CN109721470B

CN109721470B - Method for continuously preparing isopentenol

Info

Publication number: CN109721470B
Application number: CN201811653444.XA
Authority: CN
Inventors: 王蕊; 王庆吉; 王建青; 王炳春; 李进
Original assignee: China Catalyst Holding Co ltd
Current assignee: China Catalyst Holding Co ltd
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2022-03-25
Anticipated expiration: 2038-12-29
Also published as: CN109721470A

Abstract

The invention discloses a method for continuously preparing prenol, which comprises the following steps: 3-methyl-3-butene-1-ol is used as a raw material, a catalyst is dissolved in the raw material, a solvent is added according to a proportion, the raw material is injected into a reaction tube by a plunger pump under certain pressure and temperature for reaction, reaction liquid is collected after being cooled and rectified to obtain an isopentenol pure product, and the product purity is more than 99%. The method adopts a continuous mode for preparation, is simple and convenient to operate, can carry out reaction in a non-hydrogenation state, does not need to prepare the adopted catalyst in advance, does not use noble metals such as palladium, cerium and tellurium, and has low production cost.

Description

Method for continuously preparing isopentenol

Technical Field

The invention provides a method for continuously preparing isopentenol, and relates to the field of production of fine chemical products.

Background

3-methyl-2-butene-1-ol, i.e. isopentenol, is an important organic synthesis intermediate, has wide application in the fields of pesticides, synthetic perfumes and the like, and has important significance for the research of the synthesis technology of the isopentenol, along with the continuous deepening of people on the synthesis technology of the isopentenol, the application range is wider and wider, and the demand is greatly increased.

The traditional method for producing the isopentenol comprises an isoprene method, wherein isoprene is taken as a raw material and is prepared through multiple steps of oxidation, acetification, saponification and the like, the process route is long, the product selectivity is low, and the environmental pollution is serious.

In recent years, isobutene and formaldehyde are used as raw materials to prepare the isopentenol, the method is simple in process and low in pollution, isobutene and formaldehyde are condensed to obtain 3-methyl-3-butene-1-ol, the isopentenol is obtained through isomerization, a patent W02008037693 uses a heterogeneous precious metal catalyst to isomerize in a hydrogen state, and precious metals such as Pb, Se and Te are used to prepare the catalyst, so that the production cost is high, and the safety risk of a hydrogen test is high. Patent CN1071141197 uses carbonyl iron, organic base and epoxy ligand to form a catalyst, which has many catalyst components, is not easy to separate after reaction, and has long reaction time. Therefore, there is a need to develop a new method or improve the method to further prepare prenol, so that the cost is reduced and the reaction period is short.

Disclosure of Invention

The invention provides a method for continuously preparing isopentenol, which has the advantages of simple process operation, small environmental pollution, no use of noble metal catalyst, reaction cost reduction, no need of being carried out in a hydrogen state and relatively safe reaction.

The invention is realized by the following technical scheme:

mixing the raw material 3-methyl-3-butene-1-ol and a solvent according to a certain proportion, dissolving a catalyst in the mixed solution, pumping the mixed solution into a reaction tube by using a plunger pump, reacting at a certain reaction temperature and pressure, cooling the reaction solution, and rectifying to obtain the pure product of the prenol. The catalyst in the reaction is sodium methoxide, sodium ethoxide and sodium isoamylene alkoxide.

In the technical scheme, the solvent used for the reaction is methanol, acetonitrile and water.

In the technical scheme, the mass ratio of the raw materials to the solvent is 1:1-4, and the preferred mass ratio is 1: 1.5-2.5.

In the technical scheme, the dosage of the catalyst in the reaction is 0.5-5% of the raw material, and the preferred dosage of the catalyst is 1-3%.

In the technical scheme, the flow rate of the raw materials is 10g/h-200g/h, and the flow rate of the raw materials is preferably as follows: 50-100 g/h.

In the technical scheme, the used reaction tube is made of stainless steel, the diameter of the reaction tube is 3mm, the length of the reaction tube is 5m, the reaction tube is coiled into a spiral shape, and the spiral reaction tube is arranged in the heating furnace.

In the above technical scheme, the pressure required by the reaction is 5-14mpa, and the preferable reaction pressure is 8-12 mpa.

In the technical scheme, the temperature required by the reaction is 150-270 ℃, and the preferable reaction temperature is 170-240 ℃.

In the technical scheme, the reaction liquid is rectified after being cooled to obtain the pure product of the isopentenol, and the purity of the product is more than 99%.

The invention relates to a method for continuously synthesizing isopentenol, which does not need to use noble metal to prepare a catalyst, saves the cost, reduces the regeneration link of the catalyst and simplifies the process; the reaction period is short, hydrogen is not needed to participate in the reaction, and the reaction is relatively safe.

The invention adopts gas chromatography, and the model is as follows: agilent 7820A

Drawings

FIG. 1 is a gas chromatogram of a sample prenol purchased;

FIG. 2 is a gas chromatogram of a rectified product prenol prepared in example 1.

Detailed Description

The invention is further illustrated by the following examples.

