MXPA97005702A

MXPA97005702A - Method for producing aminoetiletanolamine and / or hydroxyethylpiperaz

Info

Publication number: MXPA97005702A
Application number: MXPA/A/1997/005702A
Authority: MX
Inventors: Koll Juhan; Frank Magnus
Original assignee: Akzo Nobel Nv
Priority date: 1995-02-08
Filing date: 1996-01-11
Publication date: 1998-02-01

Abstract

The present invention relates to a method for producing aminoethylethanolamine and / or hydroxyethylpiperazine by ethoxylating ethylenediamine and / or piperazine ethylene oxide in the presence of a catalyst, characterized by: continuously reacting ethylenediamine and / or piperazine with 0.05-0.5 moles ethylene oxide, preferably 0.1-0.3 moles, per mole of ethylenediamine and / or piperazine, introducing the resulting ethoxylation product stream into a distillation plant designed to process a flow of amination product obtained by amination of monoethanolamine with ammonia, and distill the flow of ethoxylation product in the distillation plant while recovering the aminoethylethanolamine and / or hydroxyethylpiperazi

Description

METHOD FOR PRODUCING AMINOETILETANOLAMINE AND / OR HYDROXYETHYLPIPERAZINE BACKGROUND OF THE INVENTION The present invention relates to a method for producing aminoethylethanolamine, hydroxyethylpiperazine or both compounds by continuously ethoxylating ethylenediamine, piperazine or a mixture thereof in an excess of ethylenediamine and piperazine. The resulting ethoxylation product stream is then processed by distillation in a distillation plant to process a flow of amination product obtained in the amination of monoethanolamine with ammonia. For a long time it has been known, for example Knorr et al, Ber. 35 (1902), p. 4470, to produce aminoethylethanolamine by reacting ethylene oxide with ethylenediamine at room temperature and in the presence of considerable amounts of water. The reaction is carried out in an excess of ethylenediamine to prevent the formation of higher adducts, such as N, N'-bis (2-hydroxyethyl) -ethylenediamine. DE-A-2, 716, 946 discloses a batch method for producing aminoethylethanolamine by reacting ethylene diamine with ethylene oxide at a temperature of 100-120 ° C and in the presence of water in a specially developed reaction apparatus. Patent Specification SU-A-1, 512,967 describes the production of N, N'-bis (2-hydroxyethyl) -ethylenediamine by ethoxylating ethylenediamine with ethylene oxide in a molar ratio of 1: 2 at a temperature of 40-50. ° C in a water solution approximately 20%. This reaction generates a large number of by-products. The publication of the patent EP-A-354 993 proposes that amines containing carbon atoms. reactive hydrogen are reacted with ethylene oxide and / or propylene oxide at an elevated temperature, conveniently at a temperature of 130-180 ° C, at a pressure above atmospheric and in the absence of any solvent, but in the presence of a catalytic amount of alkali metal hydroxide and / or alkali metal alkoxide. It is known from DE-A-2, 013, 676 to react, in a first step, ethylenediamine with ethylene oxide in the absence of a catalyst, and to react, in a second step, the higher condensation products formed in the presence of hydrogen (and optionally ammonia) and a hydration catalyst for piperazine, hydroxyethylpiperazine and N-aminoethylpiperazine. It is further known that the production of ethylenediamine by lamination of monoethanolamine with ammonia among others, results in lower amounts of ethylenediamine and piperazine substituted with one or more hydroxyethyl groups. The reaction mixture obtained in the amination is then separated by multi-stage distillation. There are many associated difficulties, with the production of aminoethylethanolamine and hydroxyethylpiperazine. Therefore, a problem is that the ethoxylation of ethylenediamine results in the formation of an undesirable number of by-products, such as di-, tri- or tetra (hydroxyethyl) -ethylenediamine which,. together with the ethylenediamine and the ethylene oxide which have not reacted as well as any amount of water present, they have to be separated from the aminoethylethanolamine, usually by vacuum distillation. The use of water as a catalyst results in the formation of a high-boiling azeotrope of ethylenediamine and water, which is difficult to break. The ethoxylation of piperazine results in the formation not only of hydroxyethylpiperazine, but also of di- (hydroxyethyl) -piperazine. The mixture of the resulting product is usually removed by vacuum distillation. If catalysts are used that are completely or partially dissolved in the reagents, these must also be * separated before processing the reaction mixture. In reactions above 100 ° C the ethylene oxide also reacts with the water present to form ethylene glycol, which results in etiien oxide losses and additional separation problems.

