JPS5920254A - Separation of ethyleneamines from chlorides - Google Patents

Abstract

PURPOSE:To extract the titled compound from an aqueous solution containing ethyleneamines and inorganic chlorides to an organic phase, selectively, economically in an industrial scale, and to separate the compound from the chlorides, by using benzyl alochol or its mixture with other organic solvent as the extractant. CONSTITUTION:Ethyleneamines (abbreviated as EA) (e.g. ethylenediamine, diethylenetriamine, etc. derived from ethane dichloride and an aqueous solution of ammonia) is extracted selectively to an organic phase from an aqueous solution containing EA and inorganaic chlorides (e.g. NaClCaCl2, etc.), and are separated from the chlorides. In the above process, >=0.3mol of benzyl alcohol or a mixture of benzyl alcohol and one or more other organic solvents (e.g. enzyl alcohol and n-butanol, etc.) is used as the extractant based on 1mol of the amino group of EA. The process has various advantages, e.g. inexpensive alkali can be used, the energy of concentration can be saved because the EA is concentrated 2-5 times in the extraction process, the crystallization and separation processes are unnecessary, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for selectively extracting ethyleneamines and separating them from inorganic chlorides from an aqueous solution containing ethyleneamines and inorganic chlorides such as ammonium chloride, sodium chloride or calcium chloride. It is something. More specifically, for example, ethylenediamine, diethylenetriamine, diethylenetriamine, etc. obtained by reaction of ethane dichloride, aqueous ammonia solution, etc.
Triethylenetetramine, tetraebrenepentamine, etc., and monohydrochlorides of ethyleneamines including chain and cyclic amines such as piperazine, reaction product liquids containing ammonia and ammonium chloride, or hydroxylation of the reaction product liquids. ) From an aqueous solution containing free ethyleneamines and chlorides such as sodium chloride or calcium chloride obtained by adding IJum, calcium hydroxide, etc., ethyleneamines are efficiently extracted into an organic phase using benzyl alcohol. , relates to a method for separating inorganic chlorides.

Currently, ethylene amines (FA) and inorganic chlorides can be separated using ethane dichloride and ammonia aqueous solution because the inorganic chlorides produced are extremely stable and have alkaline strength that can produce free amines. The reaction product is treated with sodium hydroxide to make it caustic as shown in the following formula, EA-HCl+NH4CJ+2NaOH→F,A
+N) &+2NaCl-1-2) (20 After removing free ammonia, sodium chloride is crystallized by evaporation concentration,
A method has been adopted to recover free ethyleneamines. That is, ammonia has a weak alkaline strength and does not have the ability to convert monohydrochloride of ethyleneamines into free ethyleneamines.When calcium hydroxide is used, when calcium chloride, which is a by-product, is evaporated and concentrated to crystallize and separate it, At high temperatures, a reverse reaction occurs as shown in the following equation, and ZEA+CaC1z
+2JbO-+ 2FA-HCl+Ca(OH)2↓ Since the ethylene amines cannot be recovered, the use of sodium hydroxide ram is essential.

The current method of separating ethylene amines and nail machine chloride is as follows:
1) It requires a large amount of expensive sodium hydroxide.

2) To separate the by-product sodium chloride, all of the large amount of water required during the reaction must be removed by evaporation, which requires a large amount of thermal energy. 3) Efficient separation of sodium chloride requires complex operations and expensive equipment for crystallization and separation. It has problems such as:

Under the above circumstances, the present inventors conducted intensive studies to establish a method for separating ethylene amines and inorganic chlorides that solved the above problems [7]. The present invention was achieved based on the completely unexpected finding that the following compounds are extracted into the organic phase.

That is, the present invention selectively extracts ethylene amines into an organic phase from an aqueous solution containing ethylene amines and inorganic chlorides using benzyl alcohol or a mixed solvent consisting of benzyl alcohol and one or more other organic solvents. This is a method for separating ethyleneanes and inorganic chlorides.

The present invention will be explained in detail below.

The ethyleneamines referred to in the present invention are as described in 1. Like,
It is a general term for various amines produced using ethylenediamine as a unit, and the fraction of these ethylene amines contains a high proportion of amino groups that are extremely hydrophilic compared to the carbon-carbon bond class that strengthens organophilic properties. Therefore, ethyleneamines as a whole are highly hydrophilic and cannot be extracted into the organic phase using various general organic solvents.