Example 1

Weighing 2kg of raw material 3-methyl-3-butene-1-ol, 3kg of methanol and 20g of sodium methoxide; the three materials are uniformly mixed, after the reaction tube is pressurized to 10mpa by methanol, the materials are fed by a plunger pump, and the flow rate is as follows: 50g/h, controlling the reaction temperature to be 170 ℃, controlling the reaction pressure to be 10mpa, collecting reaction liquid, and obtaining the raw material conversion rate: 42 percent, and the selectivity of the main product is more than 90 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 2

Weighing 2kg of raw material 3-methyl-3-butene-1-ol, 4kg of methanol and 40g of sodium methoxide; the three materials are uniformly mixed, after the reaction tube is pressurized to 12mpa by using methanol, feeding is started, the mixed materials are fed by adopting a plunger pump, and the flow rate is as follows: 70g/h, controlling the reaction temperature to be 190 ℃, controlling the reaction pressure to be 12mpa, collecting reaction liquid, and obtaining the raw material conversion rate: 45 percent, and the selectivity of the main product is more than 90 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 3

Weighing 2kg of raw materials of 3-methyl-3-butene-1-ol, 3kg of acetonitrile and 40g of sodium methoxide; the three materials are uniformly mixed, after the reaction tube is pressurized to 10mpa by methanol, the materials are fed by a plunger pump, and the flow rate is as follows: 70g/h, controlling the reaction temperature to be 190 ℃, controlling the reaction pressure to be 10mpa, collecting the reaction liquid, and obtaining the raw material conversion rate: 44 percent, and the selectivity of the main product is more than 90 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 4

Weighing 2kg of raw materials of 3-methyl-3-butene-1-ol, 3kg of methanol and 40g of sodium isoamylene alkoxide; three materials are uniformly mixed, after the reaction tube is pressurized to 11mpa by methanol, feeding is started, the mixed materials are fed by a plunger pump, and the flow rate is as follows: 70g/h, controlling the reaction temperature to be 200 ℃, controlling the reaction pressure to be 11mpa, collecting reaction liquid, and obtaining the raw material conversion rate: 40 percent, and the selectivity of the main product is more than 90 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 5

Weighing 2kg of raw materials of 3-methyl-3-butene-1-ol, 3kg of methanol and 40g of sodium ethoxide; three materials are uniformly mixed, after the reaction tube is pressurized to 11mpa by methanol, feeding is started, the mixed materials are fed by a plunger pump, and the flow rate is as follows: 70g/h, controlling the reaction temperature to be 200 ℃, controlling the reaction pressure to be 11mpa, collecting reaction liquid, and obtaining the raw material conversion rate: 40 percent, and the selectivity of the main product is more than 90 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 6

Weighing 2kg of raw material 3-methyl-3-butene-1-ol, 4kg of methanol and 60g of sodium methoxide; the three materials are uniformly mixed, after the reaction tube is pressurized to 12mpa by using methanol, feeding is started, the mixed materials are fed by adopting a plunger pump, and the flow rate is as follows: 70g/h, controlling the reaction temperature to 240 ℃, controlling the reaction pressure to 12mpa, collecting the reaction liquid, and obtaining the raw material conversion rate: 48 percent, and the selectivity of the main product is more than 90 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 7

Weighing 2kg of raw material 3-methyl-3-butene-1-ol, 6kg of methanol and 10g of sodium methoxide; the three materials are uniformly mixed, after the reaction tube is pressurized to 12mpa by using methanol, feeding is started, the mixed materials are fed by adopting a plunger pump, and the flow rate is as follows: 50g/h, controlling the reaction temperature to be 220 ℃, controlling the reaction pressure to be 12mpa, collecting reaction liquid, and obtaining the raw material conversion rate: 38 percent, and the selectivity of the main product is more than 92 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Example 8

Weighing 2kg of raw material 3-methyl-3-butene-1-ol, 2kg of methanol and 10g of sodium methoxide; the three materials are uniformly mixed, after the reaction tube is pressurized to 12mpa by using methanol, feeding is started, the mixed materials are fed by adopting a plunger pump, and the flow rate is as follows: 100g/h, controlling the reaction temperature at 270 ℃, controlling the reaction pressure at 12mpa, collecting the reaction liquid, and obtaining the raw material conversion rate: 35 percent, and the selectivity of the main product is more than 88 percent; and rectifying the obtained reaction liquid to obtain the isopentenol, wherein the purity of the product is more than 99%.

Claims

1. A method for continuously preparing prenol is characterized in that: mixing the raw material 3-methyl-3-buten-1-ol and a solvent according to a certain proportion, dissolving a catalyst in the mixed solution, pumping the mixed solution into a stainless steel tube reaction tube with the diameter of 3mm and the length of 5m by using a plunger pump, controlling the reaction pressure to be 5-14MPa, reacting at a certain reaction temperature, cooling the reaction solution, and rectifying to obtain an isopentenol pure product;

the catalyst is selected from sodium methoxide, sodium ethoxide and sodium isoamylene alkoxide.

2. The process for producing prenol(s) according to claim 1, wherein: the solvent used in the reaction is methanol, acetonitrile and water.

3. The process for producing prenol(s) according to claim 1, wherein: the mass ratio of the raw materials to the solvent is 1: 1-4.

4. The process for producing prenol(s) according to claim 1, wherein: the dosage of the catalyst in the reaction is 0.5 to 5 percent of the mass percentage of the raw materials.

5. The process for producing prenol(s) according to claim 1, wherein: the flow rate of the raw materials is 10g/h-200 g/h.

6. The process for producing prenol(s) according to claim 1, wherein: the temperature required for the reaction is 150-270 ℃.

7. The process for producing prenol(s) according to claim 1, wherein: the reaction liquid is rectified after being cooled to obtain the pure product of the isopentenol, and the purity of the product is more than 99 percent.