Method for synthesizing allyl alcohol

Abstract

The present invention relates to the technical field of organic synthesis. Disclosed is a method for synthesizing allyl alcohol. The synthesis method comprises the following steps: adding a water-soluble acid-resistant high-boiling-point organic solvent to an aqueous allyl acetate solution and stirring the mixture to form a homogeneous solution; then heating the homogeneous solution, and performing a hydrolysis reaction under the action of a solid acid catalyst to obtain a mixture solution containing allyl alcohol; and then distilling the mixture solution to separate out the high-boiling-point organic solvent to obtain a crude allyl alcohol product. The synthesis method provided by the present invention can significantly improve the single-pass hydrolysis conversion rate of allyl acetate at low costs and achieve efficient and continuous industrial production of allyl alcohol. Moreover, the method can realize the separation of allyl alcohol from the high-boiling-point organic solvent simply by means of a simple distillation separation process. The separated organic solvent has high purity and light color and can be reused. The method has no waste liquid and waste residue generated.

Description

Synthesis method of allyl alcohol TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of allyl alcohol. BACKGROUND

[0002] Allyl alcohol is an important chemical intermediate, which is mainly applied to the fields of pharmaceuticals, agrochemicals, plastic lenses, edible essences, perfume manufacturing, and surfactants.

[0003] Currently, allyl alcohol is mainly produced by the propylene method developed by Showa Denko K.K. in Japan: propylene, acetic acid, and oxygen are reacted under the catalysis of metal pd to obtain allyl acetate; and the allyl acetate is subjected to hydrolysis and purification to prepare allyl alcohol. The synthesis method disclosed in the related art has the following optimal synthesis conditions: the hydrolysis raw materials are allyl acetate and water, the optimal hydrolysis catalyst is a solid acidic cation exchange resin, and the hydrolysis reaction conditions are 80 DEG C and 0.5 MPa G pressure. Although the method can achieve relatively ideal effects, under the conditions, the allyl acetate is insoluble in water, and the two substances are easily separated into layers, thereby greatly reducing the hydrolysis rate and conversion rate of the allyl acetate.

[0004] Since the allyl acetate is insoluble in water, some scholars propose that acetic acid or allyl alcohol is added before entering the ion exchange resin column reactor to ensure that the allyl acetate and water form a homogeneous phase, so as to avoid separation. However, since the acetic acid or allyl alcohol is the product of the hydrolysis reaction, the addition of the two substances will inevitably reduce the hydrolysis conversion rate of the allyl acetate. In order to solve the problem of low hydrolysis conversion rate, some technologies propose a scheme of using a reactive distillation process to improve the hydrolysis conversion rate of the allyl acetate. Under the process conditions, the hydrolysis conversion rate of the allyl acetate is close to 100%. However, compared with the ordinary resin column reactor, the equipment design of the process is complex, the equipment investment is much higher, and the process is only suitable for industrial equipment with an annual output of 10 wt or more. Some technologies also propose a scheme of using a strong base (sodium hydroxide, potassium hydroxide) as a catalyst and an acid-binding agent in the reaction system, so as to promote the reaction equilibrium to the positive direction and improve the conversion rate. However, the process will produce a large amount of solid waste acetic acid salt which needs to be disposed.

[0005] Therefore, how to improve the hydrolysis conversion rate of the allyl acetate at low cost is one of the technical difficulties in realizing the efficient and continuous industrial production of allyl alcohol. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a synthesis method of allyl alcohol, which can improve the hydrolysis conversion rate of the allyl acetate at low cost and realize the efficient and continuous industrial production of allyl alcohol.

[0007] The application provides a synthesis method of allyl alcohol.

[0008] Specifically, the synthesis method of allyl alcohol comprises the following steps:

[0009] S1. adding a water-soluble and acid-resistant high-boiling organic solvent into an allyl acetate aqueous solution, and stirring to form a homogeneous solution;

[0010] S2. heating the homogeneous solution in step S1, and performing a hydrolysis reaction under the action of a solid acid catalyst to obtain a mixture solution containing allyl alcohol;

[0011] S3. performing distillation on the mixture solution in step S2 to separate the high-boiling organic solvent, and obtaining a crude allyl alcohol.

[0012] In the synthesis method of allyl alcohol, the water-soluble and acid-resistant high-boiling organic solvent in step S1 is at least one of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether. Research shows that any mass ratio combination of one or both of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether can effectively improve the hydrolysis conversion rate of allyl acetate.