However, if benzyl alcohol is used to efficiently extract ethylene amines into the organic phase, it is unclear whether benzyl alcohol can efficiently extract ethylene amines or the mechanism. However, judging from the properties of ethyleneamines, benzyl alcohol reacts with the noamine group of ethyleneamines to form an adduct, or acts on the 7E] group to form an amine of ethyleneamines. It is presumed that this is because the group is inactivated, and as a result, the hydrophilicity caused by the amino group is lost, and the whole becomes organophilic (hereinafter referred to as the property of being easily transferred to an organic solvent phase).

Although it is essential for the present invention to use benzyl alcohol for the above reasons, there are no particular limitations on the manner in which it is used. That is, the amount of benzyl alcohol necessary for the ethyleneamines to become organophilic, in other words, it varies somewhat depending on the composition of the ethyleneamines, but at least 0.3 times the mole of the amino group of the ethyleneamines,
Preferably, benzyl alcohol should be used in an amount of 0.5 mole or more. The solvent for forming the organic phase and extracting ethyleneamines is not limited to benzyl alcohol alone, but can be used in combination with various organic solvents. The solvents that can be used are those that can form an organic phase and do not react with benzyl alcohol.In particular, aliphatic solvents having 3 to 8 carbon atoms in the molecule are suitable for extractability, phase separation, ease of handling, price, etc. Alcohol is preferred. For example, benzyl alcohol@n-butanol, benzyl alcohol/i-amyl alcohol, etc. are used, and the benzyl alcohol in the mixed solvent is generally 5 to 80% by volume.
, 7-10 In addition, if the raw materials are aqueous solutions containing ethyleneamines and inorganic chlorides, the present invention provides conditions for forming these aqueous solutions,
There are no restrictions on the concentration, component ratio, etc., but embodiments in which the present invention can be advantageously used include ethylene amines, monohydrochlorides, and aqueous ammonia monopyrolyzed ammonium produced by the reaction of ethane dioxide and aqueous ammonia solution. Ethylene amines, sodium chloride, or calcium chloride, which are converted into KFj by the action of IJium, hydroxide, and hydroxyl, sodium chloride, or calcium chloride, are also aqueous solutions.

Ethyleneamines in the aqueous solution obtained by polymerization with sodium hydroxide, calcium hydroxide, etc. are in a free state, so naturally the ethyleneamines extracted into the organic phase are also extracted in a free state, but the reaction The ethylene amines extracted into the organic phase from the mixed aqueous solution of the product ethylene amine monohydrochloride, ammonia, and ammonium chloride are in a free state. The reason for this is only speculation, but due to the interaction between the amino groups of ethyleneamine monohydrochloride that are not bonded to hydrochloric acid and benzyl alcohol, the alkaline strength is lower than that of ammonia, and as a result, the alkali strength is lowered than that of ammonia. It is believed that free ethyleneamines are extracted because hydrochloric acid is achieved. One of the features of the present invention is that ethyleneamines can be selectively separated without causticization.

The extractability of ethyleneamines in the method of the present invention is expressed by the distribution coefficient expressed as the concentration ratio of (organic phase)/(aqueous phase).
Types of coexisting inorganic chlorides, concentration of ethyleneamines,
Although it varies depending on the ratio of ethylene amines and inorganic chlorides, a value of at least 05 and usually 1 to 3 can be obtained. The factor that most influences this partition coefficient is the type of inorganic chloride, and especially when the coexisting salt is calcium chloride, the extractability of ethyleneamines is inferior to other salts. This is thought to be because water coordinates with 4Ca ions to form aqua ions with weak acid properties, and the interaction between these aqua ions and ethyleneamines, which are bases, reduces the extractability into the organic phase. . Therefore, in a system where calcium chloride coexists, if ammonia is coexisted to remove the influence of the aqua ions mentioned above, the extractability of ethyleneamines will be 2.
It is preferable to carry out the extraction without removing ammonia from the liquid made heavy by Jyluciuno hydroxide, since this is improved by ~6 times.

In addition, to further improve the extractability of ethyleneamine,
An organic bath agent having a monomer group, such as acetone, methyl ethyl ketone, cycloxanone, cyclopensenone, etc., can be used in combination with benzyl alcohol. The above organic solvent containing a ketone group is a solvent capable of selectively extracting ethyleneamines even when used alone, according to the present inventors.
I have a suggestion.

