WO2013040723A1

WO2013040723A1 - Method for preparing 2-propylheptanoic acid

Info

Publication number: WO2013040723A1
Application number: PCT/CN2011/001595
Authority: WO
Inventors: 张明
Original assignee: 沈阳张明化工有限公司
Priority date: 2011-09-20
Filing date: 2011-09-20
Publication date: 2013-03-28

Abstract

Disclosed is a method for preparing 2-propylheptanoic acid, involving using 2-propylheptanol as a raw material and a metal oxide as an oxidation catalyst, and subjecting them to heating, pressurizing and pressure maintenance to complete the oxidation process, and then subjecting them to acidification, dehydration, and rectification, so as to prepare 2-propylheptanoic acid. The recovered sodium sulfate which is discharged in the dehydration procedure in the method of the present invention can be made into a by-product mirabilite. The 2-propylheptanoic acid prepared by the method of the present invention can be made into a new plastic plasticizer to replace the plastic plasticizer of phthalic acid esters, and industrial-scale production can be achieved.

Description

Method for preparing 2-propyl heptanoic acid

The invention belongs to a preparation method of chemical raw materials, in particular to a method for preparing 2-propyl heptanoic acid by using 2-propylheptanol, which is suitable for industrial scale production. Background technique

2-propylheptanoic acid, English name: 2-propylheptanoic acid, Molecular formula: C ₁₀ H ₂₀ O ₂ , Structural formula: CH ₃ (CH ₂ ) ₄ CHCOOH or

It is a colorless transparent liquid.

I

CH ₂ CH ₂ CH ₃

At present, phthalate plastics represented by dioctyl phthalate (D0P), dimethyl phthalate (DMP) and dibutyl phthalate (DBP), etc. Plasticizers, which have been recognized as harmful to the environment, are the key endocrine disrupting hormones that are monitored internationally. They are the main culprit in men's reproductive problems. Cosmetics containing them increase the risk of breast cancer in women and harm women's fertility. Infant reproductive system, when severely damaged, can lead to cell mutations, eventually to teratogenic or carcinogenic.

The derivatives of 2-propylheptanoic acid can be made into a variety of excellent new environmentally friendly plastic plasticizers, which can replace toxic and harmful phthalate plasticizers. However, there is currently no method for producing 2-propylheptanoic acid that can achieve industrial scale production. Summary of the invention

The object of the present invention is to provide a process for preparing 2-propyl heptanoic acid which has high yield, high purity, environmental protection and no pollution, and can realize industrial scale production.

The invention adopts the following technical scheme, a preparation method of 2-propylheptanoic acid, which adopts the following steps:

(1) The caustic soda and 2-propylheptanol are put into an oxidation vessel, stirred in the presence of a catalyst to a temperature of 265 to 295 ° C, and the pressure is raised to 2.8 to 3.2 Mpa to carry out an oxidation reaction to obtain a solution A;

(2) The above step solution A is cooled and diluted with water, and the sodium 2-propylheptanoate in solution A is pressed into the acidification kettle, and the pH is adjusted to 3~ at 60~9 (TC temperature is added with sulfuric acid solution). 4, the acidification reaction is carried out, after the reaction is completed, the mother liquor layer of sodium sulfate is separated, and the remainder is solution B; 1100159S

(3) The above step solution B is sequentially washed with water and dehydrated under reduced pressure to obtain crude 2-propylheptanoic acid; ( ) the crude 2-propylheptanoic acid obtained in the above step is subjected to vacuum distillation to obtain a finished product 2- Propyl heptanoic acid.

The catalyst in the step (1) is one of zinc oxide, calcium oxide, silica, alumina or magnesia or a mixture thereof.

The mass ratio of the catalyst to 2-propylheptanol in the step (1) is 1:70-80.

The molar ratio of the base of the tablet to the 2-propylheptanol in the step (1) is 1:5.

The quality of the water added in the step (2) accounts for the mass of the reaction material added in the step (1).

40%~50%.

The dehydration pressure in the step (3) is -0.65 ~ -0.9Mpa, and the temperature is 85~95 °C. The rectification pressure in the step (4) is -0, 7~-0.9Mpa, and the temperature is 210 ~ 220 Ό. The sodium sulfate mother liquor layer separated in the steps (2) and (3) is precipitated, filtered, crystallized, separated, and dried to obtain a by-product Yuanming powder.