[0013] In the synthesis method of allyl alcohol, the addition amount of the water-soluble and acid-resistant high-boiling organic solvent is 10%-50% of the mass of the allyl acetate aqueous solution; preferably, the addition amount of the water-soluble and acid-resistant high-boiling organic solvent is 20%-40% of the mass of the allyl acetate aqueous solution.

[0014] In the synthesis method of allyl alcohol, the mass fraction of allyl acetate in the allyl acetate aqueous solution in step S1 is 10%-80%. For example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, and the like.

[0015] In the synthesis method of allyl alcohol, the heating process in step S2 is that the homogeneous solution is heated to 80-140 DEG C; preferably, the heating process in step S2 is that the homogeneous solution is heated to 80-120 DEG C.

[0016] In the synthesis method of allyl alcohol, the solid acid catalyst in step S2 is filled in a fixed bed reactor in the form of a filler. When performing the hydrolysis reaction, the heated homogeneous solution is introduced into the fixed bed reactor filled with the solid acid catalyst to perform the hydrolysis reaction.

[0017] In the synthesis method of allyl alcohol, the solid acid catalyst is at least one of a strong acid macroporous ion exchange resin and a strong acid gel type ion exchange resin.

[0018] In the above-mentioned synthesis method of allyl alcohol, the temperature of the hydrolysis reaction in step S2 is 80-140°C, and the time of the hydrolysis reaction is 0.25-3h; preferably, the temperature of the hydrolysis reaction in step S2 is 80-120°C, and the time of the hydrolysis reaction is 0.25-2h. It can be understood that the time of the hydrolysis reaction is the residence time of the homogeneous solution passing through the solid acidic catalyst.

[0019] In the above-mentioned synthesis method of allyl alcohol, during the distillation in step S3, the operation pressure is normal pressure, and the temperature of the system when the distillation is stopped is 130-150°C. In the synthesis method provided by the present application, only through a simple distillation separation process, a distillate containing acetic acid, allyl alcohol, allyl acetate and water can be obtained, and the remaining part (bottom liquid) is the high-boiling-point organic solvent which is water-soluble and acid-resistant. The purity of the separated high-boiling-point organic solvent is greater than or equal to 99.3%, and the color (Pt-Co) is <20, which can be directly used as the raw material of step S1.

[0020] In the above-mentioned synthesis method of allyl alcohol, the crude allyl alcohol prepared in step S3 can be further refined by using a conventional method to obtain high-purity allyl alcohol.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] The synthesis method of allyl alcohol provided by the present application can greatly improve the single-pass hydrolysis conversion rate of allyl acetate at a low cost by adding a high-boiling-point organic solvent (mainly diethylene glycol dimethyl ether and triethylene glycol dimethyl ether) which is water-soluble and acid-resistant to an aqueous allyl acetate solution to form a homogeneous solution, and realizes efficient and continuous industrial production of allyl alcohol. Moreover, only through a simple distillation separation process, the separation of the target product allyl alcohol and the high-boiling-point organic solvent can be realized. The separated high-boiling-point organic solvent has high purity and light color, and can be repeatedly used, which also makes the present application generate no waste liquid and waste residue, and can further effectively reduce the production cost. DETAILED DESCRIPTION

[0023] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are given for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0024] The raw materials, reagents or devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels or can be obtained by known methods.

[0025] Example 1

[0026] A synthesis method of allyl alcohol, comprising the following steps:

[0027] In a pressure-resistant kettle, 20% of diethylene glycol dimethyl ether by mass of an aqueous solution of allyl acetate was added to an aqueous solution of allyl acetate (allyl acetate accounted for 30% by mass of the aqueous solution of allyl acetate), and stirred to form a homogeneous solution. The homogeneous solution was heated to 110°C, and then fed into a fixed bed reactor filled with strongly acidic macroporous ion exchange resin, and the residence time of the material in the reactor was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. It was detected that the conversion rate of allyl acetate was 87.9%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 130°C, the distillation was stopped, to obtain a distillate containing 15.29% by mass of allyl alcohol. Diethylene glycol dimethyl ether was obtained at the bottom of the kettle, with a color (Pt-Co) of 13 and a purity of 99.3% (GC).