(Patent Application No. 57-94952). However, what about mixed solvents and benzyl alcohol or organic solvents with ketone groups? Although the mechanism is completely unknown, the extractability for ethyleneamine 1 is further improved compared to the case where 1 is used alone. It becomes one.

In the method of the present invention, as mentioned above, ethyleneamines can be extracted extremely efficiently. For example, if the extraction solvent is used 2 to 10 times the volume of the raw material aqueous solution and brought into countercurrent contact with the number of extraction stages from 3 to 10, Substantially all of the ethyleneamines 1 contained in the raw material can be extracted. The distribution coefficient of chloride coexisting in the raw material is extremely small, at most 0.1, but usually 0.02 or less, and the amount of chloride extracted into the organic phase together with the upper titanium amines is extremely small. This co-extracted chloride can also be easily removed from the organic phase by simply contacting the extracted phase with a small amount of water or a small amount of an aqueous solution of ethyleneamines.

There are no particular limitations on the method for recovering ethylene amines from the organic phase containing ethylene amines.

For example, a method in which the ethyleneamines are recovered as an aqueous solution by contacting them with pure water, a method in which the ethyleneamines are recovered by distilling the organic phase, etc. can be employed, but the most preferred method is a method using an acid. That is, this method involves bringing an organic phase into contact with an acid aqueous solution to produce a salt of F-1/F-7 amine 9i. +1- is dangerous'>')-? - Because of its small size, it has a high d1'1 degree of etching/cyamine salt aqueous solution (7
This is because it can be recovered. For example, j nytylene aminka 1
]O1# of,,l:'1 degree of water 7? i? I1
．． Color 20 (l f/1 or more, usually 30 (l
An aqueous solution with a yield of P/1 or more of ethyleneamines can be easily recovered.

714, if the end product is one of the ethylene amines, an acid that forms a salt of 1 and 4 may be selected;
]'/j i': When aiming at lff1 niburene rmine, an acid and 1. and add 1 carbonated gas or carbonated water.
When the method used is 7I/+l...-, ethyleneamine 9j'i is added to carbonate aqueous solution 71 and 1. - CII-I
It! < However, this carbonate releases carbon dioxide gas and produces free ethylene amine (I) ij 111. Free ethyleneamine 1 can be recovered.

As is clear from the above explanations, the method of the present invention: 1) Expensive water 11 Sodium! It is not necessary for one unit, and inexpensive alkalis such as calcium hydroxide and magnesium hydroxide can be used.

2) Ethyleneamines can be concentrated 2 to 5 times during the extraction operation, resulting in extremely energy saving.

3) Since crystallization and separation are not required, complicated operations and expensive equipment are not required.

It solves the problems of conventional methods, such as, and is extremely superior industrially.

The present invention will be further explained below with reference to Examples, but the present invention is not limited to these Examples.

Examples 1-4 Ethyleneamines 20.07 and sodium chloride (Na
Cl) 40. 200 ml of Hensyl alcohol was added to 200 rnl of an aqueous solution containing Oy-, and after shaking for 10 minutes, static separation was performed to obtain the following results. In addition, Na in the organic phase
Cl was 11/l or less in all cases.

Example 5 TETA: 100P/l, NaC1: 200
Add 130 mJ of benzyl alcohol to 200 mJ of Vl3 aqueous solution.
Add 200ml of n-butanol mixture containing d,
After shaking for a minute, static separation was performed.

As a result, TETA: 53.8 P/IJ, N
aCl: 230 ml of organic phase with 0.5 Vl and TET
A: 44.8 tall, NaCA! :23
170 ml of 5 Vl aqueous phase were obtained.

Next, 15 m/ml of pure water was added to 150 m/ml of the organic phase, and water-saturated carbon dioxide gas was blown in at a surface degree of 100 rnly for 2 hours, followed by steady separation, and the entire amount of TETA was back-extracted into the aqueous phase as carbonate. did.

Furthermore, 15 ml of the aqueous phase obtained by back extraction was thermally decomposed in the same manner as in the reference example, and TETA: 355 f-/l, C
O2: An aqueous solution of 32 Vl was obtained.