The positive effects of the invention are as follows: The invention adopts 2-propylheptanol as a raw material, adopts a metal oxide with superior cost performance as an oxidation catalyst, completes the oxidation process by heating, boosting and holding pressure, and then undergoes acidification, dehydration and distillation. 2-propyl heptanoic acid is obtained, and the yield of the finished product is high, up to 95%, and the purity of the finished product is high, up to 99%. The technical indexes are in line with the enterprise standard Q/SZH21-2010. The method of the invention can recover the sodium carbonate sodium discharged in the dehydration process and can be used as a by-product yuan Ming powder, without three waste discharges, environmental protection and no pollution. The 2-propyl heptanoic acid obtained by the method of the invention is non-toxic and harmless, and can be made into a new environment-friendly plastic plasticizer, which is used to replace the plasticizer of phthalate, and can realize industrial Large-scale production. DRAWINGS

Figure 1 is a block diagram of the process flow of the present invention. detailed description

The chemical reaction principle of the method of the invention is as follows:

(1) Oxidation reaction:

C ₃ H ₇ C ₃ H ₇

(2) Acidification reaction:

2C ₅ H _n -CH-COONa+H ₂ SO,

C ₃ H ₇ C ₃ H ₇

The selection of each synthesis condition in the reaction process of the method of the invention is determined:

1, the molar ratio of base and 2-propylheptanol (alkali alcohol molar ratio)

Under the conditions of oxidation pressure 3Mpa, gasification temperature 27 (TC, mass ratio of catalyst to 2-propylheptanol of 1.80, the relationship between the molar ratio of alkali alcohol and various parameters of 2-propylheptanoic acid product, see Table 1: Table 1 Relationship between molar ratio of alkali alcohol and 2-propyl heptanoic acid product parameters

2. Mass ratio of catalyst to 2-propylheptanol

Under the catalytic conditions of oxidation pressure 3Mpa, oxidation temperature 270 ° C, molar ratio of alkali alcohol 1: 1. 1, catalyst is manganese dioxide, mass ratio of catalyst to 2-propylheptanol and 2-propyl heptanoic acid product The relationship of the parameters, see Table 2:

Table of relationship between mass ratio of surface catalyst and 2-propylheptanol and 2-propyl heptanoic acid product parameters Catalyst and chromatographic analysis (%)

Product yield

2-propylheptyl 2-propylheptene 2-propyl

1 ( % ) (mgKOH/g) Other Alcohol mass ratio Acid heptanol

1: 50 89.04 97.06 0.95 1.99

1: 60 90.55 302.45 97.77 1.02 1.21

1: 70 95.07 319.04 99.01 1.18 0.21

C C

1: 80 322.63 99.07 0.76 0.17

1: 90 98.98 0.85 0.17

1: 100 298.79 96.84 2.78 0' 38

1: 120 91.58 294.52 96.81 2.51 0.68

3, oxidation reaction temperature

Under the catalytic conditions of oxidation pressure 3Mpa, alkali alcohol molar ratio 1: 1.1, and catalyst manganese dioxide, the relationship between oxidation temperature and 2-propyl heptanoic acid product parameters is shown in Table 3:

Table 3 Relationship between oxidation reaction temperature and 2-propyl heptanoic acid product parameters

4, oxidation reaction pressure

The relationship between the oxidation reaction pressure and the parameters of the 2-propylheptanoic acid product under the catalytic conditions of oxidation temperature 27CTC, alkali alcohol molar ratio 1: 1.1, and catalyst as manganese dioxide, see Table 4: Table of relationship between oxidation reaction pressure and 2-propyl heptanoic acid product parameters

In summary, the conditions of the method of the present invention are determined as follows: the molar ratio of alkali alcohol is 1: 1-1.5, the mass ratio of catalyst to 2-propylheptanol is 1:70-80, and the oxidation reaction temperature is 265-295 °C. The oxidation reaction pressure is 2.8 ~ 3.2Mpa.