[0028] Comparative Example 1

[0029] A method for synthesizing allyl alcohol, comprising the following steps:

[0030] In a pressure-resistant kettle, 20% of diethylene glycol dimethyl ether by mass of an aqueous solution of allyl acetate was added to an aqueous solution of allyl acetate (allyl acetate accounted for 30% by mass of the aqueous solution of allyl acetate), and stirred to form a homogeneous solution. The homogeneous solution was heated to 110°C, and then fed into a fixed bed reactor filled with strongly acidic macroporous ion exchange resin, and the residence time of the material in the reactor was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. It was detected that the conversion rate of allyl acetate was 87.9%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 130°C, the distillation was stopped, to obtain a distillate containing 15.29% by mass of allyl alcohol. Diethylene glycol dimethyl ether was obtained at the bottom of the kettle, with a color (Pt-Co) of 13 and a purity of 99.3% (GC).

[0031] Example 2

[0032] A method for synthesizing allyl alcohol, comprising the following steps:

[0033] In a pressure-resistant kettle, 20% of diethylene glycol dimethyl ether by mass of an aqueous solution of allyl acetate was added to an aqueous solution of allyl acetate (allyl acetate accounted for 30% by mass of the aqueous solution of allyl acetate), and stirred to form a homogeneous solution. The homogeneous solution was heated to 110°C, and then fed into a fixed bed reactor filled with strongly acidic macroporous ion exchange resin, and the residence time of the material in the reactor was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. It was detected that the conversion rate of allyl acetate was 87.9%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 130°C, the distillation was stopped, to obtain a distillate containing 15.29% by mass of allyl alcohol. Diethylene glycol dimethyl ether was obtained at the bottom of the kettle, with a color (Pt-Co) of 13 and a purity of 99.3% (GC).

[0034] Comparative Example 2

[0035] A method for synthesizing allyl alcohol, comprising the following steps:

[0036] In a pressure vessel, an aqueous solution of allyl acetate (allyl acetate accounts for 80% by weight of the aqueous solution of allyl acetate) was heated to 80°C under stirring, and then was fed into a fixed bed reactor filled with strong-acid macroporous ion exchange resin and strong-acid gel-type ion exchange resin (volume ratio 4:1), and the residence time of the material was controlled to be 2 hours to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 13.4%, and the content of allyl alcohol was 6.22% by weight.

[0037] Example 3

[0038] A method for synthesizing allyl alcohol, comprising the following steps:

[0039] In a pressure vessel, an aqueous solution of allyl acetate (allyl acetate accounts for 80% by weight of the aqueous solution of allyl acetate) was heated to 80°C under stirring, and then was fed into a fixed bed reactor filled with strong-acid macroporous ion exchange resin and strong-acid gel-type ion exchange resin (volume ratio 4:1), and the residence time of the material was controlled to be 2 hours to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 13.4%, and the content of allyl alcohol was 6.22% by weight.

[0040] Comparative Example 3

[0041] A method for synthesizing allyl alcohol, comprising the following steps:

[0042] In a pressure vessel, an aqueous solution of allyl acetate (allyl acetate accounts for 80% by weight of the aqueous solution of allyl acetate) was heated to 80°C under stirring, and then was fed into a fixed bed reactor filled with strong-acid macroporous ion exchange resin and strong-acid gel-type ion exchange resin (volume ratio 4:1), and the residence time of the material was controlled to be 2 hours to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 13.4%, and the content of allyl alcohol was 6.22% by weight.

[0043] Example 4

[0044] A method for synthesizing allyl alcohol, comprising the following steps:

[0045] In a pressure-resistant kettle, a mixture of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether (mass ratio 4:1) with a mass fraction of 50% of the allyl acetate aqueous solution was added into the allyl acetate aqueous solution (allyl acetate accounted for 50% by mass of the allyl acetate aqueous solution) and stirred to form a homogeneous solution. The homogeneous solution was heated to 90°C and introduced into a fixed bed reactor containing strong acid macroporous ion exchange resin and strong acid gel type ion exchange resin (volume ratio 1:4), and the material reaction residence time was controlled to be 1 h to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 74.3%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 130°C, the distillation was stopped. The distillate containing 21.55% by mass of allyl alcohol was obtained; the kettle bottom obtained a mixture of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether (mass ratio 4:1), the color (Pt-Co) was 16, and the sum of the contents of the two was 99.5% (GC).

