take 2ml of 20-40 mesh copper oxide/zinc oxide (the mass content of copper oxide is 20%) catalyst and load it into a stainless steel tubular fixed-bed reactor, first reduce it at 300° C. for 4h in a hydrogen atmosphere, and then The temperature was lowered to 220°C, the reaction pressure was adjusted to 2Mpa, the hydrogen flow rate was 180ml/min, and the purified cyclopentyl acetate was fed with a liquid feed pump, the feed flow rate was 1.19g/g/h, and the reaction was carried out for 5h. , the conversion rate of cyclopentyl acetate was 98.7%, the selectivity of cyclopentanol was 50.6%, and the selectivity of ethanol was 31.2%.

Example 10

The specific operation is the same as that in Example 1, except that the reaction temperature of cyclopentene and acetic acid is 50°C.

Example 11

The specific operation is the same as that in Example 1, except that the reaction temperature of cyclopentene and acetic acid is 180°C.

Example 12

The specific operation is the same as in Example 1, except that the mol ratio of acetic acid and cyclopentene is 1:0.1.

Example 13

The specific operation is the same as in Example 1, except that the mol ratio of acetic acid and cyclopentene is 1:5.

Example 14

The specific operation is the same as that in Example 1, except that the feed space velocity of cyclopentene is 0.6 g/g/h.

Example 15

The specific operation is the same as that in Example 1, except that the reduction temperature of cyclopentyl acetate is 150°C, that is, the catalyst is reduced to 150°C after being reduced by hydrogen at 300°C.

Example 16

The specific operation is the same as that in Example 1, except that the reduction temperature of cyclopentyl acetate is 300°C, that is, the reduction of cyclopentyl acetate is directly carried out after the catalyst is reduced by hydrogen at 300°C.

Example 17

The specific operation is the same as that in Example 1, except that the reduction pressure of cyclopentyl acetate is 6MPa.

Example 18

Concrete operation is the same as Example 1, the difference is that the mol ratio of hydrogen and cyclopentyl acetate is 5, that is, maintaining the mass space velocity of cyclopentyl acetate constant, and adjusting the hydrogen flow rate is 20ml/min.

Example 19

The specific operation is the same as in Example 1, except that the mol ratio of hydrogen and cyclopentyl acetate is 80, that is, the mass space velocity of cyclopentyl acetate is maintained constant, and the adjusted hydrogen flow rate is 320ml/min.

The above are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Without departing from the scope of the technical solution of the present application, any changes or modifications made by using the technical content disclosed above are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims (10)

1. A method for preparing cyclopentanol from cyclopentene is characterized by comprising the following steps:

(a) cyclopentene and acetic acid are subjected to addition reaction under the action of an acid catalyst to obtain cyclopentyl acetate;

(b) and (3) carrying out hydrogenation reaction on the cyclopentyl acetate under the action of a metal catalyst to generate cyclopentanol and coproducing ethanol.

2. The process of claim 1, wherein the acid catalyst in step (a) is selected from at least one of a supported inorganic acid, a cation exchange resin, and a molecular sieve.

3. The method of claim 2, wherein the inorganic acid in the supported inorganic acid is selected from the group consisting of sodium bisulfate, sodium hydrogen phosphate, AlCl₃The carrier in the supported inorganic acid is selected from at least one of silicon dioxide, diatomite and kaolin;

preferably, the heteropoly acid is selected from at least one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid and silicomolybdic acid;

preferably, the supported inorganic acid catalyst is a phosphotungstic acid supported silica catalyst;

preferably, the weight percentage of the inorganic acid in the supported inorganic acid is 5-25%.

4. The method of claim 2, wherein the cation exchange resin catalyst is a sulfonic acid type strongly acidic macroporous ion exchange resin;

preferably, the Hammett index H of the acid strength of the cation exchange resin catalyst₀<10, ion exchange resin H⁺The exchange capacity is more than 1.0 mmol/L.

5. The method of claim 2, wherein the molecular sieve is selected from at least one of molecular sieves having a topology of FAU type, BEA type, MFI type;

preferably, the molecular sieve is selected from at least one of HY, H β and HZSM-5 molecular sieves;

preferably, as NH₃The molecular sieve has weak acid center density of 0.005-0.35mmol/g, medium-strength acid center density of 0.01-0.5mmol/g, and strong acid center density of 0.003-0.15mmol/g, measured by chemical adsorption measurement.

6. The method of claim 1, wherein the addition reaction conditions in step (a) are:

the reaction temperature is 50-180 ℃, and preferably 70-120 ℃;

the reaction pressure is 0.1-2.0 MPa, preferably 0.1-1.0 MPa

The mol ratio of cyclopentene to acetic acid is 0.1-5.0, preferably 0.2-1.0;

the feed space velocity of cyclopentene is 0.6-3.0 g/g/h, preferably 0.8-2.0 g/g/h.

7. The method of claim 1, wherein the metal catalyst of step (b) comprises a metal oxide; the metal oxide is at least one selected from copper oxide, zinc oxide, aluminum oxide, manganese oxide, nickel oxide, chromium oxide, gallium oxide, zirconium oxide and molybdenum oxide.

8. The method according to claim 1, wherein the metal catalyst in the step (b) comprises copper oxide, and the mass content of the copper oxide is 5-60%;

the metal catalyst also comprises at least one of zinc oxide, aluminum oxide, manganese oxide, nickel oxide, chromium oxide, gallium oxide, zirconium oxide and molybdenum oxide.

9. The process of claim 1, wherein the hydrogenation conditions in step (b) are:

the reaction temperature is 150-300 ℃, and preferably 200-250 ℃;

the reaction pressure is 2-6 Mpa, preferably 3-5 Mpa;

the molar ratio of the hydrogen to the cyclopentyl acetate is 5-80, and preferably 10-50;

the mass space velocity of the cyclopentyl acetate is 0.3-2.0 g/g/h, preferably 0.8-1.2 g/g/h.

10. The process of claim 1, wherein the addition reaction in step (a) and the hydrogenation reaction in step (b) are carried out independently in one or more reactors; preferably, the reactor is selected from at least one of a fixed bed reactor and a tank reactor.