Example 6 EDA: 90 t/1. CaCA'2: ] I
131 LA of benzyl alcohol to 200 ml of an aqueous solution of I P/13! 200 xanone mixture containing Munchro
After adding m and l and shaking for 10 minutes, the mixture was statically separated.

As a result, EDl: 61.8 V7! , C! L.C.
A! 2: 0.4 Vl of organic phase 222 m/and EDA
: 24. Oy/e, CaC1z: ] 24
17 Bml of aqueous phase of Wllll was obtained.

Example 7 EDA: 90 Ve, CaCl2: 1707
MeCNHl: 170P/l (D water Ill ti 21
) 200 ml of a cyclohexanone mixed solution containing 133 ml of benzyl alcohol was added to Oml, and after shaking for 10 minutes, static separation was performed.

As a result, 240 ml of organic phase with EDA: 66.9'i-/l and EDA: I 2.2 V111Ca
C12: 210! ll, NHt: 1857/l
An aqueous phase of 160 m/' was obtained.

Example 8 El) A-11Cg: l 45 F! /L N1(
3: 170 Vl (7) Schiff [1-Key I
After adding 200 ml of J-Non mixed solution and shaking for 10 minutes, static separation was performed.

As a result, EI) A: 64.9 Wll of organic phase 2
24m1 and EI) A: 19.7 VL HCl: 6
1. IY-/l, NH3: 176 ml of aqueous phase of 171 W-/l was obtained.

Example 9 EDA: 65 f-/l, DE obtained by adding 50% calcium hydroxide cake to the reaction aqueous solution obtained by the reaction of dicarboxylated ethane (EDC) and ammonia aqueous solution.
TA: 28 Vl, TETA: 16 Vl,
TEPA: 6. OVl, pentaethylenehexamine (PEHA): 4. OVl, N-aminoethylpiperazine (NAEP): 4. OV1%CaC1z: 1
76 F//1SNHi: 200 ml of a cyclohexanone mixed solution containing 133 ml of benzyl alcohol was added to 200 d of an aqueous solution of 108' it/l, and after shaking for 10 minutes, static separation was performed.

As a result, EDA: 47.2 F! −/l, D
ETA: 1B, 4Vl.

TETA: 10.5 Vl, TEPA: 3.
8 Vl, PIICHA: 2.5 Vl, N-AE
An organic phase 240d containing P: 2.2 Wll was obtained.

Example 10 EDA: 90 Vl, CaClz: 111 P
/It was subjected to three stages of countercurrent extraction using twice the volume of a 2:1 (volume ratio) mixed solvent of benzyl alcohol and cyclohexanone.

As a result, the extraction rate of EDA into the organic phase was 9996 or more, and the extraction rate of calcium chloride was 1.0%.Next, water was added at 10r to 100ml of the organic phase from which EDA had been extracted.
After 10 minutes of shaking and static separation, calcium chloride was not present in the organic phase and could be completely removed.

Reference Example Organic phase obtained in Example 1], 15 ml of pure water to 80 ml
Add 1 m of water and add 100 tnl of carbon dioxide
mln for 2 hours, static separation, and E D
The entire amount of A was extracted with carbonate (7) and back extracted into the aqueous phase.

Next, 151 nl of the aqueous phase was put into a 50 m1 three-day round bottom flask equipped with a condenser, heated with a mantle heater, and the EDA carbonate was thermally decomposed by a total reflux method at the boiling point for 2 hours.
Time run, EI) A: 335Vl, CO2: 50
An aqueous solution of Vl was obtained.

Applicant: Toyo Soda Kogyo Co., Ltd.

Claims (1)

[Claims] 1) Selectively convert ethylene amines into an organic phase from an aqueous solution containing ethylene amines and inorganic chlorides using benzyl alcohol or a mixed solvent of benzyl alcohol and one or more other organic solvents. A method for separating ethyleneamines and chlorides, characterized by extraction. 2) The method according to claim (1), in which benzyl alcohol is used in an amount of 0.3 times or more by mole relative to the amino group of the ethyleneamine. 3) The method according to claim 111, wherein an aliphatic alcohol having 3 to 8 carbon atoms is used as the other organic solvent. 4) The method according to claims (1) to (3), in which an organic solvent having a ketone group is used as the other organic solvent.