[0046] Comparative Example 4

[0047] A method for synthesizing allyl alcohol, comprising the following steps:

[0048] In a pressure-resistant kettle, tetrahydrofuran with a mass fraction of 50% of the allyl acetate aqueous solution was added into the allyl acetate aqueous solution (allyl acetate accounted for 50% by mass of the allyl acetate aqueous solution) and stirred to form a homogeneous solution. The homogeneous solution was heated to 90°C and introduced into a fixed bed reactor containing strong acid macroporous ion exchange resin and strong acid gel type ion exchange resin (volume ratio 1:4), and the material reaction residence time was controlled to be 1 h to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 74.2%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 130°C, the distillation was stopped. The distillate containing 14.34% by mass of allyl alcohol was obtained, and there was no residue at the kettle bottom.

[0049] Example 5

[0050] A method for synthesizing allyl alcohol, comprising the following steps:

[0051] In a pressure-resistant kettle, a mixed solution of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether (mass ratio 1:4) with a mass of 30% of the allyl acetate aqueous solution was added into the allyl acetate aqueous solution (allyl acetate accounted for 10% of the allyl acetate aqueous solution by mass), and stirred to form a homogeneous solution. The homogeneous solution was heated to 120°C, and then passed into a fixed bed reactor filled with strong acid gel type ion exchange resin, and the material reaction residence time was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 96.7%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 150°C, the distillation was stopped. The distillate containing 5.61% of allyl alcohol by mass was obtained; and the kettle bottom obtained a mixture of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether (mass ratio 1:4), with a color (Pt-Co) of 11, and the sum of the contents of the two was 99.5% (GC).

[0052] Example 6

[0053] A method for synthesizing allyl alcohol, comprising the following steps:

[0054] In a pressure-resistant kettle, a mixed solution of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether (mass ratio 1:4) with a mass of 30% of the allyl acetate aqueous solution was added into the allyl acetate aqueous solution (allyl acetate accounted for 10% of the allyl acetate aqueous solution by mass), and stirred to form a homogeneous solution. The homogeneous solution was heated to 120°C, and then passed into a fixed bed reactor filled with strong acid gel type ion exchange resin, and the material reaction residence time was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 96.7%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 150°C, the distillation was stopped. The distillate containing 5.61% of allyl alcohol by mass was obtained; and the kettle bottom obtained a mixture of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether (mass ratio 1:4), with a color (Pt-Co) of 11, and the sum of the contents of the two was 99.5% (GC).

[0055] Example 7

[0056] A method for synthesizing allyl alcohol, comprising the following steps:

[0057] In a pressure-resistant kettle, triethylene glycol dimethyl ether was added into an aqueous solution of allyl acetate (allyl acetate accounted for 10 wt% of the aqueous solution of allyl acetate) with a mass ratio of 30% of the aqueous solution of allyl acetate, and stirred to form a homogeneous solution. The homogeneous solution was heated to 120°C, and then passed into a fixed bed reactor filled with strong acid gel type ion exchange resin, and the residence time of the material was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 96.5%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 150°C, the distillation was stopped. The distillate containing 5.60 wt% of allyl alcohol was obtained; and triethylene glycol dimethyl ether was obtained at the bottom of the kettle, with a color (Pt-Co) of 10 and a purity of 99.6% (GC).

[0058] Example 8

[0059] A method for synthesizing allyl alcohol, comprising the following steps:

[0060] In a pressure-resistant kettle, triethylene glycol dimethyl ether was added into an aqueous solution of allyl acetate (allyl acetate accounted for 10 wt% of the aqueous solution of allyl acetate) with a mass ratio of 30% of the aqueous solution of allyl acetate, and stirred to form a homogeneous solution. The homogeneous solution was heated to 120°C, and then passed into a fixed bed reactor filled with strong acid gel type ion exchange resin, and the residence time of the material was controlled to be 0.25 h, to obtain a mixture solution containing allyl alcohol. The conversion rate of allyl acetate was 96.5%. The obtained mixture solution containing allyl alcohol was subjected to atmospheric distillation, and when the kettle temperature rose to 150°C, the distillation was stopped. The distillate containing 5.60 wt% of allyl alcohol was obtained; and triethylene glycol dimethyl ether was obtained at the bottom of the kettle, with a color (Pt-Co) of 10 and a purity of 99.6% (GC).

[0061] The conversion rates of allyl acetate in each example and comparative example are shown in Table 1.