The aim of the present invention is to produce aminoethylethanolamine and / or hydroxyethylpiperazine - in such a way that the purification process is simplified. Another object of the invention is that the reaction be carried out continuously, to avoid the problems associated with a form in reaction batches. Other objects of the invention are to achieve high yields of the desirable compounds and allow the use of reagents that are not necessarily pure. It has now been found that these objectives are achieved by reacting ethylenediamine, piperazine or a mixture thereof with ethylene oxide in the presence of a catalyst, the reaction process comprising the steps of i) continuously reacting ethylene diamine and / or piperazine with 0.05-0.5 moles of ethylene oxide, preferably 0.1-0.3 moles, per mole of ethylenediamine and / or piperazine in the presence of a catalyst, ii) introducing the resulting ethoxylation product flow into a distillation plant designed to processing a flow of amination product obtained by subjecting the monoethanolamine to amination with ammonia, and iii) distilling the flow of ethoxylation product in the distillation plant while recovering the aminoethylethanolamine and / or hydroxyethylpiperazine.

Preferably, the catalyst employed consists of water or a solid catalyst which does not dissolve during the ethoxylation reaction. Conveniently, the flow of the ethoxylation product is introduced into the distillation plant before the first column where, in the distillation of the flow of the amination product, a compound or mixture containing a compound that is part of the flow is separated. of the ethoxylation product. As a result of the method of implementation of the method according to the invention, the reaction products can be processed in a plant intended for the production of ethyleneamines by catalytic amination of monoethanolamine with ammonia, since the ethoxylated products found in the ethoxylation product stream they are also present in the flow of the amination product obtained in the catalytic amination of monoethanolamine with ammonia. In a preferred mode of implementation, it has been found highly suitable to conduct the amination and the ethoxylation in parallel and join the flow of ethoxylation product and the flow of amination product in the distillation plant. Due to the higher content of aminoethylethanolamine and / or hydroxyethylpiperazine in the product flows thus obtained, it has also been found that the recovery of ethylenediamine from the azeotrope of ethylenediamine and water is facilitated.