The invention will be further described below in conjunction with a process flow diagram.

1, oxidation

The quantitative amount of the base and catalyst are put into the oxidizer, and then the quantitative 2-propylheptanol is added, stirred, heated to 265 ~ 295 ° C, raised to 2.8 ~ 3.2Mpa, held for 20 ~ 30min, and then excluded Hydrogen, pressure relief to OMpa, oxidation reaction is completed, and solution is obtained. The entire oxidation reaction time is 1.8h~3h;

2, acidification

Cooling water is injected into the solution A obtained in the upward step, and the mass of the added cooling water accounts for 40 to 50% of the mass of the reaction material added by the oxidation reaction, the solid catalyst and impurities are filtered off, and then the aqueous solution of sodium 2-propylheptanoate is injected into the acidification. The kettle is stirred, and the pH value of the sulfuric acid is dripped through the distributor to 3 to 4, the concentration of sulfuric acid used is 45 to 55%, and the temperature of the reaction liquid is controlled at 60 to 90 ° C, and the acidification reaction is carried out, and the acidification time is 0.5 h. Lh. After the reaction is completed, the mixture is stirred with water, and the mixture is allowed to stand for separation, and the mother liquor of sodium sulfate is separated, and the remainder is solution B; 3, washing and dehydration

Add 20~40 °C water to solution B obtained in the previous step, wash twice with water, remove residual sodium sulfate by filtration; add polyamide resin at temperature 85~95 °C, pressure - 0.65 ~-0.9Mpa Dehydration of the auxiliary to obtain crude 2-propylheptanoic acid;

4, distillation

The dehydrated crude 2-propylheptanoic acid is pressed into a rectification column, and the product is condensed by a condenser at a temperature of 210 to 220 ° C under a pressure of 0.7 to - G. 9 Mpa to obtain a finished 2-propylheptanoic acid. , its purity > 99%, acid value > 322.40mgKOH / g, water 0.1%, color (platinum-cobalt color number) <10.

5, preparation of by-product yuan Ming powder

5.1 The mother liquor of sodium sulfate released during acidification, water washing and dehydration is introduced into a storage tank and stored for storage and naturally cooled. Temperature <20°C; '

5.2 The sodium sulfate solution in the storage tank is sucked into the pre-cooling sedimentation tank at a temperature of 5 ° C to precipitate;

5.3 The pre-cooled sediment mother liquor is filtered through a membrane filter, the filtrate is put into a crystallization tank, and the aqueous mother liquor is returned to the storage tank;

5.4 The filtered crystals are cooled to -5 ~ -10 ° in the crystallizer (crystallization;

5.5 Separating the crystalline sodium sulfate in a separator to remove water, obtaining sodium sulfate sodium sulfate decahydrate (Na ₂ S04 - 10H ₂ 0), sodium sulfate decahydrate content > 99.0%, pH value of 5.0 to 8.0;

5.6 The separated crystalline sodium sulfate is put into a dryer and heated to 110-120 ° C to obtain a by-product Yuan Ming powder, that is, anhydrous sodium gram.

Several specific embodiments are listed below:

Example 1:

(1) First, lOOOKg of caustic soda (NaOH) and 54.31Kg of zinc oxide were put into the oxidation vessel as a catalyst, the feed port was tightly closed, and 4345 Kg of 2-propylheptanol was added to the oxidation vessel, and the mixture was stirred and heated to 27 (TC, Boost to 3Mpa, hold 2Gmin, remove hydrogen, release pressure to OMpa, get solution A;

(2) Inject 2160 kg of water into solution A at a water injection pressure of 0.5 MPa. The 2-propylheptanoheptanoate solution in the oxidation vessel was pressed into an acidification kettle, stirred by a car, and the reaction temperature was maintained at 75 °C. Then, sulfuric acid is continuously dropped into the reaction solution through a sulfuric acid distributor, and the mass concentration of sulfuric acid used is 45%. Adjust the pH to 3. After the acidification reaction is completed, the water is further stirred for 10 minutes, the mass of the added water is 1.2 times the mass of the precipitated sodium sulfate, and after standing and layering, the lower layer of the mother liquor of sodium sulfate is discharged into the storage tank of the sodium sulfate solution, and the remainder is the solution B;

