JPS6296437A - Purification of allyl alcohol - Google Patents

Abstract

PURPOSE:To advantageously obtain the titled substance as an intermediate for synthesis of chemicals, etc., without any problem of corrosion, by adding one of three types of specific compounds such as potassium tertiary phosphate for phase-separation to an aqueous solution of ally alcohol to separate an aqueous phase and distilling an organic phase. CONSTITUTION:At least one of potassium tertiary phosphate, potassium pyrophosphate or potassium tripolyphosphate used for phase-separation is added to a mixture of allyl alcohol with water as a solid form or a concentrated aqueous solution, dissolved while stirring, allowed to stand and separated into an organic phase and a water phase. The water phase is removed and the organic phase is distilled to obtain the aimed compound. Although the larger amount of the added three types of compounds such as above cited potassium pyrophosphate is more advantageous since the water content in the separated organic phase (allyl alcohol phase) is reduced, the addition of the compounds in an amount over saturation is not preferred because of trouble accompanied by deposition of salts.

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a method for purifying allyl alcohol.

More specifically, the present invention relates to a method for efficiently removing water from an aqueous solution of allyl alcohol to obtain highly pure allyl alcohol.

[Conventional technology]

Allyl alcohol is an industrially useful substance that is used as a synthetic intermediate for many chemicals and synthetic resins, such as glycerin and diallyl phthalate.

As a method for producing allyl alcohol, the following reaction formula (1) is used.
As shown in (2), a method is known in which allyl chloride is synthesized by high-temperature chlorination of propylene and then subjected to alkaline hydrolysis.

CH2=CllCH3+Ct2→CH2−CHCH2C
L + HCt (1) CI ■ 2-CHCH2Ct 10 NaOH
-+CH2-CHCH20H+NaCt (2) This method has problems such as consuming a large amount of expensive chlorine and the need to handle chlorine and hydrogen chloride gas at high temperatures, resulting in severe corrosion of the equipment.

In recent years, a method has been proposed for producing allyl alcohol using zolopyrene as a raw material without handling chlorine or hydrogen chloride. This method uses propylene in the presence of acetic acid with oxygen or an oxygen-containing gas as shown in the following formulas (3) and (4), using a catalyst with alkali acetate and palladium, and optionally a copper compound supported on a carrier. gas phase [100-300℃, 0-30 atm (k-) pressure]
After reacting to obtain allyl acetate, the produced allyl acetate is collected by cooling (~, an acetic acid aqueous solution is added to make it homogeneous, this homogeneous solution is filled with a strongly acidic ion exchange resin,
To the heating medium, t: force n ri, A L, l tubular f'l
- Steam the reaction solution containing 1H (Hl, 5I and 7It)
f L/-C allyl alcohol is obtained (for example, Tokugansho!'> 8-137768, same 50-]
131725).

CH2= CTT-CH6+AcOH-1-' T 0
2→CH-= CHCH20AC+ H2O(3)CH
2= Cl-CH20AC-+H2O-+ CH= C
H-CH20H+AcOH (4) These compounds can be obtained by the following method as an aqueous solution of allyl alcohol (boiling point 96-97°C).
V1 water and 72.3: azeotrope at 27.7 (boiling point 8
Water cannot be removed by rli distillation to form a temperature of 75°C.

[Problems to be Solved by the Invention] The purpose of the invention is to provide a purification method that can remove water from allyl alcohol produced as an aqueous solution and omit high-purity allyl alcohol. ” (It’s about doing.

[Means and actions to solve the problem] As a force for removing water from an aqueous solution of allyl alcohol, a third component such as benzene is used as a force for removing water from an aqueous solution of allyl alcohol. One possible method is to add a large amount of Lehner and separate it by distillation, but this method is impractical since allyl alcohol requires a large amount of energy due to the large amount of water in the azeotrope.

It has been known for a long time that when salts are added to a homogeneous mixture of organic matter and water, it may separate into two phases.
7bashi is used.

The inventors of the present invention utilized this phenomenon to conduct intensive research in order to efficiently remove water from allyl alcohol aqueous solutions having particularly close azeotropic compositions to obtain high purity allyl alcohol.

When we tried adding saturated salt (NaCt), which is commonly used, the water content in allyl alcohol decreased from about 30 parts at the beginning to only about 20 parts, making it difficult to use it commercially. Tripotassium phosphate (K3PO4), I-o potassium phosphate (K4
P2O7), and potassium tripolyphosphate (K5P
601o) was found to be extremely effective for this purpose, and the present invention was completed.

That is, the present invention provides tripotassium phosphate, II! '
Potassium polyphosphate weighed at least 1
This method of purifying allyl alcohol is characterized by adding seeds to an aqueous solution of allyl alcohol, separating the aqueous phase and organic phase, removing the aqueous phase, and distilling the organic phase to obtain highly pure allyl alcohol.