[0062] Table 1

[0063] Comparing Comparative Example 1 and Example 1, it can be seen that after the addition of solvent is changed to acetic acid, the conversion rate of allyl acetate is significantly reduced; mainly because acetic acid is a reaction product, the addition of acetic acid inhibits the degree of hydrolysis of allyl acetate. Comparing Comparative Example 2 and Example 2, it can be seen that without the addition of solvent, the conversion rate of allyl acetate is significantly reduced; mainly because the aqueous solution of allyl acetate is phase-separated in this concentration range, which greatly reduces the catalytic efficiency of the acidic resin hydrolysis. Comparing Comparative Example 3 and Example 3, it can be seen that after the addition of solvent is changed to allyl alcohol, the conversion rate of allyl acetate is significantly reduced; mainly because allyl alcohol is a reaction product, the addition of allyl alcohol inhibits the degree of hydrolysis of allyl acetate. Comparing Comparative Example 4 and Example 4, it can be seen that after the addition of solvent is changed to tetrahydrofuran, the conversion rate of allyl acetate is basically unchanged. However, the boiling point of tetrahydrofuran is close to that of the product mixture, and it is easy to form an azeotropic system, which is difficult to separate by simple distillation. By comparing Example 5 and Example 6, it can be found that if the reaction temperature is increased to 140℃, the conversion rate of allyl acetate will also be increased. However, high temperature has higher requirements for the catalyst, and if an acidic ion exchange resin is used, the temperature should not exceed 120℃, otherwise the resin will decompose, and the color of the recovered mixture of diethylene glycol methyl ether and triethylene glycol methyl ether will be dark.

[0064] By comparing Examples 5, 7 and 8, it can be found that the ratio change between the added solvents diethylene glycol dimethyl ether and triethylene glycol dimethyl ether has no obvious effect on the conversion rate of allyl acetate in the reaction. Therefore, using at least one of diethylene glycol dimethyl ether or triethylene glycol dimethyl ether can effectively improve the conversion rate of allyl acetate.

[0065] In addition, it should be noted that the conversion rate of allyl acetate is affected by many factors, such as the concentration of reactants, reaction temperature, etc. Examples 1-4 show the conversion rates under different concentrations of reactants (the concentration of allyl acetate solution) and reaction temperatures. By comparing Comparative Examples 1-4, it can be seen that for different concentrations of reactants and reaction temperatures, the addition of solvents diethylene glycol dimethyl ether and / or triethylene glycol dimethyl ether can effectively improve the conversion rate of allyl acetate.

[0066] The above-described examples only express several embodiments of the present application, which are described in detail and in detail, but should not be construed as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method for the synthesis of an allyl alcohol, characterized in that, The method comprises the following steps: S1. adding a water-soluble and acid-resistant high-boiling organic solvent into an allyl acetate aqueous solution to form a homogeneous solution by stirring; S2. heating the homogeneous solution in step S1, and performing a hydrolysis reaction under the action of a solid acid catalyst to obtain a mixture solution containing allyl alcohol; S3. distilling the mixture solution in step S2 to separate the high-boiling organic solvent and obtain a crude allyl alcohol product.

2. The method of synthesis of claim 1, wherein, The water-soluble and acid-resistant high-boiling organic solvent in step S1 is at least one of diethylene glycol dimethyl ether and triethylene glycol dimethyl ether.

3. The method of synthesis according to claim 1 or 2, wherein, The water-soluble and acid-resistant high-boiling organic solvent is added in an amount of 10%-50% of the mass of the allyl acetate aqueous solution.

4. The method of synthesis of claim 3, wherein, The mass fraction of allyl acetate in the allyl acetate aqueous solution in step S1 is 10%-80%.

5. The method of synthesis of claim 1 or 2, wherein, The heating process in step S2 is heating the homogeneous solution to 80-140 ℃.

6. The method of synthesis of claim 5, wherein, The heating process in step S2 is heating the homogeneous solution to 80-120 ℃.

7. The method of synthesis of claim 1 or 2, wherein, The solid acid catalyst in step S2 is filled in a fixed bed reactor in the form of a filler.

8. The method of synthesis of claim 7, wherein, The solid acid catalyst is at least one of a strong-acid macroporous ion exchange resin and a strong-acid gel-type ion exchange resin.

9. The method of synthesis of claim 1 or 2, wherein, The hydrolysis reaction in step S2 is performed for 0.25-3 h.

10. The method of synthesis of claim 1 or 2, wherein, In the distillation process in step S3, the operation pressure is normal pressure, and the temperature of the system when the distillation is stopped is 130-150 ℃.

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