(3) The remaining solution B in the previous step enters the water washing process, and after adding water, stirring, standing layering, releasing water, filtering to remove residual sodium sulfate, and thus repeating, filtering and adding polyamide resin auxiliary, decompression - 0.9 Mpa, dehydrated at a temperature of 90 ° C to obtain crude 2-propylheptanoic acid;

(4) The dehydrated crude 2-propyl heptanoic acid is pressed into a rectification column, heated to 210 ° C, rectified at a pressure of -0.8 MPa, and condensed by a condenser to obtain a product of 2-propylheptanoic acid 4513.37. Kg, the yield is 95.42%, the purity is 99.07%, the acid value is 322.63 mgKOH/g, and the platinum-cobalt colorimetric color is 5;

(5) Preparation of by-product yuan Ming powder

(5.1) The mother liquor of sodium sulfate released during acidification, water washing and dehydration is introduced into a storage tank for storage and naturally cooled. Temperature 20 ° C;

(5.2) The sodium sulfate solution in the storage tank is sucked into the pre-cooling sedimentation tank at a temperature of -5 ° C, and precipitated; (5.3) The pre-cooled sedimentation mother liquid is filtered through a membrane filter, and the filtered matter is put into a crystallization tank, and the aqueous mother liquor is returned. Storage tank

(5.4) The filtered crystals are cooled to -5 ° C ~ - 10 ° C in a crystallizer, and crystallized;

(5.5) Separating the crystalline sodium sulfate in a separator to remove water, obtaining sodium sulfate sodium sulfate decahydrate (Na ₂ S04 · 10H ₂ 0), sodium sulfate content > 99.0%, pH value of 5.0 to 8.0;

(5.6) The separated crystalline sodium sulfate is put into a dryer and heated to 110 to 120 ° C to obtain a by-product of the product, that is, anhydrous sodium sulfate.

Example 2:

(1) First, 100OOg of caustic soda (NaOH) and 79Kg of catalyst were put into the oxidation vessel, wherein the catalyst was a mixture of zinc oxide and calcium oxide, and the feed port was tightly closed, and then 5925 Kg of 2-propylheptanol was put into the oxidation vessel, and stirring was started. , heat up to 295 ° C, pressurize to 2.8Mpa, hold pressure for 25min, remove hydrogen, release pressure to QMpa, get solution A;

(2) Inject 3151.8 Kg of water into solution A at a water injection pressure of 0.7 MPa. The 2-propyl heptanoate solution in the oxidation vessel was pressed into an acidification kettle, stirred by a car, and the reaction temperature was maintained at 60 °C. Then, sulfuric acid was continuously dropped into the reaction liquid through a sulfuric acid distributor, and the mass concentration of sulfuric acid used was 50%, and the pH was adjusted to 4. After the acidification reaction is completed, the water is further stirred for 10 minutes, the mass of the added water is 1.2 times the mass of the precipitated sodium sulfate, and after standing and layering, the lower layer of the mother liquor of sodium sulfate is discharged into the storage tank of the sodium sulfate solution, and the remainder is the solution B;

(3) The remaining solution B in the previous step enters the water washing process, adding water, stirring, standing layering, draining water, filtering to remove residual sodium sulfate, so repeated, filtering and adding polyamide resin additives, decompression - 0.80 Mpa, dehydrated at a temperature of 95 ° C to obtain crude 2-propylheptanoic acid;

(4) The dehydrated crude 2-propylheptanoic acid is pressed into the rectification column, heated to 220 ° C, rectified at a pressure of -0.9 Mpa, and condensed by a condenser to obtain a product of 2-propylheptanoic acid 6172.65. Kg, yield 95.70%, with a chromatograph calibration purity of 99.20%, acid value 323.25mgK0H / g, platinum-cobalt colorimetric 4;

Step (5) is the same as Embodiment 1.