In the purification method of the present invention, tripotassium phosphate, "! Potassium urophosphate and/or potassium tripolyphosphate (which may be an anhydrous salt or contain water of crystallization) are dissolved in allyl alcohol in the form of a concentrated aqueous solution.
(Addition 1-.9I< Stir to dissolve and then leave to stand to separate organic phase and aqueous phase.

It is advantageous to add more tripotassium phosphate, potassium birophosphate, and potassium tripolyphosphate because the water content in the separated organic phase (allyl alcohol phase) will decrease, but it is not recommended to add more than the saturation amount. It is difficult to use as an industrial process because it causes problems due to salt precipitation.

Incidentally, the solubility of tripotassium phosphate and potassium pyrophosphate in water is as shown in [Chemical Handbook, Vol. 3].
Edition Basic Edition II -] 70 Sada (Nihon Kagaku Kanawa)], and the solubility of potassium tripolyphosphate is about 67 at 20°C [Ulmanni 1 - Encyclopedia of Industrial Chemistry, Vol. 18, 332
[Page] Operation temperature should be increased [Therefore, the company emblem should be made so that the saturation concentration is not exceeded.

Table I Solubility in water (n) is 7 when the temperature is 25 to 50°C, and 3 at 50°C or higher.

The present invention'! #According to the manufacturing method, from an allyl alcohol aqueous solution (water level 3 (1%)) close to the azeotropic composition, water is reduced to 5%.
Since it can be reduced to ~10 g, high purity allyl alcohol can be obtained as the main product by distilling this. In addition, the azeotrope of the initial distillate can be used again as a raw material for the purification process, and the water can be evaporated from the aqueous phase to recover the salt as a concentrated salt or solid, which can be recycled again. can.

The purification method of the present invention will be explained below with reference to Examples and Comparative Examples. In the following explanation, the term "person" refers to the weight person.

Example 1 Karakaru solution (A) of 30 parts water and 70 parts allyl alcohol
To 500 me, add 320g of tripotassium phosphate to 180g of water.
An aqueous solution (1'()) dissolved in g was added, stirred vigorously, and left to stand, resulting in separation into two phases.

Analysis of each phase revealed that the upper phase mainly consisted of allyl alcohol, had a water content of 11.5%, and had 0 tripotassium phosphate.
．． It contained 87% sludge. On the other hand, the lower phase was mainly an aqueous solution of tripotassium phosphate and contained 0.72 parts of allyl alcohol.

When the two phases were distilled using an Oldershaw type distillation apparatus, 74 parts of allyl alcohol and 26 parts of water were distilled from the top.
A mixture with a similar azeotropic composition was obtained, and allyl alcohol containing almost no water was obtained from the bottom of the column. The liquid obtained from the bottom of the column is yellow colored, but when 95% of this was distilled out by simple distillation, the distillate was colorless high-purity allyl alcohol, and the colored substances and tripotassium phosphate remained in the column. remained as.

Example 2 50 ml of a solution consisting of 33.8% water and 66.2% allyl alcohol was placed in a separating funnel 1, and tripotassium phosphate was added little by little, stirring until no more was dissolved, and the mixture was allowed to stand still. , the liquid separated into two phases. −1=
The phase was mainly allyl alcohol, and the water content had decreased to 48 parts.

Example 3 The same treatment as in Example 2 was carried out except that potassium pyrophosphate was used instead of tripotassium phosphate, and the moisture content of the upper phase was 67%.

Examples 4 to 6 In an experiment similar to Example 1, a 60% aqueous solution of potassium pyrophosphate was used as (B), and the amounts added were 250I and 500I.
Table 2 shows the results when the weight was changed to 1000 g.

Table 2 Most of the material is potassium pyrophosphate Example 7 The same treatment as in Example 2 was carried out except that potassium tripolyphosphate was used instead of tripotassium phosphate, and the water in the upper phase was It was 6.5%.

Comparative Example 1 The same treatment as in Example 2 was carried out except that sodium chloride was used in a large excess compared to the saturated amount instead of tripotassium phosphate, and the water content in the allyl alcohol phase was 20%.

Comparative Example 2 The same operation as Comparative Example 1 was carried out except that trisodium phosphate was used instead of sodium chloride, but the liquid did not separate into two phases.

〔Effect of the invention〕

According to the allyl alcohol purification method of the present invention, the water content of the allyl alcohol phase after phase separation is reduced to nearly 5 to 10%, so the amount of steam required for subsequent distillation purification is lower than that of the conventional distillation method. Compared to refining, it requires much less.

Furthermore, since the salts used for phase separation are not corrosive like chlorides, equipment made of inexpensive materials can be used.

Claims (1)

[Claims] A method for purifying high-purity allyl alcohol, which comprises adding at least one of tripotassium phosphate, potassium pyrophosphate, or potassium tripolyphosphate to a mixture of allyl alcohol and water, separating the aqueous phase, and distilling the organic phase. .