In another preferred mode of implementation, the ethylenediamine and / or piperazine are extracted in the form of a product stream from the distillation plant wherein the flow of the ethoxylation product and the flow of the amination product are processed together. Such product flow may consist entirely or partially of the azeotrope of ethylenediamine and water (which optionally contains piperazine), in which case the water will serve as a catalyst in the ethoxylation reaction. A fraction containing ethylenediamine, which has not yet been fully processed, can then be used as a reagent. If water is used, completely or partially, as a catalyst, the ethoxylation reaction is carried out at a temperature of 20-95 ° C, preferably 40-80 ° C. Under such conditions, it has been found that it is possible to achieve a satisfactory ethoxylation regime as well as a high ethoxylation selectivity of the reactive hydrogen atoms of the amine compounds, there being practically no glycol formation or any ethoxylation of the hydroxyl groups. If the reaction is carried out in the absence of water, the appropriate reaction temperature is 20-150 ° C, preferably 40-120 ° C. If use is made of a solid ethoxylation catalyst that is not soluble during the reaction, the steps of the additional process for removing the catalyst can be avoided. Examples of suitable solid catalysts are acid ion exchangers, acid zeolites, acid clays and Lewis acids. The term solid catalysts also includes liquid catalysts that are linked to a solid carrier. It is also possible to use a solid ethoxylation catalyst in combination with water. The ethoxylation of ethylenediamine and piperazine to aminoethylethanolamine and hydroxyethylpiperazine, respectively, implies that only one of the four and two reactive hydrogen atoms of ethylenediamine and piperazine, respectively, react with ethylene oxide. According to the invention, this problem is solved by carrying out the reaction with a considerable excess of ethylenediamine and / or piperazine. In the method, one may also make use of ethylenediamine and / or piperazine which contain minor amounts of other compounds with reactive hydrogen atoms obtained from the amination plant. The ethoxylates formed from these compounds, as well as ethylenediamine and piperazine which have not reacted can be recovered as pure products or as a high boiling distillation residue, optionally together with the corresponding components of the amination flow. A suitable starting material for the ethoxylation is, for example, an ethylenediamine fraction containing at least 95% by weight of ethylenediamine and which has been obtained from the distillation plant. If the fraction is free of water, the reaction is preferably carried out in the presence of a solid catalyst in a water-free environment. It is also suitable to ethoxylate a mixture of ethylenediamine and piperazine, in which case the two amine compounds may have been obtained in the distillation plant. Such a mixture of the product may contain 6-100% by weight of ethylenediamine, preferably 80-95% by weight, and 0-40% by weight of piperazine, preferably 0-20% by weight. Preferably use is made of the ethylenediamine azeotrope formed when monoethanolamine and ammonia are reacted. Additional ethylenediamine and / or piperazine may also be added to the azeotrope, as well as additional amounts of water. Conveniently, such a product mixture contains 55-95% by weight of ethylenediamine, preferably 70-90% by weight, 1-30% by weight of water, preferably 10-20% by weight and 0-40% by weight by weight of piperazine preferably 0-10% by weight, by ethoxylation of ethylenediamine or piperazine in the special manner described and by carrying out the processing in a distillation plant for the amination products obtained in the amination of monoethanolamine with ammonia, a simple and cost-effective production mode of aminoethylethanolamine and / or hydroxyethylpiperazine is obtained. The attached Figures 1 and 2 illustrate schematically two examples of how the ethoxylation process can be integrated with a distillation plant to process a flow of amination product obtained from the amination of monoethanolamine with ammonia. The following abbreviations are used in the description of the Figures as well as in the subsequent examples. AEEA = aminoethylethanolamine DETA = diethylenetriamine EDA = ethylenediamine EO = ethylene oxide HEP = hydroxyethylpiperazine MEA = monoethanolamine PIP = piperazine Figure 1 schematically illustrates an arrangement for the integrated ethoxylation of EDA and / or PIP for AEEA and / or HEP. A, B and D are columns in a distillation plant to process a flow of amination product obtained in the amination of MEA with ammonia. C is a system of distillation columns for separating several products and E is a reactor for the ethoxylation of EDA and / or PIP. A flow of amination product 11 is introduced into the distillation column A, where the ammonia is removed. In the distillation column B, the main part of the water present in the flow of the amination product is separated and extracted through a conduit 31. The remaining amines are directed through a conduit 32 to the distillation system C, in where an azeotrope of water-EDA, EDA, PIP, DETA, AEP and HEP is __ separated by means of ducts 41, 42, 43, 44, ^ 45 and 46, respectively. Generally, the azeotrope contains 80-90% by weight of EDA, 0-5% by weight of PIP and 10-20% by weight of water. A stream 46 of high-boiling amines leaves the system of column C. In column D, these high-boiling amines are separated, by distillation, in AEEA, which is withdrawn through a conduit 51, and a lower fraction, which is withdrawn through a conduit 52. The azeotrope 41 is totally or partially and after optional cooling at a suitable reaction temperature in a cooler K, conducted through a conduit 61 to the ethoxylation reactor E. If desired, more water can be added to the azeotrope through a conduit 64, and more piperazine can be added through a conduit 63. Ethylene oxide is introduced into the reactor E through a conduit 65, suitably various places. The reaction mixture formed in the ethoxylation reactor E, which in addition to EDA and water contains EDA adducts and / or PIP adducts, is linked to the flow 22 of ammonia-free amination product for distillation. Figure 2 shows an alternative arrangement, which allows the production of more AEEA than is possible when only the azeotrope of EDA-water is used. Similar components as in Figure 1 are identified by similar designations. In view of the ethoxylation, part of the stream 42, consisting of EDA, is conducted, via a conduit 62, to an ethoxylation reactor J, which contains an acid ion exchanger as a catalyst. No need to add water. Because the reaction mixture contains EO and an excess of EDA; only EDA ethoxylates are obtained, apart from EDA, in the 71 flow of the ethoxylation product. Then, the flow 71 of the ethoxylation product joins with a flow 32 from the distillation column B, which as a result is subjected to a lower load. A large number of arrangements of the distillation plant and its integration with the ethoxylation reactor is conceived within the scope of the invention. For example, the flow 41 in Figure 2, ie the azeotrope of ethylenediamine and water, can be introduced completely or partially into the ethoxylation reactor J. If so, the flow of the ethoxylation product must, however, be linked to the flow 22 of the ammonia-free amination product of column A. The invention will now be further illustrated with the aid of two examples.