Example 3:

(1) First, 100 OKg of the caustic soda (NaOH) and 56.43 Kg of the catalyst were placed in an oxidizer, wherein the catalyst was a mixture of zinc oxide, calcium oxide and silica, the feed port was tightly closed, and 3950 Kg of 2-propyl was introduced into the oxidizer. Heptanol, stirring, heating to 265 ° C, pressurization to 3.2Mpa, hold pressure for 30min, remove hydrogen, release pressure to OMpa, get solution A;

(2) Inject 2503, 21Kg of water into solution A at a water injection pressure of 0.6 MPa. The 2-propyl heptanoate solution in the oxidation vessel was pressed into an acidification kettle, stirred by a car, and the reaction temperature was maintained at 90 °C. Sulfuric acid was then added dropwise to the reaction solution through a sulfuric acid distributor at a constant concentration of 50% sulfuric acid, and the pH was adjusted to 3.5. After the acidification reaction is completed, the water is further stirred for lOmin, the quality of the added water is 1.2 times the mass of the precipitated sodium sulfate, and after standing and layering, the lower layer of the mother liquor of sodium sulfate is discharged into the storage tank of the sodium sulfate solution, and the remainder is the solution B;

(3) The remaining solution B in the previous step enters the water washing process, and after adding water, stirring, standing layering, releasing water, filtering to remove residual sodium sulfate, and so on, filtering and adding polyamide resin auxiliary, decompression -0.65 Mpa, dehydrated at a temperature of 85 ° C to obtain crude 2-propylheptanoic acid;

(4) The dehydrated crude 2-propylheptanoic acid is pressed into a fine column, heated to 215 ° C, rectified at a pressure of -0.7 Mpa, and condensed by a condenser to obtain a product of 2-propylheptanoic acid 4120.26. Kg, received The rate is 95.82%, and the purity is 99.14%, the acid value is 324.12 mgK0H/g, and the platinum-cobalt colorimetric color is 6;

Step (5) is the same as Embodiment 1.

The above is a preferred embodiment of the present invention, and is not intended to limit the invention. Any structural changes are still within the scope of protection of the technical solutions of the present invention. ·

Claims

Claim

A method for preparing 2-propylheptanoic acid, which comprises the steps of:

(1) Putting the caustic soda and 2-propylheptanol into the oxidation vessel, stirring the temperature to 265 ~ 295 ° C in the presence of a catalyst, raising the pressure to 2. 8 ~ 3.2 Mpa, and performing an oxidation reaction to obtain a solution A;

(2) The upper step solution A is cooled and diluted with water, and the sodium 2-propylheptanoate in the solution A is pressed into the acidification kettle, and the pH is adjusted to 3~ by adding a sulfuric acid solution at a temperature of 60 to 90 °C. 4, the acidification reaction is carried out, after the reaction is completed, the sodium citrate mother liquor layer is separated, and the remaining solution is hydrazine;

(3) The above step solution is washed successively with water and dehydrated under reduced pressure to obtain crude 2-propylheptanoic acid;

(4) The crude 2-propylheptanoic acid obtained in the above step is subjected to vacuum distillation to obtain a finished 2-propylheptanoic acid. '

The method for producing 2-propylheptanoic acid according to claim 1, wherein the catalyst in the step (1) is a metal oxide or a mixture of several metal oxides.

The method for producing 2-propylheptanoic acid according to claim 1 or 2, wherein the mass ratio of the catalyst to 2-propylheptanol in the step (1) is 1:70 to 80.

The method for producing 2-propylheptanoic acid according to claim 1, wherein the molar ratio of the base of the tablet to the 2-propylheptanol in the step (1) is from 1:1 to 1.5.

The method for preparing 2-propylheptanoic acid according to claim 1, wherein the quality of the water added in the step (2) accounts for 40% to 50% of the mass of the reaction material added in the step (1). %.

The method for producing 2-propylheptanoic acid according to claim 1, wherein the dehydration pressure in the step (3) is -0.65 to -0.9 Mpa, and the temperature is 85 to 95 ° (:.

The method for producing 2-propylheptanoic acid according to claim 1, wherein the rectification pressure in the step (4) is -0.7 to -0.9 Mpa, and the temperature is 210 to 220 °C.

The method for preparing 2-propylheptanoic acid according to claim 1, wherein the mother liquor layer separated by the steps (2) and (3) is precipitated, filtered, crystallized, separated, Dry to obtain by-product Yuan Ming powder.