Example 1 A flow leaving a distillation plant according to Figure 1 and containing 72% EDA, 4% PIP and 23% water is cooled to 40 ° C and introduced into an ethoxylation reactor with a static mixer . Afterwards, ethylene oxide is added to the reactor in various stages in a molar ratio of EDA to EO of 1: 0.17. In the reaction, the temperature increases to 90-95 ° C. The flow of the reactor ethoxylation product contains 56.5% EDA, 2.5% PIP, 19.5% water, 17% AEEA, 3% HEP and 1.5% other reaction products. All the ethylene oxide is reacted. 95% of EDA spent and 93% of PIP spent reacted to AEEA and HEP. 79% of the EO supplied reacted to AEEA, while 11% reacted to HEP and 10% reacted to other products. The flow of the resulting ethoxylation product was linked to the flow of the amination product for distillation. When processed according to Figure 1, the additions of both AEEA and HEP were found in the quantities expected from the analysis *.

Example 2 A flow containing EDA (more than 99.5% by weight of EDA, cooled to 50 ° C) according to Figure 2 is introduced into an ethoxylation reactor containing a solid catalyst consisting of. an ion exchanger in the form of sulfonic acid. In addition, 0.105 moles of ethylene oxide per mole of EDA is supplied to the reactor in various stages, and the reaction is carried out at about 75 ° C. The ethoxylation flow leaving the reactor contains 85% EDA, 14% AEEA and 1% other reaction products. All the EO made a reaction. More than 99% of spent EDA reacted to AEEA. The resulting ethoxylation product flow was linked to the flow of amination product for distillation. When processing according to Figure 2, the addition of AEEA was found in the amount expected from the analysis.

Claims

1. A method for producing aminoethylethanolamine and / or hydroxyethylpiperazine by ethoxylating ethylene diamine and / or piperazine with ethylene oxide in the presence of a catalyst, characterized by continuously reacting ethylenediamine and / or piperazine with 0.05-0.5 moles of ethylene oxide, preferably 0.1-0.3 moles, per mole of ethylenediamine and / or piperazine, - introducing the resulting ethoxylation product stream into a distillation plant designed to process a flow of amination product obtained by amination of monoethanolamine with ammonia, and - distilling the ethoxylation product flow in the distillation plant while aminoethylethanolamine and / or hydroxyethylpiperazine is reclosed.

2. The method according to claim 1, characterized in that it is carried out in the presence of water as a catalyst at a temperature of 20-95 ° C., preferably 40-80 ° C.

3. The method according to claim 1, characterized in that it is carried out in the absence of water, but in the presence of a solid catalyst, which does not dissolve during the reaction and at a temperature of 20-150 ° C, preferably 40- 120 ° C.

4. The method in accordance with the claim 1, 2 or 3, characterized in that the flow of ethoxylation product is introduced into the distillation plant before the first column where, in the distillation of the flow of amination product, a compound or mixture containing a compound that it is part of the ethoxylation product flow.

5. The method according to any of claims 1-4, characterized in that the flow of ethoxylation product is linked to the flow of amination product and are distilled together in the distillation plant.

6. The method according to any of claims 1-5, characterized in that a fraction of ethylenediamine containing at least 95% by weight of ethylenediamine and which has been obtained from the distillation plant is ethoxylated.

7. The method according to any of claims 1, 2, 4 and 5, characterized in that a product mixture containing 55-95% by weight of ethylenediamine, preferably 70-90% by weight, is ethoxylated; 1-30% by weight of water, preferably 10-20% by weight; and 0-20% by weight of piperazine, preferably 0-10% by weight.

8. The method in accordance with the claim 3, 4 or 5 characterized in that a mixture of the product containing 60-100% by weight of ethylenediamine, preferably 80-95% by weight, is ethoxylated; and from 0-40% by weight of piperazine, preferably 5-20% by weight. SUMMARY In a method for producing aminoethylethanolamine, hydroxyethylpiperazine or both compounds, ethylenediamine, piperazine or a mixture thereof in an excess of ethylenediamine and / or piperazine is ethoxylated continuously. The resulting ethoxylation product flow is then processed by distillation in a distillation plant to process a flow of amination product obtained in the amination of monoethanolamine with ammonia.